Osseous disease accounts for over half of chronic pathologies, but there is a limited supply of autografts, the gold standard; hence, there is a demand for new synthetic biomaterials. Herein, we present the use of a promising, new dairy-derived biomaterial: whey protein isolate (WPI) in the form of hydrogels, modified with the addition of different concentrations of the biotechnologically produced protein-like polymeric substance poly-γ-glutamic acid (γ-PGA) as a potential scaffold for tissue regeneration. Raman spectroscopic analysis demonstrated the successful creation of WPI-γ-PGA hydrogels. A cytotoxicity assessment using preosteoblastic cells demonstrated that the hydrogels were noncytotoxic and supported cell proliferation from day 3 to 14. All γ-PGA-containing scaffold compositions strongly promoted cell attachment and the formation of dense interconnected cell layers. Cell viability was significantly increased on γ-PGA-containing scaffolds on day 14 compared to WPI control scaffolds. Significantly, the cells showed markers of osteogenic differentiation; they synthesised increasing amounts of collagen over time, and cells showed significantly enhanced alkaline phosphatase activity at day 7 and higher levels of calcium for matrix mineralization at days 14 and 21 on the γ-PGA-containing scaffolds. These results demonstrated the potential of WPI-γ-PGA hydrogels as scaffolds for bone regeneration.

A key challenge in tissue engineering is developing functional tissues that can effectively mimic the structure and function of natural tissues. This involves creating scaffolds that support cell proliferation, and differentiation. This research aimed to develop hydrogels as scaffolds that could be utilised in tissue engineering, particularly in applications that require angiogenesis. Whey protein isolate (WPI) has been employed as the main hydrogel component, as WPI hydrogels have been investigated for possible applications in bone tissue engineering. Heparin (HP) and tinzaparin (TP) were selected as additives, as they enhance cellular growth and exhibit anti-inflammatory properties. Nine different compositions were created, each with varying percentages of the additives, a control sample containing pure WPI, and samples with HP or TP at 2.5%, 5%, 7.5%, and 10% concentrations. The mechanical tests showed compressive moduli in the range of 430–620 kPa for the modified hydrogels and indicated that a 5% content of HP or TP is optimal in terms of mechanical characteristics. The highest swelling ratios of approximately 13% and 16%, respectively were noted in both modified groups (TP and HP) at the 7.5% concentration. HP 2.5% demonstrated the highest cytocompatibility among all HP concentrations, including the WPI control, while TP 10% exhibited greater cytocompatibility than other TP concentrations, also surpassing the WPI control. All hydrogels with additives enhanced cell attachment compared to the WPI control, indicating better cytocompatibility. The morphology visualization of DPSCs indicated no significant differences between the four HP or TP concentrations. TP 10% showed the most promising results in angiogenic differentiation potential tests in vitro, suggesting this composition should be studied further.