- Shanker Lal Shrivastava added an answer:How can we measure or calculate the molecular weight of the maltodextrines with different dextrose equivalents?I have DE 5-7 and DE18-20 maltodextrines and do not have the specifications.
Join the link:
- Sebastian Seiffert added an answer:How do you crosslink PEG DA hydrogel with degradable linkers?
I want to degrade PEG DA through enzymes. How do I crosslink PEG DA with degradable linkers? Is this a tricky procedure?
In addition to Hubbell's and Lutolf's great work on enzyme-cleavable gels, recommended in the previous reply, there's been an approach to forming pH-degradable hydrogels by Haag and co-workers. Here's the reference:
Angew. Chem. Int. Ed. 2013, 52(51), 13538–13543.
Greetings from Berlin,
- Titus Sobisch added an answer:In your opinion, what is the reason for chitosan nanoparticle aggregation?I have prepared chitosan nanoparticles with diameter of 40-80 nanometers as confirmed by AFM. In the second step, we prepared bionanocomposite films based on protein and chitosan nanoparticles. But in the higher particle loading, agglomeration of particles in film is observed. What is the main cause of this phenomenon? Thank you in advance for your collaboration.
Maybe electrostatic attraction or depletion flocculationFollowing
- Hossein Shaki added an answer:How can you measure the molecular weight of a synthetic polymer?In our laboratory we synthesized a new polymer by adding some molecules as branches on the base polymer chain. The molecular weight of the base polymer chain and molecules which were added are known.Dear Shashank
Thank you for your kind help.
It would be my pleasure if you send me your papers.
My email address is: firstname.lastname@example.orgFollowing
- Vladimir Montero Collado added an answer:Can MALDI mass spectrometry detect an RNA duplex?MALDI mass spec is an excellent technique used to determine the mass of short biopolymers, such as single-stranded RNAs, but can the same technique be used to detect a non-covalently linked RNA duplex? That is to say, two fully complementary RNA strands are held together by hydrogen bonding alone. My prediction is that MALDI will be able to detect both strands separately, but not the duplex as one entire unit since they're not covalently linked. Any insight into this question will be most helpful.Why not using ESI? It seems to be ideally suited for the task.Following
- Taufiq Ahmad added an answer:Can anyone please tell me the correct binding energy of c=o and c-o components in an XPS peak?When I reported the binding energy of c=o and c-o 288.6 and 286.6 respectively to a journal, the reviewers told that binding energy of these components are high. I got these values from previously reported articles. Can anyone please guide me in this regard? My educational background is biology and I am new to XPS analysis. I will be really grateful for your responses.Dear all... Thank You You very Much for Your valuable Information. Dear Dr Peter Dubruel we would contact you in case we have further doubts...Following
- Stéphane Costeux added an answer:How can I decrease the temperature of gelatin solution?I need to decrease the temperature of homogeneous gelatin solution nearly 0 before adding cross-linker. But I have trouble. Because at low temperatures gelatin becomes solid and I can't add cross-linker. Could you please help me to cope with this problem?Following
- Erik Olsson added an answer:What is a good laboratory scale method for the preparation of pregelatinized starch?I don't have access to extrusion, drum drying or spray drying equipment.One simple method is to first gelatinize the starch and then freeze dry the samples. It will take a lot of time (since the freeze drying is slow and only a small amount can be dryed at the same time), but it works.Following
- Elif Kayaalp added an answer:How can I reduce activity of glutaraldehyde?I tired to decrease its temperature and concentration before adding to the protein solution to slow down the activity. What more can I do? Could you please help me?If you use GTA as vapor instead of directly adding solution, you can obtain better results. ( this process must be in safe fume hood with using desiccator). But firstly you have to determine process time and pressure to be sure how much crosslinking occurs at which time and pressure. After you get your standart, apply it ) And then, Glycine can be used to deactivate GTA activation.Following
- Farzaneh Sabbagh added an answer:Why the MgO caused more swelling in my hydro-gels?MgO nano-particles cause a negative effect on swelling capacity.
These nano-particles can have effect on structure of hydrogel network by reducing the porosity of gel.Thanks alot dear Dr.Gyorgy , Dr.Yadollahi and Dr.Haraszti. Of course all your answers is helpful for my research. Also Thank you to give me such an important references.
- Jonathan Diaz added an answer:What are the best storage conditions to keep pectin or alginate gels (to minimize syneresis and shrinking)?What is the best protocol to produce an LM pectin gel filament (calcium concentration, drying conditions, co-solutes) in order to minimize the syneresis effect and avoid complete drying of the solution?Hi Valerie,
There are 2 very good publications about LM and HM pectin gels, if you need more references about this topic, let me know.
Löfgren, C.; Hermansson A.M. Synergistic rheological behavior of mixed HM/LM pectin gels. Food Hydrocolloids, 21. (2007). 480-486pp. Löfgren, C.; Walkenstrom, P.;
Hermansson A.M. Microstructure and reological behavior of pure and mixed pectin gels. Biomacromolecules, 3. (2002). 1144-1153pp.
In general, 1-2% pectin , and 200-300 mM CaCl2 works, but depends of pectin characteristics. Freeze-dry process is very common, but, your lost the hidrogel conformationFollowing
- Syed Umer added an answer:Is methanol a suitable solvent for the purification of biopolymers for biomedical applications?I need a methanol-free purified polymer for controlled release.Well explained by Robert. If you use methanol, then you should purify it with other non toxic solvents. DCM can work as well. Or you better try ethanol as well.Following
- Ankur Shah added an answer:Where one can buy cheap PLGA 50:50 in bulk (5 kgs - 10 kgs)? Lab grade not medical grade PLGA would be fine.I need a lot of PLGA for experiments without having to pay the steep price for medical PLGA.Marius, thanks for the info. Would send an email to Mr.Natsuji regarding the PLGA.Following
- Closed account asked a question:What is the sutable experimental conditions to form a condensate polymer between glycin and alanin?Contaning all conditionsFollowing
- Shadi Sabbagh asked a question:Topic of research: Urban Ecology/ BiomimicryResearch Question: 'The biotic implementation of Algae in ecological design on a major scale and its inverse implications on structure'
Does anyone know how one can measure the affect of Algae on certain building materials and the moisture content after a particular span of time has elapsed?Following
- Prakash Naga Pillai added an answer:How to control the degree of polymerization in chitosan oligomers production?-Chitosan is a linear heteropolysaccharide composed
of _-1,4-linked-d-glucosamine (GlcN) and N-acetyl-dglucosamine
(GlcNAc) in varying proportions. Chitosan was depolymerized either by acid hydrolysis or enzymatic degradation with a commercial preparation oligomers polymer. The chitooligosaccharides removed by two methods were selectively precipitated in methanol solutions.Following
- A.U. Daniels added an answer:What is the strongest (in terms of compressive/tesile strength) biopoymer based hydrogel?It could be an IPN/composite hydrogel of two bio-polymers as well as for example gelatin and silk. Strength should be reported when it is in hydrated form and not dry strength. Please also provide values in MPa or KPa and reference if any.See the work and publications of Prof. Jian Ping Gong and her group at U Hokkaido on double network hydrogels. They have developed remarkably strong and tough gels in which at least one of the network components is a biopolymer. I have also posted some papers on RG on this topic which I co-authored with her.
- Mahmoud Abdelaal added an answer:What is the best solvent for polylactic acid?is 25°C CHCl3 suitable?what is the molecular weight of PLA ? AND HAVE you measurement viscosity after you dissolve PLA ?Following
- Rachana Bhatt added an answer:Can the presence of hydrophobic interactions affect a protein film's thickness?Is is possible that an increase of thickness of protein-pectin films is due to the presence of different interactions, such as hydrophobic, that can lead to an increment on the free volume of films?Hello Giovanna, May be this might give some information....http://arxiv.org/ftp/arxiv/papers/1005/1005.1587.pdfFollowing
- Michael Surdu added an answer:Where to purchase a moisture content analyzer for solid materials?Can anyone suggest a good company for purchasing a moisture content analyzer? The sample amount available for measurement will be few mg and it is polymer film (synthetic as well as biopolymer). Temperature range up to 200C.Depend of do You need/. If You need very accurate measurements, the cemical analysis is the best (see other answers. But if You need an express-analysis (for example moiture of the wood, corn, etc., etc) You can ask us.Following
- Jasim Ahmed added an answer:Where to find articles/information about biodegradation of wheat starch foam ?I’m doing a few tests on biodegradation with wheat starch foam (and wheat starch foam + 0,2% PLA). I would like to verify my results and compare them with other already found data regarding this subject. Unfortunately I haven’t found similar articles yet.You can find many articles in
PACKAGING TECHNOLOGY AND SCIENCE
where biodegradability of packaging are routinely published.Following
- Gianfranco Romanazzi added an answer:Is a chitosan solution 0.5% w/v into 0.5% v/v acetic acid completely soluble?I have found data that mention an acid insoluble fraction-chitosan. Also I know that an acidic environment (pH ~ 5 with my acid) could promote the solubility by protonation of amine groups of chitosanYes, it is my favourite (with Sigma Chitosan) as compared to 1% because you reach quicker the 5.6 pH. In our experiments, each acid solution with pH lower than 2.8 can dissolve chitosan, some ones requires warming.Following
- noorunnisa khanam Patan asked a question:What is the easiest way to find out the cost of different bacteria?I want to know about cost of bacteria. Is it possible to buy commercially or not?Following
- Lala Behari Sukla added an answer:What are the recent production strategies for microbial nano cellulose and its demand?Today there is a substantial amount of research on microbial nano cellulose materials, and commercial development is now underway with some very promising applications.This is related to ferromagnetic materials based on nano-sized bacterial cellulose templates. An agglomerate free magnetic nanoparticle cellulose material and a method of forming such magnetic nanoparticle cellulose materia has been developed. Further, the magnetic nonoparticles are physically attached on the cellulose material and evenly distributeFollowing
- James Renwick Beattie added an answer:Tricks to reduce the background fluorescence of chitosan in Raman Spectroscopy - can anyone help?I'm trying to obtain a raman spectra of chitosan (natural polymer with ammine groups) but the only thing that I get is the image I attached.
As you can see, there is the raylight (it is not perfectly filtered) and then a band from 100 to 1100 cm-1. The band is supposed to be the intrensic fluorescence of chitosan. Do you have any tricks to avoid the fluorescence because I'm afraid that it covers the raman signal?
(I'm already using a 780nm laser because I read that it can reduce the fluorescence but I still have it).Another paper on thatFollowing
- Adalberto Vargas added an answer:In the analysis of polymers, which has the advantage of technics AFM Vs SEM, or that information gives me one over the other?Microestructural and surface analysis.In addition with the feedback you previously had, you have to also consider that polymers have a low conductivity and you may be forced to coat or sputter your samples when using a SEM; which can sometimes alter your results. Using both techniques is a good strategy to correlate your results and increase the amount of information obtained from your samples.Following
- Nimal Raveendran added an answer:Which is the best institute for tissue engineering research in India ?What are the institutes for tissue engineering research in India?
Which is the best one?Thank You Nirmala Takur and Sanal payyappilly
But which is the best Institute ?
How about Tissue engineering research in IIT Kanpur and NIT Rourkela ?Following
Polymers synthesized by living organisms. They play a role in the formation of macromolecular structures and are synthesized via the covalent linkage of biological molecules, especially AMINO ACIDS; NUCLEOTIDES; and CARBOHYDRATES.