Surfaces and Their Interfaces Meet Biology at the Bio-interface

Surfaces and bio-interfaces have undoubtedly become a topic which signifies one of the most rapidly expanding fields that is innovative and dynamic across the disciplines from engineering to life sciences. All solid material systems have boundaries, of which the properties are different from bulk material at the nanoscale. How these ‘‘inbetween regions’’ merge into one another becomes a critical challenge, and also a fascinating question which has moved to the forefront in the development of new technologies relevant to all aspects of life, from biomedical to microelectronics to energy production. Biological materials exhibit complex structure– property relationships which exist at multiplelength scales with elegant hierarchical organization. Understanding the interface of native biological materials and harnessing these design strategies to develop biomimetic, bioinspired, and bio-enabled materials will expedite the accomplishing of functionally integrated materials. An indepth understanding of the interface remains critical in the design of the bio-interface. The design also becomes essential to developing the controlled and predictable interactions on the surfaces, a reciprocal relationship unique to the bio-interface. Surfaces and bio-interfaces are the vital components of all bio-related materials, processes, and devices which span areas as diverse as bioinspired materials, including optics and energy conversion, regenerative and restorative medicine, biosensors, diagnostics, therapeutics, and smart textiles. The papers that are selected for this ‘‘Surfaces and Bio-interfaces’’ topic of JOM capture a collection of original research papers, as well as reviews, from a distinguished group of scientists covering the synthesis, characterization, modeling and specific applications for different materials and their interest areas. The scientific challenges and opportunities are continuing to push the boundaries of our collective understanding of surfaces and bio-interfaces, and thus are bringing new ways of looking at the interface to explore the interactions between biological components and surfaces, and to understand and to develop novel bio-inspired, biomimetic, and bio-enabled materials and processes. Articles have been selected from these gifted investigators in order to bridge our fundamental understanding of soft and hard biomaterial interfaces and to bring into focus the applications which include biomedical product development and nanoto micro-fabrication systems. Contributions to the topic were published in Surfaces and Bio-interfaces: Part I in April 2015 (JOM vol. 67, no. 4), and Surfaces and Bio-interfaces: Part II in this issue. Following is a brief introduction to these papers. Publication details are in the references. The importance of biomolecule self-assembly on the solid materials has become increasingly recognized. Molecular recognition plays a critical role in biological interactions; hierarchical composite structures often found in biological materials are a result of molecular recognition where biomolecules, mainly proteins, play a crucial role. To explore this topic, we have articles which emphasize the role of peptides as the biological self-assemblers towards designing bio-materials interfaces. In designing biohybrid functional materials and surfaces, material selectivity is vital and peptides have come a long way; however, there is still a long way to go. There is a growing interest in applying peptides as materials-selective assemblers and self-organizers, but considering the boundless application opportunities of peptides in molecular technologies, their utility is still based largely on empirical understanding of solid surface binding characteristics. Adams and coworkers demonstrated a self-organized cell templating directed by a gold surfaceselective peptide interface. Controlled cell filamentation is a step towards next-generation living material interfaces. Peptides binding to gold surfaces were also investigated in Corni’s paper, in which he extends this analysis to the interplay between geometrical matching of peptide-surface features as a function of the structural flexibility. Tucker and coworkers investigated the binding of JOM, Vol. 67, No. 11, 2015