Surface Modification Via Alkali Treatment and Its Effect on the Physicochemical and Biological Properties of Emulsion Templated Scaffolds

Abstract

Emulsion templating is an advantageous scaffold fabrication technique that provides high interconnectivity, high porosity, and control of the scaffold architecture. Polymerised emulsions with an internal phase ratio greater than 74 % are named Polymerised High Internal Phase Emulsions (PolyHIPEs). Polycaprolactone (PCL) is a synthetic, biodegradable, and biocompatible polymer widely used in tissue engineering, but the material-cell interaction of PCL-based biomaterials has been found to be limited due to the material's high hydrophobicity. This study aims to develop emulsion-templated polycaprolactone tetramethacrylate (4PCLMA)-based scaffolds and improve their biological performance using an alkaline surface modification method. For this purpose, 4PCLMA was successfully synthesised, and highly porous scaffolds were developed. PolyHIPEs were incubated in three different sodium hydroxide (NaOH) concentrations for three different incubation times. Chemical, morphological, mechanical characterisation, mass loss, water absorption capacity, water contact angle, Brunauer-Emmett-Teller analyses and biological investigations were conducted on NaOH-treated scaffolds in comparison with the control. The chemical changes induced by NaOH treatment in PolyHIPEs were confirmed by Fourier-transform infrared spectroscopy. NaOH treatment increased the water absorption capacity, hydrophilicity, surface area, and protein adsorption but decreased the weight and mechanical strength of the scaffolds. In vitro results showed that NaOH treatment did not cause cytotoxicity in L929 cells and positively affected the cell adhesion and proliferation behaviour of Saos-2 cells. This study suggests surface modification of biodegradable synthetic polymer-based PolyHIPEs by NaOH treatment as a simple, scalable and cost-effective approach to enhance cell-material interactions of the material without causing a significant change in the overall morphology, contributing to the advancement of next-generation healthcare technologies.