Nanoparticle exerts its site-specific drug delivery by avoiding the reticuloendothelial system, utilizing enhanced permeability and retention effect and tumors pecific targeting. These carriers are designed in such a way that they are independent in the environments and selective at the pharmacological site. The formation of nanoparticle and physiochemical parameters such as pH, monomer concentration, ionic strength as well as surface charge, particle size and molecular weight are important for drug delivery. Further, these nanoparticles have the capability to reverse multidrug resistance a major problem in chemotherapy
Tumor markers are substances that are produced by cancer or by other cells of the body in response to cancer or certain benign (noncancerous) conditions. Most tumor markers are made by normal cells as well as by cancer cells; however, they are produced at much higher levels in cancerous conditions. These substances can be found in the blood, urine, stool, tumor tissue, or other tissues or bodily fluids of some patients with cancer. Most tumor markers are proteins. However, more recently, patterns of gene expression and changes to DNA have also begun to be used as tumor markers.
Many different tumor markers have been characterized and are in clinical use. Some are associated with only one type of cancer, whereas others are associated with two or more cancer types. No “universal” tumor marker that can detect any type of cancer has been found.
There are some limitations to the use of tumor markers. Sometimes, noncancerous conditions can cause the levels of certain tumor markers to increase. In addition, not everyone with a particular type of cancer will have a higher level of a tumor marker associated with that cancer. Moreover, tumor markers have not been identified for every type of cancer.
CA15-3/CA27.29
- Cancer type: Breast cancer
- Tissue analyzed: Blood
- How used: To assess whether treatment is working or disease has recurred
A doctor takes a sample of tumor tissue or bodily fluid and sends it to a laboratory, where various methods are used to measure the level of the tumor marker.
If the tumor marker is being used to determine whether treatment is working or whether there is a recurrence, the marker’s level will be measured in multiple samples taken over time. Usually these “serial measurements,” which show whether the level of a marker is increasing, staying the same, or decreasing, are more meaningful than a single measurement.
Cancerous tumors are characterized by cell division, which is no longer controlled as it is in normal tissue. “Normal” cells stop dividing when they come into contact with like cells, a mechanism known as contact inhibition. Cancerous cells lose this ability. Cancer cells no longer have the normal checks and balances in place that control and limit cell division. The process of cell division, in both normal and cancerous cells, is through the cell cycle. The cell cycle goes from the resting phase, through active growing phases, and then to mitosis (division).
The ability of chemotherapy to kill cancer cells depends on its ability to halt cell division. Usually, the drugs work by damaging the RNA or DNA that tells the cell how to copy itself in division. If the cells are unable to divide, they die. The faster the cells are dividing, the more likely it is that chemotherapy will kill the cells, causing the tumor to shrink. They also induce cell suicide (self-death or apoptosis).
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