Enhanced ciprofloxacin release and antibacterial activity of composite bone cement beads for diabetic pedal osteomyelitis treatment

Abstract

Pedal osteomyelitis is an infection of the bone that is common in diabetic patients owing to the poor infection control rate where polymicrobial infections are harboured. The current treatment is complete debridement of the infected area followed intravenous antibiotics which are required in high doses although only a minute fraction reaches the local area. The biomaterials being used for the delivery of antibiotics are PMMA and calcium sulfate cement but shows drawback of non-biodegradable polymer not aiding in bone regeneration. The barrier to using calcium sulfate cement bead is quick resorption and needing a binder to control the elution of the drug in a sustained manner. In view of circumventing these constraints, we prepared a composite bone cement bead (BC) using tetracalcium phosphate, phosphoserine with ciprofloxacin (C) a broad-spectrum antibiotic and gelatin (G) (BCCG) for enhancing bone cement resorption, drug release and antibacterial activity. The prepared bone cement beads were characterized using SEM, FTIR and XRD. In vitro drug release study for 75 days was conducted where BCCG-4°% bead had shown enhanced drug release rate as compared with that of BCCG-2°% and BCC beads. The antibacterial activity of the prepared beads was done against E. coli and S. aureus for 56 days and results showcased that BCCG-4°% group had higher zone of inhibition when compared with BCCG-2°% and BCC beads. The BCC, BCCG-2°% and BCCG-4°% beads were potentially inhibiting the biofilm formation and effectively inhibited bacteria in ex-vivo studies, where there was maximum reduction in bacteria in BCCG-4°% group owing to the higher drug release rate. BC, BCC, BCCG-2°% and BCCG-4°% were biocompatible in rMSC and they adhered to the bead surface showing its high viability and attachment. Thus, the developed antibacterial bone cement can be a novel utilisable outlook for the therapy of pedal osteomyelitis.