A novel pH-sensitive and freeze-thawed carboxymethyl chitosan/poly(vinyl alcohol) blended hydrogel for protein delivery

• Published in: Polymer international Vol. 58; no. 10; pp. 1120 - 1125
• Main Authors: Li, Yan, Du, Yumin, Tang, Yufeng, Wang, Xiaoying
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.10.2009; Wiley
• Subjects: Applied sciences; Biological and medical sciences; carboxymethyl chitosan; Exact sciences and technology; freeze-thaw; hydrogel; Medical sciences; Natural polymers; Organic polymers; Physicochemistry of polymers; poly(vinyl alcohol); Properties and characterization; protein; Solution and gel properties; Starch and polysaccharides; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Biological properties; Polymer blends; carboxymethyl chitosan; Swelling; Property composition relationship; Control release polymer; poly(vinyl alcohol); Physical gel; Drug carrier; pH effect; Serum albumin; Experimental study; freeze-thaw; Freeze thaw cycle; Polyelectrolyte; Polyvinylalcohol; Chitosan derivatives; Aqueous medium; protein; Animal protein; Oside polymer; Polyacid; Hydrogel; Release
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.2639

BACKGROUND: Blended hydrogels are widely applied in medical fields. They can provide many advantages, such as biocompatibility and biodegradability. Many materials and methods are used to obtain blended hydrogels. In this work, carboxymethyl chitosan (CMCS) and poly(vinyl alcohol) (PVA) blended hydrogels were prepared using the freezing and thawing technique. The properties of the hydrogels prepared, i.e. gel fraction, swelling and pH‐responsive behaviors, were investigated. RESULTS: The gel fraction increased with increasing time of freezing and thawing as determined through gravimetric analysis. It was also found that the equilibrium degree of swelling improved obviously due to the addition of CMCS compared to pure PVA hydrogel. The blended hydrogel with composition CMCS/PVA 80/20 (by weight) possessed the highest swelling ratio. The results of the influence of pH values on the swelling behavior showed that minimum swelling ratios of the hydrogels occurred near the isoelectric point of CMCS. Protein release studies were performed under various pH conditions: the release was much slower under acid than under basic conditions. The release showed a burst in the first 15 h and then steadily increased. CONCLUSION: The addition of CMCS can improve the physical properties of pure PVA hydrogels and provide pH sensitivity. It is concluded that PVA hydrogels containing CMCS could be potentially applied as oral delivery systems for protein drugs. Copyright © 2009 Society of Chemical Industry