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Photocatalytic Inactivation of Pathogenic Viruses Using Metal Oxide and Carbon-Based Nanoparticles
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Lan Ching Sim, Wei Qing Wee, Shien Yoong Siow, Kah Hon Leong, Jit Jang Ng, Pichiah Saravanan
Woo et al. (2012) designed a microwave-irradiation-assisted filtration system to inactivate viral aerosols, which can reach a high inactivation efficiency of around 5-log. Xia et al. (2019) demonstrated the efficacy of nonthermal plasma (NTP) against MS2 virus using a packed bed nonthermal plasma reactor. Approximately 2.3-log virus was reduced in which ~2-log of the MS2 inactivated and ~0.35-log physically removed in the packed bed. Wigginton et al. (2012) used five different disinfectants, such as free chlorine (FC), heat, UV irradiation, singlet oxygen, and chlorine dioxide (ClO2), to inactivate MS2 virus. They found that each treatment method resulted in a unique inactivation mechanism. For example, ClO2 or heat treatments may be suitable for inactivating double-stranded DNA viruses with genome repair mechanisms. UV treatment was more effective for inactivating single-stranded RNA viruses without genome repair mechanisms. Nonthermal plasma (NTP) produces chemically active species, such as atomic oxygen, hydroxyl radicals, and ozone, to remove bioaerosol. However, the production of toxic byproduct, such as CO, O3, NOX and aerosol particles, restricts its application (Yu et al. 2009). Other conventional methods like UV irradiation, thermal treatment, and microwave irradiation are not practical because they require high energy consumption. Therefore, heterogeneous photocatalysis has recently emerged as an alternative technology to the current viral inactivation since the foremost discovery by Sjogren and Sierka (1994).
Ecology
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
Recently, the phage MS2 contributed to the generation of novel microorganism aerosol collectors (Lin XT et al. 2018; Pan M et al. 2018, 2019a,b; Yu et al. 2018). Schaeffer et al. (2018) used the phage MS2 to achieve the detection of viruses from bioaerosols using anion exchange resin. Concerning the inactivation of the aerosolized viruses, the phage MS2 served as a model for approaches using (i) vacuum UV photocatalysis for a flowthrough indoor air purifier with short irradiation time (Kim J and Jang 2018), (ii) noncontact ultrasonic transducer bound in high-efficiency particulate air (HEPA), filters (Versoza et al. 2018), and (iii) a packed bed nonthermal plasma reactor (Xia et al. 2019).
Human Noroviruses
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
G. Sanchez, W. Randazzo, D.H. D'Souza
Atmospheric pressure plasma (APP) uses a neutral ionized gas that comprises highly reactive species including positive and negative ions, free radicals, electrons, excited or nonexcited molecules, and photons.161 Some information is available about effect of nonthermal plasma against viral pathogen including norovirus (reviewed by Pradeep and Chulkyoon162). Recently, Ahlfeld et al.163 investigated the impact of cold APP (CAPP) on HNoVGII.4 inactivation showing that increased plasma treatment times led to decreased copy numbers of HNoV in inoculated surfaces. Similarly, Aboubakr et al.164 investigated the virucidal activity of cold atmospheric gaseous plasma (CGP) against FCV-F9, reporting that factors such as the plasma generation power, the exposure time and distance, the plasma feed gas mixture, and the virus suspension medium deeply affect the inactivation results. They also reported that virus titer reduction increased with increasing exposure time and decreasing exposure distance. They postulated that the production of reactive oxygen and nitrogen species in the solution appeared to oxidize the viral capsid proteins and thus inactivate the virus.165 Alshraiedeh et al.166 investigated an atmospheric pressure, nonthermal plasma jet operating at varying helium/oxygen feed gas concentrations that exhibited a rapid virucidal activity against MS2 bacteriophage (reduction of 3 log after 3 minutes and more than 7 log after 9 minutes). A comparative study with FCV-F9, MNV-1, and bacteriophage MS2 was performed by treating with nonthermal plasma on stainless steel surfaces, with a sensitivity range as FCV-F9 > MS2 > MNV-1.167 The effect of APP jets against MNV-1 in fresh meats was recently reported by Bae et al.168 showing that 5 minutes of APP jet treatment was effective in >99% reduction of virus titer without changes in meat quality. Dielectric barrier discharge atmospheric cold plasma was reported to inhibit only 0.7 log of TV in packaged lettuce, with a decreased inactivation effect in reduced-oxygen MAP conditions.169
Current advances in nanocarriers for biomedical research and their applications
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
George Kerry Rout, Han-Seung Shin, Sushanto Gouda, Sabuj Sahoo, Gitishree Das, Leonardo Fernandes Fraceto, Jayanta Kumar Patra
There are several methods for fabricating silic-based nanoparticulated systems, which includes different etching techniques such as electrochemical, stain, photochemical, gas, vapor, spark, induced etching and a recent emerging technique of thermal and nonthermal plasma-induced syntheses. They are generally achieved through variation in current density, electrolyte concentration, concentration of dopant (p-type or n-type) and crystalline orientation of silica wafer [22] Silica NPs consists of micropores (<2 nm), mesopores (2–50 nm) and macropores (>50 nm). Characteristic features of silica NPs such as specific size, volume, distribution and high surface tolerability to silanol functionalization are some of the other modifiable features that immensely contribute to their current efficiency and applicability [20]. Apart from their application in diagnostics and treatment of different diseases, the ability of silica-based DDSs to carry different drugs/therapeutic agents of biological origin as phytochemicals could be another application area where researches are lacking behind and need subsequent attention in near future.