The Photothermal Property Modulation Of MoS₂ And Its Application In Multimodal Of Therapy Breast Cancer

Cancer,with increasing high fatality rate and incidence,becomes one of the acute threats to public health.Nowadays,the main approaches for cancer-treating strategies including radiotherapy,surgery,chemotherapy,immunotherapy and gene therapy.However,the unsatisfactory therapeutic efficacy and side-effects are still a challenge for cancer therapy.Therefore,it is desirable for us to look for innovative therapeutic strategies to promote the therapeutic efficacy and weaken side-effects during the therapeutic process.Photothermal therapy(PTT),with the ability of converting the light energy into heat energy,kills the cancer cells via photothermal conversion agents(PTAs)which increase the temperature at the tumor.Maenwhlie,Photodynamic therapy(PDT)is extensively explored as an innovative treatment strategy.The photosensitizers(PSs)engender reactive oxygen species(ROS)to make tumor cells apoptosis.By combining PTT with PDT,a better therapeutic effect can be obtained,which then achieving a promising synergistic PTT/PDT therapy.Recent years,transition metal dichalcogenide(TMDC),with good biocompatibility and unique optical properties,has been widely used in PTT/PDT.Among them,MoS₂ plays an important role in the PTT/PDT for its high photothermal conversion efficiency(PCE)and low side-effects.To explore the effect of the combined PDT and PTT treatment based on MoS₂nanoparticles,we introduced Eu³⁺into MoS₂ and constructed MoS₂:5%Eu³⁺nanoflower nanocomposite for breast cancer therapy.Herein,the temperature of MoS₂:5%Eu³⁺nanoflowers reached up to 64.8? under the irradiation of 808 nm laser for 10 min.The PCE of MoS₂:5%Eu³⁺was 49.05%,which was 1.75 times higher than the pristine MoS₂.At the same time,MoS₂:5%Eu³⁺,as an efficient photosensitizer,also promote the cancer cells to generate reactive oxygen species(ROS)under near-infrared(NIR)laser irradiation,thus realizing the PDT for breast cancer.In addition,MoS₂:5%Eu³⁺nanoflower also possesses excellent biocompatibility and photothermol stability,so it is a promising nanoprobe for PDT/PTT cancer therapies.This work also provides a novel strategy for PCE improvement of the 2D-MoS₂ nanomaterials.Subsequently,we constructed a multifunctional MoS₂-PEI-IR820(MPI)nanoparticle-based platform.The obtained MPI has improved efficacy of PTT/PDT combination therapies and photothermal performance of MoS₂.The crystal structures of MoS₂quantum dots(MoS₂ QDs),MoS₂ nanoflower(MoS₂ NFs)and MoS₂ nanosphere(MoS₂NSs)were detected by XRD,the corresponding results indicated that MoS₂ NSs has better structure than that of the MoS₂ QDs and MoS₂ NFs.Compared with MoS₂ QDs and MoS₂NFs,MoS₂ NSs have obviously faster heating rate,and the temperature of MoS₂ NSs dramatically increased to 58.3?C when irradiated with 808 nm(1 W cm^-2)laser for 10min.MoS₂ NSs,as a kind of photothermal material,have great potencial in biomedical applications for its superior crystal and large surface area.Then,MPI nanocomposite was successfully prepared via modifing MoS₂ NSs with ethylene imine polymer(PEI)and IR820.Under 808 nm laser irradiation,the PCE of MPI nanocomposite reached?47.08%,which was 9.6%higher than MoS₂ NSs.MPI nanocomposite could not only perform NIR light triggered PTT and PDT,but also achieve in vivo fluorescence(FL)bioimaging and infrared thermographic imaging.MPI nanocomposite showed great anti-tumor effects in both in vivo and in vitro experiments.In this work,MPI nanocomposite was an ideal photothermal/photodynamic material with good biocompatibility,low toxic side-effects and high PCE.In order to improve the photothermal performance of MoS₂,we explored the application of MoS₂-based nanocomposite in multimodal therapy of breast cancer.In this work,Eu³⁺was incorporated to enhance the PCE of MoS₂,and the PCE of MPI nanocomposite was further improved by loading IR820.This work achieves remarkable accomplishment in photothermal performance and enhancement in the effect of cancer treatment,and provides a new strategy for PTT/PDT combination therapy based on MoS₂.