Biological applications of biomimetic superhydrophobic surfaces

Nature has long served as a source of inspiration for scientists and engineers. Inspired from lotus leaf, a variety of biomimetic surfaces with superhydrophobicity have been fabricated in recent years based on the combination of surface micro- and nanostructures and chemical compositions by using many different synthetic methods. These surfaces exhibit various significant applications in anti-icing, microfluidic systems, biocompatibility and other fields. As a special material property, superhydrophobicity has been proved to be used in biomedical and biological applications in recent years. Three-dimensional superhydrophobic materials may be become an ideal carrier for drug delivery in the near future since entrapped air within the material should act as a removable barrier component to retard drug release. Superhydrophobicity property can modulate and improve the interfacial reactions of biological entities and material surfaces. For example, platelets can hardly adhere and be activated on superhydrophobic surfaces so as to avoid the blood coagulation and thrombosis, which can be applied on manmade blood vessels, artificial organ implantations and other medical devices in contact with blood. Cell and biomolecule on the surfaces with special wettabilities, e.g. superhydrophobicity, superhydrophilicity, reversible switching between superhydrophobicity and superhydrophilicity, will show different behaviors, which have been demonstrated by the investigations of protein adsorption and cell adhesion, cell and biomolecule micropatterning, antibacterial, high-throughput screening. In this review, we briefly introduce the classical wettability models, and then focus mainly on their biological applications, including drug release, blood compatibility, protein adsorption, cell behavior, biomolecule and cell micropatterning. Finally, the prospect of biomimetic superhydrophobic surface in biological applications is also proposed.