Development of artificial enzymes with biomedical and industrial applications;Perspectives and future challenges

Natural enzymes, most of which are proteins, are catalysts that can speed up chemical reactions rate by reducing activation energy and mediated the biological processes under mild conditions. However, these biomolecules have some drawbacks including the high cost of synthesis, purification and low stability in extreme conditions of pH or temperatures for performing catalytic functions. So, due to these disadvantages and to overcome these limitations, easily synthesized, highly stable and low cost enzyme mimetic from molecules to inorganic nanomaterials have been developed. Developing many manmade enzymes (artificial enzyme mimetics), as alternatives to natural enzymes, using non-protein molecules become an interesting field for researchers. However, the disadvantages of enzyme mimetics are that the catalytic efficiency, specificity, and selectivity are relatively low. To date, many enzyme mimetics have been prepared and have activities analogous to cytochrome P۴۵۰, serine protease, dioxygenase, phosphodiesterase, lipase, acylase, ligase, hydrolase, aldolase, superoxide dismutase, and nitrile hydratases. Nanomaterials are chemical entities at least one dimension smaller than ۱۰۰ nm. With such an extremely small size and large surface area per unit of volume, nanomaterials have characteristic physical, chemical, photochemical, and biological properties that are very different from those of the same material in bulk form. Nano-based materials due to their physicochemical properties relative to bulk materials including large surface/volume ratios, optically active, mechanically strong and chemically reactive have various applications in different areas, including biosensing, catalysis, textile industry, drug delivery and water treatment. Enzyme mimetic behavior of some nanomaterials is one of the most interesting features ofthese materials which make nanomaterials as potential alternatives for natural enzymes. Nanomaterials, with enzyme mimic activities, which are called nanozymes, have gained much more attention among the researchers during the past decades because of their unique properties such as low-cost, high stability and simple preparation. Also, nanozymes have their catalytic activity even in the harsh environmental conditions of pH and temperatures. Nanoparticles’ catalytic activity and intrinsic ability in generating or scavenging reactive oxygen species (ROS) in general can be used to mimic the catalytic activity of natural enzymes. To date, many nanoparticles with enzyme-like activities have been found, potentially capable of being applied for commercial uses, such as in biosensors, pharmaceutical processes, and the food industry. The reported enzyme-like activities for nano-sized materials includes the superoxide dismutase-like (SOD like), oxidase-like, catalase-like, glucose oxidase-like and peroxidase-like activities. Also, enzyme-mimic activity of some metal-protein complexes have been reported, too. In general, artificial enzyme mimetics have been developed by using different non-proteinmolecules such as metal-complexes, metal-nanomaterials, polymeric and supramolecules.

کلیدواژه ها:

Artificial enzymes ، nanomaterials ، nanobiosensors ، enzyme mimetic acticity