Preparation And Properties Of Novel Photothermal Material Against Breast Cancer Tumor Cells

Breast cancer is a serious threat to the health of women all over the world.Breast-conserving surgery combined with radiotherapy and chemotherapy is the most commonly used method for the treatment of breast cancer.But chemotherapy and radiotherapy have serious side effects,and postoperative breast defects also need to be repaired in time.Therefore,new therapeutic methods are urgently needed to solve the postoperative recurrence and defect repair.In recent years,photothermal therapy(PTT)have become a research hotspot in cancer treatment.PTT has the characteristics of small side effects,short treatment time and inducing immune response.Usually,photothermal nanoparticles were injected into the body thro?gh vein,and then enriched in the tumor site thro?gh EPR effect.Photothermal materials convert light energy into heat energy to kill tumor cells and achieve therapeutic effect.However,the current photothermal reagents have some problems,such as complex synthesis route,poor photothermal stability and low photothermal conversion efficiency.More important there is a risk of long-term retention of nanoparticles by intravenous injection.Therefore,altho?gh intravenous injection of photothermal agents has great application value in tumor treatment,there are still many difficulties in the clinical application of breast cancer treatment in the short term.In order to solve the problem of complex synthesis route,the near infrared excited photothermal molecule BPD-BBTD with high photothermal conversion efficiency was synthesized by Suzuki coupling reaction in one step.At the same time,high yield and high purity of BPD-BBTD were achieved.In order to solve these problems,a novel photothermal molecule BPD-BBTD with high photothermal conversion efficiency was synthesized by simple Suzuki coupling reaction in one step.Spherical BPD-BBTD-NPs with median particle size of20-30 nm were successfully prepared by physical coating method.The combination of amphiphilic block polymer DSPE-PEG₂₀₀₀ improves its hydrophilicity.The BBTD NPs have good stability,biocompatibility,high photothermal conversion efficiency(40.3%)and photothermal cycle stability.In order to solve the long-term toxicity problem of nanoparticles retained in the body,BPD-BBTD-NPs were loaded in PDA-PAM hydrogels that could be used for tissue repair.The synergy of defect repair and photothermal therapy was constructed.The hydrogel has excellent tensile properties(stretching to 3 times as much as it is),compression resistance and tissue adhesion.When exposed to a low power(0.8 W/cm²)808 nm laser irradiation for 4 min,the synthesized BPD-BBTD hydrogel can heat up to 102 ^oC,this temperature far exceeds all reported photothermal therapy hydrogel.In vitro experiments showed that BPD-BBTD-NPs@PDA-PAM hydrogels exhibited excellent photothermal killing ability against cancer cells under low power laser irradiation(0.3 W/cm²).In conclusion,successful implementation of this project will expand the types of photothermal reagents and make a theoretical foundation for photothermal therapy of breast cancer.