Exploring the Medical Applications of SnO2 Nanomaterials: Antimicrobial, Antiviral, and Anticancer Therapies

Multidrug-resistant (MDR) bacteria (gram-positive and gram-negative) and viruses (COVID-19) have contributed to an increase in health-related issues worldwide. Clinical complications caused by MDR strains are rapidly deteriorating. Simultaneously, cancers are the primary reason for mortality and morbidity worldwide, behind cardiovascular disease. Chemotherapy is a common treatment for cancer. However, it has serious health consequences, such as suppression of bone marrow, hair loss, and gastrointestinal issues, because it eliminates all rapidly dividing cells, including normal and tumor cells. As nanoscience and technology have expanded the opportunities to investigate antibacterial, antiviral, and anticancer nanomaterials, they are becoming increasingly highly significant as drug alternatives for the treatment of antibacterial, antiviral, and anticancer activities. Biocidal activity and biocompatibility of nanomaterials (NMs) are critical for healthcare applications. NMs can overcome the blood-brain barrier, reach the pulmonary system, and adsorb through endothelial cells as they have enhanced colloidal stability and increased bioavailability. It may be intensely dependent on the production of reactive oxygen species (ROS) in NMs, due to their size, large surface areas, oxygen vacancies, ion release, and diffusion ability. The photocatalytic effects of metal oxide nanomaterials are promising for microbial, viral, and cancer cell inactivation. However, antibacterial, antiviral, and anticancer activities are strongly related to the generation of ROS in nanomaterials. On the other hand, the surfaces of metal oxide NMs, in contact with light, cause oxidative stress in cells, eventually leading to the death of bacterial, viral, and cancer cells. Tin oxide (SnO2) NMs are a potential contender for catalysis, medicine, pollution management, and energy storage due to their large band gap (3.6–3.8 eV), good thermal and chemical stability, and excellent transparency. Electron-hole pairs are formed when a metal oxide photocatalyst is exposed to light with an energy higher than its band gap. SnO2 NMs have a large surface area and can be an ideal photocatalyst. The SnO2 NMs have a positive charge, and the microbial cell surface has a negative charge due to electrostatic interaction between microbes and nanomaterials. It was used to bind and trap microbes before they could enter the host cell. They cling to the microbe particle limit for microbial entrance, replication, and cell-to-cell fusion. This chapter is focused on investigating SnO2 NMs and to emphasize their medical applications, particularly antibacterial, antiviral, and anticancer therapies.