Title : Degradation, bioactivity and cytotoxicity evaluation of Poly Hydroxy Alkanoate (PHA) reinforced with nano-Calcium Phosphate (nCaP) and chitosan for bone regeneration
Abstract:
Polyhydroxyalkanoates (PHA) exhibit tremendous potential for bone tissue regeneration, owing to their biocompatibility and biodegradability. To address limitations in supporting bone growth, researchers have employed a strategic approach of reinforcing PHA with calcium phosphate (CaP), leading to transformative advancements. This comprehensive study investigates the bioactivity properties of composites prepared using biodegradable PHA reinforced with nano-CaP and chitosan (CH), which serve as natural carriers for growth factors and demonstrate antimicrobial properties. Various in vitro methods, including Tris-HCL degradation, simulated body fluids (SBF), and cytotoxicity tests, were employed to evaluate the performance of the composites. PHA served as the matrix, while nano-CaP (3-15wt%) was incorporated as a reinforcement along with a constant 10wt% of CH. The results revealed slower and steady degradation rates for both PHA and PHA/n-CaP/CH composites, as evidenced by water uptake and mass change profiles. SBF testing, confirmed by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) analysis, demonstrated the formation of an apatite layer on the composites' surface within three days, indicating excellent bioactivity potential of nano-CaP. Furthermore, the sustained apatite layer formation after 28 days strongly indicated the composites' effectiveness in promoting bone integration in vivo. Moreover, the composites maintained a neutral pH of Tris-HCl degradation and SBF media, closely resembling the physiological environment (pH 7.40). Cytotoxicity evaluations using the Alamar Blue assay confirmed the non-toxicity of the composites to osteoblast cells, accompanied by enhanced cell proliferation and viabilities exceeding 100%. Additionally, the osteogenic differentiation of human fetal osteoblasts assessed via alkaline phosphatase activity testing further emphasized the potential of PHA and PHA/n-CaP/CH composites as promising materials for bone regeneration applications. Collectively, these findings highlight the remarkable prospects of PHA-based composites in advancing bone tissue engineering and regeneration therapies.
Audience Take Away:
- The research investigates the bioactivity properties of PHA and PHA/n-CaP/CH composites, shedding light on their potential for applications in tissue engineering and regenerative medicine.
- The water uptake and mass change profiles of the composites provide insights into their degradation behavior and potential for use as scaffolds in biomedical applications.
- The pH values of the degradation media demonstrate the stability of the composites in a physiological environment, further supporting their potential as biomaterials.
- The formation of apatite layers on the composites' surfaces indicates their excellent bioactivity capabilities, which is crucial for promoting bone regeneration and integration.
- The calcium-to-phosphate ratio in the formed apatite layer resembles that of natural bone, highlighting the biomimetic properties of the composites and their potential to support bone tissue growth and healing.
