Laser machined micropatterns as corrosion protection of both hydrophobic and hydrophilic magnesium.

Magnesium and its alloys are promising candidate materials for medical implants because they possess excellent biocompatibility and mechanical properties comparable to bone. Furthermore, secondary surgical operations for removal could be eliminated due to magnesium's biodegradability. However, magnesium's degradation rate in aqueous environments is too high for most applications.

Interfacial Phenomena of Natural Dispersants for Crude Oil Spills.

A natural surfactant was studied to simulate the dispersion process of crude oil in water. The interfacial phenomena of this natural dispersant was compared with a commercially available chemical dispersant, COREXIT EC9500A. This functional surfactant was extracted from the mucilage of the cactus species.

Responsive coatings from naturally occurring pectin polysaccharides.

Pectin polysaccharides have significant potential as all-natural, non-toxic "green" coatings that exhibit thermally-cued swelling behavior. Herein, ultra-thin coatings of highly-esterified pectin polysaccharides were cross-linked with calcium chloride (CaCl) and their swelling in water was investigated with ellipsometry. At low temperatures, the coatings swell to 2-3 times their dry layer thickness.

Protein-surface interactions on stimuli-responsive polymeric biomaterials.

Responsive surfaces: a review of the dependence of protein adsorption on the reversible volume phase transition in stimuli-responsive polymers. Specifically addressed are a widely studied subset: thermoresponsive polymers. Findings are also generalizable to other materials which undergo a similarly reversible volume phase transition.

Combining Nonadhesive Materials into Microstructured Composite Surfaces Induces Cell Adhesion and Spreading.

The synergistic effects between surface topography and chemical functionality were investigated in order to enhance the adhesion of cells to poorly adhesive materials. It has been established that many cell types are weakly adhesive to thin films of poly(-isopropylacrylamide), or PNIPAAm, and self-assembled triethylene glycol-terminated alkanethiols (EG3SAM). To enhance adhesion, a topographical cue in the form of electrospun micron-width fibers of PNIPAAm was deposited to each coating.

Shape-changing hydrogel surfaces trigger rapid release of patterned tissue modules.

The formation and assembly of diverse tissue building blocks is considered a promising bottom-up approach for the construction of complex three-dimensional tissues. Patterned shape-changing materials were investigated as an innovative method to form and harvest free-standing tissue modules with preserved spatial organization and cell-cell connections. Arrays of micro-scale surface-attached hydrogels made of a thermoresponsive polymer were used as cell culture supports to fabricate tissue modules of defined geometric shape.

Size-Exclusion "capture and release" separations using surface-patterned poly(N-isopropylacrylamide) hydrogels.

Micrometer-scale poly(N-isopropylacrylamide) (poly-NIPAAm) hydrogel monolith patterns were fabricated on solid surfaces using soft lithography. At sufficiently high aspect ratios, the hydrogel monoliths swell and contract laterally with temperature. The spaces between the monoliths form a series of trenches that catch, hold, and release appropriately sized targets.