Polymeric Nanoparticles—Tools in a Drug Delivery System in Selected Cancer Therapies

The increase in cancer cases is undoubtedly affecting the development of new therapeutic approaches. Polymeric nanoparticles are of great interest. Due to their relatively small size, the possibility of incorporating into them medicinal substances and the ease with which their physicochemical properties may be manipulated, they are being used as anticancer drug delivery systems. The aim of this review is to focus on the use of nanoscale polymeric particles in the treatment of colorectal cancer, breast cancer, ovarian cancer and glioblastoma multiforme, and to consider their potential use in cancer gene therapy. According to several reports, the use of polymer nanoparticles as drug carriers is promising in solid tumors. With their application, it is possible to precisely deliver medicinal substances to the tumor structure, to overcome the blood–brain barrier in the case of brain tumors, to reduce the side effects of anticancer agents on normal cells and to achieve a therapeutic effect with a lower drug dose. Additionally, a number of reports indicate that they can also be used in combination with other methods of cancer treatment, mainly radiotherapy.