Nanotechnology In Drug Delivery for Cancer Treatment: Lipid-Based Nanoparticles and Stumuli- Responsive Hydrogels

Cancer remains one of the leading causes of mortality worldwide, and conventional therapeutic approaches such as chemotherapy, radiotherapy, and surgery are often limited by poor drug specificity, systemic toxicity, and reduced patient compliance. The emergence of nanotechnology-based drug delivery systems offers promising solutions to these limitations by enabling precise, controlled, and targeted delivery of therapeutic agents. This review explores two cutting-edge nanoplatforms: lipid-based nanoparticles (LBNPs) and stimuli-responsive hydrogels (SRHs), both of which have demonstrated significant potential in improving the therapeutic index of anticancer drugs. LBNPs, including liposomes, solid lipid nanoparticles, and nanostructured lipid carriers, can encapsulate hydrophobic or hydrophilic drugs, protect them from premature degradation, prolong systemic circulation, and enhance accumulation in tumor tissues via the enhanced permeability and retention (EPR) effect. Surface modifications such as PEGylation and ligand conjugation impart stealth properties and active targeting capabilities, further improving efficacy while reducing off-target effects. In parallel, SRHs function as smart biomaterials capable of delivering drugs in response to specific tumor microenvironment stimuli such as pH, temperature, enzymes, redox gradients, or external triggers like light and magnetic fields. Such responsiveness allows for site-specific drug release with sustained therapeutic levels, minimizing systemic side effects. We discuss the fundamentals of each system, design considerations, mechanisms of drug release, key examples from preclinical and clinical studies, and the comparative advantages and limitations of both platforms. Furthermore, we highlight the potential of hybrid systems integrating nanoparticles within hydrogels to achieve synergistic