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Face Masks and Hand Sanitizers
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Shahzad Sharif, Mahnoor Zahid, Maham Saeed, Izaz Ahmad, M. Zia-Ul-Haq, Rizwan Ahmad
Another study focuses on the incorporation of nanostructures with the fibers to improve the strength of 3 dimensional structures. When carbon nanotubes agglomeration was done on a fluidized bed filter for the filtration of aerosols, it showed high water repellent ability with enhanced quality factor in comparison to commercial filters [84, 85]. Moreover, a polyetherimide Silica fibrous membrane showed excellent filtration capability, which was attributed to the permanent dipole moment of silica causing more charges to be trapped with better stability and adsorbing ability for viruses/pathogens [86].
Advances in Genome Editing
Published in Yashwant Pathak, Gene Delivery, 2022
A novel delivery vehicle in the form of thread-like DNA nanoclews was fabricated. In this approach, the Cas9 protein and sgRNA were integrated with DNA as a core and encased in polyetherimide. Endosomal escape is triggered by the positive charge on the polyetherimide surface, which enhances transfection efficiency (Sun et al., 2015). Besides, in another study, researchers described a novel dual-function gene carrier viz. α-helical polypeptide poly (PPABLG). With its high positive charge, PPABLG can bind Cas9 proteins and sgRNAs to form nanoparticles with the help of polyethylene glycol while maintaining its helical structure, allowing it to penetrate membranes more effectively. In vitro performance of the nanoparticles in gene editing was up to the level of 47.3 percent. Further in vivo, the nanoparticles can target and suppress the tumor growth by more than 71 percent by eliminating the Plk1 gene 66.7 percent in HeLa tumor tissues and thereby extending survival rate by 60 percent (Wang et al., 2018). Self-assembled long-circulating pH-sensitive cationic nano-liposomes were prepared for delivery of CRISPR-associated protein 9 for gene therapy in cervical cancer. CRISPR/Cas9 system efficiently repressed proliferation of human papillomavirus (HPV) 16-positive cervical tumor cells and induced programmed cell death by disabling the HR-HPV16E6/E7 oncogene (Zhen et al., 2020). In vivo genome editing of mucopolysaccharidosis I (MPS I) mice using the CRISPR/Cas9 system was investigated employing cationic liposomes as a carrier. The liposomal system was fabricated by microfluidization process by the addition of DNA at +4/−1 charge ratio. The outcome exhibited complexes of about 110 nm, with positive zeta potential of +30 mV. The incubation of the complexes with fibroblasts from MPS I patients led to a striking increase in alpha-L-iduronidase activity and decrease in lysosomal abnormalities (Schuh et al., 2018b). Lipid nanoparticles were employed for efficient genome editing with Cas9-sgRNA in vivo. Using these lipid nanoparticle formulations of these enhanced sgRNAs (e-sgRNA) and mRNA encoding Cas9, investigators proposed that a single intravenous injection into mice brings >80 percent editing of Pcsk9 in the liver. Thus, serum Pcsk9 is reduced to imperceptible levels, and cholesterol levels are suggestively dropped about 35 percent to 40 percent in animals (Yin et al., 2017). Miller and co-workers developed zwitterionic amino lipids to (co)deliver long RNAs, including Cas9 mRNA and sgRNAs. Low sgRNA doses (15 nm) delivered through nanoparticles suppress protein expression in cells by over 90 percent. In vitro (600 pM) and in vivo (1 mg/kg), mRNA delivery by zwitterionic amino lipids leads to high protein expression at modest dosages. In the liver, kidneys, and lungs of transgenic mice, intravenous co-delivery of Cas9 mRNA and sgLoxP produced floxed tdTomato expression (Miller et al., 2017). In one work, authors illustrated that by targeting the TTR or PCSK9 genes with mRNA encoding zinc finger nucleases packaged into lipid nanoparticles, the result was >90 percent knockout of gene expression in mice at mRNA concentrations 10-fold lower than previously reported (Conway et al., 2019).
Intervention of 3D printing in health care: transformation for sustainable development
Published in Expert Opinion on Drug Delivery, 2021
Sujit Kumar Debnath, Monalisha Debnath, Rohit Srivastava, Abdelwahab Omri
Immediate release polymers like Kollidon VA64 and Kollidon 12PF were found to be suitable for low-temperature FDM printing. Polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) are thermoplastic materials and are frequently used in FDM machines [42]. Newer thermoplastics such as polyether ether ketone and polyetherimide are also explored in FDM printing [43]. 3D printing scaffolds has been extensively explored in bone tissue engineering. Ceramics materials like hydroxyapatite (HA), β-tricalcium phosphate (β-TCP), α-TCP, biphasic calcium phosphates (BCP), bioactive glasses, etc. are used extensively in the preparation of 3D-printed scaffolds. However, these materials often fail to produce sufficient mechanical strength to the bone. Therefore, bio-ceramics are blended with lactose, polycaprolactone (PCL), or poly(d,l-lactic-co-glycolic acid) (PLGA). Titanium alloys are extensively used in many fields including medical implants due to their high strength-to-weight ratio, high corrosion resistance, and is biocompatible. Most of the EBM research in the biomedical field has been carried out with CP-Ti and Ti-6Al-4 V. But, these materials have some lacuna. CP-TI scaffold did not show adequate mechanical properties, whereas Ti-AL-4 V is not biocompatible [44].
3‐D printed spectacles: potential, challenges and the future
Published in Clinical and Experimental Optometry, 2020
Ling Lee, Anthea M Burnett, James G Panos, Prakash Paudel, Drew Keys, Harris M Ansari, Mitasha Yu
Material extrusion printing, also known as fused deposition modelling or fused filament fabrication involves small, fused thermoplastic beads, feed filament or eutectic metals melted into a semi‐liquid or molten state that is then dispensed from a nozzle onto a platform where the material instantly bonds to the layer below.2015 A wide range of thermoplastic materials with good mechanical strength can be used, such as polycarbonate, acrylonitrile butadiene styrene, polylactic acid, polyetherimide and nylon 12.2017 However, some of these materials also tend to be porous and are susceptible to irregularities.2017 For example, material extrusion of polycarbonate has good mechanical strength, although the end result is translucent, and therefore fails to meet the requirements for the production of spectacle lenses.
Endoplasmic reticulum stress mediates inflammatory response triggered by ultra-small superparamagnetic iron oxide nanoparticles in hepatocytes
Published in Nanotoxicology, 2018
Chengyong He, Shengwei Jiang, Huan Yao, Liyin Zhang, Chuanli Yang, Denglin Zhan, Gan Lin, Yun Zeng, Yankai Xia, Zhongning Lin, Gang Liu, Yuchun Lin
Following our previous methods (Liu et al. 2011, 2014), the USPIO- and SPIO-NPs were produced with minor modifications. After 2 mmol iron acetylacetonate, 10 mmol 1,2-hexadecanediol, 6 mmol oleic acid, and 6 mmol oleylamine were added into 20 mL benzyl ether. The mixture was heated at 300 °C for 60 min under the protection of argon gas. The iron oxide nanocrystals were then collected and mixed with stearic-alky-polyetherimide (1:3 for USPIO-NPs, 1:1 for SPIO-NPs) in chloroform. The mixed solution was slowly added into water under sonication, then vortexed for 24 h to remove chloroform. Then, the samples were subjected to centrifugation (1000 rpm, 1 min) and the supernatants were collected to remove hydrophobic iron oxide nanocrystals. The samples were dialyzed for 48 h to remove free stearic-alky-polyetherimide. The final USPIO-NPs and SPIO-NPs were free of any precursors (iron oxide nanocrystals and stearic-alky-polyetherimide). The shape and size of USPIO- and SPIO-NPs was captured by transmission electron microscope (TEM, Tecnai Spirit, FEI, USA). We further characterized their hydrodynamic size and zeta potential with a Zetasizer Nano-ZS system (Malvern, UK).