Abstract:
Cancer has been one of the leading causes of death worldwide. In 2018, 17 million new cases of cancer have been reported across the world, which resulted in 9.6 million deaths. Continued efforts have been made to achieve effective progress in treatment of the disease. Conventional cancer therapy has various drawbacks like lack of specificity, resistance toward therapy, drug-related toxicities, patient noncompliance, etc. To overcome these limitations, there is a need to shift toward advanced nanotechnology-based therapeutic agents to improve efficacy, safety, and patient compliance. Nanotechnology is interdisciplinary and involves application of materials science, medicine, biotechnology and engineering, and aiming for advancement in cancer treatment and diagnosis. In addition, nanocarriers such as quantum dots, dendrimers, liposomes, micelles, lipid nanoparticles (NPs), carbon nanotubes, gold (Au) NPs, etc. have taken treatment and diagnosis one step ahead and have proven to be beneficial in reducing side effects and drug-related toxicities. Theranostic nanocarriers are also an emerging field in cancer therapeutics, performing imaging, diagnosis, and simultaneous treatment. NPs are smart carriers designed to particularly release drug at the tumor site, resulting in increased bioavailability of the drug. This targeted delivery is achieved by exploiting the unique characteristics of tumor cells called enhanced permeability and retention (EPR) effect. Surface functionalization of nanocarriers with ligand moiety increases drug uptake inside tumor cells; this phenomenon is generally referred to as active targeting. Conjugation of ligands that are highly expressed in a particular cancer can assist to achieve cellular targeting.