Hydrogels are highly hydrated polymer networks that can be used in the regenerative medicine field as “scaffolding” for the repair of tissue. A proposed new ASTM standard will provide those working in regenerative medicine with a means of characterizing hydrogels. The standard, WK21927, Guide for Characterization of Hydrogels Used in Regenerative Medicine, is under the jurisdiction of Subcommittee F04.42 on Biomaterials and Biomolecules for TEMPs (tissue-engineered medical products), part of ASTM International Committee F04 on Medical and Surgical Materials and Devices.
According to Melissa Mather, strategic research fellow, National Physical Laboratory and an F04 member, two factors are contributing to the substantial projected growth of hydrogels for medical use: advances in polymer synthesis that enable the manufacture of tailored, environmentally sensitive gels and a paradigm shift in tissue engineering toward using the body as a bioreactor to repair itself rather than cultivating tissue in vitro for implantation.
“The move toward using the body as its own bioreactor has resulted in the development of new hydrogel systems, ones that can be injected into wound sites together with cells and growth factors to form self-assembled structures that greatly facilitate healing, the rebuilding of nerves and repair of cartilage,” says Mather.
Because hydrogels have a high water content and are mechanically weak, it can be difficult to characterize them in terms of size of the network mesh and to gather data on permeability and mechanical resilience. Many current characterization approaches use dry samples, but the act of drying can alter the structure of a hydrogel in a way that is not easily measured.
“There are a number of techniques available for characterizing hydrogels and for drying them,” says Mather. “The proposed new guide will provide a critical overview of these, presenting the information in such a way that it can be easily understood by the multidisciplinary readership active in regenerative medicine.”
Interested parties are welcome to join in the development of WK21927. “We are particularly keen to hear from anyone working with hydrogels in regenerative medicine but recognize that people from other industry sectors, for example, food science, may also wish to contribute to developing the document,” says Mather.
Technical Information: Melissa Mather, National Physical Laboratory, Teddington, England, United Kingdom
ASTM Staff: Daniel Schultz