Companies have been trying for years, if not decades, to find a way to encapsulate cells for therapeutic use in a way that protects them from the body’s reactions. Sigilon Therapeutics, a Cambridge, MA-based biotech, announced today it has raised $23.5 million from Flagship Pioneering to take its technology to clinical trials.
The company has developed capsules that hold cells engineered to secrete therapeutic proteins, which Sigilon says can target disorders of the blood and enzymes, and possibly diabetes, too. The capsules are notable, Sigilon says, because they were developed to avoid tissue scarring and immune responses that have historically killed or disabled the cells and prevented them from delivering the therapy.
Sigilon uses a chemically altered version of a polymeric capsule—specifically an alginate, which comes from algae—that prevents the immune system from recognizing the cell in the capsule as a foreign body. This capsule also prevents fibrosis, the body’s scarring response to foreign objects. The chemical alteration was developed by co-founders Daniel Anderson, a professor of chemical engineering at MIT, and Robert Langer, the prolific MIT researcher and Xconomist.
“What’s new about our platform is that the chemistry that was used really provides an anti-fibrotic effect to the alginate, which has never been seen before,” says CEO Paul Wotton. “When you put a foreign body into someone like you or me, your body starts to attack that implant. What this chemistry does is it prevents this scar tissue from occurring.”
That approach has allowed Sigilon’s encapsulated cells to remain in animals for as long as year, according to studies the company has performed. Typically, the scarring will deprive cells of nutrients or oxygen they need to survive in about a month, Wotton says.
Sigilon was founded in 2016, but the research dates back at least a decade and was initially funded by grants from the Juvenile Diabetes Research Foundation, or JDRF, Wotton says. Langer and Anderson have both received JDRF grants that total approximately $18.8 million, according to the nonprofit’s public records, which show the initial focus was on diabetes. That has since broadened.
The capability of Sigilon’s encapsulation materials is a reason for optimism, especially given the decades researchers have spent trying to effectively deliver cell therapies, says John Wilson, an assistant professor of chemical and biological engineering at Vanderbilt University. Therapeutics developed with these methods are only as good as the cells being encapsulated, Wilson adds.
“I think it’s fair to say these materials are a big enough breakthrough to usher in a new era of optimism for these approaches, at least from the standpoint of the encapsulation device,” Wilson says. “With all the recent advances in cell engineering over the past decade, it’s exciting to see new polymers for cell encapsulation emerge that can complement these advancements.”
Cellular therapies have regained popularity in recent years by biotechs targeting developing treatments for all sorts of conditions, from makers of advanced cancer treatments to biotechs such as ViaCyte, which makes packets of stem cells that are engineered to develop into pancreatic cells for diabetics. Type 1 diabetes is a big target in cell therapy world because it destroys pancreatic beta cells, which regulate blood sugar levels in the body.
One researcher who Xconomy spoke to in San Antonio believes he has a cocktail of molecules that can stimulate the new formation of insulin-secreting beta cells. Semma Therapeutics, a Cambridge-based drug developer founded by MIT professor Douglas Melton, similarly says it can generate fully functioning beta cells from pluripotent stem cells—and potentially unlimited amounts of them.
Semma says it has its own encapsulation technology that can protect beta cells from the patient’s immune system, though it hasn’t revealed
