Nanofibers and Nanosurfaces

Medical implants are developed to replace the diseased or fractured hard and soft tissues. Materials scientist and clinicians initially opted for materials which exhibited high strength, non-toxic behaviour and inert as they are not any rejection by the human body. However, with time, the failures of these materials were encountered as their properties were not close to that of human tissues (Sakka and Coulthard in Med Oral Patol Oral Cir Bucal 16:e42–e44, 2011). Developing the right environment for cells to grow with the necessary biomolecules is the major focus and to achieve this scaffolds are being developed with various materials ranging from polymers to ceramics using different processes. Advancements in characterization techniques has thrown more light on the structure of human tissues and bone. Studies have shown that the unique properties of bone were attributed to its micro/nanostructures formed by the nanostructured collagen and apatite crystals (Palmer et al. in Chem Rev 108:4754–4783, 2008; Perez et al. in J Tissue Eng Regen Med 7:353–361, 2013). In order to mimic the bone, materials were modified at micro/nano level both at the bulk and surface level. Studies have also revealed that materials with nanograins have superior osseointegration capability when compared to conventional micron materials (Thakral et al. in J Clin Diagn Res 8:ZE07–ZE10, 2014). Surface characteristics such as surface chemistry, topography, roughness, stiffness and surface charge influenced the biocompatibility [Ferrari et al. in Colloids Interfaces 3:48, 2019). This understanding led to development of several nanomaterials for biomedical applications. In the case of metals, several processing techniques were developed to form nano grained materials, whereas, in polymers, various nanofibers were prepared and tested for their bioactivity. This chapter presents some of the important surface properties and their influence on the biocompatibility and describes the effect of nano versus micron surfaces on the cellular attachment.