Nanotechnology is the study of materials in the nanoscale. By its nature, nanotechnology is interdisciplinary. Nanotechnology has made a significant stride in recent two decades in various industries. Numerous nanomaterials are devised for biomedical applications which include intracellular tracking and labeling, gene detection and hybridization, tumor or tissue targeting, pharmaceutical therapies, pathogenic inhibiting, and medical instrument coating for disinfections. High photostability and quantum yield of fluorescent nanoparticles are ideal for long-term monitoring of molecular events in living organisms. Here, we discuss delivery of three fluorescent nanoparticles in A549 cells, rotifers, Gram-negative bacteria, Gram-positive bacteria, and archaea. As these nanoparticles cannot enter cells, arginine-rich cell-penetrating peptides (CPPs) were used to enhance their internalization at the cellular or organismal level. The 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) assay and sulforhodamine B (SRB) assay demonstrated that CPP complexed fluorescent nanoparticles did not produce lethal effect in all organisms tested. The discussion of these nanomaterials in this chapter intends to broaden our understanding of their biocompatibility in organisms of various hierarchical levels.
Part of the book: Biotechnology and Bioengineering
Copper, a reddish and ubiquitous material in the world, possesses malleable and conductive properties that render copper and its alloys indispensable in vertical integration manufacturing. With advancements in nanotechnology and nanomaterials in recent decades, copper and its related nanoparticles have been engineered. Their applications include engineering, material science, photo−/electro-catalysis, biomedical drug delivery, agriculture, and antipathogen microbicides. Here, we studied the differing toxicity effects of two sizes of copper nanoparticles (CuNPs), recognized for their potent bactericidal properties. Concentration-dependent effects of both 20 and 60 nm CuNPs were significant in Escherichia coli (E. coli), Acinetobacter baumannii (A. baumannii), and Staphylococcus aureus (S. aureus). Sodium dodecyl sulfate, the dispersant of nanoparticles, caused the synergy effects with CuNPs in A. baumannii and S. aureus but not in E. coli. Four modulators were added to CuNP-treated bacteria. By these modulator treatments, programmed cell death was found in E. coli, A. baumannii, and S. aureus. By the BLAST search, caspase-related proteins were commonly identified in gut bacteria and A. baumannii but not in S. aureus. Furthermore, many proteins from E. coli, A. baumannii, and S. aureus were found to harbor the ULK1-catalytic domain. In short, CuNPs can be potent therapeutic agents against bacterial infections.
Part of the book: Various Uses of Copper Material [Working title]