Nanodrugs against cancer: biological considerations in its redesign

Cancer is a public health problem throughout the world as incidence and mortality rates are increasing year after year. Although conventional therapies such as chemotherapy and radiation show favorable results against this disease, the side effects it causes throughout the body reduce the quality of life of the patient. Therefore, nanomedicine offers us new promising tools to attack cancer through the innovation of nanodrugs, to increase the therapeutic response, reduce dosage, and without generating as many side effects as conventional therapies. For the design of nanodrugs, it is essential to know the biological barriers of the organism and the cancer barriers faced by nanodrugs, such as cell membrane openings, the solubility of the drugs to be transported, and surface electric charge and the protein corona. Due to the aforementioned, the purpose of this review article is to delve into the long journey that nanodrugs undertake from the moment they are administered until they are internalized in tumor cells, taking into account some of the biological and molecular challenges that they defy to reach to its final destination, to observe a desired therapeutic response in the cancer patient.