Cancer Nanomedicine - Science topic

The production of core-shell nanomaterials presents several technological challenges, some of which include:

My experience with core-shell nanomaterials has primarily been in the area of nanocatalysis, where core-shell nanoparticles are used as catalysts in a variety of chemical reactions. In my experience, controlling the size, shape, and composition of the core and shell is critical for achieving high catalytic activity and selectivity. Additionally, ensuring the stability and durability of the nanoparticles is important for maintaining their performance over multiple catalytic cycles.

In terms of economic viability, finding ways to scale up the production of core-shell nanoparticles while maintaining their quality and performance is a major challenge. This often requires the development of new synthesis methods that are cost-effective and scalable, without compromising on the precision and control needed to produce high-quality core-shell nanomaterials.

Overall, the production of core-shell nanomaterials presents several technological challenges, ranging from controlling the morphology and achieving synthesis precision, to ensuring stability and durability and addressing economic viability. Overcoming these challenges will be critical for the widespread adoption and application of core-shell nanomaterials in various fields, including catalysis, energy storage, and biomedicine.

Dear all, solubility depends on the chemical structure and types of existing intermolecular forces. Excessive sonication may degrade any of the compounds present in the recipe. There are many techniques to solubilize poorly soluble drugs. Please check the following links. My Regards

I am new in this field but my understanding that someone need knowledge and skill for extraction of reducing agent, synthesis of nano-particle and characterization of nanoparticle by different types of microscopy ( SEM, TEM, XRD ... etc) and studying applications ( antimicrobial activity, anti cancer activity, etc)

It is so challenging to get stable nanoparticles with high drug loading. Moreover, active targeting has many limitations that impede its applicability.

Dear swara,

You can add surfactant such as sodium dodecyl sulfate into the PBS medium.

can you tell me how to do drug release study thin film

Thank you, it was helpful.

Adobe illustrator, inkscape, CorelDRAW....

All these mentioned above software are used for 3D structure annotation 

If you've measured the particle size distribution, then 6/D[3,2] is the specific surface area in m²/cm³ (D[3,2] is the Sauter Mean Diameter - see attached) which you can convert to m²/g with knowledge of the density.  This D[3,2] and SSA is actually shown on Malvern Instruments diffraction instruments   There are routes to carry out a dye absorption (or radiotracer) experiment in a manner akin to a BET experiment.  If I recall correctly Gregg and Sing's text may deal with this type of surface area determination - you keep adding dye and measuring the uptake by the lipids tracking the concentration in the dispersed phase (which tells you how much has been absorbed) .  A Langmuir isotherm plot results which when back-extrapolated to zero concentration gives you the surface area.

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.).

For Gadolinium, see nephrogenic systemic fibrosis in patients with kidney disease.

If you have more question, I will be happy to answer you. But I think above-said description will be enough for you.

Best wishes

The guestion  does not lie within my scope.

thank you Remya

Utilising Nanoparticletweezers coupled with Radio sensitizers can help for your 

hi,

It really depends on many factors, some NPs may suspend by 2000rpm and some of them needs more than 18000 rpm

It depends on their charges

Neutral charges needs more rpm

Dear Santhosh,

Regardless of the hydrophobic nature of PLGA and so its nanonoparticles, you should be aware that Double Emulsion method is a very challenging technique, as numerous parameters play key roles in overall efficiency, yield and quality of the particles. 

You are using a high quantity of PLGA copolymer, while it's been demonstrated that the more polymer concentration, the higher portion of larger particles as well as microparticle and a large volume of aggregates. As you didn't mention and I guess, you do not filter the final mixture of particles. As a result, presence of the macro-sized aggregates could be another reason of poor water solubility, as the aggregates make the emulsion opaque and are easily seen suspended and unsolved with bare eyes!

Another point is the sonication intensity and timing which is VERY VERY VERY.. to an unimaginable extent important !!! your sonication timing and intensity sounds inadequate!

But technical suggestions:

1. Instead of 100 mg, use 25 mg PLGA in a volume of 1300 microliter of DCM(as it rapidly evaporates during sonication time!)

2. Use 1 mg of the protein in only 100 microliter(10 mg/ml water solution) 

3. Do the 1st emulsification step drop-wise! Use the "20 microliter-10 sec" method. Begin with 30w amplitude and finish with 60w for a total 60 sec time period

4. Add the 1st emulsion to 2ml of 0.25% PVA solution and do this stream-wise under sonication: Use my "150 microliter-20 sec" method for a total of 180 sec begining with 60w amplitude and finishing with 100w and finally a few sec of the maximum amplitude. 

5. add 2 ml of 0.1% PVA solution to the the 2nd emulsion and pipet the mixture, letting it thinly emulsify. Then, transfer the emulsion gently and gradually to 30 ml of 0.1% PVA solution. For solvent evaporation, half an hour of stirring followed by 15 min of vacuum evaporation at 40 oC is more preferred. 

6. You can set aside a low volume of the preparation for size and morphology characterization (DLS or SEM) without filtering, and filter the rest with a 0.45 um millipore filter. Comparing the resulted data of these two, you would figure out how much your preparation was successful in Nano-particle preparation rather than Micro-particle preparation! 

7. Centrifugation at 12000 rpm for 40 min is ok, but would be better if used 15000 for 30 min

8. THE FINAL very important suggestion: Give up with PLGA and proceed through PLGA-PEG! I promise lots of setbacks would be resolved this way as PEG moiety offers a hydrophilic corona to the NPs, resulting in enhanced solubility and colloidal stability, as well as stealth properties in body system leading to longer serum life time, and beyond..

AND PLEASE don't forget UPVOTING!

Cheers! 

Dear Neda,

Nice to meet you!

As you know, Ras protein and Ras superfamily mediate membrane association and serve as lipid anchors. So their functions are limited to the cytoplasmic side of the cell membrane, where they receive specific signals and transmit them further.

Thus, if you are going to design a Ras inhibitor peptide and corresponding nano-delivery system, first of all it must be able to penetrate the target cells! and this requires the drug and/or delivery system be actively targeted to the cancer cells. There are good tumor penetrating peptides and motifs serving also as receptor targeting ligands...

In respect of the delivery system, there are different options: Liposomes, Polymeric nanoparticles, dendrimers, targeted drug conjugates, etc. Selection depends on the research purpose and design.. I'm myself working on PLGA-b-PEG copolymer nanoparticles.

Regarding the peptide design, you should do some bioinformatics stuff, modeling and protein-protein docking. You also may go through "phage display technology" to select a specific peptide instead of de novo design. However, first of all you need to determine your very target. You may target Ras protein directly and design a peptide that specifically binds to and triggers conformational changes in "inactive Ras" (GDP-state-Ras), so that the protein is inhibited from activation; Or you may design a peptide that specifically binds to GEF(Guanine nucleotide exchange factor) which is the activator of Ras, and hence prevents from Ras activation(converting to GTP-state-Ras). 

Any way, I wish you success dear compatriot !

Sincerely,

Farzad.

Dear Shaimma, 

I completely agree the last answer: cells in ddH2O won't survive for long...I'm not used to work with Zein nanoparticles, but I did with others... Do your particles have any coating? Do you use DMEM supplemented with FBS? On the other hand...I guess you did, but have you tried to reduce the nanoparticle concentration? 

If I were you, I'd first try with PBS, then move to DMEM (without serums), and finally, with complete medium, Once you optimize the nanoparticle concentration, I'd go for the assay with cells. 

Cheers, 

Maria

 EDC/NHS chemistry is another way to attach Abs to gold NPs. 

If you can separate the nanoparticles from the solution by centrifugation or ultracentrifugation, you can measure the amount of protein bound by measuring the reduction of the protein concentration in the supernatant using any convenient protein assay, such as UV absorbance, Bradford, BCA, Lowry assay, fluorescence-based method, SDS-PAGE, etc. If the protein is too dilute, you can concentrate it by TCA precipitation.

MDA-MB-231 cells tagged with mCherry.

Enhanced metastasis suppression by targeting TRAIL receptor 2 in a murine model of triple-negative breast cancer.

Malin D, Chen F, Schiller C, Koblinski J, Cryns VL.

Clin Cancer Res. 2011

Dear Hemant,

Quite strange since this reaction is very smooth one. Are you sure about the purity of the NCA glutamic acid? Are you working in anhydrous conditions? Do you add the PEG derivative to the NCA solution or the other way round?

Please have a look to my paper:

“Secondary Structure-Induced Micro- and Macrophase Separation in Rod-Coil Polypeptide Diblock, Triblock, and Star-Block Copolymers”  

Macromolecules 2010, 43, 1093-1100

A. Sánchez-Ferrer, R. Mezzenga*

For any further question contact me.

SALUT!

Tony

Thank You for your valuable answer

Hello Irfan,

PLGA is available in 2 forms. One is ester end group and another is carboxylic end group. You can directly activate COOH grp present in PLGA using EDC/NHS and add NH2-PEG-Mal. It will form PLGA-CO-NH-PEG-Mal.

To form pegylated PLGA nanoparticles, I would recommend you to perform this reaction before preparing nanoparticles. Pegylated nanoparticles can be prepared using PLGA-CO-NH-PEG-Mal in the same way in which you prepared PLGA nanoparticles.

Best Regards,

Abhinesh

For an adjuvant activity by nanoparticles:

Fall in absorption peak usually represents aggregation of nanorods. Possibly, lot of your CTAB got washed away from the nanorods causing the aggregation.(CTAB is  weakly bound to the nanorods!). The best way to remove excess CTAB is centrifugation but still you have to optimize the speed and the duration of centrifugation as excess speed and time may again cause aggregation.

Hello

It is a bit hard to answer without knowing how do you prepare your synthesis your NP.

I have added an article with whys of modifying different kind of metalic NP by using different molecules:

After amine/carboxyl/thiol modification of the NP, you can use crosslinking or even try to conjugate it by creating acyl-chloride of modified NP with carboxylic acid: http://www.masterorganicchemistry.com/2011/12/03/reagent-friday-thionyl-chloride-socl2/ (never tried it before since crosslinking works well enough)

Hope it helps

 

I work with chitosan. I always sterilize chitosan solution using regular steam sterilizer for 30 minutes at 121 C

I do not think that collecting the blood at 24h would be useful. It's a very long time concerning reactions of blood to foreign materials. Start as early as possible (1 min if possible) and then 5, 10, 30, 60 min. At 4h, everyting is finished.

Thank you so much for the vital procedure

If you use place exchange to cap your GNPs with a positively charged ligand, I suggest you pay attention to the addition order. Adding particles dropwise to a concentrate of the capping agent (replacement ligand) will yield better results than just mixing the two solutions. The latter typically produces aggregates, apparent from a change in the red color of the solution to purple or clear.

We just published a paper in Langmuir (http://pubs.acs.org/doi/abs/10.1021/la5002013) where we used a 3-part ligand (alkane-thiol/PEG chain/quarternary amine functional group) with reduction of chloroauric acid to yield very stable positively charged GNPs. We're also using PEI polymer to perform place exchange on citrate stabilized GNPs, but here the MW, branching and order of addition are very important...this work has not yet been published.

If you use anything other than a quarternary amine, the positive charge will be pH dependent.

Also avoid using glass containers, as the positively charged GNPs will plate out on the negatively charged glass. Someone mentioned using PAMAM dendimers...I would suggest you check on the chemical stability of PAMAM once it has been solubulized in water. There are more chemically stable dendrimers, but not sure of their commercial availability.

I did target multiple myeloma affected mice with gold nanoparticles and the result was ammazing

Hi,

by superparamagnetic and 50 nm size you mean "hydrodynamic" diameter, right?

The point is a big amount of magnetic material within a localized region may preclude you using standard medical protocols for MRI. But it does not mean you cannot employ another apporaches.

Anyway, I cannot help you about the design of the device (let's hope somebody else in the forum can help you). Regarding the nanoparticle agent, I would suggest you (both for MRI and also SAR optimization) to use iron oxides about 40 nm (crystal core) -obviously not superparamagentic at RT in quasistatic conditions. You may find a nice survey on the issue by Quoc L. Vuong et al, DOI: 10.1002/adhm.201200078.

of course, aggregation of the particles, their coating and geometry of the assembly -if any- would also modify their response.

Best.

I recomend you to read this paper:

I`ve done a huge research about that for my PhD and taking into acount the literature and my personal experience on the field i would say that the optimun nanoparticle size range would be around 20-50nm not only for celular uptake but also for an optimal biodistribution in vivo. I this context, think Its important the size to be higher than 6nm to avoid renal filtration and smaller maybe than 100-200nm to avoid acumulation in liver or spleen.

don't go for size analysis with zeta analyzer since its gives bigger size than the actual size, as it calculate the hydrodynamic size of the particle. use TEM for size measurement.

Dear Deepika,

In addition to the wonderful work of Dr. Ortega article I propose to look Eiji Kita et al 2010 J. Phys. D: Appl. Phys. 43 474011

Ferromagnetic nanoparticles for magnetic hyperthermia and thermoablation therapy http://iopscience.iop.org/0022-3727/43/47/474011

I hope it will be useful

Please add some cryoprotectant e.g.mannitol(5%w/v) in your preparation and lyophilize it.Your problem would be solved.

But I can not find it. So old and no link for me to download ... May you have it?

It is a common work done in gene therapy. For more details, you can search literature regarding gene therapy.

Q-dots:

The exact method will depend on the drug and nanoparticle formulation but here is a method I 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 what ever 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.