Silk sericin stabilized proanthocyanidins for synergetic alleviation of ulcerative colitis

Silk sericin (SS) has become a noticeable drug nanocarrier due to its excellent biocompatibility and bioactivity. To further extend the application of SS, a facile one-step process was constructed to fabricate SS-stabilized-drug composites. Various insoluble drugs can be encapsulated into SS with high loading amount, and showed good dispersity in aqueous solution. For example, proanthocyanidins (PAC), a natural polyphenol with initial antioxidant and anti-inflammatory effects, can be loaded on SS to form SS/PAC composites. The SS/PAC can disperse uniformly in aqueous solution with an average particle diameter of ~136 nm, and showed high drug loading amount of 1767 mg/g. The SS/PAC exhibited high antioxidant efficiency and excellent biocompatibility (non-irritant, non-hemolysis, and non-cytotoxicity), could remarkably alleviate the symptoms of dextran sulfate sodium-induced ulcerative colitis by decreasing the disease activity index scores, inhibiting the shortening of colon length, regulating oxidative stress, suppressing inflammation, and reversing the histopathological injuries. This work provides a simple method to fabricate SS-stabilized-drug composites, promises high potential in therapeutic and pharmaceutical applications.