title: Comb-shaped conjugates comprising hydroxypropyl cellulose backbones and low-molecular-weight poly(N-isopropylacryamide) side chains for smart hydrogels: synthesis, characterization, and biomedical applications.
abstract: Hydroxypropyl cellulose (HPC) possesses a lower critical solution temperature (LCST) above 40 °C, while the poly(N-isopropylacrylamide) (P(NIPAAm)) exhibits a LCST of about 32 °C. Herein, comb-shaped copolymer conjugates of HPC backbones and low-molecular-weight P(NIPAAm) side chains (HPC-g-P(NIPAAm) or HPN) were prepared via atom transfer radical polymerization (ATRP) from the bromoisobutyryl-functionalized HPC biopolymers. By changing the composition ratio of HPC and P(NIPAAm), the LCSTs of HPNs can be adjusted to be lower than the body temperature. The MTT assay from the HEK293 cell line indicated that HPNs possess reduced cytotoxicity. Some of the hydroxyl groups of HPNs were used as cross-linking sites for the preparation of stable HPN hydrogels. In comparison with the HPC hydrogels, the cross-linked HPN hydrogels possess interconnected pore structures and higher swelling ratios. The in vitro release kinetics of fluorescein isothiocyanate-labeled dextran and BSA (or dextran-FITC and BSA-FITC) as model drugs from the hydrogels showed that the HPN hydrogels are suitable for long-term sustained release of macromolecular drugs at body temperature.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, College of Materials Science & Engineering, Beijing University of Chemical Technology, Beijing, China 100029, Brain Tumor Research Center, Beijing Neurosurgical Institute, Capital University of Medical Science, Beijing, China 100050, and State Key Laboratory of Molecular Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Beijing, China 100021.
authors.forename: F J
authors.initials: FJ
authors.lastname: Xu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: F S
authors.initials: FS
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Nie
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: W T
authors.initials: WT
authors.lastname: Yang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry; D003911:Dextrans / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006801:Humans; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry; D017879:Isothiocyanates / Q000737:chemistry; D008970:Molecular Weight; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000180:Acrylic Resins; D003432:Cross-Linking Reagents; D003911:Dextrans; D020100:Hydrogels; D017879:Isothiocyanates; C052970:poly-N-isopropylacrylamide; D012710:Serum Albumin, Bovine; C037152:isothiocyanic acid; D002482:Cellulose; C008079:hydroxypropylcellulose