Nanotextured Hemophobic Surfaces

E. Loth, M.B. Lawrence
University of Virginia, US

Keywords: blood repellency surface

Summary:

This study investigates a new concept for medical surfaces called “hemophobicity”, i.e. surface coatings that are blood repellent. Over the past decade, surface modification technology platforms have advanced significantly to improve the functionality of medical devices. Efforts to reduce contamination through wettability has led to a transition from stainless steel to surfaces that have higher contact angles, e.g. Teflon which is water-repellant, i.e. “hydrophobic”. However, Teflon is complex to sterilize and is shown in this study to not be blood repellent. Thus, development of durable, strerilizable “homophobic” coatings may represent an important goal for the medical devices industry. To focus on the protein aspects, blood and plasma samples with an anti-clotting agent were investigated in terms of their dynamic wetting angles using free droplets deposited on various surfaces. It can be seen that the superhydrophobic nanocomposite coatings based on an inexpensive polymer self-assembly provide high degree of blood repellency. Additional work showed that once there is significant air exposure starts, a gel-like protein skin forms on the surface which does not degrade the static contact angle but rapidly degrade the dynamic angles.