title: Incorporation of biphasic calcium phosphate microparticles in injectable thermoresponsive hydrogel modulates bone cell proliferation and differentiation.
abstract: To provide osteoblast cells with a three-dimensional environment closer to bone matrix, an engineered construct mimicking bone components have been designed and evaluated. A biocompatible injectable thermo-responsive hydrogel, hyaluronic acid-g-chitosan-g-poly (N-isopropylacrylamide) (HA-CPN), was used as a biomimetic organic gel matrix while embedded biphasic calcium phosphate (BCP) ceramic micoparticles were used to replace mineralized matrix. The physicochemical properties of HA-CPN/BCP hydrogel composite were characterized by X-ray diffraction, thermogravimeric analysis, differential scanning calorimetric, and Fourier transform infrared spectroscopy. Human fetal osteoblast cells were cultured in vitro in HA-CPN and HA-CPN/BCP scaffold to study cell viability, proliferation, gene expression, and maintenance of their osteoblastic differential potentials. Overall, HA-CPN/BCP can serve as a better injectable carrier for bone cells than HA-CPN with enhanced proliferation rate and alkaline phosphatase activity from biochemical assays, improved calcium deposition and mineralization of extracellular matrix by histological examinations, and elevated gene expression of all essential osteoblastic genes from quantitative real-time PCR, to provide a cell/scaffold construct with higher mechanical strength and elasticity. From in vivo nude mice subcutaneous implantation experiments, the injected cell mass can form ectopic bone tissue in HA-CPN/BCP hydrogel composite.
authors.affiliation: Department of Chemical and Materials Engineering, Chang Gung University, Kwei-San, Taoyuan 333, Taiwan, ROC. jpchen@mail.cgu.edu.tw
authors.forename: Jyh-Ping
authors.initials: JP
authors.lastname: Chen
authors.forename: Ming-Jin
authors.initials: MJ
authors.lastname: Tsai
authors.forename: Han-Tsung
authors.initials: HT
authors.lastname: Liao
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000180:Acrylic Resins; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000737:chemistry*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D008819:Mice, Nude; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011108:Polymers / Q000737:chemistry; D013329:Structure-Activity Relationship; D013696:Temperature; D013997:Time Factors
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D020100:Hydrogels; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D006820:Hyaluronic Acid; D048271:Chitosan; C020243:calcium phosphate