Nanomaterials in Cancer Therapy

Introduction

Cancer is one of the recalcitrant diseases which has a poor prognosis. It has a very low survival rate due to a lack of symptoms at the early stages (Murakami et al., 2019). Although variable leading treatment techniques are available, it is still cumbersome to treat cancer owing to the morphologies of the tumor microenvironment. Most of the tumors develop resistance towards cancer drugs due to their localization within the highly dense stroma. In addition, tumors become aggressive and metastasize to other organs at advanced stages not showing symptoms at the early stages. Despite being the most renowned treatment modalities, currently, available treatment options including chemotherapy and radiotherapy have been showing systemic adverse effects and side effects leading to healthy cells getting affected by exposure to the drugs or radiation. This creates a huge negative impact on the cancer patient's quality of life. The feeling of discomfort and complications arising from the therapy leads to a weakened immune system and makes their body not ready for the next therapy and resulting in the patients may give up on continuing these treatment options. Hence, a more sensitive and localized tumor treatment modality is expected to combat the currently existing challenges in treating a tumor. Despite the conventional tumor treatment modalities, a more specific and efficient treatment modality is desirable to gain access to the tumor microenvironment. Nanomedicine has been shown as an effective solution for localized treatment of the therapeutic agents in the tumor microenvironment owing to the excellent properties of the nanomaterials in cancer therapy (Govindan et al., 2023).

Applications of nanomaterials are diverse in treating chronic diseases, especially cancer. Its nanoscale size and excellent physicochemical properties enable it to be highly studied as a nanocarrier in drug delivery and targeted cancer therapy. Nanomaterial-based cancer medication faces leap progress from bench to bedside. Nanomaterials can be applied to target the tumour tissues via active and passive targeting. Passive targeting of nanomaterials involves their accumulation at the tumour tissues owing to their nanoscale and physicochemical properties (Bazak et al., 2015). This is because the distorted or abnormal vasculature system at the tumour region enables the accumulation of the nanosized nanomaterials at the tumour region. While active targeting of nanomaterials refers to specific targeting of the nanoparticle functionalised with biological components including antibody, peptide and protein component of nanoparticles to the compatible receptor of the overexpressed biomarker on the tumour region (Attia et al., 2019). There are some advantages offered by nanomaterials owing to their small size. One of them is their ability to escape the renal clearance system (Mundekkad & Cho, 2022). Escaping the kidney filtration system improves the half life of the nanoparticle in the blood circulation. In addition, the high surface-to-volume ratio makes it to be loaded with many biological compounds (Vinhas et al., 2017). Physicochemical properties such as pH, surface charge and hydrophilicity of the nanoparticles can be modified to make them as a more feasible carrier of therapeutic compounds.

There are various types of nanomaterial including organic, polymeric, semiconductor, magnetic and metals available in cancer nanomedicine, thanks to their respective abilities in aiding cancer treatment such as chemotherapy, radiotherapy, gene therapy, immunotherapy, photothermal and photodynamic therapy (Ali et al., 2022). Each type of nanomaterial can be used for varying purposes in cancer therapy. Organic nanomaterials such as liposomes have higher solubility and bioavailability in physiological environments which exhibit reduced toxicity towards living cells. Biodegradable nanomaterials such as carbon and silicon are widely studied nanomaterials, especially in brain tumours owing to several advantages posed by them such as their tuneable surface, non-toxic and longer half-life as they degrade at a slower rate compared to the organic nanomaterials which improved sustained release of drugs (Kashyap et al., 2023). Semiconductor and metal nanomaterials pose multifunctional properties as they can be occupied as theragnostic agents because of their fluorescence properties that enable live tracking of the therapeutic agent in living organisms.