Enhancing the bioactivity of Poly(lactic-co-glycolic acid) scaffold with a nano-hydroxyapatite coating for the treatment of segmental bone defect in a rabbit model

Abstract

Purpose: Poly(lactic-co-glycolic acid) (PLGA) is excellent as a scaffolding matrix due to feasibility of processing and tunable biodegradability, yet the virgin scaffolds lack osteoconduction and osteoinduction. In this study, nano-hydroxyapatite (nHA) was coated on the interior surfaces of PLGA scaffolds in order to facilitate in vivo bone defect restoration using biomimetic ceramics while keeping the polyester skeleton of the scaffolds. Methods: PLGA porous scaffolds were prepared and surface modification was carried out by incubation in modified simulated body fluids. The nHA coated PLGA scaffolds were compared to the virgin PLGA scaffolds both in vitro and in vivo. Viability and proliferation rate of bone marrow stromal cells of rabbits were examined. The constructs of scaffolds and autogenous bone marrow stromal cells were implanted into the segmental bone defect in the rabbit model, and the bone regeneration effects were observed. Results: In contrast to the relative smooth pore surface of the virgin PLGA scaffold, a biomimetic hierarchical nanostructure was found on the surface of the interior pores of the nHA coated PLGA scaffolds by scanning electron microscopy. Both the viability and proliferation rate of the cells seeded in nHA coated PLGA scaffolds were higher than those in PLGA scaffolds. For bone defect repairing, the radius defects had, after 12 weeks implantation of nHA coated PLGA scaffolds, completely recuperated with significantly better bone formation than in the group of virgin PLGA scaffolds, as shown by X-ray, Micro-computerized tomography and histological examinations. Conclusion: nHA coating on the interior pore surfaces can significantly improve the bioactivity of PLGA porous scaffolds.

In Vitro and in Vivo Study of Poly(Lactic–co–Glycolic) (PLGA) Membranes Treated with Oxygen Plasma and Coated with Nanostructured Hydroxyapatite Ultrathin Films for Guided Bone Regeneration Processes

“…These results are consistent with those of previous published studies, obtaining an improved in vitro mineralisation and in vivo osteogenesis capacity of composite scaffolds with an increase in both the viability and proliferation rate of cells [5,14].…”

Porous biphasic calcium phosphate ceramics coated with nano-hydroxyapatite and seeded with mesenchymal stem cells for reconstruction of radius segmental defects in rabbits

“…Moreover, the nanostructure surface after nHA coating is more conducive to the adhesion, proliferation, and osteogenic differentiation of cells. These results reported here support those of other studies in the literature [49,50] and the hypothesis that osteoinduction by BCP ceramics maybe the result of adsorbed osteogenic biomolecules on their surfaces. In addition, more newly formed bone was observed in the group seeded with MSCs than in the nHA coating group.…”

Scaffold Design for Bone Regeneration

“…3D scaffolds from these materials can be fabricated through various techniques, and tuning the molar ratios of these polymers can influence mechanical properties and degradation rates. 104,105 …”