Preparation and Characterization of Montmorillonite/Polycaprolactone Composite Scaffold Containing Strontium for Bone Tissue Engineering Studies

Abstract

Montmorillonite (MMT) has attracted much attention due to its intrinsic ability to incorporate cations. In this study, we developed scaffold combining strontium-modified MMT and polycaprolactone (SrMMT-PCL) to further utilise the osteoconductive properties of strontium. For this purpose, MMT was modified with strontium, and then blended with polycaprolactone (PCL) in specific ratios by using particulate leaching technique to obtain bone tissue-like biocomposite scaffold. The macrostructure and morphology were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The release of Sr²⁺ from scaffolds into cell culture medium was determined by inductive coupled plasma optical emission spectrometer (ICP-OES). The pore size distrubition of scaffolds was determined by mercury intrusion porosimetry. The mechanical properties were also evaluated. The results of FTIR and XRD confirmed intercalation of PCL into MMT layers. TGA studies concluded that the MMT in PCL promoted the thermal degradation of the matrix. ICP results showed that Sr²⁺ was released from composite scaffolds. The majority of pore volume seems to be occupied by pores around 250-350 mm. SEM observations demonstrated the macroporous structure of the MMT-PCL sponges obtained by using the particulate leaching method. As a result, gained data suggests that obtained tissue-engineered scaffold has the potential to serve as a suitable templete for bone tissue engineering applications.

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