Flame-made calcium phosphate nanoparticles with varying crystallinity and carbonate content were incorporated into electrospun PLGA fibers for bone tissue engineering.

Whey protein isolate (WPI) hydrogel is a promising candidate as a biomaterial for tissue engineering. Previously, WPI hydrogels containing poly-γ-glutamic acid (γ-PGA) with a molecular weight (MW) of 440 kDa demonstrated potential as scaffolds for bone tissue engineering. Here, the study compares different γ-PGA preparations of differing MW. WPI-γ-PGA hydrogels containing 40% WPI and 0%, 2.5%, 5%, 7.5%, and 10% γ-PGA were synthesised. Three γ-PGA MWs were compared, namely 10 kDa, 700 kDa, and 1100 kDa. Evidence of successful γ-PGA incorporation was demonstrated by scanning electron microscopy and Fourier transform infrared spectroscopy. Increasing γ-PGA concentration significantly improved the swelling potential of the hydrogels, as demonstrated by ratio mass increases of between 85 and 90% for each 10% variable group. Results suggested that γ-PGA delayed enzymatic proteolysis, potentially decreasing the rate of degradation. The addition of γ-PGA significantly decreased the Young’s modulus and compressive strength of hydrogels. Dental pulp mesenchymal stem cells proliferated on all hydrogels. The highest cellular growth was observed for the WPI-700 kDa γ-PGA group. Additionally, superior cell attachment was observed on all WPI hydrogels containing γ-PGA compared to the WPI control. These results further suggest the potential of WPI hydrogels containing γ-PGA as biomaterials for bone tissue engineering.

Bone-associated pathologies are major contributors to chronic pathology statistics. Current gold standard treatments present limitations such as the ability to act as scaffolds whilst effectively delivering medications to promote cellular proliferation. Recent advancements in biomaterials have suggested whey protein isolate (WPI) hydrogel as a potential candidate to act as a scaffold with the capacity for drug delivery for bone regeneration. In this study, we investigate whey protein isolate hydrogels enhanced with the phytocannabinoid cannabidiol (CBD). The use of CBD in WPI hydrogels for bone regeneration is original. The results suggest that CBD was successfully incorporated into the hydrogels bound potentially through hydrophobic interactions formed between hydrophobic patches of the protein and the hydrophobic cannabinoid. The incorporation of CBD into the WPI hydrogels improved the mechanical strength of the hydrogels. The Young’s modulus was improved from 2700 kPa ± 117 kPa to 7100 kPa ± 97 kPa when compared to the WPI control, without plant-derived cannabinoids, to the WPI with the maximum CBD concentration. Furthermore, statistically significant differences for both Young’s modulus and compressive strength were observable between the WPI control and CBD hydrogel variables. The release of CBD from the WPI hydrogels was confirmed with the results suggesting a maximum release of 20 μM over the 5-day period. Furthermore, the hydrogels supported the proliferation and synthesis of collagen and calcium, as well as the alkaline phosphatase activity of MC3T3-E1 pre-osteoblasts, which demonstrates the potential of WPI/CBD hydrogels as a biomaterial for osseous tissue regeneration.

Bone is a dynamic, mechanoresponsive tissue with intrinsic mechanoelectrical behavior. Schematic (created with BioRender) illustrates how mechanical stimulation applied to a conductive scaffold enhances osteogenic differentiation.