Science topic

Nanotechnology in Drug Delivery - Science topic

Nanotechnology in drug delivery is a multidisciplinary field representing combination of a variety of disciplines for example fundamental sciences, pharmaceutical sectors, biophysics, polymer chemistry, molecular biology, bioengineering, and biotechnology. Chemical/physical properties of the material can totally modify at the nano scale size level, which can be utilized to carry the drug/gene to unexplored targets efficiently as well as formulate extra drug available to extract the effect accurately at the site of action. Nanotechnology in drug delivery includes various applications such as, efficient targeting to organ, cellular or sub cellular level, improvement in solubility, enhanced stability (in vitro or in vivo), sustained drug release, reduction in adverse effects, etc. Pharmaceutical nanotechnology is a boost research area in academia and industry due to its noticeable benefits. This topic is an effort to bring together scientists from academia and Industry for sharing research, recent updates, and to keep updated with emergent technologies and networking.
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Hello, can anyone please named few potential drug delivery technologies that you think are novel and unique. Our comapny is looking to buy few drug delivery technologies that can serve us to compete for now and few next years. Suggestions are highly appreciated. Thanks in advance.
Regards
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Current trend is Nanotechnology based drug delivery systems like nanogels, Hydrogels for wound healing, surgical sprays, Monoclonal antibodies are in high demand in this covid state and many companies are even having patents.
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I use HPTS in DMSO for a fluorescent liposome assay.What is the concentration limit beyond which the self quenching of HPTS occurs? 
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Article Thin Film Optical Sensors Employing Polyelectrolyte Assembly
Article Cell-Penetrating Peptide Induces Leaky Fusion of Liposomes C...
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I've experimented sterilization with autoclave, but the melting point of used polymer polycaprolactone is 60 ° C and so it is not suitable for my formula...and so on sterilization with filtration because I have microparticles.
gamma radiation?
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what if the polymer is damaged by heat? or by energy-containing methods, like beta (e-BEAM, which no-one has mentioned) or gamma radiation? Filtration affects the constituents of the polymer (e.g. solid content). Please stop repeating yourselves, and cutting and pasting, but THINK!
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I am preparing temperature responsive in situ forming hydrogel loaded with Dox-Liposomes. i need to measure the particle size and zeta potential of hydrogel loaded Dox-Liposomes. I also  need to determine EE% of drug from Hydrogel loaded Dox-Liposomes. During particle size measuring, size of hydrogel particle was very higher as compare to Dox-Liposomes. i performed it with dilution of hydrgel -liposomes suspension. Is dilution  require for particle size measuring? If require, then at which ratio?
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The entrapment efficiency (EE%) is measured by dialysis membrane method.
the percentage of drug encapsulated was determined after lysis of the prepared liposomes with absolute alcohol and sonication for 10 minutes. The concentration of drug was determined by suitable method in triplicate. The encapsulation efficiency expressed as entrapment percentage was calculated through the following relationship:
Encapsulation efficiency % =Total drug−free drug/
                                                      Total drug                                ×100.
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Hi there everyone! I would like to know whether I could use Extra virgin olive oil derived polyphenols for the green synthesis silver/any other nano-particles- as a mean of drug delivery vehicle? 
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So would you suggest me to go for olive leaf aqueous extracts instead, as a starting material for the extraction of desired Phenolic compounds ?? Can I Possibly use them for the green synthesis of  metallic nanopartices or should I go for the nano-encapsulation strategy for the  optimized co delivery of both phenolics in combination of any synthetic drug of my choice, considering 1 year limited time frame required for the completion of my project.
Mr.Jai Ghosh could you possibly guide me along if you know any expertise in the field of nanomedicines/Nanobiotechnology. 
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I am searching what is the maximum molecular radius for protein based drug and/ antibody related drug.
If any one know please let me inform.
Thanks in advance.
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Hi Sanat,
If it is protein bio-therapeutics, 6-7 nm is max. The glomerular filtration process cannot filter proteins above this hydrodynamic radius. But, in some cases such as PEGylated bio-therapeutic proteins have around 9 nm. However, this is in cases of one which cleared through receptor/ ligand binding.
kind regards
Praveen
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I have ARPE-19 cells encapsulated and in alginate-gelatin hydrogels, and count the number released cells from hydrogels. But there's no model or release kinetics studies as I found. Does anyone have suggestion on that issue? If there is any publication please let me know.
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I am working on vesicular drug carriers and then incorporating them in TE Scaffolds for different application. Is there any preference of using niosomes over Liposomes for these kind of applications?
And another question, my scaffolds are made up biopolymers, So will I have any ristrictions regarding choosing the polymer and solvent system ?
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General Comparison Liposomes Niosomes.pdf
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I would like to know about the issues related with the application of metallic nanoparticles in ocular drug delivery. Specially for the drug delivery to the  the posterior segment of the eye. Which path they usually follow to cleared out from the posterior segment. What about the toxicity issue due to their possible deposition in the posterior segment if they are not able to move out from there. 
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Hi,
These are some 2017 publications relevant to your query:
Positioning metal-organic framework nanoparticles within the context of drug delivery–A comparison with mesoporous silica nanoparticles and dendrimers
S Wuttke, M Lismont, A Escudero, B Rungtaweevoranit… - Biomaterials, 2017 - Elsevier
,.,.,.,.,.,.,.,.,.,.,.,.,.,.,
Hydrophilic polymeric nanoparticles prepared from Delonix galactomannan with low cytotoxicity for ocular drug delivery
AT Ogunjimi, SMG Melo, CG Vargas-Rechia… - Carbohydrate …, 2017 - Elsevier
,.,.,.,.,.,.,.,.,.,.,.,.,.,.,,.,.,.,.,.,.,.,.,.,.,.,.,.,.,
A novel nanoparticles impregnated ocular insert for enhanced bioavailability to posterior segment of eye: In vitro, in vivo and stability studies
LV Rathod, R Kapadia, KK Sawant - Materials Science and Engineering: C, 2017 - Elsevier
,.,.,.,.,.,.,.,.,.,.,,.,.,.,.,.,.,.,.,.,.,,.,.,.,.,.,.,.,.,.,.,,.,.,.,.,.,.,.,.,.,.,
Naked eye and spectrophotometric detection of chromogenic insecticide in aquaculture using amine functionalized gold nanoparticles in the presence of major …
C Loganathan, SA John - Spectrochimica Acta Part A: Molecular and …, 2017 - Elsevier
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I want to administer Magnetic Nanoparticles (MNPs) by orally.
What are the complication I will face with respect to MNPs after oral administration (toxicity, polydispersity, etc)
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It depends on the chemical nature of magnetic NP. Every chemical has limit that is not dangerous. Magnetite or maghemite may be the most preferable but it is need to find special medicine recommendations.
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I am creating nanoliposomes to use as a delivery method to mix hydrophobic pigment zeaxanthin with hydrophilic protein GSTP1. My faculty adviser wants to use FRET to help measure how well GSTP1 moves zeaxanthin from donor liposomes to acceptor liposomes. However, we do not know what fluorophore will work with this assay, and I do not know how to find an appropriate fluorophore.
Thanks for your time.
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Hi,
Have a look at the following papers, you may find them useful:
Fluorescence Resonance Energy Transfer in Polydiacetylene ... - NCBI
https://www.ncbi.nlm.nih.gov › NCBI › Literature › PubMed Central (PMC)
by X Li - ‎2008
- - - - - -
The design and application of fluorophore–gold nanoparticle ... - NCBI
https://www.ncbi.nlm.nih.gov › NCBI › Literature › PubMed Central (PMC)
by M Swierczewska - ‎2011
__ __ __
monomeric fluorescent protein: Topics by Science.gov
-  -  -  -  -  -  -  -
Applied systems biology - DTU Orbit
by E Moravcikova - ‎2012
___  ___  ___  ___
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Can anyone suggest about the drug loading efficiency to the nanoparticles and nanotubes???Possible method for its release mechanism
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Dear Sir,
I read the above article and ok with the suggestions to. In my case I have very low volume of nanotube/ nanospheres and the paclitaxel drug which I am trying to load by simple physical adsorption method. I am able to get the peak for loading but not getting the peak for release profile  due to less volume of sample.  So, Is there any method to detect these efficiency?
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I am trying to combine other therapies with the nanoparticles-induced photothermal therapy for cancer treatment, and looking for the disadvantages of the photothermal therapy or the cancer cell resistance to PTT. As the best of my knowledge and the papers I have red,  only the HSP proteins could affect the efficiency of PTT, do anyone know other factors? Thank you.
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All proteins available at the site may respond to photo-thermal reaction according to their lability to photo reactions based on the chemical group present. You need to model/simulate the experiment with selected protein. The chaperone worker proteins are also a potential participant.
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My project involves fabricating PLGA microsphere loaded with certain drugs. Because the drugs are kind of expensive, our group decided to limit the scale down to mg. So basically I fabricate a few mg of PLGA microsphere each time. The thing is, while washing the microsphere, it tends to cluster into a plastic-like status, which is incredibly hard to dissolve. I tried to dissolve 1 mg microsphere in 18 mL dissolving solution (according to other literature, dissolving solution contains 0.1 M HCl and 0.05% Tween 80), but nothing happened in hours. Also I tried to cut the microsphere product into small pieces, but that didn't really help.
I would like to know if anyone has the experience of fabricating small scale PLGA microsphere and how to deal with the dissolving problem. Thank you very much!
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I have interpreted dissolving=dispersing product for washing to get rid of un-encapsulated drug. 
Based on what you have described, it looks like the polymer is not dispersed properly during preparation of microspheres resulting in a plastic like mass. Work on the homogenisation protocol, increase the level of wetting agent or surfactant (such as PVA) to improve dispersibility. At the end you should receive a nice dispersible product in water. 
Other probable cause of plastic like consistency is the drying protocol. if you have dried at very high temperature you can end up with a melted microspheres. 
bottom line: Refine your preparation method to avoid generating plastic like product.
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I performed a dissolution test on number of nano formulation that contains my drug with different stabilizers that have different concentrations
but when it came to dissolution test all the drug was released in less than 10 min compared to the raw drug which took 90 min . after that the UV spectrophotometer stops reading  the absorbance , like the drug isn't available in the samples
I changed the volume of the media from 500 to 250
the amount of the formulation to 10, 25, 50 mg
the rotation speed from 100 rpm to 50 rpm
the filtration with  non, 0.45 um, 0.22 um
used both apperatus1 and 2 
used a sinker
nothing seemed to change the result
has anybody faced this problem before ? how can I asses the drug release in this case
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How are you preparing your nanoparticles? Have you consider a change in the crystalline form of the API - this would definitely affect the solubility of the drug, being aligned with the results you mention. 
Other issues, regarding the analytical method itself, like filter compatibility, selectivity of the UV method - were those accounted for also? What dissolution media are you using?
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In other words, it could be encapsulated more drug than the amount of polymer used in the microencapsulation process, so as to produce, for example, a mirocapsule system containing 1,5 or 2 (and so on) mg drug/mg polymer matrix?
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Beter to modify the polymer by changing the functionalities for eg., OH, NH2 or COOH for effective binding with drug.
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I recently read several articles on single walled carbon nanotube based drug delivery system. However, in this field, multi walled carbon nanotube is less frequently used.
Does multi walled carbon nanotube has any advantages over single walled carbon nanotube in constructing drug delivery?
OR is there any difference about using single walled carbon nanotube or using multi walled carbon nanotube as the carrier for drug delivery.
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easy-fabrication?
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Although, Selenium (Se) being an essential cofactor and also acting as an antioxidant in human body (maybe some other medical benefits in conditions such as Cancer, HIV, Crohn’s disease etc). However, in medical terminology largely there is no-point recommending Se as a “supplement”, because the tiny concentrations humans require, we can get it from food only according to Recommended Dietary Allowance (RDA).
Question? If it’s a known toxic element, why investigators still encourage studies using Se nanoparticles in drug delivery? Recently, there is an increasing surge of using Se nanoparticles. Unfortunately, understanding and preventing risk often has a low priority in the competitive world of research funding and embracing a fixed idea is one of the main dangers in the evolution of any scientific discipline.
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Well explained by Mubashar Rehman.
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I have prepared Plasmid Encapsulated PLGA nanoparticle. How should i treat the HEK293T cells or any other cells with these nanoparticles to get the plasmid inserted into the cells??
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Try incubation! Rest, check from the literature.
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I am preparing niosomes from mix of Span 40,60,80 and Cholestrol and I want to use them for drug delivery. It has been long I am struggling with the concentration of ingredients. As I use 100mg for 10 ml of hydration medium which is equal to 2 e-4 mol/L, but the amount is very small to manage ( when weighting) .
My method is thin film hydration method and for now the molarity of Span which I prepare at first ( 50 cc solution of Chloroform/methanol) is 2 e-4 . I just wonder how I can determine the range of concentration which I will have the niosomes.
Thanks,
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Use stock solution dilution (after dilution another dilution on the first diluted, mean multiple dilutions) and vesicle bleach or hydrolysis and UV (Spectrophotometric, concentration based, dilution curve estimation) or HPLC-based quantitations. 
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If I prepare Eudragit nanoparticles and later convert it to suspension and use it as nasal spray, would it be ok? Remember drug is neither for respiratory tract, nor it has to target brain. I have not seen any article so far in which eudragit alone has been used in the nasal route. 
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What is the intended use of your Eudragit nanoparticle?..afterthat I can tell whether you should deliver Eudragit NP or not to deliver..
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I work with a 2 similar but structurally different PEGylated polymeric nanoparticles encapsulating a traditional chemotherapeutic drug. The nanoparticles are developed to be administered orally. Preliminary efficacy studies shows good tumor control compared to free drug for both nanoparticle formulation. But size distribution studies of the drug encapsulated nanoparticles shows 2 peaks (suggesting breakdown of nanoparticles at acidic gastric pH), implying drug release as soon as nanoparticles reach stomach for one and significant difference in size (small size about 60 nm at pH 2, 120 nm at pH 7 and 150 nm size at pH 8) with a single peak for the other. What does these results imply? Why is there a size difference with pH.
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1. Extreme acidic pH can induce hydrolysis of some polymers which might affect the size and stability of the nanoparticles.
2. The pH can influence the hydrophobicity of the polymer or drug. (please see the article attached)
3. The pH can affect the charge on the polymer and hence the size. The pKa of the polymer and drug can answer why there is an increase in size when the pH is basic.
More details on the nature of the polymer and drug can be helpful.
Explanation based on Electrostatic Interaction: Assuming it is a cationic polymer,
When using cationic polymers, the charge density of polymers increases in acidic pH. This increase in charge can either increase or decrease the size of the nanoparticles based on the counter-ions (e.g. drug, salt) present in the medium. 
Increase in Size: If there is no counter-ions to neutralize the charge, then the repulsive force between the chains of the polymer can lead to formation of less compact nanoparticles. Hence increase in size in acidic pH.
Decrease in Size: If there drug acts as a counter-ion, then there would be stronger interaction between the drug and polymer, resulting in more compact nanoparticles.
The vice versa would be true for negatively charged polymers.
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how I can increase release rate from lipid nano-capsules? (temperature 37 degree centigrade)
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Dear Alieh,
Both factors that you mentioned might or might not affect the release of the drug. However, it is worth it to change the surfactant to tween 80. It might help increasing the release of the drug.
Rafik
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I want to load two different drugs on it. name any substance
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Catechols serve as excellent anchor groups for surface functionalization of iron oxide nanoparticles. You could take a catechol derivative such as 3,4-dihydroxybenzoic acid and conjugate it to your drug(s) using metabolically labile linker such as an ester or carbamate, then directly attach your catechol-drug conjugate to the surface.
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Hi all,
I have a problem that can not make the antibody-gold nanoparticle conjugate for my lateral flow assay.
The colloidal gold is 40nm (sigma) incubate in PBS and the O.D.=1, and the antibody is rabbit mono-antibody IgG.(abcam)
The protocol is listed below.
  • Dilute the antibody by PBS(0.01M) to 0.1mg/ml
  • Add the diluted antibody (increasement from 0.4ul to 4ul) to the gold 20ul
  • Wait 2 hour for adsorption
  • Add 4ul 10% NaCl to find the optimized ratio of gold against antibody
But the solution become transparent after antibody was added within 5 mins before salt is added.
I know I have to optimize the pH value since antibody is sensitive to pH value. But I assume the mono-antibody pH value here is pretty close to the PBS. So I simply ignore the pH optimization.
I guess the antibody composition(57% PBS 42% glycerel 0.05% BSA) might interfere but I can't figure the result.
Could anyone can give me some advice?
Beg for help
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Try this gold conjugation kit, it will reduce the aggregation problem:
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I would like to study a protocol, using UV-vis spectrophotometer or an other method. Thank you!
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Usullay sink conditions are maintained while performing release studies. You can either add  a solubilizer (sodium dodesyl suphate) or some other surfactant such as Tween 80 (0.1%) to dissolution medium.  Or the second option is to use greater volumes of dissolution medium than that of solubility limits of the analysed drug.
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How can I calculate N/P ratio for a peptide as a nanocarrier and GFP as a gene?
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You could perform elemental analysis and determine the percentage of N and P and N/P from it.
You could also use photoelectron spectroscopy to determine N/P
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The drug is hydrophobic . The solubility of drug  is less than 0.5 mg/ml in water, methanol and ethanol. But drug has very good solubility in DMSO. Is it good to use DMSO as the only solvent to load the drug in nanoparticles? How to remove DMSO completely from nanoparticles? The combination of 10% DMSO and 90 % water is correct or wrong? 
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You shouldn't use a too good solvent for the drug; then the drug will rather remain in the solvent phase than adsorb to the silica surface. Actually wrote a paper on this almost ten years ago ;-) http://www.sciencedirect.com/science/article/pii/S0168365908001211
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I am trying to encapsulate a hydrophilic drug in PLGA NPs by double emulsion method. Firstly, I emulsified the internal aqueous phase with the hydrophilic drug into 10 mg/mL of PLGA dissolved in DCM. I then prob-sonicated the primary emulsion for 10 sec resulting in a white emulsion. I added the primary emulsion to another aqueous solution containing 10mg/mL surfactant while vortexing, followed by sonication for 30 sec at 4 degrees. The volume of the  outer aqueous phase containing the surfactant was  10 times larger than that of the primary emulsion. However, the final emulsion failed to form and I got just polymer aggregates in the aqueous medium. Can anybody help to prepare these NPs? Thanks.
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1. Use w/o surfactant for initial emulsification step (water in oil) - e.g., Span-80
2. Minimize amount of water for the first step
3. Increase PLGA concentration in DCM to 5-10%
4. Add NaCl or MgSO4 (2-10%) to external water phase
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Many pathological sites have acidic environments, lower pH, hence pH-responsive materials can degrade in such place. If i want to deliver pH-responsive nanocarriers into cells and let the carrier degrade because of the low pH of organelles, then release drugs and kill cells. How can i ensure that drugs will not release in extracelluar but in intracellular?
Both extracellular pathological sites and intracellular organelles have low pH. In vivo test, how can i tell drugs release inside or outside the cell.
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You can encapsulate a fluorescent dye in carrier and perform suitable imaging to visualize whether fluorescence occurs outside the cell or inside it. 
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I use chitosan and dextran sulfate as polymers, and paraffin oil. The aim of the encapsulation is the protection of the drug against enzymes and the RAPID controlled release (2-5 hours) of the drug in a medium with a neutral pH and 37ºC.  Can anyone recommend me a suitable method? 
In addition, in the preparation of the "particles", i would like to know which is the best way to wash them.
Thank you
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Thank you for all your answers
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Is it possible to precipitate Quercetin conjugated CdSe nanoparticles (Synthesized in Water) using any solvent?
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Try using organic solvents, un-harmful to the quercetin. Solvents precipitating the quercetin (as such) and solvents used in the nano-precipitative preparation of CdSe NPs may also work out! Try searching the literature and you could make out some including from these articles:
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Please give reference if possible.
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I'm not the expert but I would like to comment my opinion. I have some experiences about hybrid nanomaterials for drug delivery, a year ago. At that time, I was curious that how can our body remove the remaining amount of nanoparticles. I'm still couldn't find the real answer for me. So, I think it's a challenge point for nanoparticles.
In addition, below links are the explanation about hazards and negative effects of nanoparticles for drug delivery. Hope this comment would be useful for you. 
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I see some papers have 10% w/v tween 80 or even more, but if we increase the concentration to 10% doesn't the dissolved drug or the particle get adhered to the tube? and also that might have some effects on the dialysis membrane?
Please correct me if I am wrong.
Thank you
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The critical micellar concentration of Tween-80 is about 0.0013% and the micelle molecular weight is 76,000. This means that the Tween-80 is not going to dialyze out of the bag in any reasonable amount of time, using dialysis tubing with a typical molecular weight cutoff (e.g. 10,000) if the starting concentration is as high as 10%. If a small molecule drug associates with the micelles because of its hydrophobicity, it will also not dialyze. Nanoparticles are generally too large to dialyze in any case. Depending on what they are made of, they may be dissolved by the detergent or coated by it.
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Hi, I am working upon nano medicines. Drugs are made targeted to the site of action. So, I am wondering for how a drug can be made a targeted one. How does it reach to specific area without prior loss or being harmed?
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Hi,
Your question is based on an open research topic which needs a lot of explanations. but there are few important things to be considered.
1- specific site targeted drug.
2- Ideal polymers
3- if sustained release, then particle size is the most important.
You can find many papers on each site specific delivery system. I hope this will help.
Regards
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actually particles less than 5 nm are rapidly cleared from the circulation through extravasation or renal clearance and when the size ranges increases to 15  micrometers accumulation of particles may occur, i wish to know is there any required particle size of nano formulation to target various cancer cells...
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The ability to target/reach a cancerous tissue is not only dependent on the size. With a size between 5 and 200-300 nm it should be possible. Particles below 5 nm can be exretated by renal filtration, bigger particles can be taken up by the RES. But all these features depend a lot on other factors, e.g. surface charge/zeta potential, stealth effect of the particle (PEGylation), etc.
There is a nice review about nanomedicine approved by the authorities or that is in ongoing clinical trials ("Nanomedicine in cancer therapy: Challenges, opportunities, and clinical applications" by Witzigmann et al.).
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Porous silicon can be synthesized chemically from silicon tetrachloride or  through stain-etching with hydrofluoric acid. However, In oder to make mesoporous particle size from 100 to 200 nm is very difficult. How to make mesoporous silicon nanoparticle by bottom-up method for drug delivery ?
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Thank for your answer, it is so good. But I want to find a new method to make porous particle between 100 and 200 nm without using hydrofluoric acid to etch and by bottom-up method. 
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i want to know the mechanism of drug release from PCL nanoparticle in SGF and SIF? its because of diffusion or degradation polymer? 
dose polycaprolactone(PCL) hydrolysis in ph=1.2 ?
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Dear Fatemeh,
It is expected that PCL will undergo hydrolysis when exposed to acidic medium. The terminal ester contained in PCL is the most labile function which is believed to be cleaved in acidic medium.
You may read the paper entitled " Hydrolysis of Polylactic Acid (PLA) and Polycaprolactone (PCL) in Aqueous Acetonitrile Solutions: Autocatalysis" by Georgette L. published in Journal of environmental polymer degradation January 1998, Volume 6, Issue 1, pp 31-41 which illustrates the hydrolysis kinetics of PCL.
The Paper Abstract:
Polylactic acid (PLA) is a hydrolytically degradable aliphatic polyester. The rate of polymer hydrolysis increases with time, and that has been attributed to the high reactivity of the terminal ester and the kinetics of autocatalysis. Hydrolysis is carried out in an acetonitrile/water solution to eliminate any solid-state contributions such as diffusion and crystallinity to the degradation process. A kinetic equation is derived to describe the autocatalytic effect of the increasing carboxylic acid end-group concentration. The results of solution hydrolysis are examined and found to fit the derived equation. Hydrolysis was also carried out with polycaprolactone (PCL) in acetonitrile, where reaction kinetics were found to differ from those of PLA. The PCL polymer required external acid catalysis by the addition of HCl, whereas hydrolysis of PLA was “selfcatalyzed” by the carboxylic acid end-groups.
Hoping this will be helpful,
Rafik
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Every nanoparticles formulation has a hydrophilic polymer as a surfactant such as PVA. When nanoparticles are centrifuged for separation, does not it cause the release of drug which is entrapped in PVA? This will result in low entrapment. Need expert opinion.
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If you have an idea about particle size and density you will be able to calculate how long you will have to centrifuge at a defined acceleration for full nanoparticle separation (Stokes law). This will help you to select time and acceleration for not stressing the particle-polymer-drug composite too much.
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Direct delivery to tumors remains a problem in most nanoparticle applications because the immune system rapidly removes circulating nanoparticles by ultimately accumulating them in the liver and kidneys. Can nano graphene oxide with enhanced tunable fluorescence be used as bioimaging probes without attaching antibodies?
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It may be possible to self image the tumour cells with GO via chemodosimeter technique via selective ion channels in cancer cells. GO assisted chemodosimeter for detection of fluoride ion (carcinogenic) has successfully been developed. For details one may follow the link
Same approach may be utilized for selective detection of ion channels present in cancer cells.
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can anyone please mention a very simple method to study the drug release from an electrospun PLGA mesh by taking in conservation that it's hydrophobic
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You could use a dissolution medium at an adequate physiological pH (1.2 if the release is intended to be in the stomach; 4.5 if is in duodene; 6.8 if release is on lower intestine; or 7.0 for neutral environments) added with small amounts of Sodium Lauryl Sulphate (SLS, 0.1-1.0% p/p is currently used in dissolution tests) or Tween 80. Decide if mesh will be introduced into a rotating basket or will be submerged into the dissolution medium. I hope this helps you in some way. Best regards.
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Also tell how much volume of liquid should be used to redisperese them. How much amount of sample should be taken to redispere in liquid.  Kindly give a detailed reply
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You should strictly disperse them under conditions expected for further use, e.g. it does not make sense to disperse them in a special solvent if its application is in water buffered to a fixed pH value and defined electrolyte content.
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with the intention to delivery to lung alveoli for slow liposome release into systemic circulation?
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Hi Chris,
i don't see why not. It well know that liposomes can be loaded into hydrogel. the question is:  will the get out? but to know that you'll have to try.
one important thing is to make sure that the PGLA solution and the liposomes suspension have the same osmomolarity otherwise you will destroy them.
check the literature for liposomes in hydrogel you'll find some already working system.
hope it helped
regards,
Etienne
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I plan to synthesize a PLGA-PEG drug loaded nanoparticles using double emulsion method wherein, ethyl acetate will be used as an organic solvent and Nivolumab will be the drug to be loaded.
However since I am not doing any of the procedures in the lab, I am not able to gauge the exact proportions of all the components.
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before starting the formulations using double emulsion method you should ask yourself a few questions: 
What is the solubility of your compound, is your compound freely soluble in water, or poorly soluble, from that point you will determine if you really need double emulsions or 
you don't need ?
is your compound soluble in ethyl acetate ? 
What is the partitioning ratio of your drug in the two immiscible phases of the primary emulsion?
Try to read about physicochemical properties of your drug before proceeding with the formulation part. 
BTW, Double emulsion solvent evaporation method primarily was used for protein-loaded nanoparticles which they are highly soluble in water and insoluble in organic solvent. 
I will be delighted to discuss and answer any question related to the above topic. 
regards. 
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Which MWCO Dialysis membrane is suitable for in vitro drug release of Drug loaded nanoparticles of size ~50 nm from TEM?
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In vitro release experiment through dialysis tube mostly depends on molecular weight of your drug that is to be encapsulated or tethered with your polymer. so if the M.Wt of your drug or desired compound to whom you measured its release is less than 1000 than use can use MWCO tubing of 2000 Da... 
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i am preparing nanoparticles, drug is hydrophilic and entrapment efficiency is very low. If i find the drug release by dividing with the total drug taken its giving very low drug release so is it possible to find drug release by dividing with the total drug entrapped? Kindly send if there is any reference for it. 
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Along with all previous answers... consider correction factor every time if your are doing replenishment of your disso medium.
All drug may not be entrapped in carrier system during NP preparation hence its mandatory to find how much drug exactly incorporated in NP against total amount of drug added by you in preparation.
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I want to ask that if we are going to check the antibacterial effect of NP's encapsulated with the drug through disk diffusion method then how we can make a disc of NP's encapsulated with the drug? Is it necessary to add any diluent or binder to make the compacted disc.
Answers will be appreciated.
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Dear Muhammed,
Attached please find a paper entitled "Synergistic Antibacterial Effects of Nanoparticles
Encapsulated with Scutellaria baicalensis and Pure Chlorhexidine on Oral Bacterial Biofilms " which was published two days ago describes in details how to assess the antibacterial activity of antimicrobial NPs.
Hoping this will be helpful,
Rafik
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Hi, I am trying to administer orally MPs (approx 400 um in size, disperse in water) to ICR mice but facing difficulties like aggreagtion of MPs in gavage tip or in syringe. I tried different size gavage use for mice and rats.   I will appreciate any suggestion to solve this problem.Thanks
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Try by spending in a liquid and adding through a tubing via funnel. May get you good result...
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Greetings to everyone,
I want to deliver siRNA to Cardiomyocytes (Heart) using liposomes or polymeric nanoparticles or any other drug delivery vehicle.
For the targeted delivery to cardiomyocytes, I am looking for some specific protein which are specifically expressed or over expressed on surface of heart muscles. I would be glad to know the appropriate size of drug delivery vehicle to deliver the content in heart muscles. 
So please suggest me some appropriate marker to target the cardiomyocytes using drug delivery vehicles.
Thank you in advance :)
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You could try Integrins to target cardiomyoctes. But look for the specific one's which are overexpressed on them. 
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I want to know is there any mathematical expression between zeta potential and charge on the nanoparticles?
Can we consider that biologically synthesized protein capped NPs will have a net negative surface charge at neutral pH?
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Unfortunately, it is not possible to relate the zeta potential quantitatively to the surface charge, since the build up of the Stern layer contains contributions due to specific ion adsorption and also requires to take the size of the ions into account. A Langmuir adsorption layer is typically assumed for this. (That is what Stern did.)
There are approximations to relate the surface charge to the surface potential though, The most common and straightforward one is the Grahame's equation. It is basically just assuming charge neutrality and using the Poisson equation for the charge distribution and then you get the result. You can google it or I can send you some of my lecture slides on it. The surface potential calculated in this way is however not the zeta potential mainly for the reason mentioned above.
For the second question, you can definitely not assume this since it depends on both the particle surface potential and the adsorbed protein layer. You cannot generalize anything like that.
Good luck with your work,
Erik
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Thank you.
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No. You will place your nanoparticles in dialysis membrane available in the form of tubes and cassets. These nanoparticles filled systems will be placed in dissolution medium. If you place nanoparticles directly into disssolution medium, they will get removed when you take samples.
These are two examples. Please ask you supplier to find best options.
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Superporous hydrogel for Gastroretentive delivery
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Thanks a lot..really i appreciate your kind help.It will really help me to continue my research work and for that i am really grateful .
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Any examples out there of cross linked films/gels where the active drug is not dispersed/loaded but is actually bound to a degrading network?
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Perhaps drug eluting stent (Where bidegradable polymeric network is containing drug) is something you are asking for.
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Waiting for reply.
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The exact method will depend on the drug and nanoparticle formulation but there is a method that may be used for polymeric nanoparticles:
To measure drug release from nanoparticles, nanoparticles should be lyophilized, weighed, and resuspended in buffer (I used two different PBS/0.1% Tween-80 buffers, one at pH 7.4 and one at pH 6.5, but you can use whatever buffer is suitable for your drug/nanoparticle preparation) and then incubate in a 37 °C water bath. At various time points (I measured between 15 min and ten days) an aliquot of eluted drug medium should be removed for quantification; this volume must replaced with fresh buffer to prevent sink conditions. Drug release can be quantified by measuring the absorbance of the release media using a plate reader or HPLC, this value, of course, will be unique to the drug you are using. As a control you should also measure blank nanoparticles (with no drug) and make suitable standard curves for your drug concentration in buffer.
Please see the two attached papers of mine for methods and if you have any other questions please let me know.
Read full-text
Source
Article: Pharmacokinetics and biodistribution of lonidamine/paclitaxel loaded, EGFR-targeted nanoparticles in an orthotopic animal model of multi-drug resistant breast cancer
Lara Milane · Zhen-feng Duan · Mansoor Amiji
[Show abstract]
Full-text · Article · Aug 2011 · Nanomedicine: nanotechnology, biology, and medicine
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How do I measure a drug release profile for a drug encapsulated in a nanoparticle? - ResearchGate. Available from: https://www.researchgate.net/post/How_do_I_measure_a_drug_release_profile_for_a_drug_encapsulated_in_a_nanoparticle [accessed Feb 24, 2016].
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To find entrapment efficiency of nanoparticles, should I make calibration curve with serial dilution or stock solution dilutions (dilution series) ?
Waiting for reply..
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For determining entrapment efficiency, it is very much essential to make standard calibration curve and with its help you can find out entrapment efficiency. 
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for some formulas EE%  value is greater than LC%, and for some formulas EE% value is lower than LC%...is this normal???
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Hi Ahmed
Entrapment efficiency gives you an idea about the %drug that is successfully entrapped/adsorbed into nanoparticles. It is calculated as follows:
%EE = [(Drug added - Free "unentrapped drug")/Drug added] *100
Example: If the %EE is 30%, it means that 30% of your drug is entrapped into the nanoparticles.
Loading capacity helps you to deal with nanoparticles after their separation from the medium and to know their drug content. It is calculated using the following equation:
%LC = [Entrapped Drug/nanoparticles weight] * 100
Example: If the loading capacity is 30%, it means that 30% of the nanoparticles weight is composed of the drug! i.e. Each 1 mg nanoparticles contains 0.3 mg drug.
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I want to functionalize carbon nanotubes (multi-walled) which base fluid is oil , Which functional group do you suggest or is better to use in your opinion?
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Hi, please as Hojjat said we will need additional explanations to help you.
Best.
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Kindly respond rapidly.
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It depends on what is the continuous phase used for fabrication of nanoparticles. Assuming, the NP are prepared in aqeous base system, with DCM as the solvent., then vacuum pressure of 300- 500 mBar should be more than sufficient. Also, temperature of the system will be very important. Adjust the temperature close to boiling point of DCM i.e. 40 C. As the tg for eudragits is close to 65 C it will not hamper the shape/ structure of formed nanoparticles. Time is a dependent factor and relies on pressure and temp as independent factors.
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Hi,
I am preparing nanoparticles by w/o/w double emulsion method.Firstly I am sonicating w/o emulsion at 70 % amplitude for 2 minutes by using sonics vibracell ultrasonic processor 500 W, 20 kHz and then again sonicating the w/o/w emulsion for 2 minutes at 70 % amplitude using sonics vibracell ultrasonic processor 500 W, 20 kHz. Is it right? 
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Mine is under review right now in JCR (hoping for the best (-:) but anyway it's based on the double emulsion method described in Saltzman paper: http://www.sciencedirect.com/science/article/pii/S014296120900115X
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after preparation of nanoparticles, precipitation of the drug occurs. I want to know the causes and how to solve it.
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Hi Milad,
You need to provide more information. What is your method of preparation, how about drug solubility in organic or aqueous phases, did you use TEM to check whether the precipitate that you see is drug or it is coming from larger, micro-sized particles that were also formed? Also if you're relying only on dynamic light scattering (DLS) (e.g. malvern zetasizer, Brookhaven nanosizer, ..etc) to make sure that you actually have nanoparticles, this may not be enough. You need (have to) use TEM (or SEM) to confirm it. 
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After collecting supernatant which pore size filter is used to filter the supernatant? After filtration do we take its UV absorbance or to do anything in between? After taking its absorbance what to do next?
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I agree with Rafiq Karaman, you should construct a callibration curve.
For this purpose, you will make a number of dilution of known concentration and take their absorbance in UV-Vis spectrophotometer. Plot a graph in MS Excel between concentrations (x-axis) and their absorbances (y-axis). Then, you can take trend line to see if calibration curve is predictable  (R2 value is near to 1 i.e. 0.99) and show equation of graph.
In this equation, you will need to replace "y" with value of your absorbance of supernatant and you will find the the of "x", the concentration of drug in sample.
You can collect supernatant by centrifugation or by use of dialysis tube. Dialysis tube of differetn Molecular Weight Cut-Off are available that can retain nanoparticles but un-encapsulated molecules will come out of tube membrane due to smaller size. Usually we formulate drug loaded nanoparticle so that drug is released at desired rate. One disadvantage of using dialysis tube or similar membrane systems is that they need significant time for separation. During this time, a significant amount of drug is release which was actually encapsulated inside nanoparticles. Thus, you might find lower encapsulation than actual. Centrifugation may be less efficient in some cases but need relatively lower time.
Is this information helpful?
Regards, Mubashar Rehman
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Prompt response will be appriciated.
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First of all I would like to have a clear view about standard solution. What do you mean by standard solution?? A higher absorbance of drug in supernatant is generally observed when 
1. the centrifugation speed utilized is not sufficient enough to settle down all the drug loaded nanoparticles. This leads to presence of drug loaded nanoparticles in supernatant along with free drug. To confirm wheather all the nanoparticles have settled in form of pellet at particular centrifugation speed, you need to carry out mas balance equation. You have to collect the pellet after centrifugation. dry it and weigh it. now find the entrapment efficiency. Now calculate mass balance.
eg: If you took 100 mg polymer and 50 mg drug so total weight of nanoparticles will be 150 mg in case of 00% entrapment.
Now, if you get entrapment efficiency of 50 %..it means only 25 mg drug got entrapped. so weight of your NP will be 125 mg.. accordingly you can calculate mass balance. If its nt correct then you need to increase speed and time of centrifugation.
2. Second reason is related to interaction of drug with polymer leading to shift in absorbance which may b high or low. In that case u need to study compatibility of drug with polymer in form of solution. Drug polymer and solvent in which you are making nanoparticles. If same absorbance of drug is obatained in all cases then its okk or else you will have to go for derivatization method for estimation of your drug. 
You can cross check both the point by using HPLC for precise result.
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I have 60 ml aqueous phase and 10 ml organic phase for nanoparticles while evaporating organic phase if I evaporate 40 ml of water too at rotary evaporator, is it right?
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If you subject it for rotary flash evaporation, definitely, some amount of water will also get evaporated. The purpose for which you want to evaporate aqueous phase has not been mentioned.
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Please suggest any papers.
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Dear Asad,
To remove or avoid turbidity  Self nano emulsifying drug delivery systems (SNEDDSs) should be utilized instead of SEDDSs.
Please read the following text:
2.1.2. Self nano emulsifying drug delivery systems (SNEDDSs)
Self-nano emulsifying drug delivery systems (SNEDDS) are isotropic mixtures of oil, surfac‐tant, co-surfactant and drug that form fine oil-in-water nanoemulsion when introduced into aqueous phases under gentle agitation. SNEDDS spread readily in the gastrointestinal tract, and the digestive motility of the stomach and the intestine provide the agitation necessary for self-emulsification. SEDDSs typically produce emulsions with turbid appearance, and droplet size between 200 nm to 5 μm, while self micro emulsifying drug delivery systems (SMEDDSs) form translucent micro-emulsions with droplet size of less than 200 nm. However, self nano-emulsifying drug delivery systems (SNEDDS) produce clear or transparent emulsion with droplets size less than 100 nm. Successful formulation of SNEDDS depends on the thorough understanding of the spontaneous nano-emulsification process and also on the physicochemical and biological properties of the components used for the fabrication of SNEDDS. The factors influencing the phenomenon of self nano-emulsification are:
• The physicochemical nature and concentration of oily phase, surfactant and co-emulsifier or co surfactant or solubilizer (if included)
• The ratio of the components, especially oil-surfactant ratio
• The temperature and pH of the aqueous phase where nano-emulsification would occur
• Physicochemical properties of the drug, such as hydrophilicity/lipophilicity, pKa and polarity.
These factors should receive attention while formulating SNEDDS. In addition, the acceptability of the SNEDDS components for the desired route of administration is also very important while formulating SNEDDS.
For more details, please see attached file.
Hoping this will be helpful,
Rafik
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What amount of Eudragit rs 100 is soluble in dichloromethane, in how much volume and under what conditions?
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Dear Pharmacist,
I suggest to assist the stirring with heat or/and use more portion of the solvent (200 mg in 30 mL instead of 200 mg in 20 mL).
Rafik
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Looking for answer.
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1 mbar pressure and −110°C temperature
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Research in nano-emulsions using Franz diffusion cells.
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Its my pleasure. Good luck for your project.
Cheers
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I'm working on a niosomal encapsulation of an anticancer drug and experimenting its efficacy on various cancer cell lines in comparison with the pure (plain) drug by measuring IC 50% for each. As known, the blank niosomes (without drug) are tested to see its effect alone on cancer cell lines. Is there any probability that empty niosomes can have an IC 50% near the drug niosomal formulations or even better? Knowing that the anticancer drug used alone (without niosomal encapsulation) had not a specific indication or effect (and even may be not effective) on the cancer cell lines chosen for the experiment.
There is a theory about the effects of nanomaterials on autophagic processes in cancer (paper attached to this question). But it only handled the nano-particles with anticancer drugs (no empty niosomes to be specific). Can this theory be an answer for my question? 
Please references if available.
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Dear friend, this can be due to cytotoxicity of your starting materials or due to interaction with cell membrane. You should check literature for your starting materials.
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Hi,
I'm developing a targeted nanoparticle for drug delivery purposes where I will use anitbodies/antibody fragments as targeting devices.
As a step to quantitate the amount of antibody bound to my nanoparticles I was thinking of using an ELISA for this purpose I had two questions:
1) What kind of ELISA should I choose? A direct or sandwich ELISA?
2) I'm using a rabbit anti-human antibody (or fragments) of IgG isotype for targeting, what antibodies should I choose for detection and for capture (if sandwich)?
Thank you in advance!
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Hello! I Think that is easier the direct ELISA for the detection of antibodies, you only have to buy an antibody that recognise the specie in which you´re working. Like Murat said use an inmunoglobulin conjugated with horseradish peroxidase. I use the ELISA sandwich for antigen detection, not to antibody. Have a nice weekend!
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my blank NP absorbency in BCA method is higher than NP contain protein. it s maybe because PVA in blank NP or i dont have protein encapsulation. i confuse, also i used NaoH 1M and urea 10M+ SDS 2% and pbs for dissolve protein in pellet. please guide me if you have same experience,
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Please consult the list of compatible substances for the BCA assay.
You may have added too much of one or more interfering substances, such as urea (3 M is maximum). The pH may also be too high because of the NaOH. The combination of NaOH, urea, and SDS may be causing interference.
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I will start to work with nanocapsules and need to use a cationic polymer, like Eudragit-RS100. But, we will spray dry these nanocapsules to use in pulmonary route. As we know, Eudragit RS-100 is not a good candidate because it is not biodegradable and can be stored at the pulmonary branches. Anyone know a polymer like EUDRAGIT - RS100, but biodegradable? Thanks in advance.
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Synthetic polycation, i.e.poly Lysine, PEAD, polyarginine, PEI, etc. can also be used to form complex coacervate with equimolar of polyanion to encapsulate the cargos.
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Fe nanoparticles coated with polymer have been developed as drug carriers. Particle size <50 nm.
They are highly insoluble in organic solvents including DMSO or Ethanol.
Due to their solubility issue, their dilution is also a hassle.
We have tried sonicating the samples prior to dosing the cells.
Everytime the result is "nontoxic" even with dose as high as 2mg/ml.
I doubt that the nanoparticles are not interacting with the cells to manifest biological effects.
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Hello,
Iron nanoparticles are dense and solid spheres and they will not be soluble in any solvent. Citric acid capped very small particles of iron are only soluble in water and some solvents. The polymer coating will completely modify the properties of the underlying nanoparticles. You have not specified the polymer incase it is a biocompatible and water soluble polymer then only the particles can be soluble but it strongly depend upon the core diameter. Anyway you will get huge no. of references reporting iron oxide OR iorn nanoparticles for biomedical use and their interaction with cells. It is a well explored topic of research.
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...
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Dear Philomena,
I realize that this response is pretty late, but I just ran into your question by chance. There is a ResearchGate link provided below on a paper that, I hope, may still be helpful.
Best of luck,
Robert
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I have purchased human ApoE3 from Sigma and in the datasheet it says it should be reconstituted using sodium phosphate and DTT. Unfortunately I don't have DTT. Can I reconstitute using PBS only?
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Dear Mona,
I'm afraid that won't work unless you use another antoxidant instead of DTT.
DTT prevents the oxidation by O2 of protein SH groups to disulfide bonds. If you don't prevent oxidation, your ApoE3 will deteriorate.
Best wishes,
Robert
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I am working on drug delivery by liposomes, but my information a bout phosphorous assay is not complete. please help me. thanks
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Hi. How can I report my result about liposome phosphorous assay
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I am interested to determine the anti bacterial properties of nanocoated knitted polyster fabric. We are intended to coat the fabric with Titanium NPs. Thus, I am interested to know how to determine the antibacterial properties of such fabric?
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You can determine the antibacterial properties of nanocoated knitted polyster fabric with a novel, in situ, direct and instrumental method, which produces high resolution and quantitative results and is so versatile that it could be used to evaluate the antibacterial properties of any compound (organic, inorganic, natural or man-made) under any experimental conditions, depending on the targeted application.
For more information 
Journal of Microbiological Methods 112 (2015) 49–54,
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Pharmaceutical nanotechnology
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You can remove paclitaxel by ultracentrifugation. Wash pallet obtained with fresh solvent and repeat process until whole drug is separated.
You can also use dialysis membrane (or sac) of lower MWCO (<10 kDa) for filter separation.  
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I am attempting to prepare liposomes containing a porphyrin. During the liposomr formation, the sonication step of the prep. Seems to force the porphyrin to leave the liposomes and aggregate in the rehydration solution. Why is this happening and how do i stop it from happening
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I have mostly done this with water soluble porphryin compounds, which maybe is a little easier.  I also found that stirring alone never produced liposomes, but that sonication was needed.  
I found also that it was difficult to reproduce preps from the literature- there is substantial "art" required.  For example, I found that the drying stage was pretty critical to the quality of the liposomes.  The nature of the thin film with lipid depended on size and type of container ( i found certain brand vials gave much better results than any other glassware),  speed of rotation, etc.  The thinner the better was my experience.
I actually only removed the majority of chloroform via rotovap, then hand rotated the vial under vacuum to coat a thin film over the entire surface (so using a wider range of motion than the rotovap can do) until dry.  Then over night on the vacuum line to complete dryness.
Since you think your lipid layer is "hardened" I would maybe work on optimizing this film making step first- try thinner films, different glassware, and maybe even the lipid/por ratio (or lipid types).  Personally overnight drying improved my yield and repeatability, but if your application can stand trace chloroform, you should give it a try.
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I want make mesoporous lignin particles for a drug delivery project. Can somebody suggest me a method. ?
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You can see this link for mesoporous lignin synthesis:
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My nanoparticles are coated with chitosan and the freeze dried nanoparticles are not able to be dispersed in water. It forms some flakes, which is impossible even to suck through the needle.
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