Encapsulated sustained-release whey protein improves muscle mass and strength in sarcopenic mice

In a murine model of sarcopenia, researchers tested whether slowing the release of whey protein isolate could improve muscle mass and physical function. Although whey protein is rich in branched-chain amino acids, rapid digestion limits its effectiveness against age-related muscle loss. To address this, the authors built a single-protein particle encapsulation system by assembling metal-polyphenol networks onto polymerized whey protein isolate particles bridged with hyaluronic acid. This system precisely controlled protein release in the gastrointestinal tract. In sarcopenic mice, the formulation significantly increased lean body content, grip strength, grid hanging time, exhaustion time, and exhaustion distance. The treatment activated the PI3K/AKT/mTOR pathway and suppressed the muscle atrophy factors MuRF-1 and Atrogin-1 in the ubiquitin-proteasome system.