Whey Protein Isolate/Calcium Silicate Hydrogels for Bone Tissue Engineering Applications—Preliminary In Vitro Evaluation

Whey protein isolate (WPI) hydrogels are attractive biomaterials for application in bone repair and regeneration. However, their main limitation is low mechanical strength. Therefore, to improve these properties, the incorporation of ceramic phases into hydrogel matrices is currently being performed. In this study, novel whey protein isolate/calcium silicate (WPI/CaSiO(3)) hydrogel biomaterials were prepared with varying concentrations of a ceramic phase (CaSiO(3)). The aim of this study was to investigate the effect of the introduction of CaSiO(3) to a WPI hydrogel matrix on its physicochemical, mechanical, and biological properties. Our Fourier Transform Infrared Spectroscopy results showed that CaSiO(3) was successfully incorporated into the WPI hydrogel matrix to create composite biomaterials. Swelling tests indicated that the addition of 5% (w/v) CaSiO(3) caused greater swelling compared to biomaterials without CaSiO(3) and ultimate compressive strength and strain at break. Cell culture experiments demonstrated that WPI hydrogel biomaterials enriched with CaSiO(3) demonstrated superior cytocompatibility in vitro compared to the control hydrogel biomaterials without CaSiO(3). Thus, this study revealed that the addition of CaSiO(3) to WPI-based hydrogel biomaterials renders them more promising for bone tissue engineering applications.