Platelet microparticles: An effective delivery system for anti-viral drugs

Abstract Platelet microparticles are the most frequent bloodstream microparticles (∼70–90%) which act as a vector for delivery of mRNA, miRNA and signaling proteins under physiological conditions. A variety of platelet microparticles were produced during the storage of platelet concentrates. In this study, platelet microparticles were isolated from platelet concentrates at day 3 of storage and used to deliver anti-HIV drugs including Lamivudine and Tenofovir. At first, encapsulation efficiency and release of anti-HIV drugs were evaluated by spectrophotometry at different wavelengths. Then, cellular uptake, cytotoxicity and HIV-1 inhibitory effects of drugs and drugs-platelet microparticles were assessed using flow cytometry, MTT and P24 assay kit in vitro. Our data showed that the platelet microparticles (300–1000 nm) have high ability for entrapment of Lamivudine and Tenofovir drugs up to 60% and 40%, respectively. Moreover, the release of drugs from the microparticles slowly occurred. HIV-1 inhibitory effects of Lamivudine- and Tenofovir-platelet microparticles were increased in comparison with drugs alone at different concentrations. Also, the toxicity of drugs loaded in the microparticles was decreased at various doses due to their slow release compared to drugs. Generally, platelet microparticles could be considered as a safe, inexpensive and natural vehicle for anti-HIV drug delivery compared to other synthetic nanoparticles.