Investigating electrospun shape memory patches as Gentamicin drug delivery system

Goal of this study is to apply electrospinning technology for manufacturing polymeric drug delivery systems with thermal sensitive shape memory behaviour. The hypothesis is to obtain electrospun patches loaded with an antibiotic drug to be implanted into the human body by minimal invasive technique, as local anti-infective therapy for surgical site infections treatment. Polylactide-co-polycaprolactone 70:30 (PLLA-co-PCL 70:30) was selected as temperature responsive polymer due to its Tg° value (32-42 °C) in the range of body temperature. Gentamicin (GS) was selected because used in last-line therapy against multidrug-resistant bacteria with several side effects upon its systemic administration. After been manufactured, the electrospun patches underwent thermalshape memory thermal treatment (SMT) applying different thermal conditions and they were characterized before and after SMT by SEM, DSC, mechanical testing and antibacterial effect on S. Aureus clinical strains. The results show that shape memory property of PLLA-co-PCL 70:30 patches is maintained both after GS loading and SMT at 60 °C that did not affect both nanofiber morphology and drug release. A change in copolymer conformation due to electrospinning occurs and GS loading, as highlighted by changes in patches thermal behaviour. The matrices mechanical properties address their application to internal surgical wounds, mainly soft tissues. Patches antimicrobial effect gave promising positive results for Gentamicin-susceptible strains, including a clinical isolate.