Nano LIFE

Isolation of circulating tumor cells (CTCs) from cancer patients is of high value for disease monitoring and metastasis diagnosis. Although many new detection methods have emerged in recent years, the detection of CTCs is a current challenge due to lack of specific and sensitive markers. In our previous work, cancer cell surfaces, from over 20 cancer cell lines, have been shown to be negatively-charged regardless of their phenotype by using electrically-charged nanoparticles as a probe. The strong electrostatic interaction between the negative cancer cells and positively charged nanoparticles can well remain in a physiological liquid environment in the presence of serum proteins, enabling effective binding between them. As a result, the cancer cells can be magnetically separated by employing an external magnet. In this technical report, we present preliminary results on the investigation of CTC isolation from both mimetic and clinical blood samples. We show high CTC detection sensitivity by the positively-charged magnetic nanoparticles (PMNs) even at the original concentration of 10 cells per mL mimetic blood sample. The CTCs in the peripheral blood of colorectal cancer patients were isolated and identified by cellular morphology and immunofluorescence staining.

Healthcare-associated infections are a significant concern in acute care facilities across the US. Studies have shown the importance of a hygienic patient environment in reducing the risk of such infections. This has caused an increased interest in ultraviolet (UV-C) light disinfectant technology as an adjunct technology to provide additional pathogen reduction to environmental surfaces and patient care equipment (i.e., surfaces). It is also well known that UV-C light can cause premature degradation of materials, particularly certain plastic materials. However, there is little information in the literature regarding characterizing this degradation of plastics and other materials used for surfaces in healthcare. This study aims to evaluate multiple characterization techniques and propose a systematic approach to further understand early onset degradation of plastics due to UV-C exposure. Susceptibility and modes of degradation of multiple plastic materials were compared using the techniques evaluated. Ten grades of plastic materials were exposed to UV-C light in a manner consistent with standards given in the healthcare and furniture industry to achieve disinfection. These materials were characterized for visual appearance, chemical composition, surface roughness and hardness using light microscopy, spectrophotometry, contact angle analysis, infrared spectroscopy, profilometry and nanoindentation. All characterization methods were able to identify one or more specific degradation features from UV-C exposure covering different aspects of physicochemical properties of the surfaces. However, these methods showed different sensitivity and applicability to identify the onset of surface damage. Different types of surface materials showed different susceptibility and modes to degradation upon UV-C light exposure. UV-C disinfection can cause detectable damage to various surfaces in healthcare. A characterization approach consisting of physical and chemical characterizations is proposed in quantifying surface degradation of a material from UV-C exposure to address the complexity in modes of degradation and the varied sensitivity to UV-C from different materials. Methods with high sensitivity can be used to evaluate onset of damage or early stage damage.

In this paper, the effects of the organic reducing agent and 3-aminopropyltrimethoxysilane on the synthesis and properties of mono-, bi-, and trimetallic noble metal nanoparticles were considered; the antimicrobial activity of these nanomaterials was also evaluated. It was shown that 3-aminoptopyltrimethoxysilane-treated noble metal cations undergo rapid conversion into nanoparticles in the presence of three organic reducing agents, namely, 3-glycidoxypropyltrimethoxysilane (3-GPTMS), cyclohexanone and formaldehyde; the nanoparticles were formed on the order of one minute under microwave incubation. Bimetallic nanoparticles were formed by simultaneous or sequential reduction of metal cations; the formation of trimetallic nanoparticles containing gold, silver and palladium was demonstrated using a similar approach. The nanoparticles were characterized using UV-Visible light spectrophotometry, transmission electron microscopy and zeta potential measurements. All three nanoparticles exhibited a size $\le$10nm size. The nanoparticles showed antimicrobial activity against Acinetobacter baumannii. Scanning electron microscopy imaging showed an alteration in the size and shape of nanoparticle-treated bacterium, with bleb formation and cell wall disruption observed within 1h of incubation at the MBC values of the nanoparticles. Fluorescence spectrophotometric imaging of silver nanoparticle-Acinetobacter baumannii interactions suggested selective binding of silver nanoparticles to surface proteins. Our results showed the preparation of the novel silver nanoparticles with potent Anti-Acinetobacter baumannii activity, which can serve as an alternative to conventional antimicrobial agents.

The chemical and physical synthetic strategies for the preparation of nanomaterials are time-consuming, costly and toxic. To address these issues, Phyto-assisted synthesis of nanomaterials can be considered as a promising strategy. Herein, V₂O₅ nanomaterial has been synthesized by using Azadirachta indica (Neem) leaf extract. The V₂O₅ nanomaterial was characterized by employing multiple techniques, such as UV-Vis, FTIR, XRD, FE-SEM and EDX. The results showed that V₂O₅ nanomaterial possesses nanoplate’s type morphology with 30–50nm diameters. Further, cyclic voltammetric studies showed the good durability during the voltammetric scans in 2M KCl electrolyte at 50mV/s scan rate and the V₂O₅ nanoplates may be served as a promising cathodic candidate in Li-ion secondary batteries. Moreover, the antimicrobial activity of the prepared V₂O₅ nanoplates was evaluated against the bacteria viz. S. typhi, S. aureus, B. subtilis, E. coli and fungi; F. species, A. flavus, P. triticina and A. niger by using the serial dilution method. The results suggested that V₂O₅ nanoplates possess comparable antimicrobial activity comparable to standard drug Streptomycin against the used pathogens.