Role of mesoporous silica nanoparticles in combating mercury-induced stress in Vigna radiata (mung bean) and Bacillus coagulans (soil bacteria)

The last few decades have witnessed a dramatic progress of human civilization via industrialization, which, in turn, is associated with a surge in pollution of the environment. Heavy metals being one of the most hazardous pollutants have posed a serious threat to life sustaining ecosystem. Among the various remediation techniques, presently, the use of nanoparticles as adsorbents and chelator of heavy metal ions has emerged being practical and cost effective. Mesoporous silica nanoparticles, due to its unique structural attributes, have found application in adsorption of heavy metals in solutions. This study encompasses elucidation of the role of mesoporous silica nanoparticles MCM 41 and MCM 48 in mitigating stress caused by toxic dose of heavy metal Hg2+ (25 ppm) on growing seedlings of Vigna radiata and probiotic soil bacteria Bacillus coagulans. The results revealed that application of the nanoparticles at specific concentration can stimulate an increase in growth of plantlets, decrease in the yield reactive oxygen species like superoxide anion and hydrogen peroxide, reduction of lipid peroxidation, increase in antioxidant enzyme activity in Vigna radiata, and enhancement of growth of Bacillus coagulans as compared to that of Hg2+ alone. Moreover, it was found that MCM 41 was effective at higher dosages compared to MCM 48, which indicates the structure to function relationship.

A comparative study on the modulatory role of mesoporous silica nanoparticles MCM 41 and MCM 48 on growth and metabolism of dicot Vigna radiata

With the advent of nanoscience, nanotechnology and their applications in various fields, mesoporous silica nanoparticles have gained popularity due to their stability, biocompatibility, unique honeycomb-like structures - ordered and random by nature, large surface to volume ratio, porosity, active surfaces, high loading capacity, ease of interactions with solvent, solute and suspended particles. These multitudes of intrinsic properties have motivated us towards an interdisciplinary detailed study on applications of mesoporous silica with an intention in increasing efficacy of productivity, growth if any, in plant life. This study aims at finding modus operandi of the structural uniqueness and eccentricity of various types of mesoporous silica in maneuvering their own functionality as a potential regulator for growth of seedlings of model plant Vigna radiata. We undertook characterization of surface, morphology, epitome of porosity for MCM 41 and MCM 48 using various experimental techniques followed by application of the same to growing seedlings at various dosages. It turned out that mesoporous silica nanoparticles, inarguably have higher efficacy in promoting plant growth, reducing stress, and enhancing basic metabolic rates at optimum dosage. Optimal operation point was determined at effective dosages for MCM 41 and MCM 48 those are being much lower than that of conventional silica nanoparticles. This optimum dosage is attributed to the structures of the nanoparticles used and implied further that higher pore volume, higher surface to volume ratio in case of MCM 41 at higher dosage lead to better adsorption of ions and functionality in contrast to that of MCM 48.

Novel Drug and Gene Delivery System and Imaging Agent Based on Marine Diatom Biosilica Nanoparticles

Mesoporous silica nanoparticles (MSNs) have great potential for applications as a drug delivery system (DDS) due to their unique properties such as large pore size, high surface area, biocompatibility, biodegradability, and stable aqueous dispersion. The MSN-mediated DDS can carry chemotherapeutic agents, optical sensors, photothermal agents, short interfering RNA (siRNA), and gene therapeutic agents. The MSN-assisted imaging techniques are applicable in cancer diagnosis. However, their synthesis via a chemical route requires toxic chemicals and is challenging, time-consuming, and energy-intensive, making the process expensive and non-viable. Fortunately, nature has provided a viable alternative material in the form of biosilica from marine resources. In this review, the applications of biosilica nanoparticles synthesized from marine diatoms in the field of drug delivery, biosensing, imaging agents, and regenerative medicine, are highlighted. Insights into the use of biosilica in the field of DDSs are elaborated, with a focus on different strategies to improve the physico-chemical properties with regards to drug loading and release efficiency, targeted delivery, and site-specific binding capacity by surface functionalization. The limitations, as well as the future scope to develop them as potential drug delivery vehicles and imaging agents, in the overall therapeutic management, are discussed.