Galactosylated Chitosan Modified Magnetic Mesoporous Silica Nanoparticles Loaded With Nedaplatin For The Targeted Chemo-photothermal Synergistic Therapy Of Cancer

Cancer is one of the diseases that seriously endanger human life and health in the world today,it is divided into many types,it has a high incidence and fatality rate,at present,the main treatment methods for clinical treatment of cancer are chemotherapy,radiotherapy,surgical treatment,hyperthermia?HT?,ultrasound therapy,etc.,and two or more treatments are combined to treat cancer.Therefore,the subject is to be constructed based on Nedaplatin?NDP?as a basic drug,galactosylated chitosan?GC?modified magnetic mesoporous silica nanoparticles?MMSNs?as the carrier of the dual targeting drug delivery system NDP@MMSN-COOH-GC NPs,the system combined with photothermal therapy?PTT?has the following advantages:?1?The active targeting of GC modified MMSNs allows the drug to accumulate effectively in the tumor site,avoid systemic toxicity and improve biosecurity;?2?Nanocarriers by virtue of its own good photothermal effect,so that photothermal therapy greatly increased the preparation of in vivo and in vitro anti-tumor effect.The relevant experiments of this study are as follows:1.The synthesis and characterization of NDP@MMSN-COOH-GC NPs.Water-soluble Fe₃O₄ was prepared by co-precipitation method.Then with the Fe₃O₄as the magnetic nucleus,the TEOS as the silicon source,CTAB as the template agent,the magnetic mesoporous silica nanoparticles were prepared by Sol-gel method,and its surface was carboxyl modified,with Glutaraldehyde as crosslinking agent,using the role of carboxyl and galactosylated chitosan amino acid,the MMSN-COOH-GC NPs coated with GC were characterized by infrared,DLS,SEM,TEM and nitrogen adsorption-desorption,and the warming of the carriers at different times of 808 laser irradiation was investigated.Finally,the prescription process was screened with the EE%and DL%as the index,and the NDP@MMSN-COOH-GC NPs preparation with double targeting effect was finally obtained by optimizing the preparation conditions of the preparation.Infrared spectroscopy showed that the Fe₃O₄ has been successfully prepared,the MMSNs surface has been successfully modified on the amino and carboxyl,GC has been successfully coated on the MMSNs-COOH,TEM diagram showed that the Fe₃O₄ particle size is about 15nm,MMSN-COOH NPs and MMSN-COOH-GC NPs particle size increased to about 100nm;Zeta potential graph showed that the zeta potential of sodium citrate modified Fe₃O₄ was-12.6 mV,in addition,after the MMSNs surface successfully modified the amino,the potential was positive,increased to+16.7 mV,and once again modified the carboxyl,the potential became-21.8 mV,after the MMSN-COOH NPs was coated with GC,the potential became+18.0 mV.The magnetic test results showed that the saturation magnetization value?Ms?of Fe₃O₄ nanoparticles was 65 emu/g,which has ultra-paramagnetic magnetism,and the saturation magnetization values of MMSN-COOH Nps and MMSN-COOH-GC NPs were 38 emu/g and 28 emu/g respectively.The N₂adsorption-desorption curve indicated that the isotherm of MMSN-COOH NPs conformed to the IV isotherm of IUPAC classification,which showed that MMSN-COOH NPs belong to mesoporous materials.In addition,the specific surface area was calculated by BET method was 568.80 m2/g,and the pore volume calculated by BJH was 1.15 cm3/g and the aperture is 6.3 nm.Compared with deionized water,nanocarriers can quickly heat up to 43?under 808 laser irradiation within 3 minutes,so that they can achieve the purpose of photothermal therapy.Finally,after a variety of conditions screening,the drug loading and the encapsulation efficiency of NDP@MMSN-COOH-GC NPs were 24.6%±1.34%and 33.09%±1.22%.The resultsofinvitroreleaseof thepreparationshowed that the NDP@MMSN-COOH-GC NPs group had a sustained release effect,compared with the NDP@MMSN-COOH NPs group.In addition,it also shows that the heat generated by magnetic nanoparticles under the exposure of NIR lasers can accelerate drug release from preparations.2.The antitumor efficiency of NDP@MMSN-COOH-GC NPs combined with PTT in vitro.Based on the A549 cells of human lung adenocarcinoma,the anti-tumor activity and mechanism of NDP@MMSN-COOH-GC NPs in vitro were studied by a series of in vitro experiments.The cytotoxicity results showed that the blank nanocarriers had no obvious toxicity to the A549 cell,in addition,NDP@MMSNS-COOH-GC NPs combined with PTT could more effectively inhibit the proliferation of tumor cells,and the cell uptake results showed that the nanocarriers could effectively enter to the A549 cell.The results of cell cycle experiments showed that NDP and its preparation combined with or without PTT and PTT all can block cell blocking in S period and induce apoptosis.The results of apoptosisexperimentshowedthatthetotalapoptosisrateof NDP@MMSNS-COOH-GC NPs+NIR laser was the highest,and more induced apoptosis of A549 cells.The above results showed that NDP@MMSNS-COOH-GC NPs combined with PTT can obviously inhibit the proliferation of tumor cells and has good anti-tumor activity in vitro.3.The antitumor efficiency of NDP@MMSN-COOH-GC NPs combined with PTT in vivo.A series of in vivo experiments were carried out to study the anti-tumor activity of NDP@MMSN-COOH-GC NPs combined with photothermal therapy based on the S180 tumor-bearing mice model The results of Near infrared?NIR?fluorescence in vivo imaging showed that IR783@MMSN-COOH-GC NPs?the tumor site was bound with magnets?could effectively target the drug to the tumor site,and the tumor tissue still had strong fluorescence signal after 24h,which proved the targeting ability of the nanocarriers.The results of changes of relative tumor volume showed that the NDP@MMSN-COOH-GC NPs+MT+NIR laser group had the best therapeutic effect and the best tumor suppressor effect.In addition,the results showed that there was no significant decrease in body weight of other groups compared with the NDP group,indicating that the preparation and nanocarriers had high biosecurity.The results of HE staining showed that there was no obvious pathological change in the heart,liver,spleen,lung and kidney of each group,which explained the safety of the preparation.However,the results of HE staining showed that most of the apoptosis necrosis occurred in tumor cells in NDP@MMSN-COOH-GC NPs+MT+NIR laser group.In summary,it is proved that the NDP@MMSN-COOH-GC NPs combined with PTT can effectively inhibit the proliferation of tumor,and it has the good biosecurity.