This singular subject emphasis on erythropoietin nanoparticles including original research articles on cytoprotective effects of Nanoerythropoietin and its advantages. Moreover, the special issue includes papers on the action of Nanoerythropoietin as a chemoprotective agent. In the following, we present the original papers published in this special edition [1]. Deal with erythropoietin loading chitosan-tripolyphosphate nanoparticles. This paper presents the result of an in vivo study investigating the effect of Erythropoietin (EPO) loading Chitosan-Tripolyphosphate (CS-TPP) nanoparticles on an Immunoglobulin a Nephropathy (IgAN) rat model. They prepared and characterized EPO-CS-TPP nanoparticles and administered to the IgAN rat models [2,3]. Analyzed Hemoglobin (Hb), Blood Urea Nitrogen (BUN) and Creatinine (Cr) levels as hallmarks of nephropathy. They report significant improvement in the therapeutic effects in the IgAN model CSTPP-EPO group [4]. Investigate the role of recombinant human erythropoietin loading chitosantripolyphosphate nanoparticles in busulfan-induced genotoxicity. This paper presents the result of an in vitro studyinvestigating the genoprotective effects of CS-TPP-EPO nanoparticles on busulfan induced genotoxicity and oxidative stress. CS-TPP-EPO nanoparticles reduced the genotoxic effects of busulfan significantly by reduction of the level of DNA damage via blocking ROS generation [5]. Deal with Erythropoietin-loaded oligochitosan nanoparticles. This article presents the result of an in vivo study investigating erythropoietin-loaded oligochitosan nanoparticles for treatment of periventricular leukomalacia [6-9]. Analyzed the results of Histology experiments, GAP-43, MRI experiments and Behavior tests. They report that Nanoparticles prolonged the time course of EPO metabolization in the liver and the stable release of EPO from the nanoparticles kept the plasma concentration of EPO at around 100 IU/ml during the 8 h-12 h post-injection and suggest that oligochitosan based nanoparticles are an effective vehicle for drug delivery [10-13]. Design and characterized another type of erythropoietin nanoparticles. They prepare EPO-loaded poly (DLlactide-co-glycolide) nanoparticles using double emulsion method (w/o/w) with least processrelated stress on the encapsulated drug. The bioassay results showed that EPO-loaded nanoparticles were able to maintain the physiological activity of EPO for 14 days after single subcutaneous injection compared with pure and marketed EPO formulae (EPREX® ).