Multidomain hybrid hydrogels : Spatially resolved photopatterned synthetic nanomaterials combining polymer and low-molecular-weight gelators

A simple approach to a patterned multidomain gel is reported, combining a pH-responsive low-molecular-weight gelator (LMWG) and a photoinducible polymer gelator (PG). Using SEM (scanning electron microscopy), NMR spectroscopy, and CD, we demonstrate that self-assembly of the LMWG network occurs in the presence of the PG network, but that the PG has an influence on LMWG assembly kinetics and morphology. The application of a mask during photoirradiation allows patterning of the PG network; we define the resulting system as a "multidomain gel"-one domain consists of a LMWG, whereas the patterned region contains both LMWG and PG networks. The different domains have different properties with regard to diffusion of small molecules, and both gelator networks can control diffusion rates to give systems capable of controlled release. Such materials may have future applications in multikinetic control of drug release, or as patterned scaffolds for directed tissue engineering.