Porous clinoptilolite—nano biphasic calcium phosphate scaffolds loaded with human dental pulp stem cells for load bearing orthopedic applications

Clinoptilolite (Cpt)-nanohydroxyapatite (HA) (Cpt-HA) scaffolds were fabricated as a potential material for loadbearing orthopaedic applications. Cpt-HA materials were successfully synthesized by using microwave assisted reflux method followed by the fabrication of three-dimensional (3D) porous scaffold via thermal decomposition process using polyethylene glycol (PEG)/ polyvinyl alcohol (PVA) as porogens. The scaffold materials were characterized using x-ray diffraction, Fourier transform Infra-red, Scanning electron microscopy and Energy dispersive spectroscopy techniques. Incorporation of Cpt in HA scaffold significantly increased the compressive strength and surface hardness while scaffolds retained an interconnected porous structure with 64% porosity. Human dental pulp stem cells (DPSCs) were isolated from the third molar and used as pluripotent-like cell model to evaluate the biological properties of Cpt-HA scaffolds. Highest cellular attachment and proliferation were observed for DPSCs seeded on 2.0 g Cpt-HA scaffolds compare to pure HA. Similarly, significantly higher ALP activity of cells was observed on Cpt-HA scaffolds compared to pure HA. The enhanced proliferation and osteogenic response of the DPSCs cultured on Cpt-HA scaffolds suggest that the fabricated scaffolds can be used in bone tissue engineering. In this work, we have successfully shown that the interconnected porous Cpt-HA scaffolds have superior mechanical biological properties compared to pure HA scaffold.