Gold nanoparticles (Au NPs) have unique and tunable size- and shape-dependent optical and chemical properties and little toxicity. In this chapter, we describe results on Au NPs employed as cell-binding entities at biomaterials’ interfaces. Hereby, Au NPs with different sizes and shapes were nano- or micro-patterned on the surface of poly(ethylene glycol) (PEG)-based hydrogels by using our recently developed patterning strategies based on soft lithography. These hybrid biomaterials can be applied in various biological or biomedical applications, such as for fundamental cell studies considering adhesion and migration, tissue engineering, drug delivery, or as biosensors by using surface plasmon resonance (SPR) or surface-enhanced Raman spectroscopy (SERS).
Part of the book: Noble and Precious Metals
Multifunctional biomedical materials capable of integrating optical functions open up promising new possibilities for the application of photosensitive materials. For example, they are highly desirable for advanced intraocular lens (IOL) implants. For this purpose, we propose hydrogels, based on poly(ethylene glycol) (PEG) prepolymers, which are photochemically crosslinkable and thereby patternable. Various photoinitiators are used and investigated spectroscopically; those with high sensitivity in the optical region of the spectrum are advantageous. Hydrogel films have been obtained, which are applicable for light-based patterning and, hence, for functionalization of both surface and volume: It is shown that a local change in optical properties can be induced in special hydrogel films by photochemical crosslinking. Such a local light-induced material response forms the basis for volume holographic patterning. Cytocompatibility of hydrogels and compositions is evaluated via cytotoxicity tests. Exploiting the interrelationship between structure and function is highly relevant for biomedical materials with multifunctionality.
Part of the book: Holography