Microneedle patches: new drug carriers improve cancer treatment
As a rule, microneedle patches deliver drugs to the body more efficiently or faster than injections or oral tablets. Microneedles can deliver more medication than an injection, and it is not destroyed in the digestive tract. Usually, after a while, the needles dissolve harmlessly. Also, depending on the design of the microneedles, the drug can be quickly absorbed into the body in 5 minutes or gradually released over the course of a month. Therefore, microneedles of different designs are used to treat different types of cancer.
Next, we'll look at how microneedles are improving the treatment of two types of cancer. We will begin each example by explaining how a particular type of treatment works.
Precise Immunotherapy for Skin Cancer
Cancer cells are able to defend themselves against the anti-cancer activity of immune cells. Cancer cells use the chitcode, a receptor on T cells that triggers their apoptosis. The fact is that T-cells, in the course of their development, can also mutate and become harmful. Therefore, in their membrane there is a PD1 (programmed cell death) protein. Activation of PD1 blocks the work of the T cell and triggers apoptosis. Through PD1, the immune system kills those T cells that become harmful.
Many cancer cells produce and display PD-L1, a ligand that binds to and activates PD1. As a result, PD-L1 suppresses the work of T cells, making tumor cells invulnerable to immunity. Since the late 20th century, scientists have been developing immunotherapy, a treatment that is supposed to protect immune cells and stimulate their anti-cancer activity. Antibodies for immunotherapy bind to PD-L1 and prevent it from turning off T cells. Immunotherapy is already being treated in patients whose tumors are producing a lot of PD-L1. For them, immunotherapy is often more effective than conventional chemotherapy.
Microneedles help treat skin cancer as accurately as possible. Nanospheres are placed inside them - capsules with antibodies inside. When the microneedle enters the dermis, it gradually dissolves, and capsules with antibodies gradually emerge from its matrix. But antibodies are released only near the cancerous tumor. The fact is that the capsules dissolve only when the acidity of the medium increases. And the environment around the tumor is acidic due to a very active metabolism and a large amount of waste from cancer cells.
Thus, antibodies are only released when they reach the tumor. And the patient can even use such a patch on his own, without the supervision of a doctor and at home.
Targeted chemotherapy for pancreatic cancer
Molecules for chemotherapy disrupt the most important processes in the cell. They interfere with the work of DNA or the intracellular skeleton - they stop cell reproduction, thereby triggering cell death. This affects cancer because the tumor grows rapidly and absorbs compounds from the blood more actively than other tissues. Tumors often develop resistance to one drug or another. Therefore, doctors prescribe several drugs at once - combined chemotherapy is more effective than drugs alone.
Pancreatic cancer is one of the most lethal. He is treated with gemcitabine, a drug that stops the doubling of the genetic material of cells, that is, blocks their division and tumor growth in general. But it is toxic to other living cells and not effective enough against cancer because it is injected into the blood. And a cancerous tumor makes the pancreatic tissue around it poorly permeable to any substances. These problems can be corrected with microneedles.
Bioengineers have created a patch whose microneedles deliver gemcitabine exactly inside the pancreas. The plaster is made in a special shape, with small suction cups - like an octopus - so that it stays on the pancreas better. And he did an excellent job with the introduction of the drug: he maintained a high concentration of the drug in the gland without killing living cells throughout the body. Within three weeks of this treatment, cancerous tumors were reduced by almost 75%. They were compared with mice that were injected with the same doses of the drug as in microneedles. They felt worse and lost weight (due to the toxicity of the treatment), and their cancers were poorly treated with such low doses of the drug.
Cancer treatment, especially immunotherapy, remains relevant due to the development of treatment improvements. It is very important to continue to research the topic and develop better versions of immunotherapy. And it's much easier to do this with Chemdiv's PD-1/L1 Library - it's a complete set of reagents for any experiment. And if you are researching something else, then in the catalog on our site you will surely find a library that will also help in your work.
1. Jamaledin, Rezvan, et al. "Engineered microneedle patches for controlled release of active compounds: recent advances in release profile tuning." Advanced Therapeutics 3.12 (2020): 2000171.
2. Li, Dongdong, et al. "Progress and perspective of microneedle system for anti-cancer drug delivery." Biomaterials 264 (2021): 120410.
3. Wang, Chao, et al. "Enhanced cancer immunotherapy by microneedle patch-assisted delivery of anti-PD1 antibody." Nano letters 16.4 (2016): 2334-2340.
4. Fu, Xiao, et al. "Bioinspired adhesive microneedle patch with gemcitabine encapsulation for pancreatic cancer treatment." Chemical Engineering Journal 431 (2022): 133362.