It appeared that several polymorphisms in MDR transporter genes especially MDR1 have influenced the regulatory mechanisms and explained differences in glucocorticoid responses.The liver is one of the body's tissues that has regenerative abilities. But if the damage is too much, it needs to medical interventions for the regeneration. Liver donor shortage causes researchers to turn to other treatments. Tissue engineering is a new approach to liver regeneration. Hydrogels are polymeric networks of hydrophilic, flexible, and similar to natural tissue. Therefore, they are used to encapsulate cells These constructs are potent substrates to induce differentiation of stem cells to the hepatocytes. According to inadequate availability of the hepatocytes, an alternative cell is required to produce hepatocyte-like cells. Due to the self-renewal and differentiation properties of stem cells, they are suitable cell sources to replace the lostcells. This review has focused on liver regeneration, advantages and disadvantages of hydrogels for liver regeneration, injectable materials, hydrogel fabrication methods, including 3D printing, and stem cells for liver regeneration. Furthermore, this paper shows in vitro, preclinical, and clinical trial studies of hydrogel and stem cells for liver regeneration. Graphical abstract.To evaluate the public interest in rheumatic diseases during the coronavirus disease 2019 (COVID-19) pandemic. Google Trends was queried to analyze search trends in the United States for numerous rheumatic diseases and also the interest in a rheumatologist. Three 8-week periods in 2020 ((March 15-May 9), (May 10-July 4), and (July 5-August 29)) were compared to similar periods of the prior 4 years (2016-2019). Compared to a similar time period between 2016 and 2019, a significant decrease was found in the relative search volume for more than half of the search terms during the initial March 15-May 9, 2020 period. However, this trend appeared to reverse during the July 5-August 29, 2020 period where the relative volume for nearly half of the search terms were not statistically significant compared to similar periods of the prior 4 years. In addition, this period showed a significant increase in relative volume for the terms Axial spondyloarthritis, ankylosing spondylitis, psoriatic arthritis, rheumatoid arthritis, Sjögren's syndrome, antiphospholipid syndrome, scleroderma, Kawasaki disease, Anti-Neutrophil Cytoplasmic Antibody (ANCA)-associated vasculitis, and rheumatologist. There was a significant decrease in relative search volume for many rheumatic diseases between March 15 and May 9, 2020 when compared to similar periods during the prior 4 years. However, the trends reversed after the initial period ended. There was an increase in relative search for the term "rheumatologist" between July and August 2020 suggesting the need for rheumatologists during the COVID-19 pandemic. Policymakers and healthcare providers should address the informational demands on rheumatic diseases and needs for rheumatologists by the general public during pandemics like COVID-19.Rheumatoid arthritis (RA) is an inflammatory disorder characterized by progressive joint destruction. Recent studies have demonstrated that osteoclasts are responsible for bone destruction in RA. Receptor activator of nuclear factor kappa B ligand (RANKL), an osteoclast differentiation factor, belongs to the tumor necrosis factor superfamily and plays a critical role in osteoclast differentiation. RANKL is highly expressed in the synovial tissues in patients with RA and is involved in osteoclast development and thus bone destruction in RA. Denosumab, a specific antibody to human RANKL, efficiently suppressed the progression of bone destruction in patients with RA in a randomized controlled study and is considered a putative therapeutic option for RA.Periodontitis, one of the most common infectious diseases in humans, is characterized by inflammation of the periodontal tissue and subsequent destruction of the alveolar bone, which ultimately leads to tooth loss. Recently, it was revealed that the osteoclastic bone damage that occurs during periodontitis is dependent on the receptor activator of NF-kB ligand (RANKL) produced by osteoblastic cells and periodontal ligament cells. Immune cells provide essential cues for the RANKL induction that takes place during periodontal inflammation. The knowledge accumulated and experimental tools established in the field of "osteoimmunology" have made crucial contributions to a better understanding of periodontitis pathogenesis and, reciprocally, the investigation of periodontitis has provided important insights into the field. This review discusses the molecular mechanisms underlying periodontal bone loss by focusing on the osteoimmune interactions and RANKL. Osteogenesis imperfecta (OI) is a well-known heritable disorder of connective tissue characterized by skeletal fragility and low bone mass. Nearly 90% of patients with OI have disease variants in COL1A1 and COL1A2 that encode for the α1 and α2 chains of type I collagen. A retrospective analysis of 185 probands who were diagnosed with OI in Shanghai Jiao Tong University Affiliated Sixth People's Hospital from March 2005 to December 2019 was performed. A total of 140 mutations in COL1A1 and 45 mutations in COL1A2 were identified, of which 18 variations were novel. In the phenotype analysis, there were more sporadic cases than familial OI cases in China (54.6% vs. 45.4%, P < 0.001). A total of 98.9% of patients presented with a fracture history. The most common fracture sites were extremity long bones (femur, tibia-fibula and radius-ulna accounted for 36.6%, 17.1% and 11.7%, respectively). Patients with OI types III and IV, especially type III, had a higher proportion of dentinogenesis imperfecta (DI) than patients with OI type I (55% vs. 28%, P < 0.001). Interestingly, G767S and D1219N in COL1A1 and G337S in COL1A2 were the most frequent (3.52%, 2.11% and 8.89%, respectively), which seem to be hotspot mutations in the COL1A1 and COL1A2 genes in Chinese patients. This study describes the mutations in the main pathogenic genes, COL1A1 and COL1A2, and the clinical characteristics of osteogenesis imperfecta in China. Furthermore, these findings help reveal the genetic basis of Asian OI patients and contribute to genetic counselling.This study describes the mutations in the main pathogenic genes, COL1A1 and COL1A2, and the clinical characteristics of osteogenesis imperfecta in China. find more Furthermore, these findings help reveal the genetic basis of Asian OI patients and contribute to genetic counselling.