Microbial Nano-Factories: Synthesis and Biomedical Applications

Abstract

In the recent times, nanomaterials have emerged in the field of biology, medicine, electronics, and agriculture due to their immense applications. Owing to their nanoscale sizes, they present large surface/volume ratio, characteristic structures, and similar dimensions to biomolecules resulting in unique properties for biomedical applications. The chemical and physical methods to synthesize nanoparticles have their own limitations which can be overcome using biological methods for the synthesis. Moreover, through the biogenic synthesis route, the usage of microorganisms has offered a reliable, sustainable, safe, and environmental friendly technique for nanosynthesis. Bacterial, algal, fungal, and yeast cells are known to transport metals from their environment and convert them to elemental nanoparticle forms which are either accumulated or secreted. Additionally, robust nanocarriers have also been developed using viruses. In order to prevent aggregation and promote stabilization of the nanoparticles, capping agents are often secreted during biosynthesis. Microbial nanoparticles find biomedical applications in rapid diagnostics, imaging, biopharmaceuticals, drug delivery systems, antimicrobials, biomaterials for tissue regeneration as well as biosensors. The major challenges in therapeutic applications of microbial nanoparticles include biocompatibility, bioavailability, stability, degradation in the gastro-intestinal tract, and immune response. Thus, the current review article is focused on the microbe-mediated synthesis of various nanoparticles, the different microbial strains explored for such synthesis along with their current and future biomedical applications.

Antibacterial, Antifungal, and Antioxidant Activities of Silver Nanoparticles Biosynthesized from Bauhinia tomentosa Linn

“…We inferred from molecular modeling and docking studies that the biosynthesized AgNPs can effectively bind to microbes and act as antimicrobial agents (Figure 11) [66,70,99]. Thus, the use of B. tomentosa Linn extracts for the synthesis of biomedically important AgNPs therefore has several advantages, since the environmentally friendly synthesis provides stable and highly effective AgNPs with a highly effective redox potential for highly effective antimicrobial activity and possible biomedical applications (Figure 12) [7,34,41,[43][44][45][46][47].…”

“…Thus, the use of B. tomentosa Linn extracts for the synthesis of biomedically important AgNPs therefore has several advantages, since the environmentally friendly synthesis provides stable and highly effective AgNPs with a highly effective redox potential for highly effective antimicrobial activity and possible biomedical applications ( Figure 12 ) [ 7 , 34 , 41 , 43 , 44 , 45 , 46 , 47 ].…”

“…Additionally, its extracts contain a diverse set of metabolites that could be possibly used in the reduction of silver ions, as a capping and stabilizing agent in the synthesis of nanoparticles [ 35 , 40 , 41 , 42 ]. Biological synthetic methods can produce AgNPs that are frequently more stable and less toxic than nanoparticles obtained using conventional methods [ 7 , 34 , 41 , 43 , 44 , 45 , 46 , 47 ]. The surface of green synthesized AgNPs has strong bioactive antioxidant and antimicrobial activity [ 34 ].…”

Recent Trends and Advances of Co3O4 Nanoparticles in Environmental Remediation of Bacteria in Wastewater

“…These specific methods fall under either top-down or bottom-up approaches of synthesis. Biological methods and some chemical methods are bottom-up approaches of synthesis, and some chemical methods, particularly physical or mechanical methods, are top-down approaches of synthesis [ 29 , 31 ].…”

Mechanistic Aspects of Microbe-Mediated Nanoparticle Synthesis

“…Microorganisms such as bacteria, fungi, yeast, and algae are often favored for NP synthesis due to simpler cultivation, rapid growth rate, and their capacity to grow at atmospheric pH, temperature, and pressure conditions. Different biological agents behave differently with different metal solutions in order to form NPs (Fariq et al, 2017;Saravanan et al, 2020;Ghosh et al, 2021). Metal ions are initially trapped on the surface of the cell followed by the reduction of metal ions to NPs with the presence of enzymes synthesized by the microbes.…”