Hydroxyapatites and nano-hydroxyapatites as scaffolds in drug delivery towards efficient bone regeneration: A review

Abstract

Bone regeneration is a complex process that requires materials capable of supporting structural integrity, promoting cell proliferation, and enabling effective drug delivery. Nano-hydroxyapatite (nHA), with its biocompatibility and close resemblance to natural bone minerals, has emerged as a promising material in bone tissue engineering. nHA enhances osteoconductivity, mechanical strength, and drug-loading capacity, making it an effective tool for treating bone defects. Therefore, the potential of combining nHA with bioactive agents and polymers offers new opportunities for long-term, targeted treatments for bone diseases and injuries. This review highlights the role of nHA in drug-delivery systems for bone regeneration, focusing on its properties, synthesis methods, and interactions with bone tissue. Then, key challenges include optimizing scaffold porosity, controlling degradation rates, and improving mechanical stability. Next, advanced applications, such as gene therapy and intelligent drug delivery systems, are also explored. Additionally, some research gaps on the utilization of nHA in drug delivery of bone regeneration were surveyed. Finally, future perspectives on the nHA-based scaffolds for smart drug delivery in the reconstruction and repair of bone were discussed.