The major cause of death worldwide is cancer. Chemotherapy, radiation therapy, immunotherapy, and targeted
therapy are examples of conventional cancer treatments. However, there are significant obstacles to effective cancer
treatment, including cytotoxicity, lack of selectivity, and multidrug resistance. Cancer diagnosis and therapy have
radically changed with the development of nanotechnology. Through lessening its side effects, nanotechnology has
particular advantages in cancer treatment. Nanoparticles (1–100 nm) can be utilized to treat cancer because of their
unique benefits, which include improved permeability and retention (PR), decreased toxicity, increased stability,
biocompatibility, and precise targeting. The unique drug delivery method using nanoparticles makes use of the
properties of the tumor and its surroundings. Nanoparticles not only overcome multidrug resistance but also address
the shortcomings of traditional cancer treatment. Additionally, nanoparticles are being studied more thoroughly as
new multidrug resistance mechanisms are discovered and examined. Being able to bypass the drug efflux
mechanism linked to such a phenotype and directing drugs to target cancer cells specifically gives them an additional
means of avoiding multidrug resistance. There has been a comparison of the effectiveness of active and passive
nanoparticle (NP) targeting techniques in cancer theranostics. New cancer therapeutics were developed and
improved using a variety of nanomaterials, including inorganic or organic, and synthetic polymers. This review
addresses the function of NPs in cancer treatment, including targeting mechanisms and various drug delivery
techniques for cancer therapy