Investigations among marine animals showed that sharks stay totally free of any microorganism attachment, hence completely immune from microbial infections. Further research revealed that sharkskin reduces drag force due to its surface micro-structure which led to some speculations among scientists that the unique morphology might be responsible for the prevention of microorganism attachment. Herein we have investigated the biological properties of sharkskin morphology by mimicking its surface micro-topography onto polymeric membranes. We aimed to understand the antibacterial properties of sharkskin mimicked micro-patterned polymeric membranes and the underlying mechanisms. Among commonly used polymers, Chitosan (CH) was chosen due to its potentials for mimicking micro and nano-structures along with its excellent biological properties. Caffeic Acid Phenethyl Ester (C) and Ampicillin Sodium Salt (A) were used as model antibacterial agents in the form of composite.
For mechanical characterization, Elongation at break and Tensile Strength tests were conducted. As for physicochemical properties, swelling test, water contact angle (WCA), Fourier-transform infrared spectroscopy (FTIR), and X-Ray Photoelectron Spectroscopy (XPS) were used. Our results have shown significant differences in mechanical properties, swelling ratio, and water contact angle among experimental groups. Therefore, in vitro experiments were conducted as well in order to evaluate cellular responses of mammalian cells along with bactericidal properties using Human Keratinocyte cell lines as model cell line and Gram-positive Staphylococcus aureus bacterial strain as model bacteria.
Obtained results of this study so far revealed that sharkskin polymeric membranes have indeed potentials for reducing bacterial biofilm formation most probably via preventing bacterial adhesion.