Human microvasculature fabrication using thermal inkjet printing technology

Abstract

The current tissue engineering paradigm is that successfully engineered thick tissues must include vasculature. As biological approaches alone, such as VEGF, have fallen short of their promises, one may look for an engineering approach to build microvasculature. Layer-by-layer approaches for customized fabrication of cell/scaffold constructs have shown some potential in building complex 3D structures. With the advent of cell printing, one may be able to build precise human microvasculature with suitable bio-ink. Human microvascular endothelial cells (HMVEC) and fibrin were studied as bio-ink for microvasculature construction. Endothelial cells are the only cells to compose the human capillaries and also form the entire inner lining of cardiovascular system. Fibrin has been already widely recognized as tissue engineering scaffold for vasculature and other cells, including skeleton/smooth muscle cells and chondrocytes. In our study, we precisely fabricated micron-sized fibrin channels using a drop-on-demand polymerization. This printing technique uses aqueous processes that have been shown to induce little, if any, damage to cells. When printing HMVEC cells in conjunction with the fibrin, we found the cells aligned themselves inside the channels and proliferated to form confluent linings. The 3D tubular structure was also found in the printed patterns. We conclude that a combined simultaneous cell and scaffold printing can promote HMVEC proliferation and microvasculature formation.

Three-dimensional bioprinting of thick vascularized tissues

“…Threedimensional bioprinting is an emerging approach for creating complex tissue architectures (10,11), including those with embedded vasculature (12)(13)(14)(15), that may address the unmet needs of tissue manufacturing. Recently, Miller et al (15) reported an elegant method for creating vascularized tissues, in which a sacrificial carbohydrate glass is printed at elevated temperature (>100°C), protectively coated, and then removed, before introducing a homogeneous cell-laden matrix.…”

Advances in bioprinted cell-laden hydrogels for skin tissue engineering

“…This technology has been used to print a variety of compounds in prescribed 2D patterns, including growth factors [119], proteins [5], polymers [85], nanoparticles [190] and drugs [94]. The capability of inkjet bioprinting to print mammalian cells with high accuracy, and little or even no reduction of cell viability, was also demonstrated using different cell types, such as embryonic rat motoneurons [206], human microvascular endothelial cells [34], mouse embryonic fibroblasts [194], and retinal ganglion cells [12]. The formation of transient pores in the cell membrane has been observed during inkjet printing, which were reported as self-repaired in 2 h subsequent to printing [35].…”

“…Bioprinting technologies are attractive to engineer a vascular tree within thick constructs by the precise layer by layer deposition of multiple cell types and ECMlike bioinks into prescribed spatial locations at high resolution [202]. Promising approaches to generate vascular networks have been reported using inkjet [34,209], laserassisted [203], and extrusion bioprinting [16,92,132]. In general, such approaches are based on four main strategies: (1) direct patterning vascular cells onto a receiving substrate [203], (2) continuous printing of polymeric bioink loaded with endothelial cells followed by polymer removal [96], (3) printing perfusable channels in a 3D construct for subsequent injection of a cell suspension into the empty channel [92], and (4) printing of multicellular spheroids [132].…”

Development of a Bacterial Culture System Using a Paper Platform to Accommodate Media and an Ink-Jet Printing to Dispense Bacteria

“…Therefore, E. coli cells transfer was tested as a model of bacterial cells by using ink-jet technology. Because ink-jet technology is no longer only an office printing technology (Abe et al, 2008); it has gradually become a versatile tool in various fields for accurately dispensing very small quantities of fluids on substrates, such as human organs or cells (Mironov et al, 2009;Guillemot et al, 2010;Xu et al, 2005;Cui and Boland, 2009). Futhermore, numerical and experimental investigation of a fluid flow through porous media is important for a wide range of applications varying from environmental analyses to inkjet printing technology (Mohd Irwan et al, 2010).…”