Background: Bone loss rapidly increases 6 months post tooth extraction, which causes the atrophy of the alveolar bone. Two kinds of biomaterials which can stimulate bone regeneration are bioceramics and polymers. Making a composite of biomaterials results in better physical and biomolecular characteristics in comparison with a bioceramic or a polymer alone. Hydroxyapatite nanoparticles (HANPs) are one of the bioceramics commonly used for bone regeneration; they can degrade faster than hydroxyapatite (HA) microparticles, but have an insufficient pore size. Polyvinyl alcohol (PVA) and poly lactic-co-glycolic acid (PLGA) are polymers which have been used for biomedical applications. However, PLGA alone has insufficient cell attachment and PVA alone slowly degrades in the bone tissue.
Objectives: The aim of the present study was to analyze the biodegradation properties of the HANP/PLGA/PVA composites and investigate the pore size.
Material and methods: The HANP/PLGA/PVA composites were prepared using the freeze-drying method, with 20% (w/w) of HANP and 20% (w/w) of PLGA. Morphology and the pore size were determined by means of the field emission scanning electron microscopy (FE-SEM) analysis. Biodegradation properties were determined by calculating water uptake and water loss for 1, 3 and 6 weeks. Statistical analysis was performed based on the one-way analysis of variance (ANOVA) at p < 0.05.
Results: The HANP/PLGA/PVA composites had the greatest mean pore size and a rougher surface than others (176.00 ±61.93 μm; p < 0.05). Moreover, the HANP/PLGA/PVA composites had the greatest water uptake, significantly in the 3rd (730.46%; p < 0.05) and 6th weeks (731.07%; p < 0.05), and water loss in the 6th week (67.69%; p < 0.05).
Conclusions: The HANP/PLGA/PVA composites have optimal pore size, morphology and degradability, which shows their high potential as an effective bone scaffold to repair the alveolar defect post tooth extraction.
Keywords: biodegradable; bone regeneration; hydroxyapatite nanoparticle; poly lactic-co-glycolic acid; polyvinyl alcohol.