Restiex® is a delayed-swelling hydrogel and is available for experimentation but not for clinical use as a tissue expander.
Re-Shapable Tissue Expanding Hydrogel
This PowerPoint was used in our Controlled Release Society (CRS) 2011 presentation.
Most current tissue expanders are comprised of a silicon rubber balloon through which saline is injected causing the balloon to inflate stretching the tissue. These expanders must be injected repeatedly over the course of several weeks to months in order to stretch the tissue to the desired size. Due to these multiple injections and these materials being non-biocompatible the incidence of infection with this procedure is fairly high (an estimated 2-15%). Other "self-filling" expanders are made with a silicone shell which controls the expansion rate and can only be used as the purchased size and shape without being modified prior to implantation. To overcome these problems the PolySciTech® division of Akina has been researching an in-house proprietary hydrogel material that has inherent properties controlling its expansion without the need for an external membrane.
The objective of current tissue expanding hydrogels research at PolySciTech, Inc. is to develop a novel hydrogel-based tissue expander that has delayed expansion with the capacity to be reshaped by the surgeon at the time of implantation. This is accomplished by chemically conjugating "delay" components with "swelling" components so that as the hydrogel is exposed to moisture its expansion is in a slow and delayed manner allowing for the tissue to be expanded without damage or necrosis.By altering the composition of the "swelling" and "delay" components these hydrogels can have their swelling properties altered.
Also, judicious selection of these ingredients creates an expander that is very flexible and soft while it is dry allowing it to be cut by the surgeon at the time of implantation allowing voids of any size and shape to be custom filled.
These hydrogels can serve as tissue expanders by having their delay time preprogrammed to allow the initial incision to heal prior to expansion. Phase I research performed at PolySciTech®, supported by NIH small business innovative research grant, has established that these hydrogels can be made that fit the requirements necessary for a surgical device. PolySciTech has been awarded a phase II research grant by the NIH and is currently determining safety and efficacy of these devices for use in dental applications. These materials have shown promise when used in animal models. We are interested in partnering with another company which has the manufacturing capabilities to generate these materials at medical grade quality. Please contact us to discuss this opportunity further.