This new injectable 'biogel' reportedly is effective in delivering anti-cancer agents directly into cancerous tumors and killing them. The compound is made from chitosane, a biodegradable material extracted from the shells of crustaceans, to which gelling agents are added.
For most, the term biogel conjures up images of a vaguely translucent, semi-solid gelatinous material that is applied to the body either topically or internally. Now, researchers at the University of Montreal Hospital Research Centre (CRCHUM) have successfully developed an injectable biogel that is liquid at room temperature and solidifies at 37°C—human body temperature—that can deliver anti-cancer agents directly into cancerous tumors.
“The strength of this biogel is that it is compatible with anti-cancer immune cells,” explained Réjean Lapointe, Ph.D., director of the laboratory of immuno-oncology at CRCHUM and associate professor in the department of medicine at the University of Montréal. “It is used to encapsulate these cells and eventually administer them using a syringe or catheter into the tumour or directly beside it. Instead of injecting these cells or anti-cancer drugs throughout the entire body via the bloodstream, we can treat cancer locally. We hope that this targeted approach will improve current immunotherapies.”
A current and reasonably successful form of immunotherapy involves treating cancer patients with anti-cancer immune cells (CD8+ T cells) taken from their bodies and grown in the laboratory to amplify the total number of cells. The immune cells are then reinjected back into the patient’s bloodstream, which allows them help control the growth and spread of the cancer.
The biogel developed by the CRCHUM team will allow physicians to administer the patient-derived T cells directly into tumors, as well as provide a nutrient growth media for immune cells to continually grow and attack the cancer.
“With our technique, we only need to administer a few dozen million T cells, instead of the billions currently required,” noted Dr. Lapointe. “We can also administer compounds that 'awaken' the immune system to fight against cancer.”
The findings from this study were published recently in Biomaterials through an article entitled “Chitosan thermogels for local expansion and delivery of tumor-specific T lymphocytes towards enhanced cancer immunotherapies.”
The investigators went through several years of trial and error, trying to balance the physiochemical properties such as pH, osmolality, macroporosity, and gelation rates before developing the current biogel formulation.
“The compound is made from chitosan, a biodegradable material extracted from the shells of crustaceans, to which gelling agents are added,” remarked Sophie Lerouge, Ph.D., principal scientist at the CRCHUM and professor in the department of mechanical engineering at the École de technologie supérieure in Montréal. “The formulation is liquid at room temperature, which facilitates its injection, but quickly takes on a cohesive and resistant structure at 37 degrees. We also needed a hydrogel that was non-toxic for the body and provided excellent survival and growth of the encapsulated cells.”
The researchers tested the biogel on several in vitro models including melanoma and kidney cancer, where the encapsulated T cells thrived and were able to maintain their anti-cancer functions for several weeks. “The T lymphocytes in the gel are functional and can grow for two to three weeks, be released from the gel, and kill the cancerous cells,” stated Dr. Lapointe.
The team’s next step is to demonstrate the effectiveness of the biogel in animals and humans, where if successful, this novel approach could be added to current cancer therapies within a few years.