Hydrogels are crosslinked polymer chains with three-dimensional (3D) network structures, which can absorb relatively large amounts of fluid. Because of the high water content, soft structure, and porosity of hydrogels, they closely resemble living tissues. Research in recent years shows that hydrogels have been applied in various fields, such as agriculture, biomaterials, the food industry, drug delivery, tissue engineering, and regenerative medicine. Along with the underlying technology improvements of hydrogel development, hydrogels can be expected to be applied in more fields. Although not all hydrogels have good biodegradability and biocompatibility, such as synthetic hydrogels (polyvinyl alcohol, polyacrylamide, polyethylene glycol hydrogels, etc.), their biodegradability and biocompatibility can be adjusted by modification of their functional group or incorporation of natural polymers. Hence, scientists are still interested in the biomedical applications of hydrogels due to their creative adjustability for different uses. In this review, we first introduce the basic information of hydrogels, such as structure, classification, and synthesis. Then, we further describe the recent applications of hydrogels in 3D cell cultures, drug delivery, wound dressing, and tissue engineering.

Canine distemper (CD) is one of the most contagious and lethal viral diseases in dogs. Despite the widespread use of vaccines, the prevalence of the CD virus (CDV) has increased at an alarming rate in recent years. In this phylodynamic study, we investigated the spatiotemporal modes of dispersal, viral demographic trends, and effectiveness of vaccines for CDV. A total of 188 full-length CDV hemagglutinin (H) gene sequences dataset were subjected to recombination analysis, including seven from modified live vaccine (MLV) strains and 12 from Taiwan specimens. After excluding the MLV strains and potential recombinant strains, alignments of 176 of 188 previous CDV strains were further used to analyze phylodynamic characteristics, and evidence of selection, and co-evolution. The CDV genotype consisted of MLV-associated genotypes such as America-1 and Rockborn-like strains, which were characterized by long terminal branches and no distinct geographical patterns among lineages. In contrast, wild-type isolates clustered into lineages with a spatiotemporal structure and short terminal branches. Co-circulation and extensive diversification were simultaneously observed. The sequence variation signature was shaped by both geographic diversity and host tropism. Codon 506 was identified as a multi-epistatic interacting in the H protein. The topological signature revealed in this study suggests different epidemic scenarios. For example, a ladder-like backbone is a hallmark of directional selection, and cladogenesis at long terminal branches indicates the emergence of a surviving lineage. The stable effective viral population of CDV indicate the effectiveness of vaccines currently used to control the virus.

It is becoming increasingly evident that certain phytochemicals possess cancer chemopreventive properties. In this study, the antiproliferative activity of extracts from different parts of the jaboticaba (Myrciaria cauliflora) plant was evaluated for its effect on human oral carcinoma cell lines. The cytotoxicities of various plant extract concentrations were examined and the 50% maximal inhibitory concentration (IC₅₀) was determined. Water extracts of jaboticaba seeds showed concentration-dependent antiproliferative effects. Annexin V/propidium iodide positivity with active caspase-3 induction indicated that the treated cells underwent apoptosis. Several important regulatory proteins (Bcl-2, Bcl-xL, Bid, and survivin) involved in apoptosis were also evaluated. The antioxidant activity of jaboticaba was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays, and the drug concentration eliciting 50% maximum stimulation (SC₅₀) was determined. The present findings suggest that water extracts of jaboticaba seeds exhibit an antiproliferative effect against oral cancer cells by inducing apoptosis through downregulating survivin expression and thereby activating caspase-mediated Bid cleavage.

Coronavirus Disease 2019 (COVID-19) pandemic, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become the global challenge. Reaching global herd immunity will help end the COVID-19 pandemic. However, vaccine shortage and vaccine hesitancy are the obstacles to achieve global herd immunity against SARS-CoV-2. The current homologous vaccine regimen is experimentally switching to heterologous vaccination at several study sites. However, the reactogenicity of heterologous ChAdOx1-S and mRNA vaccination against SARS-CoV-2 is still unclear. We have conducted a systematic review to summarize the current findings on the safety and immunogenicity of this heterologous vaccination and elucidate their implications against SARS-CoV-2. This systematic review was conducted by the guidelines of PRISMA. Articles were searched from PubMed and other sources (MedRixv and Google scholar) starting from 1 January to 5 September 2021. The search term was heterologous ChAdOx1-S and BNT162b2 or mRNA-1273 vaccination. Our review found that participants with ChAdOx1/BNT162b2, ChAdOx1-S/mRNA-1273 or BNT162b2/ChAdOx1-S did not have the serious adverse events seen with homologous vaccination. Participants with the heterologous regimen (ChAdOx1/BNT162b2, ChAdOx1-S/mRNA-1273 or BNT162b2/ChAdOx1-S), compared with those with two doses of ChAdOx1-S, have shown a more robust immune responses against SARS-CoV-2, such as higher levels of responsive antibodies or increased numbers of spike-specific T-cells. Nevertheless, these immune responses were slightly diminished in the recipients of BNT162b2/ChAdOx1-S. Also, the safety study of heterologous ChAdOx1-S/mRNA vaccination was based on small populations. Further studies to enclose diverse categories, such as race/ethnicity or geography, may be necessary. Overall, the heterologous immunization with ChAdOX1-S and the mRNA vaccine may improve the vaccine shortage related slow pace of reaching herd immunity, especially using the heterologous immunization with ChAdOx1-S/BNT162b2.

Chloroquine (CQ) and its derivative, hydroxychloroquine (HCQ), have attracted wide attention for treating coronavirus disease 2019 (COVID-19). However, conflicting outcomes have been found in COVID-19 clinical trials after treatment with CQ or HCQ. To date, it remains uncertain whether CQ and HCQ are beneficial antiviral drugs for combating COVID-19. We performed a systematic review to depict the efficacy of CQ or HCQ for the treatment of COVID-19. The guidelines of PRISMA were used to conduct this systematic review. We searched through articles from PubMed, Web of Science and other sources that were published from 1 January 2020 to 31 October 2020. The search terms included combinations of human COVID-19, CQ, and HCQ. Eleven qualitative articles comprising of four clinical trials and seven observation studies were utilized in our systematic review. The analysis shows that CQ and HCQ do not have efficacy in treatment of patients with severe COVID-19. In addition, CQ and HCQ have caused life-threatening adverse reactions which included cardiac arrest, electrocardiogram modification, and QTc prolongation, particularly during the treatment of patients with severe COVID-19. Our systematic review suggested that CQ and HCQ are not beneficial antiviral drugs for curing patients with severe COVID-19. The treatment effect of CQ and HCQ is not only null but also causes serious side effects, which may cause potential cardiotoxicity in severe COVID-19 patients.

Characterized with a high recurrence rate and low detection rate, prevention is the best approach to reduce mortality in hepatocellular carcinoma (HCC). The overexpression of Phosphatidylinositol-3,4,5-Trisphosphate Dependent Rac Exchange Factor 2 (PREX2) is observed in various tumors, including HCC; and the frequent PREX2 mutations in melanoma are associated with invasiveness. We sought to identify somatic mutations and the functional changes in mutational signatures of PREX2. Genomic DNA sequencing was performed in 68 HCC samples with three types of hepatitis viral infection status: HBs Ag-positive, anti-HCV Ab-positive, and negative for any hepatitis B or C markers. Stabilities and interactions of proteins as well as cell proliferation and migration were evaluated. Fourteen non-silent point mutations in PREX2 were detected, with 16 of 68 HCC patients harboring at least one non-silent mutation. All mutant forms of PREX2, except for K400f, had an extended half-life compared with wild-type PREX2. Moreover, only the half-life of S1113R was twice that of the wild-type. PREX2 mutant-S1113R also promoted migration and activated the AKT pathway as well as impaired HectH9-mediated ubiquitination. Our study identified a gain-of-function mutation of PREX2 – S1113R in HCC. Such mutation enhanced PREX2 protein stability, promoted cell proliferation, and was associated with aggressiveness of HCC.