New approach to electron microscopy imaging of gel nanocomposites in situ

New Avenues for Capturing Mineralization Events at Biomaterial Interfaces with Liquid-Transmission Electron Microscopy

Liquid-transmission electron microscopy (liquid-TEM) provides exciting potential for capturing mineralization events at biomaterial interfaces, though it is largely unexplored. To address this, we established a unique approach to visualize calcium phosphate (CaP)-titanium (Ti) interfacial mineralization events by combining the nanofabrication of Ti lamellae by focused ion beam with in situ liquid-TEM. Multiphasic CaP particles were observed to nucleate, adhere, and form different assemblies onto and adjacent to Ti lamellae. Here, we discuss new approaches for exploring the interaction between biomaterials and liquids at the nanoscale. Driving this technology is crucial for understanding and controlling biomineralization to improve implant osseointegration and direct new pathways for mineralized tissue disease treatment in the future.

Green Synthesis of Metallic Nanoparticles and Their Prospective Biotechnological Applications: an Overview

The green synthesis of nanoparticles (NPs) using living cells is a promising and novelty tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs; however, biological methods are preferred due to its eco-friendly, clean, safe, cost-effective, easy, and effective sources for high productivity and purity. High pressure or temperature is not required for the green synthesis of NPs, and the use of toxic and hazardous substances and the addition of external reducing, stabilizing, or capping agents are avoided. Intra- or extracellular biosynthesis of NPs can be achieved by numerous biological entities including bacteria, fungi, yeast, algae, actinomycetes, and plant extracts. Recently, numerous methods are used to increase the productivity of nanoparticles with variable size, shape, and stability. The different mechanical, optical, magnetic, and chemical properties of NPs have been related to their shape, size, surface charge, and surface area. Detection and characterization of biosynthesized NPs are conducted using different techniques such as UV-vis spectroscopy, FT-IR, TEM, SEM, AFM, DLS, XRD, zeta potential analyses, etc. NPs synthesized by the green approach can be incorporated into different biotechnological fields as antimicrobial, antitumor, and antioxidant agents; as a control for phytopathogens; and as bioremediative factors, and they are also used in the food and textile industries, in smart agriculture, and in wastewater treatment. This review will address biological entities that can be used for the green synthesis of NPs and their prospects for biotechnological applications.