en Legal Medicine Original Research Original Research <p><strong>Background: </strong>Membrane-derived microparticles (PMPs) are produced from platelets during activation, storage, and apoptosis. PMP can transfer some adhesion molecules such as CXCR4 to CXCR4-negative cells. In this study, the ability of PMPs to deliver CXCR4 molecule to CXCR4-null targets (Daudi, K562 and U937 cell line) was evaluated and the different concentrations of PMPs were examined to transfer CXCR4.<br> <strong>&nbsp;&nbsp; Methods:</strong> In this experimental study, PMPs were prepared using serial centrifugations. After confirmation of PMP with flow cytometry, PMP concentration was evaluated using the Bradford method. CXCR4-negative cell lines (1&times;105 cells/ml) were cultured in RPMI1640 with 10% FBS and 1% antibiotic. PMPs in 7 different concentrations were added to cell culture plates and incubated for 1 hour at 37&ordm;c and 5% CO2. The presence of CXCR4 on cells was analyzed by flowcytometry.<br> &nbsp;&nbsp; <strong>Results:</strong> In this study, characterization of PMPs and cell lines were done by flow cytometry. Then, the PMPs&rsquo; ability to transfer CXCR4 to null cells (Daudi, K562 and U937 cell lines) was evaluated in 7 concentrations (10, 20, 50,125, 250, 500, 1000 &mu;g/mL); incubation lasted for 1 hour. The best result of transferring CXCR4 by PMP was done in the concentration of 250&micro;g/mL.<br> &nbsp;&nbsp; <strong>Conclusion: </strong>PMPs in different concentrations can transfer CXCR4 to target cells. Also, the increase of PMPs concentration up to 250&micro;g/mL can increase the CXCR4 presence on null cells.<br> &nbsp;</p> CXCR4, Microparticles, Platelet 336 341 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-3101-1&slc_lang=en&sid=1 Tahereh Manoochehrabadi manoochehrabadit68@gmail.com 200319475328460062642 200319475328460062642 No Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran Zohreh Sharifi z.sharifi@ibto.ir 200319475328460062643 200319475328460062643 Yes Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran Fatemeh Yari f.yari@ibto.ir 200319475328460062644 200319475328460062644 No Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran