Nano LIFE

Iron oxides are naturally occurring compounds, and several methods have been developed for generating iron oxide nanoparticles (IONPs) with a focus on precisely modulating their size and physicochemical properties. Facile synthesis approaches, narrow size distribution, ease of surface modification, tunable magnetic properties, and size-dependent elimination from blood circulation, make IONPs attractive for use in different biomedical applications. This review describes the use of IONPs for application in tissue repair and regeneration with a focus on neural and musculoskeletal tissues.

Emerging pathogens have no known therapies or vaccines and therefore can only be controlled via traditional methods of contact tracing, quarantine and isolation that require rapid and widespread testing. The most recent outbreak from an emerging pathogen is due to the highly transmissible SARS-CoV-2 virus causing COVID-19 disease, which is associated with no symptoms or mild symptoms in 80–90% of the infected individuals, while in the remainder of the patients it exhibits severe illness that can be lethal or persist for several weeks to months after infection. The first tests to diagnose infection by SARS-CoV-2 were developed soon after the genome of the virus became known, and use probes to measure viral RNA by reverse transcriptase-polymerase chain reaction (RT-PCR). These tests are highly sensitive and specific but can require several days to return results, which makes contact tracing and more generally efforts to control the spread of the infection very difficult. Furthermore, the sensitivity threshold is orders of magnitude below the viral load necessary for transmission; therefore, individuals recovering from the infection may still be have a positive test and be required to isolate unnecessarily while they are no longer infectious. Antigen tests were subsequently developed that use antibodies mostly targeted to the nucleocapsid protein of the virus. These tests are about 100 times less sensitive than RT-PCR, yes they detect viral loads that are about 1/10 that needed for transmission. Furthermore, such tests are potentially much cheaper than RT-PCR and yield results in 15 min or less. Antibody, also known as serological testing, is available and can provide useful information to understand the extent to which a population has been exposed to the virus; however, it is not a good indicator of current infection and not useful for infection control. Viral transmission models that incorporate testing and contact tracing show that infection control is much more readily achieved by increasing testing frequency than by using higher sensitivity testing. For example, compared to no testing at all, testing once every other week has a marginal benefit, while testing weekly can decrease the number of infections to 20–40%, and testing twice weekly or more can bring about a 95%$+$ reduction in infections. These lessons learned from dealing from the COVID-19 pandemic should guide future planning against potential emerging viruses.

Programmed cell death, or apoptosis, and controlled cell division, or mitosis, are two highly regulated processes in the cell cycle. A balance between apoptosis and mitosis is critical for multiple distinct states including embryonic development, immune cell activation, stem cell differentiation, tissue formation (wound healing), and tumor prevention, among others. A cell undergoing apoptosis shows a series of characteristic morphological changes similar to normal mitosis and an aberrant form of mitosis. During each of these processes, nuclear chromatin condenses, the nuclear lamina and cytoplasmic membranes disintegrate, and cells decrease in volume. The morphological resemblance among cells undergoing these processes suggests that the underlying intracellular signaling pathways influence the mitotic cell fate. In this paper, the relationship of intracellular signaling pathways, cell cycle dynamics, and apoptotic cell signaling pathways is discussed. The mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/Ras/Raf/ERK), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), Janus kinase/signal transducer and activator of transcription (JAK/STAT), wingless-related integration site (Wnt), and transforming growth factor beta (TGF-$\beta )$ are major cell signaling pathways that transmit signals from multiple cell surface receptors to transcription factors in the nucleus. The pathways are stimulated by cytokines, growth factors, and external stimuli, i.e., reactive oxygen species which induce signal transduction pathways and regulate complex processes such as cell cycle progression, cell proliferation, cellular growth, differentiation, and apoptosis. Aberrant mutations in particular genes and proteins of these pathways contribute to cancers usually by inhibiting pro-apoptotic proteins (e.g., Bak, Bax, Noxa, Puma, etc.) and stimulating antiapoptotic proteins (e.g., Bcl-2, Bcl-XL, Mcl-1, etc.). The cell cycle is regulated by intracellular signaling pathways such as the MAPK/Ras/Raf/ERK and PI3K pathways to produce the synthesis of cyclin D and other mitosis regulating proteins (Myc and Jun). Cyclin D1 binds to cyclin-dependent kinase (CDK) 4 and CDK 6 (CDK4/6) to form an effective complex, activate several substrates, and initiate the cell cycle. The prominent molecules that regulate signaling pathways in normal and cancer cells are described.

Corona virus disease or its pandemic (COVID-19), because of novel corona virus-2 (SARS-nCoV-2), has become a big challenge worldwide to discover an effective therapeutic regime for its prevention and treatment. Researchers and scientists are continuously exploring new ideas and strategies to come up with an effective treatment that can confront against the novel corona virus, but no significant results have been documented in any of the reported study up till. Neither an effective vaccine nor any antiviral therapeutic agent has been approved to treat Covid-19. In the present scenario, immunotherapy by transferring of antibody enriched convalescent sera to the infected patient seems to be one of the promising treatment approaches. This paper focuses on exploring the suitability of using CP transfusion therapy on Covid-19 patients, highlighting the risks and challenges associated with its treatment for gaining maximum clinical benefits and better treatment outcome. The findings derived from the serological assays provide a valuable information that would help to support diagnosis, treatment and prevention of SARS-CoV-2 infection.

Background: The influence of coronary atherosclerosis and related treatment drugs on acute exacerbation of chronic obstructive pulmonary disease (AECOPD) development requires in-depth study. The study investigated the effect of coronary artery calcification (CAC) and drugs for CAC on the development of AECOPD.

Methods: This retrospective clinical study recruited subjects with AECOPD from May 2017 to May 2019. All subjects performed spirometry and coronary computed tomography (CT), and were divided into three groups according to whether coronary CT revealed CAC and whether they had received oral aspirin and statins: AECOPD group, AECOPD$+$CAC nonmedication and AECOPD$+$CAC medication. The t-test and nonparametric test were used for analyzing the lung function, arterial blood gas, routine blood and lipid between groups.

Results: Compared with the AECOPD group, Lym% were significantly higher ($P=0.033$) in both the AECOPD$+$CAC nonmedication and the AECOPD$+$CAC medication. The AECOPD$+$CAC medication group also had significantly higher PaO₂ ($P<0.05$). WBC, Neu, and Neu% in the AECOPD$+$CAC medication group were significantly lower ($P<0.05$) compared to the AECOPD group.

Conclusions: Aspirin and statins for the treatment of cardiovascular diseases may be linked to improving lung function, normalizing blood gas levels, and reducing inflammation in patients with AECOPD and CAC. Further, randomized controlled trials are needed to explore this topic.