The Clinical Translation of Organic Nanomaterials for Cancer Therapy: A Focus on Polymeric Nanoparticles, Micelles, Liposomes and Exosomes

The application of nanotechnology in the medical field is called nanomedicine. Nowadays, this new branch of science is a point of interest for many investigators due to the important advances in which we assisted in recent decades, in particular for cancer treatment. Cancer nanomedicine has been applied in different fields such as drug delivery, nanoformulation and nanoanalytical contrast reagents. Nanotechnology may overcome many limitations of conventional approaches by reducing the side effects, increasing tumor drug accumulation and improving the efficacy of drugs. In the last two decades, nanotechnology has rapidly developed, allowing for the incorporation of multiple therapeutics, sensing and targeting agents into nanoparticles (NPs) for developing new nanodevices capable to detect, prevent and treat complex diseases such as cancer.In this review, we describe the main drug nanoformulations based on different types of organic NPs, the advantages that the new formulations present in comparison with their free drug counterparts and how nanodrugs have improved clinical care. We subdivided them into four main groups: polymeric NPs, liposomes, micelles and exosomes, a small subgroup that has only recently been used in clinical trials.The application of nanotechnology to pharmaceutical science has allowed us to build up nanosystems based on at least two stage vectors (drug/nanomaterial), which often shown better pharmacokinetics (PK), bioavailability and biodistribution. As a result of these advantages, the nanomaterials accumulate passively in the tumor (due to the enhanced permeability and retention, effect, EPR), thereby decreasing the side effects of free drug. Recently, many new drug formulations have been translated from bench to bedside.It is important to underline that the translation of nanomedicines from the basic research phase to clinical use in patients is not only expensive and time-consuming, but that it also requires appropriate funding. After many years spent in the design of innovative nanomaterials, it is now the time for the research to take into consideration the biological obstacles that nanodrugs have to overcome. Barriers such as the mononuclear phagocyte system, intratumoral pressure or multidrug resistance are regularly encountered when a cancer patient is treated, especially in the metastatic setting.