Multiple organs consists of macroporous structures such as the lung, bone, and kidney. However, when creating porous materials, added factors are quickly washed away, thus there is a need to bind them to the material.
Elastin-like Recombinamer (ELR) hydrogel is a type of biomaterial that has proved to have excellent biocompatible properties , where we here create a macroporous version using the cryogelation technique and functionalize it with recombinant glycosaminoglycans to have a controlled release of growth factors.
ELR is a two-part solution, which are modified so that one part has an alkyne modification while the second part has an azide modification. When these two parts are mixed a covalent bond is formed resulting in a hydrogel. ELR cryogel was created by forming the hydrogel in subzero temperatures. Azide containing glycosaminoglycans were covalently added during the formation to slow the release of growth factors.
ELR cryogels were subcutaneously implanted in mice, where cryogels with added growth factor only showed an increased blood vessel formation but the addition of recombinant glycosaminoglycans in combination with growth factor showed a change in the immune response going from a more inflammatory state to a more regenerative state shown by the shift of present macrophage phenotypes.
The data showed that an ELR-based cryogel is a promising synthetic scaffold for tissue engineering, mimicking the 3D environment of the extracellular matrix and that recombinant glycosaminoglycans can be added for a controlled release of growth factors.
Financial support was received from the Swedish Heart-Lung Foundation, Swedish Research Council, Crafoord Foundation, Royal Physiographical Society of Lund, Österlund Foundation.
 A. Ibanez-Fonseca et al. J Tissue Eng Regen Med. 2018;12:e1450–e1460."