Rapid homogeneous endothelialization of high aspect ratio microvascular networks.

Microvascularization of an engineered tissue construct is necessary to ensure the nourishment and viability of the hosted cells. Microvascular constructs can be created by seeding the luminal surfaces of microfluidic channel arrays with endothelial cells. However, in a conventional flow-based system, the uniformity of endothelialization of such an engineered microvascular network is constrained by mass transfer of the cells through high length-to-diameter (L/D) aspect ratio microchannels.

Microablation of collagen-based substrates for soft tissue engineering.

Noting the abundance and importance of collagen as a biomaterial, we have developed a facile method for the production of a dense fibrillar extracellular matrix mimicking collagen-elastin hybrids with tunable mechanical properties. Through the use of excimer-laser technology, we have optimized conditions for the ablation of collagen lamellae without denaturation of protein, maintenance of fibrillar ultrastructure and preservation of native D-periodicity. Strengths of collagen-elastin hybrids ranged from 0.

Generation of spatially aligned collagen fiber networks through microtransfer molding.

The unique biomechanical properties of native tissue are governed by the organization and composition of integrated collagen and elastin networks. An approach for fabricating spatially aligned, fiber-reinforced composites with adjustable collagen fiber dimensions, layouts, and distribution within an elastin-like protein matrix yielding a biocomposite with controllable mechanical responses is reported. Microtransfer molding is employed for the fabrication of hollow and solid collagen fibers with straight or crimped fiber geometries.

MEMS-assisted spatially homogeneous endothelialization of a high length-to-depth aspect ratio microvascular network.

The endothelialization of an engineered microvascular network is constrained by the mass transport of the endothelial cells through high length-to-depth (l/d) aspect ratio microchannels. This paper presents a deformable, reentrant microvascular scaffold as a microelectromechanical systems (MEMS)-assisted approach for spatially homogeneous endothelial cell seeding of high l/d (>200) aspect ratio microvasculature. Nickel electroplating and micromolding were employed for the fabrication of the polydimethylsiloxane (PDMS) reentrant microvascular scaffold.

A TEMPLATE-BASED FABRICATION TECHNIQUE FOR SPATIALLY-DESIGNED POLYMER MICRO/NANOFIBER COMPOSITES.

This paper reports a template-based technique for the fabrication of polymer micro/nanofiber composites, exercising control over the fiber dimensions and alignment. Unlike conventional spinning-based methods of fiber production, the presented approach is based on micro-transfer molding. It is a parallel processing technique capable of producing fibers with control over both in-plane and out-of-plane geometries, in addition to packing density and layout of the fibers.