title: SYNTHESIS AND CHARACTERIZATION OF POLYSIALIC ACID/CARBOXYMETHYL CHITOSAN HYDROGEL WITH POTENTIAL FOR DRUG DELIVERY.
abstract: A novel hydrogel was prepared from polysialic acid (PSA) and carboxymethyl chitosan (CMCS) using glutaraldehyde as the cross-linking agent. The resulting PSA-CMCS hydrogel exhibited pH sensitivity, in which the swelling ratio under acidic conditions was higher than those under neutral or alkaline conditions. The swelling ratio of PSA-CMCS hydrogel at equilibrium depended on the medium pH, the cross-linking agent concentration, and the ratio of PSA to CMCS (w/w). Bovine serum albumin (BSA) and 5-fluorouracil (5-FU) were used as model drugs to prepare hydrogel delivery systems. The loading efficiencies of the hydrogel for BSA and 5-FU were 26.25 and 36.74%, respectively. Release behaviors of BSA and 5-FU were influenced by the pH. MTT assays confirmed that PSA-CMCS hydrogel has no cytotoxicity toward the NIH-3T3 cell line; in fact, the 100% aqueous extract of the PSA-CMCS hydrogel enhanced cell growth. These results suggest that PSA-CMCS hydrogel may be a promising pH-sensitive delivery system, especially for hydrophobic chemicals.
authors.forename: J R
authors.initials: JR
authors.lastname: Wu
authors.forename: X B
authors.initials: XB
authors.lastname: Zhan
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Zheng
authors.forename: H T
authors.initials: HT
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000031:analogs & derivatives*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D065546:Drug Liberation; D005472:Fluorouracil / Q000008:administration & dosage; D005976:Glutaral / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008855:Microscopy, Electron, Scanning; D041681:NIH 3T3 Cells; D016062:Porosity; D012794:Sialic Acids / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D000964:Antimetabolites, Antineoplastic; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D020100:Hydrogels; D012794:Sialic Acids; C021319:polysialic acid; D048271:Chitosan; D005976:Glutaral; D005472:Fluorouracil