硫化铜纳米片的可控合成及光热治疗应用文献综述

Controlled synthesis of copper sulfide nanoplates for photothermal therapy

• Author: MAGUE CLARENCE JOELLE
• Supervisor: SUN XIAO LIAN
• Institute: China pharmaceutical university

1. Introduction

In todayrsquo;s society, with the growing environmental problems and food safety problems, the incidence of cancer is also increasing.

Cancer is the second leading cause of death in the world after cardiovascular diseases. Today, millions of cancer people extend their life due to early identification and treatment. Cancer is not a new disease and has afflicted people throughout the world. The number of people who has been diagnosed with cancer increases in different degree every year. Cancer has become one of the main diseases that threaten the safety of human life. Of all cancers, lung cancer, cancer of the stomach and liver cancer are most deadly. At present, the traditional methods of cancer treatments are chemotherapy, physical radiation therapy and surgical resection. These traditional cancer treatments are suitable for early cancer resection, while as for the advanced cancer, radiotherapy and chemotherapy will be the better choices.

Copper (II) sulfide nanoparticles are semiconductor chalcogenides with unique electronic and optical properties. As semiconductor, the bandgap of copper sulfide varies depending on its atomic composition between 1.2 eV for Cu2S to 2.0 eV for CuS, which allows it to absorb a large fraction of the solar spectrum(1 )As plasmonic material, it absorbs near-infrared (NIR) light converting it into heat due to the excitation of direct (band-to-band) transitions, indirect transitions, and plasmonic photoexcitation(2) Those electro-optical properties make copper sulfide nanoparticles useful in not only photovoltaic cells but also a wide variety of biomedical applications including electrochemical sensing(3) photothermal therapy(4) diagnosis,theragnosis(5) and combination therapies(6).

In this thesis we will present in introduction, the different cancer therapy method, the photothermal therapy principle, the photothermal therapy agents, the synthesis of cuS NPs and the objectives of the study; the second part of our thesis will describe our methods and the third part we will present our result.

• 1. Cancer therapy method
• Surgery:

Many people even today consider that many types of cancers are incurable and may delay to consult a doctor in early stage. After anesthesia was invented in 1846, surgeons Bilroth, Handley and Halsted led cancer operations by removing entire tumor together with lymph nodes. Later Paget a surgeon reported that cancer cells were spread from primary tumor to other places through the blood stream (metastasis). Understanding the mechanism(s) of cancer spreading became a key element in recognizing the limitations of cancer surgery.

In the beginning of 1970s, progress in ultrasound (sonography), computed tomography (CT scans), magnetic resonance imaging (MRI scans) and positron emission tomography (PET scans) have replaced most exploratory operations. Using miniature video cameras and endoscopy, surgeons can remove colon, esophagus and bladder tumors through tubes. Recently, less invasive ways of destroying tumors without removing them are being studied including liquid nitrogen spray to freeze and kill cancer cells (cryosurgery). Lasers also can be used to cut the tumor tissue of cervix, larynx, liver, rectum, skin and other organs (7).

• Chemotherapy:

During the last decades of the 20th century, surgeons developed new methods for cancer treatment by combining surgery with chemotherapy and/or radiation. Roentgen discovered X-rays after 50 years of anesthesia was discovered. Later doctors identified that nitrogen mustard can kill rapidly proliferating lymphoma cancer cells. Over the years, use of many chemotherapy drugs has resulted in the successful treatment of many types of cancers. Now new approaches are being studied to reduce the side effects of chemotherapy including use of new combinations of drugs, liposomal and monoclonal antibody therapy to target specifically cancer cells, chemo protective agents to reduce chemotherapy side effects, hematopoietic stem cell transplantation and agents that overcome multidrug resistance(7).

• Radiation therapy

In 1896 Roentgen discovered “X-ray” and after 3 years later radiation was used for cancer diagnosis and in treatment. In the early 20th century, researchers discovered that radiation could cause cancer as well as cure it. Now several radiation therapies are being used, these include: conformal proton beam therapy (proton beam will be used for killing tumor cells instead of X-rays); stereotactic surgery and stereotactic therapy (gamma knife can be used to deliver and treat common brain tumor); intra-operative radiation therapy (cancer has been removed surgically followed by radiation to the adjacent tissues (7).

• Immunotherapy

Use of biological agents that mimic some of the natural signals that body uses to control tumor growth is called immunotherapy. These natural biological agents can now be produced in the laboratory including interferons, interleukins, cytokines, endogenous angioinhibitors and antigens. In 1990s scientists produced therapeutic monoclonal antibodies rituximab and trastuzumab that specifically targeted lymphoma and breast cancer cells. At present scientists are developing vaccines to boost the bodyrsquo;s immune response against cancer cells.