The Study Of HA/PLGA Targeted Nano Drug Delivery Systems For Cancer Stem Cells

Cancer is one of the common diseases that seriously threatens human life andhealth. A small group of cancer cells have self-renewal capacity, proliferation anddifferentiation potential, but also have a strong tumorigenic ability, drug resistanceand radiotherapy resistance, which are called cancer stem cells. Cancer stem cells(CSCs) are involved in the fundamental causes of tumor-initiating, drug resistanceand recurrence. Thus, CSCs-focused therapy is destined to form the core of anyeffictive anticancer strategy. Nanoparticles have great potential in the developmentof CSCs-targeting drugs, especially in nano drug delivery and gene carrier area,which need to be improved in terms of targeting strategies and precision. Thecurrent active targeting strategies are relatively single, mainly through some specificcell surface markers of CSCs, such as CD44, CD133, CD24, etc. But some normalcells also have the same cell surface markers found in the CSCs, which greatlyreduces the targeting efficiency of the nanoparticles. Therefore, the development ofnanoparticles which have efficient targeting, controlled release and goodbiocompatibility is an urgent problem in the field of nanomedicine.For the above-mentioned hot issues, the novel self-assembled nanoparticles ofhyaluronic acid (HA)/poly(lactide-co-glycolide)(PLGA) that combined targetingCSCs and loading drug were successfully synthesized. PLGA with highbiocompatibility and biodegradability was successfully conjugated withpoly(ethylene glycol)(PEG). PEG-PLGA nanoparticles (PEG-PLGA NPs) wereprepared by the single-emulsion solvent evaporation method. PEG could improvethe stability of the nanoparticles and prolong the circulation. HA was grafted ontoPEG-PLGA NPs to enhance active targeting toward CD44-overexpressing4T1cancer stem cells. To acquire more active targeting toward CSCs, Doublecortin LikeKinase1monoclonal antibody (anti-Dclk1) was grafted to the surface ofnanoparticles via sodium periodate oxidation and sodium borohydride reduction.Hence, the nanoparticles showed effective cancer stem cells targeting via the doublemoities-HA and anti-Dclk1. Firstly, the size, morphology, and zeta potential of thesenanoparticles were characterized by dynamic light scattering (DLS), scanningelectron microscopy (SEM), transmission electron microscopy (TEM) and Zetapotential instrument, followed by studies of nanoparticles encapsulation efficiency,drug loading and in vitro drug release properties. Then, cytotoxicity of thenanoparticles was tested by MTT bromide assay. Finally, we used two-dimensionalcultured4T1cells, three-dimensional cultured4T1cells and underthree-dimensional culture conditions screened for4T1cancer stem cells as in vitro cell model, tumor-bearing nude mice as in vivo model to systematically testtargetability of the nanoparticles toward cancer stem cells. These results showed thatthe nanoparticles could be an efficient nano drug delivery system for targeting4T1cancer stem cells with high biocompatibility. The results demonstrated that the novelcopolymers nanoparticles have good biocompatibility and drug delivery capabilities,which specifically targeted4T1cancer stem cells through hyaluronic acid and thespecific antibody. These novel copolymers nanoparticles could provide novel ideasand methods for the treatment of cancer stem cells, with a great potential forapplication.