title: Structure and biocompatibility of an injectable bone regeneration composite.
abstract: With the development of minimally invasive techniques, injectable materials have become one of the major hotspots in the biomaterial field. We have developed an injectable bone regeneration composite (IBRC) using calcium alginate hydrogel as matrix to carry nano-hydroxyapatite/collagen particles. In this work, we evaluated the homogeneity of IBRC by dry/wet weight ratio test. The results showed that the structural homogeneity was determined by controlling the molar ratios of trisodium phosphate to calcium sulfate rather than alginate concentration in the studied ranges. Pore sizes of wet IBRC samples were characterized by thermoporometry. The pore properties of dried IBRC were tested by mercury porosimetry. Average pore size and porosity of dried IBRC declined with increasing alginate concentration. In contrast, surprisingly, pore size of wet homogeneous IBRC increased with increasing alginate concentration. Meanwhile, the swelling ratio did not increase with varying alginate concentration, but the swelling degree increased with increasing alginate concentration. In vitro cell culture showed that IBRC had no obvious cytotoxic effect on the rat bone mesenchymal stem cells. The morphology and viability of cells were also related to MR value. IBRC had good histocompatibility with a mild short-term inflammatory response in rat dorsum muscle. In addition, the excellent ability of IBRC to promote bone healing was confirmed by 5-mm-diameter cranial defects using histological analysis and bone mineral density measurement.
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China.
authors.forename: Rongwei
authors.initials: R
authors.lastname: Tan
authors.forename: Qingling
authors.initials: Q
authors.lastname: Feng
authors.forename: He
authors.initials: H
authors.lastname: Jin
authors.forename: Jinyu
authors.initials: J
authors.lastname: Li
authors.forename: Xing
authors.initials: X
authors.lastname: Yu
authors.forename: Zhending
authors.initials: Z
authors.lastname: She
authors.forename: Mingbo
authors.initials: M
authors.lastname: Wang
authors.forename: Huanye
authors.initials: H
authors.lastname: Liu
mesh_terms: D020341:Absorbable Implants; D000464:Alginates / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000737:chemistry* / Q000378:metabolism; D002133:Calcium Sulfate / Q000737:chemistry; D018929:Cell Culture Techniques; D003094:Collagen / Q000737:chemistry; D017886:Durapatite / Q000737:chemistry; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D007267:Injections; D008422:Materials Testing / Q000379:methods; D059630:Mesenchymal Stem Cells / Q000166:cytology; D053758:Nanoparticles / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D016062:Porosity; D051381:Rats; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D018786:Bone Substitutes; D010710:Phosphates; C509317:nano-hydroxyapatite-collagen; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D003094:Collagen; D017886:Durapatite; C018279:sodium phosphate; D002133:Calcium Sulfate