ABSTRACT
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.
ABSTRACT
Aluminum salts are the most popular adjuvants applied in human vaccines currently. However,they can′t achieve satisfying results in the development of novel vaccines because of the cellular immune responses induced by them are weak and their adjuvant activities for some novel vaccines are poor, especially in vaccination against peptide antigens with small molecular weight. cGAMP (cyclic guanosine monophosphate-adenosine monophosphate) has recently been known as a mammalian second messenger, which plays an important role in the innate immune signaling pathway and is capable of boosting the immuno-genicity of vaccines,activating antigen-presenting cells and enhancing specific T cell responses. cGAMP is expected to become a new generation of vaccine adjuvants against infectious diseases and cancer. In this re-view,we summarize the application and current situation of vaccine adjuvants, describe the discovery of cGAMP and its mechanism as a vaccine adjuvant,and focus on the advances in using cGAMP in the fields of vaccination against infectious diseases, intradermal immunization and tumor immunotherapy. Finally, it is also pointed out that cGAMP,as a novel vaccine adjuvant,will have a broad prospect of application in areas such as anti-tumor,anti-virus,anti-inflammatory and vaccines.