Treating Melanoma with a “Chemotherapy Paste” for Better Tolerance
According to the American Skin Cancer Foundation, melanoma is the most lethal form of cancer due to its capability of spreading from the skin to almost anywhere else in the body. For that reason, it has traditionally been necessary to take a very aggressive stance when treating skin cancers, using intravenous chemotherapy, radiation therapy, and surgery. For better tolerance and less crippling systemic side effects, scientists have developed a “chemotherapy paste” that can be applied directly to the skin to bypass the systemic treatment modality, and treat melanoma without the patient experiencing nausea and vomiting often associated with intravenous chemotherapy.
The culprits behind skin cancer are squamous cells, basal cells, and melanocytes. Melanocytes are the cells which are subject to becoming melanoma. They manufacture a brownish pigment called melanin, which imparts a tan or brown color to the skin, and protect deeper skin layers from harmful rays of the sun. When skin is exposed to the sun, melanocytes produce more melanin, which causes the skin to become darker.
Melanoma is a skin cancer which develops from melanocytes, and although it can develop anywhere on the skin surfaces, melanoma develops most commonly on the chest and on the back for men, whereas for women it most frequently develops on the legs. For both men and women, it can also develop on the face and neck. Melanoma occurs less frequently than either squamous cell cancers or basal cell cancers, but all three cells can be targets for skin cancer.
The skin is normally the first line of defense against any kind of harmful microbe or material, which would otherwise penetrate the body and wreak havoc. Unfortunately, this brilliant barrier also prevents useful drugs from being directly admitted onto the skin to treat skin diseases until recently.
A group of researchers developed a “chemotherapy paste” that incorporates nanoparticles called transfersomes to aid drug delivery through the skin to directly treat skin cancer. These transfersomes encase chemotherapy—in this case, paclitaxel—in a phospholipid bilayer-based surfactant that render the drug malleable to help penetrate the skin’s epidermal layers. A peptide was added to the transfersome complex to enhance its ability to infiltrate the skin and cancer cells and deliver paclitaxel directly to the tumor. To prolong the skin-penetrating effects, the “chemotherapy paste” was encased in a hydrogel medium to cover the “painted-on” site of the paste.
When the transfersome paste was applied to mice with melanoma, tumor sizes were reduced by half after 12 days compared to the set of mice that were receiving chemotherapy injections alone. However, it is still too early to see if the same results will transfer to humans, though a non-systemic “chemotherapy paste” approach to treating cancer will be a breakthrough that can vastly improve quality of life for cancer patients.