Biomedical subjects

Peter M Moran

Publications and source records attributed to Peter M Moran.

3 recordsLinked to original sources

PubMed2006

Three-dimensional metallized features on polymeric substrates by microcontact printing.

We demonstrate the formation of 3-D metallized features on a polymeric substrate by microcontact printing. A patterned silicon stamp was "inked" with catalytic particles. Thereafter, particles were selectively removed from the raised regions of the stamp. A molten polymer was embossed against the stamp. Upon cooling and separation, the catalytic particles that were within the recessed areas of the stamp were transferred to the polymer. The polymer was then immersed in an electroless plating bath, and metallization occurred selectively on the areas where the catalytic particles were present. We have achieved 3-D metallized columns as small as 500 nm in diameter and about 1 mum tall.

Journal Article↗

PubMed2005

A technique for preparing protein gradients on polymeric surfaces: effects on PC12 pheochromocytoma cells.

A technique for preparing micropatterns and gradients of proteins on polymeric substrates has been developed in this work. Peroxides were generated on the substrate surface by UV preirradiation and they initiated graft polymerization of acrylic acid (AA) onto the surface upon a second UV irradiation. Micropatterns and gradients of poly(acrylic acid) (PAA) were formed when the substrate was placed under or moved with respect to a photomask during UV preirradiation. Protein micropatterns and gradients were fabricated on the surface by covalently linking to the carboxyl groups on PAA chains. To test cell response to the protein gradient surfaces, PC12 pheochromocytoma cells were cultured on laminin-bound substrates in serum-free medium supplemented with nerve growth factor (NGF). It is found that both the attachment and neurite outgrowth behaviors of PC12 cells were dependent on the surface laminin density. However, the unreacted carboxyl groups on the polymer surface negatively affected PC12 cells. This weakened the positive influence from laminin.

Acrylic Resins↗

PubMed2005

Influence of carboxyl group density on neuron cell attachment and differentiation behavior: gradient-guided neurite outgrowth.

A UV pre-irradiation step followed by a UV grafting step was used to graft poly(acrylic acid) (PAA) on polymeric substrates. These substrates were then used to investigate the influence of carboxyl groups (-COOH) on cell behavior. Both the attachment and differentiation behaviors of C17.2 cells showed a -COOH group density-dependent response. In order to achieve an even distribution of cells on a -COOH gradient surface for neuron differentiation studies, an Ar plasma post-treatment was applied to the PAA-grafted surfaces. It greatly improved the cell adhesion properties with little damage to -COOH groups. This allows uniform distributions of seeded cells even on substrates with -COOH gradients. A linear or stepped -COOH gradient was found to be capable of serving as a repelling cue to guide the outgrowth of neurites from C17.2 cells. Up to 3.7 times more cells developed neurites growing down the -COOH gradient than growing up it.

Acrylic Resins↗