Biomimetic Synthesis of Nanocrystalline Hydroxyapatite Composites: Therapeutic Potential and Effects on Bone Regeneration

Abstract

The development of a novel alloplastic graft with both osteoinductive and osteoconductive properties is still necessary. In this study, we tried to synthesize a biomimetic hydroxyapatite microspheres (gelatin/nano-hydroxyapatite microsphere embedded with stromal cell-derived factor-1: GHM-S) from nanocrystalline hydroxyapatites and to investigate their therapeutic potential and effects on bone regeneration. In this study, hydroxyapatite was synthesized by co-precipitation of calcium hydroxide and orthophosphoric acid to gelatin solution. The microbial transglutaminase was used as the agent to crosslink the microspheres. The morphology, characterization, and thermal gravimetric analysis of microspheres were performed. SDF-1 release profile and in vitro biocompatibility and relative osteogenic gene expression were analyzed, followed by in vivo micro-computed tomography study and histological analysis. The synthesized hydroxyapatite was found to be similar to hydroxyapatite of natural bone tissue. The stromal cell-derived factor-1 was embedded into gelatin/hydroxyapatite microsphere to form the biomimetic hydroxyapatite microsphere. The stromal cell-derived factor-1 protein could be released in a controlled manner from the biomimetic hydroxyapatite microsphere and form a concentration gradient in the culture environment to attract the migration of stem cells. Gene expression and protein expression indicated that stem cells could differentiate or develop into pre-osteoblasts. The effect of bone formation by the biomimetic hydroxyapatite microsphere was assessed by an in vivo rats’ alveolar bone defects model and confirmed by micro-CT imaging and histological examination. Our findings demonstrated that the biomimetic hydroxyapatite microsphere can enhance the alveolar bone regeneration. This design has potential be applied to other bone defects.

Histomorphometric and Radiographic Analysis of Biological Responses Following the Use of Pure Hydroxyapatite and Hydroxyapatite with Collagen

“…In our study, there was no significant difference between pure hydroxyapatite (HaP) and hydroxyapatite with collagen (HaCol) in relation to inflammatory response, biocompatibility, new bone formation, and the biodegradability of the material deployed in a critical defect in the calvaria of rats. In conjunction with previous reports about in vivo bone regeneration] the results of the present study have shown that the histological response could be used as a preliminary source of information regarding the biocompatibility and biodegradability of material implanted in the calvaria of rats [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”

3D Hierarchical, Nanostructured Chitosan/PLA/HA Scaffolds Doped with TiO2/Au/Pt NPs with Tunable Properties for Guided Bone Tissue Engineering

“…Scaffold dedicated to bone-tissue engineering should provide a temporary mechanical support for the damaged area and stimulate tissue regeneration [2,9]. Therefore, it must be characterized by highly porous architecture, to enable bone ingrowth, as well as neovascularization.…”

“…Their properties, such as high surface area and porosity make them a highly desired materials in terms of bone-tissue-defect treatment [17][18][19]. However, due to the hierarchical nature of the bone, nanofibrous/porous composites seem to be the most promising ones [5,9].…”

Clinical and Radiographic Evaluation of Nanohydroxyapatite Powder in Combination with Polylactic Acid/Polyglycolic Acid Copolymer as Bone Replacement Graft in the Surgical Treatment of Intrabony Periodontal Defects: A Retrospective Case Series Study

“…Nanostructured hydroxyapatite (NHA) can mimick the surface characteristics of the inorganic component of the native bone matrix, enhancing the regenerative performance. NHA favours the rapid formation of a stable microvasculature, an essential requisite to support the metabolic needs of bone-forming cells and newly formed tissue [42]. This complex process includes a biomolecular communication between endothelial cells, involved in the formation of the vascular network, macrophages and mesenchymal osteoprogenitor cells [43].…”