Recent advances of chitosan-based nanoparticles for biomedical and biotechnological applications

Silver nanoparticles are well known potent antimicrobial agents. Although significant progresses have been achieved on the elucidation of antimicrobial mechanism of silver nanoparticles, the exact mechanism of action is still not completely known. This overview incorporates a retrospective of previous reviews published and recent original contributions on the progress of research on antimicrobial mechanisms of silver nanoparticles. The main topics discussed include release of silver nanoparticles and silver ions, cell membrane damage, DNA interaction, free radical generation, bacterial resistance and the relationship of resistance to silver ions versus resistance to silver nanoparticles. The focus of the overview is to summarize the current knowledge in the field of antibacterial activity of silver nanoparticles. The possibility that pathogenic microbes may develop resistance to silver nanoparticles is also discussed.

In this brief report, we offer a concise overview on current cancer epidemiology garnered from the official databases of World Health Organization and American Cancer Society and provide recent information on frequency, mortality, and survival expectancy of the 15 leading types of cancers worldwide. Overall, cancer poses the highest clinical, social, and economic burden in terms of cause-specific Disability-Adjusted Life Years (DALYs) among all human diseases. The overall 0–74 years risk of developing cancer is 20.2% (22.4% in men and 18.2% in women, respectively). A total number of 18 million new cases have been diagnosed in 2018, the most frequent of which are lung (2.09 million cases), breast (2.09 million cases), and prostate (1.28 million cases) cancers. Beside sex-specific malignancies, the ratio of frequency between men and women is >1 for all cancers, except thyroid (i.e., 0.30). As concerns mortality, cancer is the second worldwide cause of death (8.97 million deaths) after ischemic heart disease, but will likely become the first in 2060 (~18.63 million deaths). Lung, liver, and stomach are the three most deadly cancers in the general population, while lung and breast cancers are the leading causes of cancer related-mortality in men and women, respectively. Prostate and thyroid cancers have the best prognosis, with 5-year survival ~100%, while esophagus, liver, and especially pancreas cancers have the worst prognosis, typically <20% at 5 years. We hope that this report will provide fertile ground for addressing health-care interventions aimed at preventing, diagnosing, and managing cancer around the world.