Chitosan is a biodegradable and biocompatible natural polymer that has been extensively explored in recent decades. The Food and Drug Administration has approved chitosan for wound treatment and nutritional use. Furthermore, chitosan has paved the way for advancements in different biomedical applications including as a nanocarrier and tissue-engineering scaffold. Its antibacterial, antioxidant, and haemostatic properties make it an excellent option for wound dressings. Because of its hydrophilic nature, chitosan is an ideal starting material for biocompatible and biodegradable hydrogels. To suit specific application demands, chitosan can be combined with fillers, such as hydroxyapatite, to modify the mechanical characteristics of pH-sensitive hydrogels. Furthermore, the cationic characteristics of chitosan have made it a popular choice for gene delivery and cancer therapy. Thus, the use of chitosan nanoparticles in developing novel drug delivery systems has received special attention. This review aims to provide an overview of chitosan-based nanoparticles, focusing on their versatile properties and different applications in biomedical sciences and engineering.

The current study was devised to develop alternative, nonantibiotic, and economically viable treatments for bovine mastitis. The concentration of 6.25 μg/mL (25 nm) CuNPs was selected as intramammary (IM) treatment in S. aureus‐induced mastitis in rats as this concentration showed a significant zone of inhibition through the in vitro sensitivity test and minimal cell toxicity on fibroblast cell lines. After, this in vivo study was conducted, and rats were divided into four groups of 6 rats each: group I (healthy control/deionized water), group II (disease control), group III (CuNPs), and group IV (gentamicin). Injection of gentamicin IM for 5 days was selected on the basis of an antibiotic sensitivity test. The therapeutic efficacy of CuNPs was assessed on the basis of clinical signs, mammary gland architecture, bacterial load, oxidative stress parameters, and histopathology of mammary glands. The clinical signs of mastitis in group III ameliorated within 3 days of treatment while in group IV clinical signs ameliorated within 4 days of initiation of treatment. On the 5th day after randomization, bacterial load, mammary gland weights, TOS (Total Oxidant Status), and OSI (oxidative stress index) were significantly lower in the CuNPs group compared to the disease control group and commercial antibiotic group. Similarly, TAS of group III was significantly higher compared to that of groups II and IV indicating that CuNPs have better ameliorative efficacy in mastitis. Treatment with IM, CuNPs @ 6.25 μg/mL showed early recovery, reduced bacterial loads, and amelioration of oxidative stress indices henceforth resulting in marked amelioration in histopathological changes compared to rats in group IV. From this study, it may be concluded that CuNPs may provide a potential alternative therapeutic regimen for the treatment of bovine mastitis.

The 21st century has seen a massive spring up in the applications of nanobiotechnology. Incorporation of functionalized and modified nanostructures in various biomedical applications has generated significant research interests such as implant and tissue engineering, diagnosis, and therapy, thereby aiding in improvement of human health. The unique properties of nanoparticles including non-toxicity and biocompatibility with a large surface area make it possible to modify their surface with different chemicals including different polymers, antibodies, and drug molecules. Therefore, they are utilized for targeted drug delivery in order to carry drugs and selectively release them in desired tissues which reduces destructive effects on healthy cells. This chapter mainly covers the basic properties of nanoparticles including nanomedicine, their preparation and focuses on their diagnosis, and therapeutic applications in disease including cancer and other challenging ailments.

The emergence of biogenic nanomaterials as novel antimicrobials introduces a new paradigm in human health care. Based on the recent reports of the World Health Organization, infectious diseases pose one of the greatest health challenges. Increased multi-drug resistance prevalence among human pathogens, due to the inefficiency of commercially available antimicrobial drugs in the market is a great threat to humans. The poor solubility, stability and side effects of the antibacterial therapy prompted the researchers to explore new innovative strategies for developing new antimicrobials. Recently, biogenic nanoparticles have proven their effectiveness against multidrug-resistant (MDR) pathogens as an alternative to conventional antibiotics. Biogenic nanoparticles such as silver nanoparticles (AgNPs) and Zinc Oxide nanoparticles (ZnONPs) are easy to produce, biocompatible, provide enhanced uptake and are eco-friendly. Moreover, the capping of the biogenic nanocrystals provides an active surface for interaction with biological components, facilitated by free active surface functional groups to enhance their efficacy and delivery. Inorganic nanocrystals (AgNPs and ZnONPs) are effective both as nano-bactericides and as nanocarriers against sensitive and MDR) pathogens. The present chapter focuses on the utilization of the recent nanosystems to combat drug resistance in human pathogens. Nanomedicine represents a new generation of potiential antimicrobial candidates capable of combating the drug resistance in various pathogenic organisms.

Complex enzyme interactions play a role in the spread of cancer, a process fueled by unregulated cell proliferation. DNA topoisomerases, which are important for fixing DNA topological problems, have