Osteoinductive and biodegradable composite biomaterials for bone regeneration were prepared by combining poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) with siliceous mesostructured cellular foams (SMC), using the porogen leaching method. Surface hydrophilicity, morphology, and recombinant human bone morphogenetic protein 2 adsorption/release behavior of the SMC/PHBHHx scaffolds were analyzed. Results of scanning electron microscopy indicated that the SMC was uniformly dispersed in the PHBHHx scaffolds, and SMC modification scaffolds have an interconnected porous architecture with pore sizes ranging from 200 to 400 μm. The measurements of the water contact angles suggested that the incorporation of SMC into PHBHHx improves the hydrophilicity of the composite. In vitro studies with simulated body fluid show great improvements to bioactivity and biodegradability versus pure PHBHHx scaffolds. Cell adhesion and cell proliferation on the scaffolds was also evaluated, and the new tools provide a better environment for human mesenchymal stem cell attachment, spreading, proliferation, and osteogenic differentiation on PHBHHx scaffolds. Moreover, micro-computed tomography and histological evaluation confirmed that the SMC/PHBHHx scaffolds improved the efficiency of new bone regeneration with excellent biocompatibility and biodegradability and faster and more effective osteogenesis in vivo.
Keywords: bone regeneration; mesoporous; rhBMP-2; scaffolds; stem cells.