Invisible polymer tightens skin and delivers drugs

A silicone-based polymer has been developed that can temporarily protect skin and with further development could be used to deliver drugs

Scientists at Massachusetts Institute of Technology (MIT), Massachusetts General Hospital, Living Proof and Olivo Labs developed the polymer that could be used to deliver drugs to help treat skin conditions such as eczema and other types of dermatitis.

The silicone-based polymer is applied on the skin as a thin coating and in tests with human subjects was able to enhance skin hydration and could also be adapted to provide long-lasting ultraviolet protection, according to MIT.

Daniel Anderson, an associate professor in MIT’s department of chemical engineering and one of the authors of the paper describing the material, said: “It’s an invisible layer that can provide a barrier, provide cosmetic improvement, and potentially deliver a drug locally to the area that’s being treated. Those three things together could really make it ideal for use in humans.”

The researchers created a library of more than 100 possible polymers, all of which contained a chemical structure known as siloxane — a chain of alternating atoms of silicon and oxygen. These polymers can be assembled into a network arrangement known as a cross-linked polymer layer (XPL).

“We started thinking about how we might be able to control the properties of skin by coating it with polymers that would impart beneficial effects,” Anderson said. “We also wanted it to be invisible and comfortable.”

The researchers tested the materials in search of one that would best mimic the appearance, strength, and elasticity of healthy skin.

The best-performing material has elastic properties very similar to those of skin, according to MIT.

In laboratory tests, it returned to its original state after being stretched more than 250% and MIT said the novel XPL’s elasticity was much better than that of two other types of wound dressings now used on skin — silicone gel sheets and polyurethane films.

The XPL is currently delivered in a two-step process. First, polysiloxane components are applied to the skin, followed by a platinum catalyst that induces the polymer to form a cross-linked film that remains on the skin for up to 24 hours.

This catalyst has to be added after the polymer is applied because after this step the material becomes too stiff to spread. Both layers are applied as creams or ointments and once spread onto the skin XPL become essentially invisible, according to MIT.

“I think it has great potential for both cosmetic and noncosmetic applications, especially if you could incorporate antimicrobial agents or medications,” said Thahn Nga Tran, a dermatologist and instructor at Harvard Medical School.