Abstract: This document describes a process of producing gel microparticles, which are consistent in size and morphology. Through the process of coacervation, large volumes of gel microparticle slurry can be produced by scaling up reactor vessel size. Particles can be repeatedly dehydrated and rehydrated in accordance to their environment, allowing for the storage of particles in a non-solvent such as ethanol. Gel slurries exhibit a Bingham plastic behavior in which the slurry behaves as a solid at shear stresses that are below a critical value. Upon reaching the critical shear stress, the slurry undergoes a rapid decrease in viscosity and behaves as a liquid. The rheological behavior of these slurries can be adjusted by changing the compaction processes such as centrifugation force to alter the yield-stress. The narrower distribution and reduced size of these particles allows for an increase in FRESH printing fidelity.

Abstract: In one aspect, a method includes providing support material within which the structure is fabricated, depositing, into the support material, structure material to form the fabricated structure, and removing the support material to release the fabricated structure from the support material. The provided support material is stationary at an applied stress level below a threshold stress level and flows at an applied stress level at or above the threshold stress level during fabrication of the structure. The provided support material is configured to mechanically support at least a portion of the structure and to prevent deformation of the structure during the fabrication of the structure. The deposited structure material is suspended in the support material at a location where the structure material is deposited. The structure material comprises a fluid that transitions to a solid or semi-solid state after deposition of the structure material.

Abstract: In one aspect, a method includes providing support material within which the structure is fabricated, depositing, into the support material, structure material to form the fabricated structure, and removing the support material to release the fabricated structure from the support material. The provided support material is stationary at an applied stress level below a threshold stress level and flows at an applied stress level at or above the threshold stress level during fabrication of the structure. The provided support material is configured to mechanically support at least a portion of the structure and to prevent deformation of the structure during the fabrication of the structure. The deposited structure material is suspended in the support material at a location where the structure material is deposited. The structure material comprises a fluid that transitions to a solid or semi-solid state after deposition of the structure material.

Abstract: A method for micro-tissue encapsulation of cells includes coating a tissue scaffold stamp with an extracellular matrix compound; depositing the tissue scaffold stamp onto a thermoresponsive substrate; seeding the tissue scaffold stamp with a cell culture; incubating the cell culture on the tissue scaffold stamp at a temperature that is specified, wherein the cell culture forms a cell patch that is attached to the extracellular matrix compound; removing the thermoresponsive substrate by lowering the temperature; removing the tissue scaffold stamp from the cell patch to form a micro-tissue structure by dissolving the tissue scaffold stamp in a solvent; folding the micro-tissue structure by suspending the micro-tissue in the solvent to enable the cell patch to fold the micro-tissue structure; collecting the folded micro-tissue structure from the solvent; and administering the folded micro-tissue structure to an organism.

Abstract: In one aspect, a method includes providing support material within which the structure is fabricated, depositing, into the support material, structure material to form the fabricated structure, and removing the support material to release the fabricated structure from the support material. The provided support material is stationary at an applied stress level below a threshold stress level and flows at an applied stress level at or above the threshold stress level during fabrication of the structure. The provided support material is configured to mechanically support at least a portion of the structure and to prevent deformation of the structure during the fabrication of the structure. The deposited structure material is suspended in the support material at a location where the structure material is deposited. The structure material comprises a fluid that transitions to a solid or semi-solid state after deposition of the structure material.

Abstract: An article has a surface topography for resisting bioadhesion of organisms and includes a base article having a surface. A composition of the surface includes a polymer. The surface has a topography comprising a pattern defined by a plurality of spaced apart features attached to or projected into the base article. The plurality of features each have at least one microscale dimension and at least one neighboring feature having a substantially different geometry. An average feature spacing between adjacent ones of the features is between 10 ?m and 100 ?m in at least a portion of the surface. The surface topography can be numerically represented using at least one sinusoidal function. In one embodiment, the surface can comprise a coating layer disposed on the base article.

Abstract: A coated surface for resisting or enhancing bioadhesion includes at least one patterned polymer including coating layer having a plurality of features attached to or projected into a base surface. The features each have at least one microscale (<1 mm) dimension and have at least one neighboring feature having a substantially different geometry. The patterned coating layer preferably provides an average roughness factor (R) of from 4 to 50. The coating layer resists or enhances bioadhesion as compared to the base surface.