Microbial Interactions at Nanobiotechnology Interfaces. Группа авторов

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1 Shape‐ and Size‐Dependent Antibacterial Activity of Nanomaterials

       Senthilguru Kulanthaivel and Prashant Mishra

       Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India

Objectives

1.1 Introduction

Over the past three decades “Nanotechnology” has emerged as a promising strategy to overcome impasses that have accumulated in various fields of science and technology (Albanese, Tang, & Chan, 2012). Nanomaterials (NMs) are defined as minuscule structures having at least one of their dimensions equal to or between 1 and 100 nm. Since there is no single universally accepted definition, so far various organizations have given their own definition to the term “NMs” (Boverhof et al., 2015). US Food and Drug Administration (USFDA) defines nanomaterial as “materials that have at least one dimension in the range of approximately 1–100 nm and exhibit dimension dependent phenomena” (Bleeker et al., 2012). As per Environmental Protection Agency (EPA) definition, “NMs can exhibit unique properties dissimilar than the equivalent chemical compound in a larger dimension.” Similarly, the International Organization for Standardization (ISO) defines it as “material with any external nanoscale dimension or having internal nanoscale surface structure.” EU Commission has described it as “a manufactured or natural material that possesses unbound, aggregated or agglomerated particles where external dimensions are between 1–100 nm size range” (Jeevanandam et al., 2018).

      NMs generally exist in the shape of spheres, cubes, rods, tubes, flowers, and platelets (Machado et al., 2015). NMs in the nanoscale dimensions possess a high surface area‐to‐volume ratio and also a high number of atoms/molecules present on the surface rather than the interior of the materials. These are the properties that majorly contribute to the unique functionality of the nanoscale materials, which vary from the bulk of the same material. Therefore, modulation in their structural properties such as change of size or shape will significantly affect their optical, electrical, magnetic, and biological activity (He et al., 2010; Machado et al., 2015). This is one of the distinct advantages of nanotechnology where by engineering the design or production parameters we can modulate the functionality of the NMs specific to particular application (Machado et al., 2015). Hence, the recent studies in nanotechnology are majorly focused on understanding the effect of physicochemical properties such as size, shape, and surface chemistry of the material on the optical, electrical, magnetic, and biological activities.

Considering the aforementioned advantages, NMs have found enormous applications in various fields and products such as cosmetics, catalysts, fillers, biomedical devices, and semiconductors. As per data report from 2015, approximately more than 1800 products from 622 companies in 32 countries contain engineered NMs. In summary, 762 (i.e. around 42%) of the total products are used in the health and fitness category where silver is the most predominantly used NM, in almost 435 products, which are around 24% of the total. Further, СКАЧАТЬ