Abstract
BACKGROUND: Whitlockite (WH) is a magnesium-containing calcium phosphate mineral that occurs naturally in bone and teeth. Its biological relevance lies in its ability to promote osteogenesis and provide mechanical stability, making it a strong candidate for bone repair applications. Introducing mesoporosity into Whitlockite is expected to further enhance its biological activity by increasing surface roughness and surface area, which improves protein adsorption and supports cell growth. OBJECTIVE: This work focused on preparing mesoporous Whitlockite (Meso-Wh) through a controlled acid treatment method, followed by detailed structural and surface characterization, and an in vitro evaluation of its cytocompatibility. METHODS: Whitlockite was synthesized using a precipitation-hydrothermal method with calcium nitrate, magnesium nitrate, and diammonium hydrogen phosphate precursors. Mesoporosity was induced by hydrochloric acid treatment (pH 4). The particles were characterized using scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption studies with BET and BJH analysis. Cytocompatibility was tested by an indirect MTT assay using MG-63 osteoblast-like cells. RESULTS: SEM images showed that Meso-Wh particles were smaller and rougher compared with untreated Whitlockite. EDS confirmed calcium, phosphorus, oxygen, and magnesium as the major elements. XRD patterns indicated reduced crystallinity in Meso-Wh, and FTIR spectra revealed broadening of phosphate bands, suggesting lattice disorder due to acid treatment. BET analysis gave a surface area of 63.07 m(2)/g, while BJH pore distribution confirmed mesopores mainly in the 2-5 nm range. MTT results showed good cytocompatibility, with high cell viability at 25-75 % extract dilutions and a slight decrease at 100 %. The positive control exhibited marked cytotoxicity. CONCLUSION: Acid treatment effectively produced mesoporous Whitlockite with enhanced surface area and nanoscale porosity, without altering its chemical composition, indicating its suitability for further development as a bone tissue engineering scaffold.