Decoration of Material Surfaces with Complex Physicochemical Signals for Biointerface Applications

The surface properties of biomaterials are crucial at controlling biological interactions. Cells or tissues sense different stimuli from surfaces and respond accordingly. A number of studies have reported that fabricating complex stimuli-presenting surfaces is beneficial for mimicking and understanding the in vivo scenario where multi-physicochemical cues are present. Biological responses toward these surfaces could be either negative, such as immune responses, or positive, such as tissue regeneration. An ideal material surface should, therefore, be multifunctional, triggering the desired biological process and suppressing the unwanted side effects. The methods for material surface decoration can be very sophisticated, depending on the applications such as biosensors, medical devices, and/or implants. To date, decorating material surfaces with complex chemistries and topographies is still challenging, and methods are not straightforward. The majority of the methods require multiple steps and combinational approaches that include mask-based techniques, lithography, wet or dry etching, wet chemistry, or vapor-based coatings, among others. Although these methods have been established in the laboratory, easy-to-access and straightforward approaches need to be explored. This Review summarizes the state-of-the-art techniques for generating patterned multichemical and multitopographic signals on material surfaces, and the potential of having these surfaces in biointerface applications.