Essay --

Introduction Cancer is a wide-ranging group of diseases caused by uncontrolled cell growth that more than 200 different types have been identified. In this disease, the cells divide and grow intensity, forming malignant tumors, and invading nearby parts of the body(1). Cancer has been in the whole of human history. The oldest written record dates back to about 1600 years BC in Egypt described breast cancer(2). The cause of cancer is complex and partly unknown. Although only 5-10% of cancers are due to inherited gene defects, tobacco, poor diet, certain infections, treated with radiation, lack of physical activity, obesity and pollution can directly damage genes and ultimately lead to carcinogenic mutations (3). Rendering to recent statistics, cancer is responsible for 23% of all deaths in USA and is the second most common cause of death after heart disease (4). It is expected that by 2020 the world population reaches 7.5 billion that 15 million new cases diagnosed and 12 million patients will lose their lives (5). Based on figures provided in 2013 by the American Cancer Society, the most common cancer in women is breast cancer (29%) and in men is prostate cancer (28%) (6). Surgery as a primary method in treatment of solid cancers involved in pain relief and patients survival. In surgery the tumor was completely removed along with the lymph nodes in the area. This method is the only way to eliminate some cases of cancer (7). Other intrusive processes that commonly used are radiation and chemotherapy with the aim of killing the cancerous cells. Because they grow and divide faster than healthy cells so they are sensitive to chemotherapeutic and radiation agents(8). Regarding that the efficiency of a method directly depends on its ab... ...sed to form silica xerogels loaded with drugs, so a changing production conditions(as the ratio of reagents, temperature and concentration of catalyst may alter the properties of xerogels(14). In comparison, mesoporous silica nanoparticles (MSN) form into homogenous structure with higher surface area that is favorable for adsorption of therapeutic drugs(41). MSN particles possess the ability to load large and small molecules, adsorption of DNA and gene transfering(14). A variety of drugs including antibiotics(42), anticancer drugs(41) and heart disease drugs(43) are loaded into mesoporous silica nanoparticles by chemichal or physical adsorption mechanism(41). Through the work of various research groups, it has been shown that silica particles are biocompatible and have a great potential for a variety of diagnostic and therapeutic applications, but recent studied