title: Injectable and biodegradable temperature-responsive mixed polymer systems providing variable gel-forming pH regions.
abstract: Aqueous solutions of biodegradable polymers exhibiting sol-to-gel transitions in response to external stimuli such as temperature and pH are expected to be used as injectable polymers (IPs) for biomedical applications. In this study, we prepared novel biodegradable temperature-responsive IP systems providing variable gel-forming pH regions. We synthesized PCGA-b-PEG-b-PCGA (tri-PCG) and attached carboxylic acid or primary amine groups on both termini, tri-PCG-COOH and tri-PCG-NH2, and investigated the temperature-responsive sol-to-gel transition behavior of the mixtures of these two copolymers at various pHs. We found that the gel-forming pH region of the mixed system could be easily controlled by simply changing the mixing ratios of these polymers.
authors.affiliation: a Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering , Kansai University , Suita , Japan.|b Japan Society for the Promotion of Science , Tokyo , Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yoshida
authors.affiliation: a Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering , Kansai University , Suita , Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kawahara
authors.affiliation: a Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering , Kansai University , Suita , Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Mitsumune
authors.affiliation: a Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering , Kansai University , Suita , Japan.|c Organization for Research and Development of Innovative Science and Technology (ORDIST), Kansai University , Suita , Japan.|d PREST, Japan Science and Technology Agency , Kawaguchi , Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Kuzuya
authors.affiliation: a Faculty of Chemistry, Materials and Bioengineering, Department of Chemistry and Materials Engineering , Kansai University , Suita , Japan.|c Organization for Research and Development of Innovative Science and Technology (ORDIST), Kansai University , Suita , Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ohya
mesh_terms: D000588:Amines / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007267:Injections; D044367:Phase Transition; D011108:Polymers / Q000737:chemistry*; D013696:Temperature
chemical_list: D000588:Amines; D002264:Carboxylic Acids; D005782:Gels; D011108:Polymers
keywords: Injectable polymer; biodegradable; hydrogel; pH-responsive; sol-to-gel transition; temperature-responsive