Biomimetic sharkskin surfaces with antibacterial, cytocompatible, and drug delivery properties

Highlights: • Sharkskin topography regulates the rate of drug release via the swelling ratio. • Sharkskin topography considerably reduced bacterial biofilm formation. • 2.5 mg mL^-1 Amp together with 500 μM CAPE content yielded maximum antibacterial effect and minimum cell cytotoxicity. • The combination of CAPE and Amp with sharkskin surface topography resulted in the effective delivery of high doses of the drugs. Fighting with the infection is one of the most challenging and costly burdens of the healthcare system. Several types of antibiotics and antibacterial agents have been designed and used in combating this dilemma. Nevertheless, the overuse of drugs and the difficulties of proper delivery have led to the development of drug-resistance in many species of bacteria which has reduced the efficacy of antibiotics. Furthermore, localized delivery of these drugs can be more effective in eliminating biomaterial surface-associated infection compared to systemic administration. This type of infection occurs mostly by the formation of a bacterial biofilm layer on the surface of the implantable biomaterial which is the interface between the biomaterial and the tissue. Sharkskin topography is known for its antibacterial properties due to its unique pattern. Herein, antibacterial properties and drug release potentials of sharkskin mimicked chitosan membranes are investigated with the aim of studying the impact of this topography in reducing bacterial biofilm formation on drug-loaded polymeric membranes. Ampicillin sodium salt and caffeic acid phenethyl ester (CAPE) loaded chitosan (CH) membranes were fabricated. Gram-positive Staphylococcus aureus bacteria strain is used in antibacterial experiments, and human dermal fibroblast (HDFa) and keratinocyte (HaCaT) cells were used as model cell lines in cytocompatibility tests. Drug release, bacterial biofilm growth, and swelling ratio test results show the superiority of sharkskin topography in controlling the rate of drug release as well as considerably reducing bacterial biofilm formation. Furthermore, it was established that 2.5 mg mL⁻¹ Amp content along with 500 μM CAPE yield in maximum antibacterial effect while not having cytotoxic effects on mammalian cells. Fabricated sharkskin mimicked drug-loaded membrane, which utilizes the combination of antibacterial compounds and antibacterial surface topography, also acts as an effective carrier for high concentrations of drugs.