Achieving enhanced stabilization and controlled release of curcumin via cross-linked polydopamine particles

Development of efficient drug delivery systems remains a critical challenge in pharmaceutical applications, necessitating novel approaches to improve drug loading and release profiles. In this study, a novel method is presented for fabricating crosslinked polydopamine particles (XPDPs) using a water/water Pickering emulsion system. The emulsion is composed of poly(ethylene glycol) and dextran, stabilized by polydopamine (PDA) particles. This method yields XPDPs with a mean particle size of 0.55 μm, significantly smaller than PDA particles (1.025 μm), resulting in a higher surface area favorable for drug loading. The adsorption mechanism involves electron sharing and covalent bonding between the carrier and drug molecules. The adsorption, release, and drug delivery kinetics of the XPDPs are compared with those of the non-crosslinked PDA particles. The results demonstrate that XPDPs exhibit improved adsorption properties due to their crosslinked structure and increased positive charge due to presence of secondary amines. During a 28-h period, curcumin release from PDA declines from around 80 %-40 %, while for XPDA, it decreases from approximately 60 %-35 % as the pH shifts from 7.4 to 5. While PDA particles display a burst release profile, XPDPs show a more gradual and sustained release, attributed to their enhanced structural stability. Molecular simulations were conducted to estimate the solubility parameters, confirming the compatibility between PDA and dextran for effective drug loading.