Bioinspired engineered proteins enable universal anchoring strategy for surface functionalization

Size-Controllable and pH-Sensitive Whey Protein Microgels as High-Performance Aqueous Biolubricants

Developing efficient aqueous biolubricants has become a significant focus of research due to their prevalence in biotribological contacts and enormous potential in soft matter applications. In this study, size-controllable, pH-sensitive whey protein microgels were prepared using a water-in-water emulsion template method from protein-polysaccharide phase separation. The granular hydrogel from the protein microgels exhibited superior lubricity, obtaining 2.7-fold and 1.7-fold reductions in coefficient of friction (μ) compared to native protein and human saliva (μ = 0.30 compared to 0.81 and 0.52, respectively). The microgels also exhibited outstanding load-bearing capabilities, sustaining lubrication under normal forces up to 5 N. Microgels with a smaller size (1 μm) demonstrated better lubricating performance than 6 and 20 μm microgels. The exceptional lubricity was from a synergistic effect of the ball-bearing mechanism and the hydration state of the microgels. Particularly at pH 7.4, the hydration layer surrounding highly negative charges contributed to the electrostatic repulsion among the swollen microgels, leading to an improved buffer ability to separate contact surfaces and effective rolling behavior. Such pH-dependent repulsion was evidenced using a surface forces apparatus that the adhesion between the whey protein-coated surfaces and protein-mica surfaces decreased from 4.49 to 0.97 mN/m and from 7.89 to 0.36 mN/m, respectively, with pH increasing from the isoelectronic point to 7.4. Our findings fundamentally elucidated the tribo-rheological properties and lubrication mechanisms of the whey protein microgels with excellent biocompatibility and environmental responsiveness, offering novel insights for their food and biomedical applications requiring aqueous biolubrication.

Fabrication of pH-stimuli hydrogel as bioactive materials for wound healing applications

Hydrogels exhibit exceptional suitability as wound dressing due to their remarkable three-dimensional (3D) characteristics. Here, we have reported the fabrication of hydrogels from biopolymers carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and gelatin via a simple blending method to mimic the natural extracellular matrix. Scanning electron microscopy (SEM), water contact meters (WCM), and Fourier-transform infrared spectroscopy (FTIR) were used to evaluate the chemical structural, morphological, and wettability behavior. The wetting and degradation behavior were also found to be different for different formulations (Min. (51.60o) and Max. (113.60o)) and (Min. (38.82 mg) and Max. (3.72 mg)), respectively. Swelling was investigated in different media, including phosphate buffer saline solution (PBS) and aqueous media. It was observed that the hydrogel displayed the highest degree of swelling in an aqueous medium (Min. (597.32-1121.49 %) and Max. (1089.51-2139.73 %)) compared to PBS media (Min. (567.01-1021.85 %) and Max. (899.13-1639.17 %)). The release of Neomycin was studied in a PBS medium via the Franz diffusion method at 37 °C. The maximal release in various media demonstrated pH-responsive behavior. The viability and proliferation of fibroblast (3T3) cell lines were examined in vitro to evaluate cytocompatibility. Human Embryonic Kidney (HEK) 293 cells were used to evaluate the hydrogels' ability to promote vascularization and angiogenesis. Therefore, the data demonstrate that hydrogels that have been manufactured have qualities that make them promising for use as wound dressings in wound healing applications.

Dual-Protection Inorganic-Protein Coating on Mg-Based Biomaterials through Tooth-Enamel-Inspired Biomineralization

Biocompatible magnesium alloys represent revolutionary implantable materials in dentistry and orthopedics but face challenges due to rapid biocorrosion, necessitating protective coatings to mitigate dysfunction. Directly integrating durable protective coatings onto Mg surfaces is challenging because of intrinsic low coating compactness. Herein, inspired by tooth enamel, a novel highly compact dual-protection inorganic-protein (inorganicPro) coating is in situ constructed on Mg surfaces through bovine serum albumin (BSA) protein-boosted reaction between sodium fluoride (NaF) and Mg substrates. The association of Mg ions and BSA establishes a local hydrophobic domain that lowers the formation enthalpy of NaMgF3 nanoparticles. This process generates finer nanoparticles that function as "bricks," facilitating denser packing, consequently reducing voidage inside coatings by over 50% and reinforcing mechanical durability. Moreover, the incorporation of BSA in and on the coatings plays two synergistic roles: 1) acting as "mortar" to seal residual cracks within coatings, thereby promoting coating compactness and tripling anticorrosion performance, and 2) mitigating fouling-accelerated biocorrosion in complex biosystems via tenfold resistance against biofoulant attachments, including biofluids, proteins, and metabolites. This innovative strategy, leveraging proteins to alter inorganic reactions, benefits the future coating design for Mg-based and other metallic materials with tailored anticorrosion and antifouling performances.