New Efficiency Targeting Reactive Oxygen Species (ROS)-responsive Nanoplatform For Drug Delivery And Oral Squamous Cell Carcinoma Therapy

Purpose:Oral tongue squamous cell carcinoma (OSCC) is the most prevalent mortality of oral cancer, and many significant efforts have been made in prevention, diagnosis, and treatment of OSCC in recent years, but there has been only modest progress in improving the survival rate of the patients. Over the past two decades, drug delivery nanoparticles system has been widely used to treat various diseases, especially in cancer treatment. The administration of DDSs shows the unique characters of improving drug stability, providing controllable loaded drug release, and prolonging drug circulation time in blood in comparison with free drug. Although these DDSs have achieved encouraging results, the clinic translation is far from the expected. Therefore, ideal DDSs should be possessed the characteristics:controlled loaded drug release, targeting ability, good biocompatibility and biodegradability. We introduce novel DDSs which can possess the ability of ROS-triggered drug controlled release, passive targeting of RGD on the surface of DDSs, good biocompatibility and biodegradability according to PLGA and PEG. Thus New biosafe, passive targeting with ROS-responsive TK containing linker block copolymer (Meo-PEG-TK-PLGA, RGD-PEG-TK-PLGA) were designed and prepared. Our research is wished to lay a good foundation for the further study of DDSs in Oral Cancer therapy, and to provide a good treatment strategy.Method:1. It was prepared a new safe amphiphilic diblock (Meo-PEG-TK-PLGA) with ROS-responsive TK-containing linker polymer which employed PEG and PLGA. The structure and molecular of Meo-PEG-TK-PLGA were detected respectively by NMR and GPC. Meanwhile GPC was used to measure degradation of Meo-PEG-TK-PLGA incubated in 50 μM KO2 containing mixture solution of DMF and water (9:1, v/v) to analyze the reactive product. The NPs were prepared by nanoprecipitation, and the characterization and ROS-responsive behavior of NPs can be observed with TEM and DLS. CLSM was used to determine the endosomal escape ability of NPs. It was checked behavior of loaded drug controlled release by the In vitro drug release analysis. In vitro and vivo cytotoxicity analysis determined the biosafe of Meo-PEG-TK-PLGA and that self-assembled NPs. The DOX loaded Meo-PEG-TK-PLGA NPs was tested the ability of antitumor through the in vitro antitumor analysis.2. It was synthesized a new, biosafe, targeting, amphiphilic block (RGD-PEG-TK-PLGA) which possessed ROS-triggered behavior with TK-containing Linker, and well biocompatibility and biodegradability for PLGA and PEG. NMR and GPC was respectively checked the structure and molecular of RGD-PEG-TK-PLGA polymer. Characterization and ROS-triggered behavior of RGD-PEG-TK-PLGA NPs were detected by DLS and TEM. Endosomal escape ability of NPs and intracellular ROS changes with NPs treatment were all determined by CLSM. Flow cytometry was used to check the changes of uptake ability of cancer cells after RGD modified NPs. The NPs pharmacokinetics and safety of polymer and TOS loaded NPs were evaluated. The analysis of in vitro and vivo antitumor was evaluated the antitumor ability of DOX loaded NPs.Results:1. The results of GPS and NMR were all demonstrated the success in synthesis of Meo-PEG-TK-PLGA and the degradation of Meo-PEG-TK-PLGA was PLGA and PEG that was showed ROS-responsive behavior and good biocompatibility. DLS and TEM results showed good stability and small size Meo-PEG-TK-PLGA NPs, strongly verified the NPs ROS-responsive behavior. The result of increased DOX release rate upon the addition of KO2 concentration that demonstrated TK-containing linker of Meo-PEG-TK-PLGA could be cleaved by KO2 and thus result in the breakage of the DOX loaded NPs that indicated the ROS-responsive behavior of Meo-PEG-TK-PLGA NPs. CLAM results implied the good endosomal escape ability of the NPs of the Meo-PEG-TK-PLGA. In vitro cytotoxicity of Meo-PEG-TK-PLGA NPs could demonstrate the polymer is safe, and in vitro antitumor analysis implied NPs could deliver DOX and respond to ROS stimuli resulting to rapidly release the drug to induce remarkable anticancer effect.2. Successful synthesis of RGD-PEG-TK-PLGA was detected by NMR and GPC assay. The results of DLS and TEM demonstrated NPs characterization of small size, good stability and ROS-responsive loaded drug release. CLSM imagines indicated the good endosomal escape ability of RGD-PEG-TK-PLGA NPs and the changes with increased ROS levels incubated by TOS. Flow cytometry results demonstrated increased uptake of cancer cells with RGD modified NPs and increased ROS levels could not change the uptake ability of cancer cells. Pharmacokinetics assay indicated RGD-PEG-TK-PLGA NPs could remarkably prolong the drug circulation time in blood. In vitro and vivo anticancer results indicated excellent anticancer ability of RGD-PEG-TK-PLGA NPs, in vitro and vivo cytotoxicity assay all showed RGD-PEG-TK-PLGA NPs was safety and well biocompatibility and biodegradability in vitro and vivo.Conclusions:Two new block copolymers with ROS-cleavable TK-containing linker was designed and prepared. These polymers can self-assemble into NPs with small size by using nanoprecipitation. With the presence of the hydrophilic PEG shells and hydrophobic cores, these NPs show high stability, satisfied drug loading ability, targeting of RGD modified, excellent ROS sensitivity and good compatibility.