Reconstruction of a Rabbit Ulna Bone Defect Using Bone Marrow Stromal Cells and a PLA/β‐TCP Composite by a Novel Sintering Method

Abstract

Bioceramic, synthetic, and natural polymers associated with cell adhesion and growth, have been used as matrices for bone tissue engineering. Successful bone regeneration depends on cellular interaction with these matrices. The purpose of this study was to fabricate polylactic acid (PLA)/ b-tricalcium phosphate (b-TCP) composites with a novel sintering method in order to enhance cellular interaction with matrices for bone regeneration. We prepared the composite by pressing and thermal treatment of the mixture of PLA, b-TCP, and NaCl, after which we seeded bone marrow stromal cells (BMSCs) on the PLA/b-TCP composite scaffolds and either cultured them in vitro or subcutaneously implanted them into nude mice. Also, we examined enhanced bone regeneration in the rabbit defect model. The BMSCs more effectively formed bone-like structures on the PLA/b-TCP composite scaffolds compared to scaffolds containing PLA alone. In addition, fabricating the PLA/b-TCP composite scaffolds using our novel sintering method, instead of a conventional solvent casting method, significantly enhanced alkaline phosphatase activity and calcium deposition in the new bone tissue. We confirmed this enhanced bone regeneration in the rabbit defect model using representative radiography and histological studies. We propose that the superior bone-forming characteristics of PLA/b-TCP cell-composite constructs prepared by our novel sintering method may result from greater surface exposure of the b-TCP particles, which may yield higher osteogenic and osteoconductive properties. This study revealed that generating biodegradable and osteogenic PLA/ b-TCP cell-composite constructs with our novel sintering method could significantly enhance bone regeneration and may be useful for bone tissue engineering.

Self-Assembling Peptide Nanofibers Coupled with Neuropeptide Substance P for Bone Tissue Engineering

“…It also improves tissue regeneration by enhancing cell attachment, proliferation, and differentiation. As we confirmed the effects of polylactic acid/beta-tricalcium phosphate (PLA/b-TCP) scaffold in our previous work, 25 we expected that the composite scaffold enhances osteogenic differentiation of recruited MSCs by increasing alkaline phosphatase (ALP) activity during tissue regeneration in the present system. This modified KLD12 peptide was evaluated for its ability to recruit MSCs and promote bone regeneration.…”

“…We confirmed that the b-TCP particles which were exposed on the surface of the scaffolds improved ALP activity and calcium deposition in our previous work. 25 Therefore, we expected that recruited MSCs by SP could be differentiated into osteocytes in this system. In the case of vascularized tissues, angiogenesis helps regenerate and maintain the tissue.…”

“…3,25,[27][28][29][30] In this study, we combined PLA/b-TCP scaffolds to KLD12/KLD12-SP, KLD12 or PBS for mechanical strength and osteoinductivity. For successful tissue regeneration, matching of scaffold degradation rate with tissue regeneration rate is important.…”

Bi-layered PLCL/(PLGA/β-TCP) composite scaffold for osteochondral tissue engineering

“…From the EDX analysis for identifying the particles, it was confirmed that the main atoms comprising the particles were Ca and P. It is thought that exposure to β-TCP particles affects calcium deposition and subsequent bone tissue formation. 19…”