Showing papers by "Vladimir Mironov published in 2010"
TL;DR: This work presents the emerging concept of organ printing or robotic additive biofabrication of an intra-organ branched vascular tree, based on the ability of vascular tissue spheroids to undergo self-assembly for tissue engineering based on organ-printing technology using self-assembling vascular tissue Spheroids.
Abstract: Importance of the field: Effective vascularization of thick three-dimensional engineered tissue constructs is a problem in tissue engineering. As in native organs, a tissue-engineered intra-organ vascular tree must be comprised of a network of hierarchically branched vascular segments. Despite this requirement, current tissue-engineering efforts are still focused predominantly on engineering either large-diameter macrovessels or microvascular networks.Areas covered in this review: We present the emerging concept of organ printing or robotic additive biofabrication of an intra-organ branched vascular tree, based on the ability of vascular tissue spheroids to undergo self-assembly.What the reader will gain: The feasibility and challenges of this robotic biofabrication approach to intra-organ vascularization for tissue engineering based on organ-printing technology using self-assembling vascular tissue spheroids including clinically relevantly vascular cell sources are analyzed.Take home message: It is not p...
211 citations
TL;DR: It is safe to state that bioprinting technology is coming of age as the field is consolidating and maturing.
Abstract: The International Conference on Bioprinting and Biofabrication in Bordeaux (3B'09) demonstrated that the field of bioprinting and biofabrication continues to evolve. The increasing number and broadening geography of participants, the emergence of new exciting bioprinting technologies, and the attraction of young investigators indicates the strong growth potential of this emerging field. Bioprinting can be defined as the use of computer-aided transfer processes for patterning and assembling living and non-living materials with a prescribed 2D or 3D organization in order to produce bio-engineered structures serving in regenerative medicine, pharmacokinetic and basic cell biology studies. The use of bioprinting technology for biofabrication of in vitro assay has been shown to be a realistic short-term application. At the same time, the principal feasibility of bioprinting vascularized human organs as well as in vivo bioprinting has been demonstrated. The bioprinting of complex 3D human tissues and constructs in vitro and especially in vivo are exciting, but long-term, applications. It was decided that the 5th International Conference on Bioprinting and Biofabrication would be held in Philadelphia, USA in October 2010. The specially appointed 'Eploratory Committee' will consider the possibility of turning the growing bioprinting community into a more organized entity by creating a new bioprinting and biofabrication society. The new journal Biofabrication was also presented at 3B'09. This is an important milestone per se which provides additional objective evidence that the bioprinting and biofabrication field is consolidating and maturing. Thus, it is safe to state that bioprinting technology is coming of age.
169 citations
TL;DR: Results are reported of experimental testing of two simple quantitative tissue spheroid fusion‐based in vitro high‐throughput screening assays of tissue maturation, hypothesize that the fusion kinetics of these tissue spheroids will provide an efficacious in vitro assay of the level of tissues maturation.
Abstract: Organ printing or computer-aided robotic layer-by-layer additive biofabrication of thick three-dimensional (3D) living tissue constructs employing self-assembling tissue spheroids is a rapidly evolving alternative to classic solid scaffold-based approaches in tissue engineering. However, the absence of effective methods of accelerated tissue maturation immediately after bioprinting is the main technological imperative and potential impediment for further progress in the development of this emerging organ printing technology. Identification of the optimal combination of factors and conditions that accelerate tissue maturation ('maturogenic' factors) is an essential and necessary endeavour. Screening of maturogenic factors would be most efficiently accomplished using high-throughput quantitative in vitro tissue maturation assays. We have recently reviewed the formation of solid scaffold-free tissue constructs through the fusion of bioprinted tissue spheroids that have measurable material properties. We hypothesize that the fusion kinetics of these tissue spheroids will provide an efficacious in vitro assay of the level of tissue maturation. We report here the results of experimental testing of two simple quantitative tissue spheroid fusion-based in vitro high-throughput screening assays of tissue maturation: (a) a tissue spheroid envelopment assay; and (b) a tissue spheroid fusion kinetics assay.
70 citations
TL;DR: In order to maintain epithelial integrity during EMT the number of epithelial cells must increase at a controlled rate, and the results show that an EMT is promoted more efficiently by an increase in cell-substrate adhesion than by a decrease incell-cell adhesion.
Abstract: An epithelial-mesenchymal transformation (EMT) involves alterations in cell-cell and cell-matrix adhesion, the detachment of epithelial cells from their neighbors, the degradation of the basal lamina and acquisition of mesenchymal phenotype. Here we present Monte Carlo simulations for a specific EMT in early heart development: the formation of cardiac cushions. Cell rearrangements are described in accordance with Steinberg's differential adhesion hypothesis, which states that cells possess a type-dependent adhesion apparatus and are sufficiently motile to give rise to the tissue conformation with the largest number of strong bonds. We also implement epithelial and mesenchymal cell proliferation, cell type change and extracellular matrix production by mesenchymal cells. Our results show that an EMT is promoted more efficiently by an increase in cell-substrate adhesion than by a decrease in cell-cell adhesion. In addition to cushion tissue formation, the model also accounts for the phenomena of matrix invasion and mesenchymal condensation. We conclude that in order to maintain epithelial integrity during EMT the number of epithelial cells must increase at a controlled rate. Our model predictions are in qualitative agreement with available experimental data.
21 citations
TL;DR: In this article, the authors numerically model a glycerol-water microsphere fabrication process during acoustic excitation-based single- nozzle continuous jetting using a volume of fluid method.
Abstract: Microspheres or droplets are increasingly finding various biomedical applications as drug microspheres and multicellular spheroids. Single nozzle-based continuous jetting with the help of acoustic excitation and/or carrier stream is a basic process for mono-disperse microsphere fabrication. Precise control of microsphere size and size distribution in single nozzle jetting is still of great manufacturing interest. The objective of this study is to numerically model a glycerol-water microsphere fabrication process during acoustic excitation-based single nozzle continuous jetting. Using a volume of fluid method, this study has investigated the effects of material properties and fabrication conditions such as the acoustic excitation frequency and amplitude and the carrier stream velocity on the size of microspheres fabricated. (1) The microsphere diameter decreases as the glycerol volume percentage increases. (2) The excitation frequency and pressure have a pronounced effect on the microsphere size. The microsphere diameter decreases as the excitation frequency increases, and the microsphere diameter increases with the excitation pressure amplitude. (3) The microsphere size decreases as the carrier stream velocity increases. [DOI:10.1115/1.4002187]
20 citations