Tissue Engineering: Controlling Spatial Organization of Multiple Cell Types in Defined 3D Geometries (Adv. Mater. 41/2012)

2012 ◽  
Vol 24 (41) ◽  
pp. 5542-5542
Author(s):  
Halil Tekin ◽  
Jefferson G. Sanchez ◽  
Christian Landeros ◽  
Karen Dubbin ◽  
Robert Langer ◽  
...  
Biomaterials ◽  
2019 ◽  
Vol 216 ◽  
pp. 119277 ◽  
Author(s):  
Rosanne M. Raftery ◽  
David P. Walsh ◽  
Lia Blokpoel Ferreras ◽  
Irene Mencía Castaño ◽  
Gang Chen ◽  
...  

2020 ◽  
Author(s):  
Weifang Liu ◽  
Armen Abnousi ◽  
Qian Zhang ◽  
Yun Li ◽  
Ming Hu ◽  
...  

AbstractChromatin spatial organization (interactome) plays a critical role in genome function. Deep understanding of chromatin interactome can shed insights into transcriptional regulation mechanisms and human disease pathology. One essential task in the analysis of chromatin interactomic data is to identify long-range chromatin interactions. Existing approaches, such as HiCCUPS, FitHiC/FitHiC2 and FastHiC, are all designed for analyzing individual cell types. None of them accounts for unbalanced sequencing depths and heterogeneity among multiple cell types in a unified statistical framework. To fill in the gap, we have developed a novel statistical framework MUNIn (Multiple cell-type UNifying long-range chromatin Interaction detector) for identifying long-range chromatin interactions from multiple cell types. MUNIn adopts a hierarchical hidden Markov random field (H-HMRF) model, in which the status (peak or background) of each interacting chromatin loci pair depends not only on the status of loci pairs in its neighborhood region, but also on the status of the same loci pair in other cell types. To benchmark the performance of MUNIn, we performed comprehensive simulation studies and real data analysis, and showed that MUNIn can achieve much lower false positive rates for detecting cell-type-specific interactions (33.1 - 36.2%), and much enhanced statistical power for detecting shared peaks (up to 74.3%), compared to uni-cell-type analysis. Our data demonstrated that MUNIn is a useful tool for the integrative analysis of interactomic data from multiple cell types.


2019 ◽  
Author(s):  
Anh Tong ◽  
Quang Long Pham ◽  
Vatsal Shah ◽  
Akshay Naik ◽  
Paul Abatemarco ◽  
...  

ABSTRACTAccording to the U.S. Department of Health & Human Services, nearly 115,000 people in the U.S needed a lifesaving organ transplant in 2018, while only ∼10% of them have received it. Yet, almost no artificial FDA-approved products are commercially available today – three decades after the inception of tissue engineering. It is hypothesized here that the major bottlenecks restricting its progress stem from lack of access to the inner pore space of the scaffolds. Specifically, the inability to deliver nutrients to, and clear waste from, the center of the scaffolds limits the size of the products that can be cultured. Likewise, the inability to monitor, and control, the cells after seeding them into the scaffold results in nonviable tissue, with an unacceptable product variability. To resolve these bottlenecks, we present a prototype addressable microfluidics device capable of minimally disruptive fluid and cell manipulations within living cultures. As proof-of-concept, we demonstrate its ability to perform additive manufacturing by seeding cells in spatial patterns (including co-culturing multiple cell types); and subtractive manufacturing by removing surface adherent cells via focused flow of trypsin. Additionally, we show that the device can sample fluids and perform cell “biopsies” (which can be subsequently sent for ex-situ analysis), from any location within its Culture Chamber. Finally, the on-chip plumbing is completely automated using external electronics. This opens the possibility to perform long-term computer-driven tissue engineering experiments, where the cell behavior is modulated in response to the minimally disruptive observations (e.g. fluid sampling and cell biopsies) throughout the entire duration of the cultures. It is expected that the proof-of-concept technology will eventually be scaled up to 3D addressable microfluidic scaffolds, capable of overcoming the limitations bottlenecking the transition of tissue engineering technologies to the clinical setting.


Micro ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 181-193
Author(s):  
Kouki Inomata ◽  
Michiyo Honda

Microvessels in bone are indispensable for maintaining bone homeostasis based on a dynamic remodeling system. In cell-based tissue engineering, vascularization into the regenerative bone is a key strategy to avoid hypoxia and necrosis around re-implanted tissues. Previous studies have shown that direct contact between osteoblasts and endothelial cells stimulates differentiation of both cell types. However, no studies have revealed the dominant/submissive relationship. In the present study, we examined the effect of hypothermia on monoculture and co-culture to assess which cells tightly coordinated osteogenesis and angiogenesis in the co-culture system. As for osteoblasts, exposure to hypothermia suppressed cellular proliferation, migration, and differentiation. Evaluation of the behavior of endothelial cells showed that hypothermia should not affect basic functions such as proliferation and migration. Under co-culture conditions, both osteogenic differentiation and the formation of vessel-like angiogenic structures were suppressed by hypothermia, but the spatial organization of alkaline phosphatase-positive cell clusters, which tend to localize around microvascular lumens, was not altered. These data suggest that hypothermia attenuates heterotypic intercellular crosstalk which robustly depends on osteoblasts to inhibit both osteogenesis and angiogenesis in the co-culture system. Taken together, this approach will provide new insights into the relationship between osteoblasts and endothelial cells in tissue engineering.


2004 ◽  
Vol 845 ◽  
Author(s):  
Priya Kesari ◽  
Tao Xu ◽  
Thomas Boland

ABSTRACTTissues and organs exhibit distinct shapes and functions nurtured by vascular connectivity. In order to mimic and examine these intricate structure-function relationships, it is necessary to develop efficient strategies for assembling tissue-like constructs. Many of the top-down fabrication techniques used to build microelectromechanical systems, including photolithography, are attractive due to the similar feature sizes, but are not suitable for delicate biological systems or aqueous environments. A layer-by layer approach has been proposed by us to pattern functional cell structures in three dimensions. Freeform cell structures are created by the inkjet method, in which cells are entrapped within hydrogels and crosslinked on demand. The cells are viable, functional and show potential for cell maturation as exemplified by the diversion of hematopoietic stem cells into multiple cell types. These results show promise for many tissue engineering applications.


2012 ◽  
Vol 24 (41) ◽  
pp. 5543-5547 ◽  
Author(s):  
Halil Tekin ◽  
Jefferson G. Sanchez ◽  
Christian Landeros ◽  
Karen Dubbin ◽  
Robert Langer ◽  
...  

2021 ◽  
Author(s):  
Natsumi Masumoto ◽  
Yuki Suzuki ◽  
Songkui Cui ◽  
Mayumi Wakazaki ◽  
Mayuko Sato ◽  
...  

Abstract Parasitic plants infect other plants by forming haustoria, specialized multicellular organs consisting of several cell types, each of which has unique morphological features and physiological roles associated with parasitism. Understanding the spatial organization of cell types is, therefore, of great importance in elucidating the functions of haustoria. Here, we report a three-dimensional (3-D) reconstruction of haustoria from two Orobanchaceae species, the obligate parasite Striga hermonthica infecting rice (Oryza sativa) and the facultative parasite Phtheirospermum japonicum infecting Arabidopsis (Arabidopsis thaliana). In addition, field-emission scanning electron microscopy observation revealed the presence of various cell types in haustoria. Our images reveal the spatial arrangements of multiple cell types inside haustoria and their interaction with host roots. The 3-D internal structures of haustoria highlight differences between the two parasites, particularly at the xylem connection site with the host. Our study provides cellular and structural insights into haustoria of S. hermonthica and P. japonicum and lays the foundation for understanding haustorium function.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 935
Author(s):  
Theresa Schmidt ◽  
Yu Xiang ◽  
Xujin Bao ◽  
Tao Sun

Tissue engineering (TE) was initially designed to tackle clinical organ shortage problems. Although some engineered tissues have been successfully used for non-clinical applications, very few (e.g., reconstructed human skin) have been used for clinical purposes. As the current TE approach has not achieved much success regarding more broad and general clinical applications, organ shortage still remains a challenging issue. This very limited clinical application of TE can be attributed to the constraints in manufacturing fully functional tissues via the traditional top–down approach, where very limited cell types are seeded and cultured in scaffolds with equivalent sizes and morphologies as the target tissues. The newly proposed developmental engineering (DE) strategy towards the manufacture of fully functional tissues utilises a bottom–up approach to mimic developmental biology processes by implementing gradual tissue assembly alongside the growth of multiple cell types in modular scaffolds. This approach may overcome the constraints of the traditional top–down strategy as it can imitate in vivo-like tissue development processes. However, several essential issues must be considered, and more mechanistic insights of the fundamental, underpinning biological processes, such as cell–cell and cell–material interactions, are necessary. The aim of this review is to firstly introduce and compare the number of cell types, the size and morphology of the scaffolds, and the generic tissue reconstruction procedures utilised in the top–down and the bottom–up strategies; then, it will analyse their advantages, disadvantages, and challenges; and finally, it will briefly discuss the possible technologies that may overcome some of the inherent limitations of the bottom–up strategy.


2020 ◽  
Author(s):  
Betul Akgol Oksuz ◽  
Liyan Yang ◽  
Sameer Abraham ◽  
Sergey V. Venev ◽  
Nils Krietenstein ◽  
...  

AbstractChromosome conformation capture (3C)-based assays are used to map chromatin interactions genome-wide. Quantitative analyses of chromatin interaction maps can lead to insights into the spatial organization of chromosomes and the mechanisms by which they fold. A number of protocols such as in situ Hi-C and Micro-C are now widely used and these differ in key experimental parameters including cross-linking chemistry and chromatin fragmentation strategy. To understand how the choice of experimental protocol determines the ability to detect and quantify aspects of chromosome folding we have performed a systematic evaluation of experimental parameters of 3C-based protocols. We find that different protocols capture different 3D genome features with different efficiencies. First, the use of cross-linkers such as DSG in addition to formaldehyde improves signal-to-noise allowing detection of thousands of additional loops and strengthens the compartment signal. Second, fragmenting chromatin to the level of nucleosomes using MNase allows detection of more loops. On the other hand, protocols that generate larger multi-kb fragments produce stronger compartmentalization signals. We confirmed our results for multiple cell types and cell cycle stages. We find that cell type-specific quantitative differences in chromosome folding are not detected or underestimated by some protocols. Based on these insights we developed Hi-C 3.0, a single protocol that can be used to both efficiently detect chromatin loops and to quantify compartmentalization. Finally, this study produced ultra-deeply sequenced reference interaction maps using conventional Hi-C, Micro-C and Hi-C 3.0 for commonly used cell lines in the 4D Nucleome Project.


Author(s):  
Natsumi Masumoto ◽  
Yuki Suzuki ◽  
Songkui Cui ◽  
Mayumi Wakazaki ◽  
Mayuko Sato ◽  
...  

AbstractParasitic plants infect other plants by forming haustoria, specialized multicellular organs consisting of several cell types each of which has unique morphological features and physiological roles associated with parasitism. Understanding the spatial organization of cell types is, therefore, of great importance in elucidating the functions of haustoria. Here, we report a three-dimensional (3-D) reconstruction of haustoria from two Orobanchaceae species, the obligate parasite Striga hermonthica infecting rice and the facultative parasite Phtheirospermum japonicum infecting Arabidopsis. Our images reveal the spatial arrangements of multiple cell types inside haustoria and their interaction with host roots. The 3-D internal structures of haustoria highlight differences between the two parasites, particularly at the xylem connection site with the host. Our study provides structural insights into how organs interact between hosts and parasitic plants.One-sentence summaryThree-dimensional image reconstruction was used to visualize the spatial organization of cell types in the haustoria of parasitic plants with special reference to their interaction with host roots.


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