The novel coronavirus, known as 2019-nCoV or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused an epidemic with high mortality and morbidity since December 2019, in Wuhan, China. The infection has now been transmitted to more than 210 countries worldwide and caused more than 200,000 deaths. Similar to other coronaviruses such as Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV), SARS-CoV-2 appears to less commonly affect pediatrics and to cause less severe disease along with fewer symptoms compared to adults. Available data suggest that the pediatric population is just as likely as adults to become infected with SARS-CoV-2. However, they may be asymptotic or have milder symptoms than adults; they can be potential carriers of the disease. This article reviews the present understanding of SARS-CoV-2 infection in the pediatric age group in comparison with MERS-CoV and SARS-CoV.

Purpose Organoids are three-dimensional cultures of stem cells in an environment similar to the body’s extracellular matrix. This is also a novel development in the realm of regenerative medicine. Stem cells can begin to develop into 3D structures by modifying signaling pathways. To form organoids, stem cells are transplanted into the extracellular matrix. Organoids have provided the required technologies to reproduce human tissues. As a result, it might be used in place of animal models in scientific study. The key goals of these investigations are research into viral and genetic illnesses, malignancies, and extracellular vesicles, pharmaceutical discovery, and organ transplantation. Organoids can help pave the road for precision medicine through genetic editing, pharmaceutical development, and cell therapy. Methods PubMed, Google Scholar, and Scopus were used to search for all relevant papers written in English (1907–2021). The study abstracts were scrutinized. Studies on the use of stem-cell-derived organoids in regenerative medicine, organoids as 3D culture models for EVs analysis, and organoids for precision medicine were included. Articles with other irrelevant aims, meetings, letters, commentaries, congress and conference abstracts, and articles with no available full texts were excluded. Results According to the included studies, organoids have various origins, types, and applications in regenerative and precision medicine, as well as an important role in studying extracellular vesicles. Conclusion Organoids are considered a bridge that connects preclinical studies to clinical ones. However, the lack of a standardized protocol and other barriers addressed in this review, hinder the vast use of this technology. Lay Summary Organoids are 3D stem cell propagations in biological or synthetic scaffolds that mimic ECM to allow intercellular or matrix-cellular crosstalk. Because these structures are similar to organs in the body, they can be used as research models. Organoids are medicine’s future hope for organ transplantation, tumor biobank formation, and the development of precision medicine. Organoid models can be used to study cell-to-cell interactions as well as effective factors like inflammation and aging. Bioengineering technologies are also used to define the size, shape, and composition of organoids before transforming them into precise structures. Finally, the importance of organoid applications in regenerative medicine has opened a new window for a better understanding of biological research, as discussed in this study.

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Osteoarthritis is the most common human joint disease in the world. It is also one of the most common skeletal muscle defects, destructive joint changes, and the leading cause of disability and reduced quality of life. Destructive changes in inflammatory joints are associated with a range of biochemical events, including the overproduction of inflammatory cytokines. Cytokines are protein compounds that play an essential role in causing and regulating inflammation. A balance between pro-inflammatory and anti-inflammatory cytokines is crucial in maintaining a stable body. In some inflammatory diseases, including osteoarthritis, the balance between these compounds is disturbed, and the balance shifts to pre-inflammatory cytokines. For this reason, researchers today are trying to find an effective way to reduce inflammation and treat osteoarthritis by using certain compounds. Current treatments for osteoarthritis, including nonsteroidal anti-inflammatory drugs, glucocorticoids, and hyaluronic acid, are mainly based on reducing pain and inflammation. However, they have limited effects in controlling symptoms and improving the patient's quality of life. Also, due to the high level of side effects, synthetic drugs have led to the identification of compounds of natural origin to give patients a chance to use painkillers and anti-inflammatory drugs with fewer side effects. This review study aimed to present the role of quercetin as a natural compound in reducing the expression of pro-inflammatory cytokines in osteoarthritis. This study also discusses the relationship between inflammation and cartilage destruction and other inflammation-related factors caused by cytokines.