Biomedical Applications of Waste-Recycled CNMs: Exploring Antioxidant and Anti-cancerous Efficacy

The growing environmental burden of waste materials has sparked novel recycling methods for converting wastes into high-value CNMs (CNMs) with considerable biomedical applications. Waste-recycled CNMs such as graphene, carbon dots (CDs), carbon nanotubes (CNTs), and related derivatives provide long-term, cost-effective, and environmentally responsible alternatives for enhanced medicinal research. This chapter provides a detailed assessment of cutting-edge approaches for synthesizing CNMs from various waste streams employing green chemistry frameworks such as hydrothermal carbonization, pyrolysis, and microwave-assisted synthesis. It focusses on the physicochemical features of these materials that explain their significant antioxidant action by scavenging reactive oxygen species (ROS), thereby alleviating oxidative stress, which is linked to a variety of clinical conditions. Further, this chapter also details multiple ways in which these agents exhibit anticancer properties, including apoptosis, tumor growth inhibition/metastasis; facilitating targeted delivery of chemotherapeutic agents combined with their ability to hold massive amounts of drug compared to other traditional drug carrier systems. Several in vitro and in vivo studies indicate that CNMs exhibit promising therapeutic efficiency in consort with favorable safety profiles. This chapter further explores the utilization of CNMs produced from waste sources in advanced therapies such as photothermal and photodynamic cancer treatments in addition to biosensors providing early and accurate cancer diagnosis. This chapter covers several key translational challenges including issues connected with reproducibility, regulatory compliance, material standardization, and environmental sustainability. In order to provide up-to-date evidence and defining strategic research priorities, this work highlights the imperative of multidisciplinary collaboration. Such integration is important in proceeding nanomedicine toward clinical viability though inserting it inside the principles of circular economy, thereby confirming both therapeutic efficiency and ecological responsibility.