3D jet writing of mechanically actuated tandem scaffolds.

The need for high-precision microprinting processes that are controllable, scalable, and compatible with different materials persists throughout a range of biomedical fields. Electrospinning techniques offer scalability and compatibility with a wide arsenal of polymers, but typically lack precise three-dimensional (3D) control. We found that charge reversal during 3D jet writing can enable the high-throughput production of precisely engineered 3D structures.

Engineered Fibrillar Fibronectin Networks as Three-Dimensional Tissue Scaffolds.

Extracellular matrix (ECM) proteins, and most prominently, fibronectin (Fn), are routinely used in the form of adsorbed pre-coatings in an attempt to create a cell-supporting environment in both two- and three-dimensional cell culture systems. However, these protein coatings are typically deposited in a form which is structurally and functionally distinct from the ECM-constituting fibrillar protein networks naturally deposited by cells. Here, the cell-free and scalable synthesis of freely suspended and mechanically robust three-dimensional (3D) networks of fibrillar fibronectin (fFn) supported by tessellated polymer scaffolds is reported.

3D Jet Writing: Functional Microtissues Based on Tessellated Scaffold Architectures.

The advent of adaptive manufacturing techniques supports the vision of cell-instructive materials that mimic biological tissues. 3D jet writing, a modified electrospinning process reported herein, yields 3D structures with unprecedented precision and resolution offering customizable pore geometries and scalability to over tens of centimeters. These scaffolds support the 3D expansion and differentiation of human mesenchymal stem cells in vitro.

Needleless Electrohydrodynamic Cojetting of Bicompartmental Particles and Fibers from an Extended Fluid Interface.

Electrohydrodynamic cojetting can result in fibers (electrospinning) and particles (electrospraying) with complex, bicompartmental architectures. An important consideration for application of bicompartmental particles and fibers is the limited throughput derived from the use of parallel capillaries, which require laminar flow to form a multifluidic interface. Here, a novel synthesis approach that takes advantage of an extended bicompartmental fluid interface formed at the sharp edge of a 2D plate is reported.

Engineered Human Stem Cell Microenvironments.

Stem cells have the ability to self-renew and differentiate into specialized cell types, and, in the human body, they reside in specialized microenvironments called "stem cell niches." Although several niches have been described and studied , their functional replication is still incomplete. The culture of pluripotent stem cells may represent one of the most advanced examples in the effort to create an artificial or synthetic stem cell niche.