A biomimetic lubricating nanosystem for synergistic therapy of osteoarthritis.

Failure of articular cartilage lubrication and inflammation are the main causes of osteoarthritis (OA), and integrated treatment realizing joint lubrication and anti-inflammation is becoming the most effective treat model. Inspired by low friction of human synovial fluid and adhesive chemical effect of mussels, our work reports a biomimetic lubricating system that realizes long-time lubrication, photothermal responsiveness and anti-inflammation property. To build the system, a dopamine-mediated strategy is developed to controllably graft hyaluronic acid on the surface of metal organic framework. The design constructs a biomimetic core-shell structure that has good dispersity and stability in water with a high drug loading ratio of 99%. Temperature of the solution rapidly increases to 55 °C under near-infrared light, and the hard-soft lubricating system well adheres to wear surfaces, and greatly reduces frictional coefficient by 75% for more than 7200 times without failure. Cell experiments show that the nanosystem enters cells by endocytosis, and releases medication in a sustained manner. The anti-inflammatory outcomes validate that the nanosystem prevents the progression of OA by down-regulating catabolic proteases and pain-related genes and up-regulating genes that are anabolic in cartilage. The study provides a bioinspired strategy to employ metal organic framework with controlled surface and structure for friction reduction and anti-inflammation, and develops a new concept of OA synergistic therapy model for practical applications.

Multi-scale ultrasound induced composite coacervates of whey protein and pullulan polysaccharide on emulsion forming and stabilizing mechanisms.

A non-destructive technique known as multi-scale ultrasound (MSU) was employed to modify the emulsion consisting of glycosylated bovine whey protein (WP) and pullulan (Pu). To assess the effect on the structural and emulsifying properties of the WP-Pu, the formulated emulsion, was treated with divergent MSU at (single: 20 kHz, 40 kHz, and 60 kHz; dual: 20-40 kHz, 40-60 kHz, and 20-60 kHz; and tri: 20-40-60 kHz) frequency for a duration of 30 min. The tri-frequency, treated emulsion showed improved emulsifying stability compared to the control and MSU-treated single, and dual-frequency samples, as indicated by the particle size, structural morphology, and adsorbed protein. The molecular docking and numerous spectral analysis provided evidence that WP can undergo successful phenolation. This modified form of WP then interacts with Pu through various forces, including H-bonding and other mechanisms, resulting in the formation of a composite emulsion. The rheological properties revealed that both the control emulsion and the MSU-treated emulsion exhibited non-Newtonian pseudoplastic flow behavior. This behavior is characterized by shear thinning, where the viscosity decreases with increasing shear rate. The shear rates tested ranged from 1 to 300 1/s, additionally, the degree of crystallinity increased from 18.2° to 19.4°. Overall, the tri-frequency effect was most pronounced compared to single and dual-frequency. Ultrasonication, an emerging non-thermal technology, proves to be an efficient approach for the formulation of WP-Pu composites. These composites have significant potential for use in drug delivery systems and functional foods.