Smart Nanoparticles for Targeted Cancer Therapy

Cancer remains one of the major death situations all over the world and more effective and specific therapeutic approaches have to be developed urgently. Although the conventional chemotherapy is effective, it is generally attributed with systemic toxicity and low tumor tissue selectivity. Over the last few years, nanotechnology has emerged with a hope that the above limitations could be overcome through the design and use of Nano carriers as a method to deliver drugs to cancer. Nano carriers Nano-engineered materials that are encapsulant on a Nano scale, have the room to advance the nature of therapeutic agents such as the stability, bio-availability, and delivery efficiency of the therapeutical agents lying within. A major goal of Nanocarrier systems is to prevent premature degradation of drugs in the systemic circulation and to permit accumulation of such drugs at the tumour site in therapeutically effective concentrations. The targeted delivery can reduce the exposure of drugs to the healthy tissues hence, the adverse side effects. Nanoparticle-mediated drug targeting has two major strategies; active and passive targeting. Passive targeting is done using the increased permeability and retention (EPR) effect whereby the abnormal and leaky endothelium in the tumor tissues enables the nanoparticle to selectively accumulate in tumor. Active targeting is the process of functionalization of nanocarriers by use of specific ligand, e.g., antibodies, peptides, or small molecules, which are able to interfere with overexpressed receptor on the surface of cancer cell, improving cellular uptake and tumor specificity. Nanocarriers are designed and manufactured in such a way that determines their success in treating cancer. Major parameters that would have a huge impact are particle size, shape, cell surface charge, and hydrophilicity-/hydrophobicity balance which would have a massive effect on the uptake of these particles into the body and its pharmacokinetics, cellular uptake as well as biocompatibility. As an example, the size of nanoparticle usually is 10-200 nm, which is more or less ideal in terms of tumour penetration and retention. The circulation time and immune recognition of the graft can be prolonged by surface changes, e.g. polyethylene glycol (PEG)ylation. The recent trends in Nanocarrier system are the development of nanoparticles with stimuli responsive behaviors, multi-functional hybrid Nanomaterials, and customized nanomedicine. Such intelligent systems have the capability to release drugs when triggered by a given stimulus in a tumor microenvironment e.g. pH, temperature, enzymes or redox gradients which further adds to the therapeutic efficacy and limits the off-target effects. To sum up, nanocarriers are the innovative solution in cancer treatment as they provide better drug delivery, treatment selectivity, and low-toxicity. Further application of both nanomaterial infrastructures and functionalization of Nano materials promises a bright future of cancer treatment, more effective, more personalized and safer.