Investigation on Conjugation Capacity of New Chitosan Carriers Based on Conjugated Model Toward Enzyme Delivery

Abstract

In this work, for the first time, the authors report their observations on cross-linking condition, and its effects on conjugation capacity of a bioactive model. Therefore, carriers of chitosan films and microspheres were produced by using glutaraldehyde as bifunctional cross-linking agent. The following stages were carried out: preparation of cross-linked chitosan films and microspheres, conjugation of drug model on films and microspheres, investigation on the properties of the synthesized carriers and finally enzyme immobilization studies. Based on our results, degree of cross-linking and drug conjugation capacity, as two important factors, affect simultaneously the thermal, morphological, and hydrolytic behavior of the carriers in film and microsphere forms. From the experimental data, with increasing the degree of cross-linking and drug conjugation capacity, the drug release was increased up to 12% w/w of glutaraldehyde; however, on further increasing the degree of cross-linking (18% w/w), the drug released in a burst manner. Also, regarding to the results from drug and enzyme conjugates, it is possible to design diversity of the chitosan derivatives based on different degree of cross-linking as well as enzyme conjugation capacity as reliable carriers.