Marine-Inspired Enzymatic Mineralization of Dairy-Derived Whey Protein Isolate (WPI) Hydrogels for Bone Tissue Regeneration

Abstract

Whey protein isolate (WPI) is a by-product from the production of cheese and Greek yoghurt comprising β-lactoglobulin (β-lg) (75%). Hydrogels can be produced from WPI solutions through heating; hydrogels can be sterilized by autoclaving. WPI hydrogels have shown cytocompatibility and ability to enhance proliferation and osteogenic differentiation of bone-forming cells. Hence, they have promise in the area of bone tissue regeneration. In contrast to commonly used ceramic minerals for bone regeneration, a major advantage of hydrogels is the ease of their modification by incorporating biologically active substances such as enzymes. Calcium carbonate (CaCO3) is the main inorganic component of the exoskeletons of marine invertebrates. Two polymorphs of CaCO3, calcite and aragonite, have shown the ability to promote bone regeneration. Other authors have reported that the addition of magnesium to inorganic phases has a beneficial effect on bone-forming cell growth. In this study, we employed a biomimetic, marine-inspired approach to mineralize WPI hydrogels with an inorganic phase consisting of CaCO3 (mainly calcite) and CaCO3 enriched with magnesium using the calcifying enzyme urease. The novelty of this study lies in both the enzymatic mineralization of WPI hydrogels and enrichment of the mineral with magnesium. Calcium was incorporated into the mineral formed to a greater extent than magnesium. Increasing the concentration of magnesium in the mineralization medium led to a reduction in the amount and crystallinity of the mineral formed. Biological studies revealed that mineralized and unmineralized hydrogels were not cytotoxic and promoted cell viability to comparable extents (approximately 74% of standard tissue culture polystyrene). The presence of magnesium in the mineral formed had no adverse effect on cell viability. In short, WPI hydrogels, both unmineralized and mineralized with CaCO3 and magnesium-enriched CaCO3, show potential as biomaterials for bone regeneration.

The Effect of Chitosan on Physicochemical Properties of Whey Protein Isolate Scaffolds for Tissue Engineering Applications

“…The samples containing only WPI (WPI_0) did not influence cell viability regardless of extract dilution (Figure 10), which confirm that WPI is cyto-compatible with MG-63 cells. Similar materials based on WPI have already been tested by Plastun et al [74] on L929 fibroblasts and by Norris et al [75] on MC3TC-E1 cells. Both studies found out that WPI-based materials were not cytotoxic against different cell types.…”

Development of Biscuits Made from Maggot Flour and Whey Protein Isolate as a High-Protein Snack for School-Age Children

“…Ash content ash content of a product is also related to the mineral content of an ingredient (Sulistyoningsih et al, 2019). The mineral content contained in maggot is 30.46 g/kg or 3.046% (Ahmad et al, 2022), while whey protein isolate contains 0.7% minerals (Norris et al, 2020). The higher mineral content of maggot flour resulted in the highest ash content of F3.…”

The Enrichment of Whey Protein Isolate Hydrogels with Poly-γ-Glutamic Acid Promotes the Proliferation and Osteogenic Differentiation of Preosteoblasts

“…For instance, in [15], cytocompatible WPI-bioactive glass composites were produced, supporting MG-63 osteoblast cellular functioning. In [16], WPI-WPI Urease hydrogels were synthesized, demonstrating that WPI-PG hydrogels support the growth of osteosarcoma-derived MC3T3-E1 cells. Hence, such WPI-PG hydrogels may provide a medicinal route to restrict microbial infections, whilst presenting desirable mechanical properties and promoting stem-cell attachment.…”