Nano-based carriers for pulmonary drug delivery: A review on the available drug delivery applications and toxicity issues

In the last decade, nanocarriers have been widely used to target specific organs and disorders of any kind. Nonetheless, the commercialization of nanocarriers for many disorders have not been finalized; toxicity matters, materials which have not granted approval by regular authorities, or unavailability of clinical studies are some of the issues which the researchers should overcome to force the marketing of nanoparticles. Pulmonary diseases affect million people worldwide, in example, pulmonary infections, malignancies, asthma and chronic obstructive pulmonary disease are among the most frequent. It has been reported that the local administration of drugs to lungs via inhalers can solve the most side effects arouse by per os or intravenous delivery. Therefore, in this review the current state of drug delivery nanosized carriers which can be applied via inhalation are discussed and analyzed. Moreover, the possible toxicity issues due to their small size or materials used for the preparation of such nanocarriers are being discussed. It was performed a thorough literature research based on databases as PubMed® and ScienceDirect® by using nanocarriers, pulmonary, lung disorders, inhalation, toxicity as keywords. According to our inclusion criteria, studies including the previous terms, focusing on nanoparticles that can be applied for lung disorders management, were added. From our point of view, this bibliographic analysis can enhance the present knowledge of researchers for inhalable nanostructures, targeting pulmonary diseases.