Polymer-Based Drug Delivery Systems, Development and Pre-Clinical Status.

Background: The nanomedicine is considered as the application of nanotechnology in the medical field where nanoparticles are sized in the nanoscale range. Drug delivery technologies are becoming increasingly important as a scientific area of investigation. Controlled-release systems and drug-targeting systems represents an alternative to traditional delivery nanoparticles, and the use of polymers is increasing nowadays. Although polymers could be classified as excipients, they are capable of modifying the biopharmaceutical and biokinetic behaviour of the transported active molecule increasing its efficacy and stability, and reduced cytotoxicity on healthy peripheral tissues.

Methods: The goal of this work is to collect and analyse the most current polymeric nanoparticles development as controlledrelease and drug-targeting systems in cancer, infectious diseases and immunomodulation areas, as alternatives to conventional therapies.

Results: This review provides an update on the polymeric nanoparticles development analysing the trend of polymeric-based drug delivery systems, future opportunities and challenges of this fast-growing area.

Conclusion: With the thorough comprehension of biological effects depending on structure, it is possible to design specific systems for specific diseases, treatments and patients. The ability of polymer- based nanoparticles to modify and improve pharmacokinetics and pharmacodynamics, associated to techniques for enhancement of the therapeutic efficiency with minimal side effects, demonstrate the advantages of these systems.