RESUMEN
OBJECTIVE To prepare and evalu ate doxorubicin-loaded red blood cell membrane chitosan-targeted nanoparticles of targeting tumor cell folate acid （FA）receptor（FA-RBC-DOX-CS-NPs）. METHODS Doxorubicin-loaded chitosan nanoparticles （DOX-CS-NPs） were prepared by ion cross-linking method. FA and amino polyethylene glycol phospholithin （NH2- PEG2000-DSPE）were covalently linked to modify the red blood cell membrane to construct FA-RBC-DOX-CS-NPS. FA-RBC- DOX-CS-NPs were characterized and investigated on in vitro drug release characteristics ，antitumor activity and endocytosis ability （investigation with human breast cancer MCF- 7 cells）. RESULTS Average particle size of FA-RBC-DOX-CS-NPs was （254.200± 2.651）nm，and polydispersity index was 0.199±0.031；Zeta potential was （－10.100±0.213）mV. FA-RBC-DOX-CS-NPs released fast in the tumor microenvironment （pH6.5）. Cellular experiments showed that ，the nanoparticles could inhibit the activity of MCF- 7 cell proliferation and improve the efficiency of endocytosis. CONCLUSIONS FA-RBC-DOX-CS-NPs are prepared successfully. The nanoparticles have good tumor cell targeting and endocytosis ability ，and can realize the enrichment of drugs in tumor cells.
RESUMEN
The mother can deliver nutrients to the fetus only through the placenta during pregnancy. Folic acid plays an important role in placenta development and fetal growth, and is involved in cell division, embryogenesis and fetal growth. The ability of transplacental folic acid is one of the limiting steps of folate application. Folic acid and its active forms arrive at the fetus by three transporters: folic acid receptor, reduced folic acid carrier and proton coupled folic acid transporter. The expression and transport capacity of transporters were changed significantly with pregnancy complications such as hypertension, fetal growth restriction and premature delivery. Antiepileptic drugs, progesterone, antihypertensive drugs, drug abuse, and heavy metals can alter the transport of folic acid and across the placental barrier of other drugs by regulating the placental folate transporter.