Multifunctional Photothermal Diagnosis And Treatment System Based On Heptathiocyanine Self-Assembly Material

Malignant tumor is one of the main causes of death of mankind,which not only threatens the life and health of countless people,but also brings torture and pain to the patients’ families.While there has been a welcome decline in death rates for some cancers,the global rise in cancer deaths shows that the fight against cancer remains daunting.At present,the main therapeutic methods are surgery,radiotherapy and chemotherapy,which all have their own limitations and do great harm to the patient’s fragile body.In contrast,photothermal therapy is non-invasive,high efficiency and controllable advantages are extremely obvious.Heptamethine cyanine molecules in photothermal therapy can form supramolecular aggregates through self-assembly to improve photothermal stability and photothermal conversion efficiency.It can also realize dynamic imaging monitoring through photoacoustic and fluorescent signals.At the same time,high hydrogen peroxide content and lack of oxygen in the microenvironment at the tumor site will not only induce malignant cell proliferation and disease deterioration,but also may induce inflammation,diabetes and other diseases.Nanozymes with catalase activity can not only eliminate hydrogen peroxide,but also produce oxygen to alleviate the hypoxic environment of tumors.Therefore,we designed a multifunctional photothermal supramolecular diagnosis and treatment system with enzyme activity by introducing selenium to achieve the decomposition of hydrogen peroxide and the relief of hypoxic environment.In vitro experiments verified the excellent photothermal ability of the system catalase activity,and animal experiments proved that the system has the ability to achieve photothermal therapy,photoacoustic imaging and fluorescence imaging,and can achieve the purpose of treating tumors through photothermal therapy and catalase activity..