title: Temperature, pH and redox responsive cellulose based hydrogels for protein delivery.
abstract: Cellulose based hydrogels are important due to their biocompatibility, non-toxicity and natural origin. In this work, a new set of pH, temperature and redox responsive hydrogels were prepared from carboxymethylcellulose (CMC) and poly(N-isopropylacrylamide). Copolymeric (CP) hydrogels were synthesized by copolymerizing N-isopropylacrylamide (NIPA) and methacrylated carboxymethylcellulose, semi-interpenetrating network (SIPN) hydrogels were prepared by polymerizing NIPA in presence of CMC. Two types of cross-linkers were used viz. N,N'-methylenebisacrylamide (BIS) and N,N'-bis(acryloyl)cystamine (CBA), a redox sensitive cross-linker. The structures of the hydrogels were characterized by FTIR and SEM studies. The CP hydrogels were found to be more porous than corresponding SIPNs which resulted in higher swelling for the CP hydrogels. Swelling for both the hydrogels were found to increase with CMC content. While the swelling of SIPN hydrogels showed discontinuous temperature dependency, CP hydrogels showed gradual decrease in water retention values with increase in temperature. CBA cross-linked hydrogels showed higher swelling in comparison to BIS cross-linked hydrogels. Additionally, lysozyme was loaded in the hydrogels and its in vitro release was studied in various pH, temperature and in presence of a reducing agent, glutathione (GSH). The release rate was found to be maximum at lower temperature, lower pH and in presence of GSH.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
authors.forename: Sujan
authors.initials: S
authors.lastname: Dutta
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
authors.forename: Pousali
authors.initials: P
authors.lastname: Samanta
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302, India. Electronic address: dibakar@chem.iitkgp.ernet.in.
authors.forename: Dibakar
authors.initials: D
authors.lastname: Dhara
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000737:chemistry*; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D004337:Drug Carriers; D020100:Hydrogels; D002482:Cellulose; D009113:Muramidase
keywords: Hydrogels; Interpenetrating network; Microstructure; Protein release; Swelling behavior