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Even though activated carbon fiber (ACF) filters have been widely used in air cleaning for the removal of hazardous gaseous pollutants, because of their extended surface area and high adsorption capacity, bacteria may breed on the ACF filters as a result of their good biocompatibility; ACF filters can themselves become a source of bioaerosols. In this study, silver particles were coated onto an ACF filter, using an electroless deposition method and their efficacy for bioaerosol removal was tested. First, various surface analyses, including scanning electron microscopy, inductively coupled plasma and X-ray diffraction were carried out to characterize the prepared ACF filters. Filtration and antimicrobial tests were then performed on the filters. The results showed that the silver-deposited ACF filters were effective for the removal of bioaerosols by inhibition of the survival of microorganisms, whereas pristine ACF filters were not. Two bacteria, Bacillus subtilis and Escherichia coli, were completely inhibited within 10 and 60 min, respectively. Electroless silver deposition did not influence the physical characteristics of ACF filters such as pressure drop and filtration efficiency. The gas adsorptive ability of the silver-deposited ACF filter, as represented by the micropore specific surface area, decreased by about 20% compared to the pristine filter because of the blockage of the ACF micropores by silver particles. Therefore, the amount of silver particles on the ACF filters needs to be optimized to avoid excessive reduction of their adsorptive characteristics and to show effective antimicrobial activity.

Because of their extraordinary physical properties and biocompatibility, black phosphorus (BP) nanosheets (NSs) have been intensively employed in chemo-phototherapies, such as plasmonic inorganic nanoparticles or graphene NSs, over the past few years. However, most biomedical studies using BP NSs are only concerned with the optical property of BP NSs to repeatedly demonstrate chemo-phototherapeutic efficacies, although BP NSs have different properties from inorganic nanoparticles or graphene NSs, such as corrugated crystal structure, hydrophilicity, and biodegradability. Moreover, it is still a challenging issue to efficiently fabricate uniform BP NSs for clinical translation because of the top-down nature of fabrication, despite the easy preparation of coarse BP flakes. It is thus essential to explore their most suitable bioapplications as well as suggest an easy-to-access strategy to produce uniform BP NSs for realization as advanced therapeutic materials. To rationalize these issues, this report introduces a plug-and-play nanorization, ultrasonic bubble bursting, of coarse BP flakes for continuous BP NS production, and the resulting uniform NSs (∼40 nm lateral dimension, ∼0.15 polydispersity index) were used as base materials to load drug (doxorubicin), targeting agent (chitosan-polyethylene glycol), and cancer growth inhibitor (programmed death ligand 1 and small interfering RNA) for achieving efficacious chemo-photoimmunotherapy of colorectal cancer.

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A polyol synthesis of silver nanoparticles in the presence of ultrasonic irradiation was compared with other configurations (at ambient temperature, 120° C, and 120 °C with injected solutions) in the absence of ultrasonic irradiation in order to obtain systematic results for morphology and size distribution. For applying ultrasonic irradiation, rather fine and uniform spherical silver particles (21±3.7 nm) were obtained in a simple (at ambient temperature without mechanical stirring) and fast (within 4 min, 3.61×10(-3) mol min(-1)) manner than other cases (at ambient temperature (for 8 h, 0.03×10(-3) mol min(-1)): 86±16.8 nm, 120 °C (for 12 min, 1.16×10(-3) mol min(-1)): 64±14.9 nm, and 120 °C with injected solutions (during 12 min): 35±6.8 nm; all other cases contained anisotropic shaped particles). Even though the temperature of polyol reaction reached only at 80 °C (<120 °C) in the presence of ultrasonic irradiation, a uniform mixing (i.e. enhanced collision between silver particle and surrounding components) by ultrasonic irradiation might induce a better formation kinetics and morphological uniformity.

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Several novel nanoparticle composites were conveniently obtained by appropriately reacting freshly produced aerosol metal nanoparticles with soluble organic components. A serial reactor consisting of a spark particle generator coupled to a collison atomizer was used to fabricate the new materials, which included nanomagnetosols (comprising iron nanoparticles, the drug ketoprofen, and a Eudragit shell), hybrid nanogels (comprising iron nanoparticles and an N-isopropylacrylamide, NIPAM, gel), and nanoinorganics (gold immobilized silica). A fourth hybrid material, consisting of iron-gold nanoparticles and NIPAM) was obtained via an aerosol into liquid configuration, in which aerosol iron-gold particles were collected into a NIPAM/ethanol solution and then formed into nanogels with NIPAM under ultrasonic treatment. The strategy outlined in this work is potentially generalizable as a new platform for creating biocompatible nanocomposites, using only clinically approved starting materials in a single pass and under low-temperature conditions.