Rational Design of Semiconductor Nanostructures for Functional Subcellular Interfaces

Abstract

CONSPECTUS One of the fundamental questions guiding research in the biological sciences is how cellular systems process complex physical and environmental cues and communicate with each other across multiple length scales. Importantly, aberrant signal processing in these systems can lead to diseases that can have devastating impacts on human lives. Biophysical studies in the past several decades have demonstrated that cells can respond to not only biochemical cues but also mechanical and electrical ones. Thus, the development of new materials that can both sense and modulate all of these pathways is necessary. Semiconducting nanostructures are an emerging class of discovery platforms and tools that can push the limits of our ability to modulate and sense biological behaviors for both fundamental research and clinical applications. These materials are of particular interest for interfacing with cellular systems due to their matched dimension with subcellular components (e.g., cytoskeletal filaments), and easily tunable properties in the electrical, optical and mechanical regimes. Rational design via traditional or new approaches, such as nanocasting and mesoscale chemical lithography, can allow us to control micro- and nanoscale features in nanowires to achieve new biointerfaces. Both processes endogenous to the target cell and properties of the material surface dictate the character of these interfaces. In this Account, we focus on (1) approaches for the rational design of semiconducting nanowires that exhibit unique structures for biointerfaces, (2) recent fundamental discoveries that yield robust biointerfaces at the subcellular level, (3) intracellular electrical and mechanical sensing, and (4) modulation of cellular behaviors through material topography and remote physical stimuli. In the first section, we discuss new approaches for the synthetic control of micro- and nanoscale features of these materials. In the second section, we focus on achieving biointerfaces with these rationally designed materials either intra- or extracellularly. We last delve into the use of these materials in sensing mechanical forces and electrical signals in various cellular systems as well as in instructing cellular behaviors. Future research in this area may shift the paradigm in fundamental biophysical research and biomedical applications through (1) the design and synthesis of new semiconductor-based materials and devices that interact specifically with targeted cells, (2) the clarification of many developmental, physiological, and anatomical aspects of cellular communications, (3) an understanding of how signaling between cells regulates synaptic development (e.g., information like this would offer new insight into how the nervous system works and provide new targets for the treatment of neurological diseases), (4) and the creation of new cellular materials that have the potential to open up completely new areas of application, such as in hybrid information processing systems.

High‐Aspect‐Ratio Nanostructured Surfaces as Biological Metamaterials

“…[24,46,227] The process has also been combined with atomic layer deposition to fabricate hollow nanotubes. [228] The benefit of vapor-liquid-solid growth is the large parameter space, [3] allowing a variety of complex geometries to be formed, [229,230] including more esoteric structures such as kinked nanowires. [231,232] However the process is generally limited to inorganic semiconductor materials and relatively high process temperatures, and the nature of the growth mechanism means that the orientation of nanowires is dependent upon the crystal orientation of the underlying substrate.…”

“…[1] But irrespective of their use, all of these systems are ultimately governed and mediated by the fundamental biological mechanisms occurring at the cell membrane-nanostructure interface.We highlight results that have cross-field importance and where appropriate refer to a number of excellent perspectives and other reviews relevant to each field. [1][2][3][4][5][6][7][8][9][10][11] The wide range of application areas also come with an equally large variety of fabrication and characterization approaches. Hence, this review also Materials patterned with high-aspect-ratio nanostructures have features on similar length scales to cellular components.…”

The Rise of Fiber Electronics

“…Forinvivo detection, sensing fibers efficiently penetrated into various tissues without complex surgeries or obvious damage to the film sensors.D ecades ago,m etal wires [84] were developed to detect electricity signals of neurons and monitor brain activities.They enabled important discoveries in neuroscience,r anging from the discovery of grid cells to the mapping and stimulation of the motor cortex. [86] Multifunctional and high-density recording [87,88] represents another trend of fiber sensors in vivo.W ith the advancement of optical fibers and genetic engineering,optical function was introduced to fiber probes and has boosted their optogenetic capabilities. [38] Low-modulus elastomers showing reduced mechanical mismatches with biological tissue were thus developed to obtain more stable and effective interfaces.F or example, ap olymer-based elastomeric composite with aY oungs modulus five orders of magnitude lower than that of its tungsten counterparts can be extruded.…”

On the Interaction between 1D Materials and Living Cells

“…Silicon NWs and NTs have been widely demonstrated as key materials to build-up functional interfaces for bioelectronics [ 5 , 7 , 32 , 33 , 34 , 35 , 36 , 37 ], allowing for cutting-edge applications in subcellular biointerfaces [ 37 , 38 ]. The first application of Si NWs in bioelectronics emerged in 2006 by Patolsky and co-workers, in the form of open gate Si NW field-effect transistors (FETs) to record extracellular events from rat neurons [ 39 ].…”