Silk fibroin nanoparticles for celecoxib and curcumin delivery: ROS-scavenging and anti-inflammatory activities in an in vitro model of osteoarthritis

This paper aims at demonstrating silk fibroin nanoparticles (SFNs) promote anti-inflammatory properties of celecoxib (CXB) or curcumin (CUR), and could be exploited for osteoarthritis (OA) treatment. Nanoparticles were prepared by desolvation method and physico-chemically characterized (FT-IR, DSC, TGA, SEM, size distribution and drug release); empty and drug loaded nanoparticles were tested for their ROS-scavenging activity, hemolytic properties, cytotoxicity, and anti-inflammatory potency in an OA in vitro model. Results indicate that a controlled drug release has been achieved by varying the drug loading. Curcumin plus SFNs exhibited a synergistic antioxidant effect, while CXB was, in some manner, inhibitory. Both free drugs resulted highly cytotoxic while cell viability reached high values when encapsulated in SFNs. No appreciable differences in anti-inflammatory activity was evidenced between CUR loaded SFNs and CXB. In conclusion, SFNs is an optimal carrier to improve cyto- and hemo-compatibility of both CUR and CXB.