1. Field of the Invention
The field of the invention relates to a method of preparing the radiation-sensitive copolymer carrier for coating radiated nanoparticles and/or chemotherapy drugs used in proton therapy.
2. Description of the Related Art
Cancer, also known as malignant tumor, has been the first place of top ten causes of death for a long time; especially lung cancer and liver cancer are the most common types of cancer. Cancer occurs due to human cell diseases, and is treated in common clinical treatment of surgery, radiation, therapy, chemotherapy, and targeted therapy so far. Different treatment effects toward focus of infection of cancer vary from indications to assorted treatments.
The basic principle of radiation therapy is utilizing radioactivity to block the double helical chains in DNA (deoxyribonucleic acid) of cancer cell nucleus for the purpose of killing the cancer cells or inhibiting their growth. Traditional photon therapy that produces gamma radiation or X-radiation through human body, while the energy decaying exponentially relative to the increasing depth into tissue, many other normal tissue would be influenced by the radioactivity before cancer cells being destroyed. The feature of proton therapy is that the energy increasing with distance and slowing down at the range end, namely the location of targeted tumor, to release the maximum energy in an instant, forming a Bragg peak for providing effective treatment to cancer cells with high doses of chemotherapy drugs, and being almost no harm to healthy tissue. For the sake of proton therapy having the feature of spread-out Bragg peak (SOBP), the risk of damaging normal tissue during treatment can be reduced along with a minimum side effect relatively.
The physical characteristics of proton and X-radiation are different. X-radiation can treat tumor located in deep tissue for powerful penetration that accompanies defective effect of leaving high doses at forward tissue before reaching the tumor and damaging adjacent normal tissue with considerable residual doses after penetrating the tumor. Proton releases little energy during through tissue to reach the tumor, but discharges large energy in the tumor after reaching preferred depth of the tumor, the feature is called Bragg peak, without leaving any energy on normal tissue after penetrating the tumor. Because a single Bragg peak is not wide enough, it is necessary to combine several Bragg peaks to expand it to tumor size for enhancing proton therapeutic effect. Proton therapy is currently the most advanced tumor radiation therapy technology in the world for little damage to normal cells around the focus of infection and less side effects relatively, and is expected to be universalized in the future.
Traditional radiation therapy utilizes X-radiation to position and treat tumor, but is unable to accurately control the position and the dose for the tumor to avoid normal tissue between body surface and the tumor from receiving the dose and being damaged. A therapeutic method with accurate positioning and dose is in demand for cancer treatment.
US patent publication No. 2007/0031337 A1 discloses a method of proton tomography utilizing good combination characteristic of gold nanoparticle with antibody to attract antigen in the cancer cells to achieve better treatment positioning and chemotherapy drug dose control. Utilizing proton computer tomography (PCT) system for cancer treatment can be expected to become a trend in the future. However, the cited reference, US patent publication No. 2007/0031337 A1, didn't disclose the preparation of a carrier that can be utilized for coating radiated nonoparticles and/or chemotherapy drugs.