A hydrogel developed at the Massachusetts Institute of Technology (MIT) could allow drugs to release the active ingredients over a period of time. Current techniques for doing this involve surgical implantation, but this new hydrogel can be delivered through an injection.
Cellulose or other polymers are used to encase nanoparticles, made of Peg-Pla copolymers. This structure allows bonds in the structures to break apart when being squeezed through a small space, such as a needle. After shear forces are released, the polymer molecules match up with new partners, reforming the hydrogel.
"Now you have a gel that can change shape when you apply stress to it, and then, importantly, it can re-heal when you relax those forces. That allows you to squeeze it through a syringe or a needle and get it into the body without surgery," Mark Tibbitt from MIT's Koch Institute for Integrative Cancer Research said.
The new hydrogel can carry one or two drugs per dose, including treatments for cancer, heart disease and macular degeneration. The inner core is designed to carry small molecules, such as chemotherapy drugs, which repel water, while the outer core is suited to delivering water-loving molecules, such as antibodies and proteins. Each of two drugs can be employed for different purposes and released at independent rates.
Current hydrogels designed for medical use are manufactured with irreversible chemical bonds between polymer molecules, similar to the material in soft contact lenses. This material is not able to change shape as it is being implanted into patients, requiring surgical procedures. Some researchers have also worked on creating proteins that self-assemble into hydrogels, but the process is complex.
Cancer surgery often leaves behind malignant cells that can form tumors, resulting in the return of the disease in patients. The new hydrogel could attract and attack these cells, aiding in recovery.
"Removing the tumor leaves behind a cavity that you could fill with our material, which would provide some therapeutic benefit over the long term in recruiting and killing those cells. We can tailor the materials to provide us with the drug-release profile that makes it the most effective at actually recruiting the cells," Eric Appel of the Koch Institute said.
Growth factors delivered by the hydrogel could help repair damage in hearts, rebuilding muscle.
Patients suffering from macular degeneration are currently subject to receiving injections in their eyes once a month to treat the disorder. Delivering drugs through this new hydrogel would allow the medicine to be released over the course of several months, reducing the number of visits needed.
Development of the new injectable hydrogel was detailed in the journal Nature Communications.