PLA-coated Imwitor® 900 K-based herbal colloidal carriers as novel candidates for the intra-articular treatment of arthritis

Although there are several treatments for rheumatoid arthritis (RA), outcomes are unsatisfactory and often associated with many side effects. We attempted to improve RA therapeutic outcomes by intra-articular administration of dual drug-loaded poly(lactic) acid (PLA)-coated herbal colloidal carriers (HCCs). Curcumin (CU) and resveratrol (RES) were loaded into HCCs because of their safety and significant anti-inflammatory activity. HCCs were prepared using a high-pressure, hot homogenization technique and evaluated in vitro and in vivo using a complete Freund's adjuvant-induced arthritis model. Transmission electron microscope (TEM) evaluated coating selected formulations with PLA, which increased particle sizes from 52 to 89.14 nm. The entrapment efficiency of both formulations was approximately 76%. HCCs significantly increased the amount of RES and CU released compared with the drug suspensions alone. The in vivo treated groups showed a significant improvement in joint healing. PLA-coated HCCs, followed by uncoated HCCs, yielded the highest reductions in knee diameter, myeloperoxidase (MPO) levels, and tumor necrosis factor-alpha (TNFα) levels. Histological examination of the dissected joints revealed that PLA-coated HCCs followed by uncoated HCCs exhibited the most significant joint healing effects. Our results demonstrate the superiority of intra-articularly administered HCCs to suppress RA progression compared with RES or CU suspensions alone.