Understanding of Polydopamine Formulation for Oral Therapeutic Delivery in Ulcerative Colitis Treatment

Oral therapeutic delivery remains challenged by gastrointestinal tract (GI) barriers, which hinders the successful transition of therapeutic candidates into clinical treatments. Polydopamine (PDA), with its versatile ability to overcome GI barriers, offers a promising drug formulation technology to address the challenge. Nevertheless, many critical questions remain unanswered regarding the practicality of PDA-based formulations. Building on the previous research, which tackled multiple physicochemical aspects, the current study aims to address another three outstanding issues, including the quantification of residual dopamine (DA) in PDA-based formulations, the examination of these formulations stimulatory effects on colon tissue, and the potential anti-inflammatory properties. To facilitate this investigation, a curcumin-containing nanomedicine (CP@CCS) is prepared as a representative PDA-based formulation. The results reveal a marked decrease of residual DA within the formulation. In the treatment of ulcerative colitis (UC), the formulation do not provoke the substantial contractions in colon tissue typically induced by DA. Furthermore, in vivo evaluation verified the supplementary anti-UC benefits of PDA. These outcomes add evidence for the practicality of PDA-based formulations in terms of safety and therapeutic efficacy. Finally, a conceptual framework is proposed for understanding the role of PDA in oral therapeutic delivery, thereby providing insightful directions for subsequent research.