Intra-articular administration of drugs to the joint in the treatment of joint disease has the potential to minimize the systemic bioavailability and the usual side-effects associated with oral drug administration. In this work, a drug delivery system is proposed to achieve an anti-inflammatory local effect using resveratrol (RSV). This study aims to develop microcapsules made of poly-(ε-caprolactone) (PCL) by ultrasonic atomization to preserve the antioxidant activity of RSV, to prevent its degradation and to suppress the inflammatory response in activated RAW 264.7 macrophages. An experimental design was performed to build a mathematical model that could estimate the effect of nozzle power and polymer concentration on particle size and encapsulation efficiency. RSV-loaded microcapsules showed adequate morphology, particle size, and loading efficiency properties. RSV formulations exhibited negligible cytotoxicity and an efficient amelioration of inflammatory responses, in terms of Nitric Oxide (NO), ROS (Reactive Oxygen Species), and lipid peroxidation in macrophages. Thus, RSV-loaded microcapsules merit consideration as a drug delivery system suitable for intra-articular administration in inflammatory disorders affecting the joint.

Microencapsulation of the therapeutical monoclonal antibody infliximab (INF) was investigated as an innovative approach to improve its stability and to achieve formulations with convenient features for intra-articular administration. Ultrasonic atomization (UA), a novel alternative to microencapsulate labile drugs, was compared with the conventional emulsion/evaporation method (Em/Ev) using biodegradable polymers, specifically Polyactive^® 1000PEOT70PBT30 [poly(ethylene-oxide-terephthalate)/poly(butylene-terephthalate); PEOT-PBT] and its polymeric blends with poly-(D, L-lactide-co-glycolide) (PLGA) RG502 and RG503 (PEOT-PBT:PLGA; 65:35). Six different formulations of spherical core–shell microcapsules were successfully developed and characterized. The UA method achieved a significantly higher encapsulation efficiency (69.7–80.25%) than Em/Ev (17.3–23.0%). Mean particle size, strongly determined by the microencapsulation method and to a lesser extent by polymeric composition, ranged from 26.6 to 49.9 µm for UA and 1.5–2.1 µm for Em/Ev. All formulations demonstrated sustained INF release in vitro for up to 24 days, with release rates modulated by polymeric composition and microencapsulation technique. Both methods preserved INF biological activity, with microencapsulated INF showing higher efficacy than commercial formulations at comparable doses regarding bioactive tumor necrosis factor-alpha (TNF-α) neutralization according to WEHI-13VAR bioassay. Microparticles’ biocompatibility and extensive internalization by THP-1-derived macrophages was demonstrated. Furthermore, high in vitro anti-inflammatory activity was achieved after treatment of THP-1 cells with INF-loaded microcapsules, significatively reducing in vitro production of TNF-α and interleucine-6 (Il-6). Graphical Abstract

Varroa destructor is the most serious threat to honey bees worldwide. Although synthetic miticides remain the primary control method, increasing resistance and residue concerns have heightened interest in natural alternatives. Essential oils, particularly those rich in carvacrol, have shown promising acaricidal activity. However, carvacrol’s high volatility, low stability, and potential toxicity to bees limit its practical use. Microencapsulation emerges as an effective strategy to improve carvacrol stability, control its release, and reduce toxicity. In this study, carvacrol was encapsulated as the core material into core-shell microcapsules using calcium alginate and carboxymethyl cellulose as wall materials through jet-vibration technology and ionic gelation. A central composite experimental design and response surface methodology were applied to optimize CRV loading and cross-linking agen concentration. The optimized microcapsules exhibited high sphericity, a mean particle size of 3.5–4.04 mm, and an encapsulation efficiency of 88.75 ± 2.84%. In vitro release studies demonstrated a sustained, near zero-order release profile over 14 days. Cytocompatibility was confirmed in keratinocyte cells, and in vivo assays with Apis mellifera showed that encapsulated carvacrol significantly reduced bee mortality compared to free carvacrol. Overall, the developed alginate-CMC microcapsules represent a promising and safer delivery system for carvacrol-based treatments against Varroatosis in beekeeping