surely it is possible , most of polysaccharides possess a great value of bio compatibility and biodegradability . Alginate also follows the same concept since its a polysaccharide , one of its discriminating assets is that its an anionic polymer as a result it can be mixed with chitosan (which is a cationic polymer) and forms intertwined networks of two polymers and can be used as scaffolds.

Dear Sepehr

Thanks for your response. But I think that my question has been created an ambiguity for you. It is well-known that both chitosan and alginate are individually biocompatible biopolymers. But I am going to achieve similar bioactivity of the alginate without the using any biopolymer. In fact, how is it possible to attain chemical and biological properties of alginate similar those of chitosan without its blending by other polymers for example, chitosan?

ok i think i get it now , correct me if i'm wrong but did you mean you want the same properties of chitosan from alginate (without mixing it with other polymers) ? if so then you should try to mimic the same functional groups of chitosan consequently you should first start with decarboxylation of alginate (im not sure if that's possible or not) and then you could start adding your functional groups of choice . Decarboxylation of alginate might not be possible but you could try adding ammonia to alginate and study the structure of final product .

That's great. I have been focused on the chemical modification of this polymer during recent months. The first suggested method is impossible because the solubility limitations of SA. I have been examined different procedures to surface and bulk modification of alginates. I think that we have similar ideas for the expected tasks of alginate. The treatment of SA with ammonia affords the insoluble ammonium alginate in organic solvents. Therefore, the first step is the dissolution of SA in organic solvent. Do you have any study on this field?

I haven't had much of studies on alginate but since i,ve been working with chitosan over past few years i know a lot on that case . Its the same case scenario with chitosan too since its only soluble in water/acetic acid mixture. I was thinking about employment of a surfactant which could help a great deal in giving away a homogeneous solution. Other than that i dont think we could do so much due to hydrophilic behavior of alginate .

The dissolution of chitosan is very easier than alginate in organic compounds, specially when the chitosan chains degraded to the short chains in the presence of oxidizers. Unfortunately, the degraded alginate obtained from its treatment by common oxidizers is yet insoluble in organic solvents. In addition, the solubility of modified SA is insignificant compared to the modified or degraded chitosan.

What we do for chitosan is the treatment with sodium hydroxide under high temperature for 48hrs but even then it can not be solved in a neutrolized PH it has to be acidic, thats why its not 100% soluble in water . Im not sure which conditions you employ for oxidization of alginate but keep in mind that the oxidizer concentration should be very high and also a high temp near 90c is required , not to mention that treatment duration should be around 2 days or even more . That is an interesting subject which has a lot of potentials .

I agree with you. But, the problem is the irregular chemical structure of SA. It has been formed from three different blocks which limit its reactivity and the ability of solvation. In fact, alginate is an amorphous biopolymer therefore, we have further problems for the dissolution of oligomerized SA compared to the chitosan.

Dear Sepehr

Did you any chemical modification on chitosan for altering its solubility or biological properties?

Yes as i mentioned it before i did the deacetylation with sodium hydroxide solution in order to reach a better solubility in water and it worked in my case . Generally speaking i believe lowering the molecular weight of the polymer would help in case of solubility , essentially in case of alginate as you were saying its a tri-block copolymer.