There are specific areas where the nanoparticles administration may have an advantage over microparticles based on drug delivery system. One area that has been of great interest is the use of the biodegradable polymer nanoparticles as PLGA or some modification on its surface for delivery of anti-cancer agents and other therapeutic agents. The understanding of the degradation phenomenon of PLGA is important as it determines the rate and mechanism of release of the therapeutic agent. The acidic (lactic acid and glycolic acid) monomers and oligomers thus formed further catalyze the degradation of the parent polymer, a process known as autocatalys. There has been found that PLGA formulation is able to produce a significant efficacy, measured as a reduction of tumor volume and an activation of apoptosis a nivel in vivo [1].  Therefore, the dose and the exposure time are two essential parameters for cisplatin to induce effective apoptosis. All these together seem to support the use of sustained-release formulations to increase the efficacy of this agent while decreasing the adverse effects [2].

The PLGA-mPEG nanoparticles loaded with cisplatin exhibited anticancer activity on cells comparable to that of free cisplatin. This indicates that cisplatin remains active after entrapment in the nanoparticles, providing the nanoparticles will result in a more selective delivery of cisplatin to tumors in vivo due to the Enhanced Permeability and Retention effect with cisplatin used in mice, resulting in prolonged cisplatin residence in systemic circulation and reducing toxic effect of the intravenous administration [3].  Multidrug resistance (MDR), whereby cancer cells become resistant to the cytotoxic effects of various structural and mechanical unrelated chemotherapeutic agents, this is a major problem in the clinical treatment of cancer. PLGA nanoparticles were loaded with viniscristina and verapamil improved the uptake in cells MCF-7 resistant to this medicament [4]. There has been found using both in vitro and in vivo evaluations that the ability of nanoparticles grafted with peptide to target the tumor endothelium improved the anti- tumoral efficacy of placitaxel [5].

The application of nanoparticles from a biodegradable polymer such as PLGA, improves solubility, the retention time and efficiency in drug delivery for therapeutic purposes. This can reduce the toxicity and therefore the side effects thereof. These particles are widely used for the internalization of drugs for cancer treatment.

[1]   D. Moreno, S. Zalba, I. Navarro, C. Tros de Ilarduya, y M.J. Garrido, Pharmacodynamics of cisplatin-loaded PLGA nanoparticles administered to tumor-bearing mice, European Journal of Pharmaceutics and Biopharmaceutics 74 ( 2010)  265-274.

[2]   D. Moreno, C.T. de Ilarduya, E. Bandrés, M. Buñuales, M. Azcona, J. García-Foncillas, y M.J. Garrido, Characterization of cisplatin cytotoxicity delivered from PLGA-systems European Journal of Pharmaceutics and Biopharmaceutics   68 (2008) 503-512.

[3]   E.C. Gryparis, M. Hatziapostolou, E. Papadimitriou, y K. Avgoustakis, Anticancer activity of cisplatin-loaded PLGA-mPEG nanoparticles on LNCaP prostate cancer cells, European Journal of Pharmaceutics and Biopharmaceutics,   67 (2007) 1-8.

[4]   X.R. Song, Z. Cai, Y. Zheng, G. He, F.Y. Cui, D.Q. Gong, S.X. Hou, S.J. Xiong, X.J. Lei, y Y.Q. Wei, Reversion of multidrug resistance by co-encapsulation of vincristine and verapamil in PLGA nanoparticles, European Journal of Pharmaceutical Sciences, 37 (2009 )300-305.

[5]   F. Danhier, B. Vroman, N. Lecouturier, N. Crokart, V. Pourcelle, H. Freichels, C. Jérôme, J. Marchand-Brynaert, O. Feron, y V. Préat, Targeting of tumor endothelium by RGD-grafted PLGA-nanoparticles loaded with Paclitaxel, Journal of Controlled Release 140 (2009) 166-173.