Core-satellite Nanosystem For Antiangiogenic And Antivasculogenic Mimicry Therapy

Tumor angiogenesis is closely related to the tumor growth,invasiveness,metastasis,recurrence and prognosis.Within deeply anti-angiogenesis research,vasculogenic mimicry,which an absolutely new way for tumor blood supply and totally different from common tumor vessels have been found.Vasculogenic mimicry,which refers to a tumor blood vessel structure not rely on the proliferation of endothelial cells but forms by cancer cells.Vasculogenic mimicry can form tubular network and supply blood for tumor.In present study,we developed a novel nanodrug delivery system,which was named Core-satellites.Core-satellites could combinate anti-angiogenesis and anti-vasculogenic mimicry therapy target together.Firstly,Maleimide poly（ethylene glycol）-poly（lactide）（Mal-PEG-PLA）andmethoxy poly（ethylene glycol）-poly（lactide）（CH₃O-PEG-PLA）copolymers were synthesized by the ring opening polymerization.The Core were prepared with a composition-optimized blend of Mal-PEG-PLA,DC-Cholesterol and CH₃O-PEG-PLA using the O/W emulsion-evaporation technique,which loaded dasatinib.Tertiary butyl oxygen carbonyl poly（ethylene glycol）-poly（2-（Hexamethyleneimino）ethyl methacrylate）（t-Boc-PEG-C7A-MA）andmethoxy poly（ethylene glycol）-poly（2-（Hexamethyleneimino）ethyl methacrylate）（CH₃O-PEG-C7A-MA）copolymers were synthesized by Atom Transfer Radical Polymerization.The Satellite were prepared with a composition-optimized blend of Py-s-s-PEG-C7A-MA and CH₃O-PEG-C7A-MA using the drop-stir evaporation technique,which loaded SU5416.Core-satellites were prepared with a composition-optimized blend of Core and Satellite nanoparticles which two nanoparticles were conjugated by maleimide group and mercapto group in HEPES（p H 7.1,0.02M）.Reaction mixture were separated to get final core-satellites.The particle size of Core-satellites was around 162.9 nm（DLS assay）and the Zeta potential was about 0.1 m V.The observation under the transmission electron microscopy（TEM）showed that the nanoparticles were uniformly spherical in shape with smooth surfaces and without any aggregation or adhesion.Using HPLC to detect nanoparticles dasatinib and SU5416 drug loading was 1.06±0.1%and 0.41±0.05%.Core-satellites were stable and didn’t release SU5416 in p H 7.4 but could release SU5416 quickly in p H 6.7 PBS（0.01M）.With courmarin-6 and Di R as the fluorescent probe load in core and satellite nanoparticles respectively.Using the confocal laser scanning microscopy（CLSM）to observe under p H 7.4 and p H 6.7 PBS（0.01M）,which showed that satellites would burst in weak acidic and could make core nanoparticle surface expose positive charge.Surface positive charge would enhance tumor cell uptake.In the experiment range（dasatinib concentration of 10-1000 n M）,core nanoparticels caused none cytotoxicity to HUVEC and B16F10.SU5416 in 1-10μM caused significantly cytotoxicity to HUVEC and none cytotoxicity to B16F10.In inhibiting B16F10 tubule formation assay,10 n M dasatinib could cause significantly inhibition rate.When dasatinib concentration up to 100 n M,the inhibition rate was approach to 95%.However,SU5416 at all tested concentrations could not have any effective inhibition.In inhibiting HUVEC tubule formation assay,the inhibition rate of SU5416 was dose-dependent.3μM SU5416 could approximately inhibit 50%.The inhibition rate of core nanoparticles（dasatinib concentration:300 n M）was 60%.At last,C57BL/6 mice were subcutaneously inoculated with B16F10 and used nanomedicine to cure tumor bearing mice.Compare with other experimental control groups,core-satellites group had significantly anti-tumor activity by measure tumor volume.The effects of nanomedicine anti-angiogenesis and anti-vasculogenic mimicry were further verified by immunohistochemistry.As an original novel drug delivery system,core-satellites,was developed for the first time as the drug delivery carrier of anti-angiogenic and anti-vasculogenic mimicry agents.The systematic investigation for the core-satellites preparation and characterization,anti-angiogenic activity,anti-vasculogenic mimicry activity.Revealed the potential significance of nanodrug delivery system for tumor angiogenesis therapy.