ABSTRACT
Multifunctional biomedical materials capable of integrating optical functions are highly desirable for many applications, such as advanced intra-ocular lens (IOL) implants. Therefore, poly(ethylene glycol)-diacrylate (PEG-DA) hydrogels are used with different photoinitiators (PI). In addition to standard UV PI Irgacure, Erythrosin B and Eosin Y are used as PI with high sensitivity in the optical range of the spectrum. The minimum PI concentrations for producing new hydrogels with PEG-DA and different PIs were determined. Hydrogel films were obtained, which were applicable for light-based patterning and, hence, the functionalization of surface and volume. Cytotoxicity tests confirm cytocompatibility of hydrogels and compositions. Exploiting the correlation of structure and function allows biomedical materials with multifunctionality.
ABSTRACT
In the present work, a soft lithographic process is used to create nanometer-sized line patterns of gold nanoparticles (Au NPs) on PEG-based hydrogels. Hereby nanometer-sized wrinkles on polydimethylsiloxane (PDMS) are first fabricated, then functionalized with amino-silane and subsequently coated with Au NPs. The Au NPs are electrostatically bound to the surface of the wrinkled PDMS. In the next step, these relatively loosely bound Au NPs are transferred to PEG based hydrogels by simple contacting, which we denote "nano-contact transfer". Nano-patterned Au NPs lines on PEG hydrogels are thus achieved, which are of interesting potential in nano-photonics, biosensor applications (using SERS) and to control nanoscopic cell adhesion events.
