RGD-Conjugated Copolymer Incorporated into Composite of Poly(lactide-co-glycotide) and Poly(l-lactide)-Grafted Nanohydroxyapatite for Bone Tissue Engineering

• Published in: Biomacromolecules 2011-07, Vol.12 (7), p.2667-2680
• Main Authors: Zhang, Peibiao, Wu, Haitao, Wu, Han, Lù, Zhongwen, Deng, Chao, Hong, Zhongkui, Jing, Xiabin, Chen, Xuesi
• Format: Article
• Language: English
• Subjects: Aminoacid polymers; Animals; Applied sciences; Biological and medical sciences; Bone Regeneration - drug effects; Bone Substitutes - chemical synthesis; Bone Substitutes - chemistry; Bone Substitutes - pharmacology; Cell Adhesion; Cell Cycle; Cell Proliferation - drug effects; Cell Survival; Coated Materials, Biocompatible - chemical synthesis; Coated Materials, Biocompatible - chemistry; Coated Materials, Biocompatible - pharmacology; Composites; Durapatite - chemistry; Exact sciences and technology; Forms of application and semi-finished materials; Materials Testing; Medical sciences; Mice; Molecular Structure; Nanocomposites - chemistry; NIH 3T3 Cells; Oligopeptides - chemistry; Osteoblasts - cytology; Physicochemistry of polymers; Polyesters - chemistry; Polyglactin 910 - chemistry; Polymer industry, paints, wood; Porosity; Rabbits; Surface Properties; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Synthetic biopolymers; Technology of polymers; Technology. Biomaterials. Equipments; Tissue Engineering
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm2004725

Various surface modification methods of RGD (Arg-Gly-Asp) peptides on biomaterials have been developed to improve cell adhesion. This study aimed to examine a RGD-conjugated copolymer RGD/MPEG-PLA-PBLG (RGD-copolymer) for its ability to promote bone regeneration by mixing it with the composite of poly(lactide-co-glycotide) (PLGA) and hydroxyapatite nanoparticles surface-grafted with poly(l-lactide) (g-HAP). The porous scaffolds were prepared using solvent casting/particulate leaching method and grafted to repair the rabbit radius defects after seeding with autologous bone marrow mesenchymal cells (MSCs) of rabbits. After incorporation of RGD-copolymer, there were no significant influences on scaffold’s porosity and pore size. Nitrogen of RGD peptide, and calcium and phosphor of g-HAP could be exposed on the surface of the scaffold simultaneously. Although the cell viability of its leaching liquid was 92% that was lower than g-HAP/PLGA, its cell adhesion and growth of 3T3 and osteoblasts were promoted significantly. The greatest increment in cell adhesion ratios (131.2–157.1% higher than g-HAP/PLGA) was observed when its contents were 0.1–1 wt % but only at 0.5 h after cell seeding. All the defects repaired with the implants were bridged after 24 weeks postsurgery, but the RGD-copolymer contained composite had larger new bone formation and better fusion interface. The composites containing RGD-copolymer enhanced bone ingrowth but presented more woven bones than others. The combined application of RGD-copolymer and bone morphological protein 2 (BMP-2) exhibited the best bone healing quality and was recommended as an optimal strategy for the use of RGD peptides.