Low-temperature thermal treatment’s impact on hydroxyapatite nanofiber characteristics

Abstract

Bone fractures caused by trauma or injury have been a worldwide public health concern. Therefore, bone tissue engineering has emerged as a viable option for addressing these issues by providing a variety of novel scaffold construction approaches. Bone is composed primarily with hydroxyapatite and carbonated apatite, which is 65% of the total mass. Therefore, many strategies have been conducted in fabricating bone scaffold with hydroxyapatite as the main biomaterials. The combination of electrospinning procedure and sol–gel method in generating hydroxyapatite nanofibers has some advantages due to the ability in replicating the content or structure of natural bone's extracellular matrix (ECM). The fibers were electrospun from a mixture of sol formed from polyvinylpyrrolidone (PVP)as the carrier and the calcium phosphate (CaP) precursors, followed by a thermal treatment that alter the fiber characteristics. Based on previous studies, the thermal treatment of pure hydroxyapatite phase has been suggested at least 600 °C However, no studies have done the thermal treatment at low temperature. Thus, this study investigates the impact of low-temperature thermal treatment on hydroxyapatite nanofibers. Observation on diameter and porosity of the fabricated fibers was conducted based on SEM images. The diameter of the fibers was decreased form 35.23 nm to 24.69 nm after the thermal treatment. Besides, the Ca/P molar ratio of the fabricated nanofibers was decreased from 15 to 8.16 after thermal treatment showing the potential of this formulation in achieving hydroxyapatite phase stoichiometry of 1.67. For future study, formulation at different PVP concentrations and different temperatures also need to be done in achieving better hydroxyapatite nanofibers properties.