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Articles 1 - 17 of 17
Full-Text Articles in Biomedical Engineering and Bioengineering
Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui, Thomas Boland
Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui, Thomas Boland
Thomas Boland
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 …
Electrophysiological Characterization Of Embryonic Hippocampal Neurons Cultured In A 3d Collagen Hydrogel, Tao Xu, Peter Molnar, Gregory Cassie, Mainak Das, Thomas Boland, Jay Hickman
Electrophysiological Characterization Of Embryonic Hippocampal Neurons Cultured In A 3d Collagen Hydrogel, Tao Xu, Peter Molnar, Gregory Cassie, Mainak Das, Thomas Boland, Jay Hickman
Thomas Boland
Rat embryonic hippocampal neurons were cultured in (1) 3D collagen hydrogels as 'entrapped' evenly distributed cells, (2) at the interface of two collagen layers (sandwich model), and (3) on the surface of collagen coated coverslips (2D model). In the 'entrapment' model the neuronal processes grew out of the plane of the cell body and extended into the collagen matrix, in contrast to the sandwich model where the cells and their processes rarely left the plane in which they were seeded. Hippocampal neurons 'entrapped' in the 3D collagen gel grew the same number, but shorter, processes and exhibited improved survival compared …
Fabrication And Characterization Of Bio-Engineered Cardiac Pseudo Tissues, Tao Xu, Catalin Baicu, Michael Aho, Michael Zile, Thomas Boland
Fabrication And Characterization Of Bio-Engineered Cardiac Pseudo Tissues, Tao Xu, Catalin Baicu, Michael Aho, Michael Zile, Thomas Boland
Thomas Boland
We report to fabricate functional three-dimensional (3D) tissue constructs by using an inkjet based bio-prototyping method. With the use of the modified inkjet printers, contractile cardiac hybrids that exhibit the forms of the 3D rectangular sheet and even the ‘half heart’ (with two connected ventricles) have been fabricated by arranging alternate layers of biocompatible alginate hydrogels and mammalian cardiac cells according to pre-designed 3D patterns. In this study, primary feline adult and H1 cardiomyocytes were used as model cardiac cells. Alginate hydrogels with controlled micro-shell structures were built by spraying cross-linkers in micro-drops onto un-gelled alginic acid. The cells remained …
Synthesis And Characterization Of Biodegradable Elastomeric Polyurethane Scaffolds Fabricated By The Inkjet Technique.”, Changhong Zhang, Xuejun Wen, Narendra Vyavahare, Thomas Boland
Synthesis And Characterization Of Biodegradable Elastomeric Polyurethane Scaffolds Fabricated By The Inkjet Technique.”, Changhong Zhang, Xuejun Wen, Narendra Vyavahare, Thomas Boland
Thomas Boland
Biodegradable polyurethanes (PUs) were synthesized from methylene di-p-phenyl-diisocyanate (MDI), polycaprolactone diol (PCL-diol) and N,N-bis (2-hydorxyethyl)-2-aminoethane-sulfonic acid (BES), serving as a hard segment, soft segment and chain extender, respectively. MDI was chosen due to its reactivity and wide application in synthesis of biomedical polyurethanes due to its reactivity; PCL-diol was chosen because of its biodegradability; and BES was chosen because it allowed the introduction sulfonic acid groups onto the polymer chains. We evaluated the polyurethanes' degradation rate, mechanical properties, hydrophilicity, antithrombogenecity, and ability to support fibroblast cell attachment and growth by comparing with polymers having a 2,2-(methylimino)diethanol (MIDE) chain extender. Mechanical …
Loading Dependent Swelling And Release Properties Of Novel Biodegradable, Elastic And Environmental Stimuli-Sensitive Polyurethanes, Changhong Zhang, Kejia Zhao, Tj Hu, Xiaofeng Cui, Nathan Brown, Thomas Boland
Loading Dependent Swelling And Release Properties Of Novel Biodegradable, Elastic And Environmental Stimuli-Sensitive Polyurethanes, Changhong Zhang, Kejia Zhao, Tj Hu, Xiaofeng Cui, Nathan Brown, Thomas Boland
Thomas Boland
A novel degradable, elastic, anionic, and linear polyurethane was synthesized from hexamethylene diisocyanate, polycaprolactone diol, and a bicine chain extender. The chemical structure, mechanical properties, degradation rate, and swelling ratio were characterized by comparing the polymer with a polyurethane containing a 2,2-(methylimino) diethanol chain extender. Due to the incorporation of negatively charged carboxyl side groups, the bicine extended polymers exhibited higher micro-phase separation, better mechanical properties in dry condition, and better sensitivity to environmental stimuli than controls, as demonstrated by its high swelling ratio at elevated pH, lower ionic strength, or higher temperature. The swelling ratio of membranes showed reversible …
Application Of Inkjet Printing To Tissue Engineering, Thomas Boland, Tao Xu, Brook Damon, Xiaofeng Cui
Application Of Inkjet Printing To Tissue Engineering, Thomas Boland, Tao Xu, Brook Damon, Xiaofeng Cui
Thomas Boland
ecent advances in organ printing technology for applications relating to medical interventions and organ replacement are described. Organ printing refers to the placement of various cell types into a soft scaffold fabricated according to a computer-aided design template using a single device. Computer aided scaffold topology design has recently gained attention as a viable option to achieve function and mass transport requirements within tissue engineering scaffolds. An exciting advance pioneered in our laboratory is that of simultaneous printing of cells and biomaterials, which allows precise placement of cells and proteins within 3-D hydrogel structures. This advance raises the possibility of …
Viability And Electrophysiology Of Neural Cell Structures Generated By The Inkjet Printing Method, Tao Xu, Cassie Gregory, Peter Molnar, S Jalota, Sarit Bhaduri, Thomas Boland
Viability And Electrophysiology Of Neural Cell Structures Generated By The Inkjet Printing Method, Tao Xu, Cassie Gregory, Peter Molnar, S Jalota, Sarit Bhaduri, Thomas Boland
Thomas Boland
Complex cellular patterns and structures were created by automated and direct inkjet printing of primary embryonic hippocampal and cortical neurons. Immunostaining analysis and whole-cell patch-clamp recordings showed that embryonic hippocampal and cortical neurons maintained basic cellular properties and functions, including normal, healthy neuronal phenotypes and electrophysiological characteristics, after being printed through thermal inkjet nozzles. In addition, in this study a new method was developed to create 3D cellular structures: sheets of neural cells were layered on each other (layer-by-layer process) by alternate inkjet printing of NT2 cells and fibrin gels. These results and findings, taken together, show that inkjet printing …
Inkjet Printing Of Viable Mammalian Cells, Tao Xu, Joyce Jin, Cassie Gregory, Jay Hickman, Thomas Boland
Inkjet Printing Of Viable Mammalian Cells, Tao Xu, Joyce Jin, Cassie Gregory, Jay Hickman, Thomas Boland
Thomas Boland
The purpose of this study was to explore the use of a commercial thermal printer to deposit Chinese Hamster Ovary (CHO) and embryonic motoneuron cells into pre-defined patterns. These experiments were undertaken to verify the biocompatibility of thermal inkjet printing of mammalian cells and the ability to assemble them into viable constructs. Using a modified Hewlett Packard (HP) 550C computer printer and an HP 51626a ink cartridge, CHO cells and rat embryonic motoneurons were suspended separately in a concentrated phosphate buffered saline solution (3 x). The cells were subsequently printed as a kind of "ink" onto several "bio-papers" made from …
Advances In Tissue Engineering: Cell Printing, David Varghese, Malay Deshpande, Priya Kesari, S Ohri, Thomas Boland
Advances In Tissue Engineering: Cell Printing, David Varghese, Malay Deshpande, Priya Kesari, S Ohri, Thomas Boland
Thomas Boland
No abstract provided.
Inkjet Printing For High Throughput Cell Patterning, Elisabeth Roth, Tao Xu, Mainak Das, Cassie Gregory, Jay Hickman, Thomas Boland
Inkjet Printing For High Throughput Cell Patterning, Elisabeth Roth, Tao Xu, Mainak Das, Cassie Gregory, Jay Hickman, Thomas Boland
Thomas Boland
The adaptation of inkjet printing technology to the complex fields of tissue engineering and biomaterial development presents the potential to increase progress in these emerging technologies through the implementation of this high-throughput capability via automated processes to enable precise control and repeatability. In this paper, a method of applying high-throughput inkjet printing to control cellular attachment and proliferation by precise, automated deposition of collagen is presented. The results indicate that commercial inkjet printing technology can be used to create viable cellular patterns with a resolution of 350 microm through the deposition of biologically active proteins. This method demonstrates a combination …
Construction Of High- Density Bacterial Colony Arrays And Patterns By The Ink Jet Method, Tao Xu, Sevastioni Petridou, Eric Lee, Elisabeth Roth, Narendra Vyavahare, Jay Hickman, Thomas Boland
Construction Of High- Density Bacterial Colony Arrays And Patterns By The Ink Jet Method, Tao Xu, Sevastioni Petridou, Eric Lee, Elisabeth Roth, Narendra Vyavahare, Jay Hickman, Thomas Boland
Thomas Boland
We have developed a method for fabricating bacterial colony arrays and complex patterns using commercially available ink-jet printers. Bacterial colony arrays with a density of 100 colonies/cm(2) were obtained by directly ejecting Escherichia coli (E. coli) onto agar-coated substrates at a rapid arraying speed of 880 spots per second. Adjusting the concentration of bacterial suspensions allowed single colonies of viable bacteria to be obtained. In addition, complex patterns of viable bacteria as well as bacteria density gradients were constructed using desktop printers controlled by a simple software program.
Tissue-Engineering Constructs, Using Photopolymerizable Hydrogels And Stereolithography.”, Busaina Dhariwala, Elaine Hunt, Thomas Boland
Tissue-Engineering Constructs, Using Photopolymerizable Hydrogels And Stereolithography.”, Busaina Dhariwala, Elaine Hunt, Thomas Boland
Thomas Boland
One of the most important aspects of tissue engineering is the design of the scaffold providing the mechanical strength and access to nutrients for the new tissue. For customized tissue engineering, it is essential to be able to fabricate three-dimensional scaffolds of various geometric shapes, in order to repair defects caused by accidents, surgery, or birth. Rapid prototyping or solid free-form fabrication (SFF) techniques hold great promise for designing three-dimensional customized scaffolds, yet traditional cell-seeding techniques may not provide enough cell mass for larger constructs. This article presents a novel attempt to fabricate three-dimensional scaffolds, using hydrogels combined with cell …
Cell And Organ Printing 2: Fusion Of Cell Aggregates In Three-Dimensional Gels, Thomas Boland, Vladimir Mironov, Anna Gutowska, Elisabeth Roth, Roger Markwald
Cell And Organ Printing 2: Fusion Of Cell Aggregates In Three-Dimensional Gels, Thomas Boland, Vladimir Mironov, Anna Gutowska, Elisabeth Roth, Roger Markwald
Thomas Boland
We recently developed a cell printer (Wilson and Boland, 2003) that enables us to place cells in positions that mimic their respective positions in organs. However, this technology was limited to the printing of two-dimensional (2D) tissue constructs. Here we describe the use of thermosensitive gels to generate sequential layers for cell printing. The ability to drop cells on previously printed successive layers provides a real opportunity for the realization of three-dimensional (3D) organ printing. Organ printing will allow us to print complex 3D organs with computer-controlled, exact placing of different cell types, by a process that can be completed …
Cell And Organ Printing 1: Protein And Cell Printers, Cris Wilson, Thomas Boland
Cell And Organ Printing 1: Protein And Cell Printers, Cris Wilson, Thomas Boland
Thomas Boland
We have developed several devices for positioning organic molecules, molecular aggregates, cells, and single-cell organisms onto solid supports. These printers can create stable, functional protein arrays using an inexpensive technology. The cell printer allows us to create cell libraries as well as cellular assemblies that mimic their respective position in organs. The printers are derived from commercially available ink-jet printers that are modified to dispense protein or cell solutions instead of ink. We describe here the modifications to the print heads, and the printer hardware and software that enabled us to adapt the ink-jet printers for the manufacture of cell …
Characterization Of Patterned Self-Assembled Monolayers And Protein Arrays Generated By The Ink-Jet Method, Laura Pardo, Thomas Boland
Characterization Of Patterned Self-Assembled Monolayers And Protein Arrays Generated By The Ink-Jet Method, Laura Pardo, Thomas Boland
Thomas Boland
Commercial ink-jet printers were used with little modification to deposit alkanethiols onto gold substrata and several proteins onto silica supports. The resulting patterns of alkanethiols form self-assembled layers comparable to those obtained by microcontact printing or solution adsorption. The method has been used successfully to create binary chemical gradients and patterns of tertiary functionality. The proteins form dense patterns on the substrates and seem to maintain their configuration as measured by their ability to bind their specific ligands. Four different proteins were printed simultaneously, allowing for positive and negative controls. This "drop-on-demand" printing method is an inexpensive, flexible alternative to …
Organ Printing: Computer Aided Jet Based 3d Tissue Engineering, Vladimir Mironov, Thomas Boland, Thomas Trusk, Gabor Forgacs, Roger Markwald
Organ Printing: Computer Aided Jet Based 3d Tissue Engineering, Vladimir Mironov, Thomas Boland, Thomas Trusk, Gabor Forgacs, Roger Markwald
Thomas Boland
Tissue engineering technology promises to solve the organ transplantation crisis. However, assembly of vascularized 3D soft organs remains a big challenge. Organ printing, which we define as computer-aided, jet-based 3D tissue-engineering of living human organs, offers a possible solution. Organ printing involves three sequential steps: pre-processing or development of "blueprints" for organs; processing or actual organ printing; and postprocessing or organ conditioning and accelerated organ maturation. A cell printer that can print gels, single cells and cell aggregates has been developed. Layer-by-layer sequentially placed and solidified thin layers of a thermo-reversible gel could serve as "printing paper". Combination of an …
A Quantitative Approach To Studying Structures And Orientation At Self- Assembled Monolayer/Fluid Interfaces", Laura Pardo, Thomas Boland
A Quantitative Approach To Studying Structures And Orientation At Self- Assembled Monolayer/Fluid Interfaces", Laura Pardo, Thomas Boland
Thomas Boland
Self-assembled monolayers (SAMs) have become a standard tool for exploring surface interactions. Although well characterized, SAMs are known to undergo structural and conformational changes in the presence of solution, yet the ability to quantify these changes remains an obstacle due to limited analytical techniques. In this study, we determine changes in structure and conformation of CH3, OH, and COOH terminated hexadecanethiols on gold in water by means of a new technique known as evanescence reflection spectroscopy. This FTIR application, in conjunction with a semiempirical formalism, is capable of providing both qualitative and quantitative understanding of the molecular structure and orientation …