Laser processing of protein films as a method for accomplishment of cell patterning at the microscale

Surface patterning techniques for proteins on nano- and micro-systems: a modulated aspect in hierarchical structures

The surface patterning of protein using fabrication or the external functionalization of structures demonstrates various applications in the biomedical field for bioengineering, biosensing and antifouling. This review article offers an outline of the existing advances in protein patterning technology with a special emphasis on the current physical and physicochemical methods, including stencil patterning, trap- and droplet-based microfluidics, and chemical modification of surfaces via photolithography, microcontact printing and scanning probe nanolithography. Different approaches are applied for the biological studies of recent trends for single-protein patterning technology, such as robotic printing, stencil printing and colloidal lithography, wherein the concepts of physical confinement, electrostatic and capillary forces, as well as dielectrophoretics, are summarised to understand the design approaches. Photochemical alterations with diazirine, nitrobenzyl and aryl azide functional groups for the implication of modified substrates, such as self-assembled monolayers functionalized with amino silanes, organosilanes and alkanethiols on gold surfaces, as well as topographical effects of patterning techniques for protein functionalization and orientation, are discussed. Analytical methods for the evaluation of protein functionality are also mentioned. Regarding their selectivity, protein pattering methods will be readily used to fabricate modified surfaces and target-specific delivery systems for the transportation of macromolecules such as streptavidin, and albumin. Future applications of patterning techniques include high-throughput screening, the evaluation of intracellular interactions, accurate screening and personalized treatments.

Biofabrication for neural tissue engineering applications

Unlike other tissue types, the nervous tissue extends to a wide and complex environment that provides a plurality of different biochemical and topological stimuli, which in turn defines the advanced functions of that tissue. As a consequence of such complexity, the traditional transplantation therapeutic methods are quite ineffective; therefore, the restoration of peripheral and central nervous system injuries has been a continuous scientific challenge. Tissue engineering and regenerative medicine in the nervous system have provided new alternative medical approaches. These methods use external biomaterial supports, known as scaffolds, to create platforms for the cells to migrate to the injury site and repair the tissue. The challenge in neural tissue engineering (NTE) remains the fabrication of scaffolds with precisely controlled, tunable topography, biochemical cues, and surface energy, capable of directing and controlling the function of neuronal cells toward the recovery from neurological disorders and injuries. At the same time, it has been shown that NTE provides the potential to model neurological diseases in vitro, mainly via lab-on-a-chip systems, especially in cases for which it is difficult to obtain suitable animal models. As a consequence of the intense research activity in the field, a variety of synthetic approaches and 3D fabrication methods have been developed for the fabrication of NTE scaffolds, including soft lithography and self-assembly, as well as subtractive (top-down) and additive (bottom-up) manufacturing. This article aims at reviewing the existing research effort in the rapidly growing field related to the development of biomaterial scaffolds and lab-on-a-chip systems for NTE applications. Besides presenting recent advances achieved by NTE strategies, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.