Orally Targeted Delivery of Tripeptide KPV via Hyaluronic Acid-Functionalized Nanoparticles Efficiently Alleviates Ulcerative Colitis

Overcoming adverse effects and selectively delivering drug to target cells are two major challenges in the treatment of ulcerative colitis (UC). Lysine-proline-valine (KPV), a naturally occurring tripeptide, has been shown to attenuate the inflammatory responses of colonic cells. Here, we loaded KPV into hyaluronic acid (HA)-functionalized polymeric nanoparticles (NPs). The resultant HA-KPV-NPs had a desirable particle size (∼272.3 nm) and a slightly negative zeta potential (∼-5.3 mV). These NPs successfully mediated the targeted delivery of KPV to key UC therapy-related cells (colonic epithelial cells and macrophages). In addition, these KPV-loaded NPs appear to be nontoxic and biocompatible with intestinal cells. Intriguingly, we found that HA-KPV-NPs exert combined effects against UC by both accelerating mucosal healing and alleviating inflammation. Oral administration of HA-KPV-NPs encapsulated in a hydrogel (chitosan/alginate) exhibited a much stronger capacity to prevent mucosa damage and downregulate TNF-α, thus they showed a much better therapeutic efficacy against UC in a mouse model, compared with a KPV-NP/hydrogel system. These results collectively demonstrate that our HA-KPV-NP/hydrogel system has the capacity to release HA-KPV-NPs in the colonic lumen and that these NPs subsequently penetrate into colitis tissues and enable KPV to be internalized into target cells, thereby alleviating UC.