scholarly journals A synthetic, three-dimensional bone marrow hydrogel

2018 ◽  
Author(s):  
Lauren E. Jansen ◽  
Thomas P. McCarthy ◽  
Michael J. Lee ◽  
Shelly R. Peyton

Three-dimensional (3D) synthetic hydrogels have recently emerged as desirable in vitro cell culture platforms capable of representing the extracellular geometry, elasticity, and water content of tissue in a tunable fashion. However, they are critically limited in their biological functionality. Hydrogels are typically decorated with a scant 1-3 peptide moieties to direct cell behavior, which vastly underrepresents the proteins found in the extracellular matrix (ECM) of real tissues. Further, peptides chosen are ubiquitous in ECM, and are not derived from specific proteins. We developed an approach to incorporate the protein complexity of specific tissues into the design of biomaterials, and created a hydrogel with the elasticity of marrow, and 20 marrow-specific cell-instructive peptides. Compared to generic PEG hydrogels, our marrow-inspired hydrogel improves stem cell differentiation and proliferation. We propose this tissue-centric approach as the next generation of 3D hydrogel design for applications in tissue engineering.

2018 ◽  
Vol 18 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lara Termini ◽  
Enrique Boccardo

In vitro culture of primary or established cell lines is one of the leading techniques in many areas of basic biological research. The use of pure or highly enriched cultures of specific cell types obtained from different tissues and genetics backgrounds has greatly contributed to our current understanding of normal and pathological cellular processes. Cells in culture are easily propagated generating an almost endless source of material for experimentation. Besides, they can be manipulated to achieve gene silencing, gene overexpression and genome editing turning possible the dissection of specific gene functions and signaling pathways. However, monolayer and suspension cultures of cells do not reproduce the cell type diversity, cell-cell contacts, cell-matrix interactions and differentiation pathways typical of the three-dimensional environment of tissues and organs from where they were originated. Therefore, different experimental animal models have been developed and applied to address these and other complex issues in vivo. However, these systems are costly and time consuming. Most importantly the use of animals in scientific research poses moral and ethical concerns facing a steadily increasing opposition from different sectors of the society. Therefore, there is an urgent need for the development of alternative in vitro experimental models that accurately reproduce the events observed in vivo to reduce the use of animals. Organotypic cultures combine the flexibility of traditional culture systems with the possibility of culturing different cell types in a 3D environment that reproduces both the structure and the physiology of the parental organ. Here we present a summarized description of the use of epithelial organotypic for the study of skin physiology, human papillomavirus biology and associated tumorigenesis.


2009 ◽  
Vol 1239 ◽  
Author(s):  
Karla Brammer ◽  
Seunghan Oh ◽  
Sungho Jin

AbstractTwo important goals in stem cell research are to control the cell proliferation without differentiation, and also to direct the differentiation into a specific cell lineage when desired. Recent studies indicate that the nanostructures substantially influence the stem cell behavior. It is well known that mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into stromal lineages such as adipocyte, chondrocyte, fibroblast, myocyte, and osteoblast cell types. By examining the cellular behavior of MSCs cultured in vitro on nanostructures, some understanding of the effects that the nanostructures have on the stem cell’s response has been obtained. Here we demonstrate that TiO2 nanotubes produced by anodization on Ti implant surface can regulate human mesenchymal stem cell (hMSC) differentiation towards an osteoblast lineage in the absence of osteogenic inducing factors. Altering the dimensions of nanotubular-shaped titanium oxide surface structures independently allowed either augmented human mesenchymal stem cell (hMSC) adhesion at smaller diameter levels or a specific differentiation of hMSCs into osteoblasts using only the geometric cues. Small (˜30 nm diameter) nanotubes promoted adhesion without noticeable differentiation, while larger (˜70 - 100 nm diameter) nanotubes elicited a dramatic, ˜10 fold stem cell elongation, which induced cytoskeletal stress and selective differentiation into osteoblast-like cells, offering a promising nanotechnology-based route for novel orthopaedics-related hMSC treatments. The fact that a guided and preferential osteogenic differentiation of stem cells can be achieved using substrate nanotopography alone without using potentially toxic, differentiation-inducing chemical agents is significant, which can be useful for future development of novel and enhanced stem cell control and therapeutic implant development.


2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Jinkyu Lee ◽  
Sangmin Lee ◽  
Sung Min Kim ◽  
Heungsoo Shin

Abstract Background Fabrication of three-dimensional stem cell spheroids have been studied to improve stem cell function, but the hypoxic core and limited penetration of nutrients and signaling cues to the interior of the spheroid were challenges. The incorporation of polymers such as silica and gelatin in spheroids resulted in relatively relaxed assembly of composite spheroids, and enhancing transport of nutrient and biological gas. However, because of the low surface area between cells and since the polymers were heterogeneously distributed throughout the spheroid, these polymers cannot increase the cell to extracellular matrix interactions needed to support differentiation. Methods We developed the stem cell spheroids that incorporate poly(ι-lactic acid) single-segmented fibers synthesized by electrospinning and physical and chemical fragmentation. The proper mixing ratio was 2000 cells/μg fibers (average length of the fibers was 50 μm - 100 μm). The SFs were coated with polydopamine to increase cell binding affinity and to synthesize various-sized spheroids. The function of spheroids was investigated by in vitro analysis depending on their sizes. For statistical analysis, Graphpad Prism 5 software (San Diego, CA, USA) was used to perform one-way analysis of variance ANOVA with Tukey’s honest significant difference test and a Student’s t-test (for two variables) (P < 0.05). Results Spheroids of different sizes were created by modulating the amount of cells and fibers (0.063 mm2–0.322 mm2). The fibers in the spheroid were homogenously distributed and increased cell viability, while cell-only spheroids showed a loss of DNA contents, internal degradation, and many apoptotic signals. Furthermore, we investigated stemness and various functions of various-sized fiber-incorporated spheroids. In conclusion, the spheroid with the largest size showed the greatest release of angiogenic factors (released VEGF: 0.111 ± 0.004 pg/ng DNA), while the smallest size showed greater effects of osteogenic differentiation (mineralized calcium: 18.099 ± 0.271 ng/ng DNA). Conclusion The spheroids incorporating polydopamine coated single-segmented fibers showed enhanced viability regardless of sizes and increased their functionality by regulating the size of spheroids which may be used for various tissue reconstruction and therapeutic applications.


Author(s):  
Amit Paul ◽  
David Franz ◽  
Sumaira Yahya ◽  
Shan Sun ◽  
Michael Cho

Recent evidence suggests that stem cell differentiation can be regulated by modulation of the cell’s biomechanics. The cytoskeletal structures and arrangements in stem cells undergoing differentiation are dramatically altered, and these alterations vary by lineage. The complexity of events associated with the transformation of these precursor cells leaves many questions unanswered about morphological, structural, proteomic, and functional changes in differentiating stem cells. A thorough understanding of stem cell behavior, both experimentally and computationally, would allow for the development of more effective approaches to the expansion of stem cells in vitro and for the regulation of their commitment to a specific phenotype.


2016 ◽  
Vol 310 (5) ◽  
pp. C348-C356 ◽  
Author(s):  
Magdalena Arévalo Turrubiarte ◽  
Marie-Hélène Perruchot ◽  
Laurence Finot ◽  
Frédérique Mayeur ◽  
Frédéric Dessauge

Immortalized bovine mammary epithelial cells (BME-UV1) and immortalized bovine mammary alveolar cells (MAC-T) have been extensively used as in vitro cell models to understand milk production in dairy cows. Precise knowledge about their phenotype and performance remains, however, unknown. This study aims to characterize MAC-T and BME-UV1 profiles when cultured in two-dimensional adherent, three-dimensional adherent (Matrigel), and three-dimensional no adherent [ultralow attachment (ULA)] supports. MAC-T and BME-UV1 were compared according to their proliferation capacities and to specific cell surface markers CD24, CD326 [epithelial cell adhesion molecule (EpCAM)], CD10, and integrin CD49f (α-6). Cytokeratin (CK14 and CK19), signal transducer and activator of transcription 5, and other proteins (occludin and cadherin-1) were analyzed. BME-UV1 in ULA support expressed higher CD49f marker. A different intensity of CD49 staining allowed the discrimination between the two cell lines in adherent condition. CD10, EpCAM, and CK19 expressions show that BME-UV1 cells have luminal capacity, while MAC-T has a myoepithelial profile with a high expression of CK14. BME-UV1 cells possess a closer committed progenitor profile due to their higher expression in aldehyde dehydrogenase and EpCAM. We observed that BME-UV1 cells have a better capacity to form spherical structures, mammospheres, in Matrigel than MAC-T, which was confirmed by the higher mammosphere area. In the ULA condition, BME-UV1 proliferated over the 6 days of culture. Taken together, our results clearly confirm the BME-UV1 luminal profile and MAC-T ductal/myoepithelial-like phenotype.


2015 ◽  
Vol 21 (1-2) ◽  
pp. 310-319 ◽  
Author(s):  
Veronika Hruschka ◽  
Aram Saeed ◽  
Paul Slezak ◽  
Racha Cheikh Al Ghanami ◽  
Georg Alexander Feichtinger ◽  
...  

2021 ◽  
Vol 11 (23) ◽  
pp. 11209
Author(s):  
Catarina R. Pedrosa ◽  
Christel Chanseau ◽  
Christine Labrugère ◽  
Sivashankar Krishnamoorthy ◽  
Marie-Christine Durrieu

Human mesenchymal stem cells (hMSCs) respond to the characteristics of their surrounding microenvironment, i.e., their extracellular matrix (ECM). The possibility of mimicking the ECM offers the opportunity to elicit specific cell behaviors. The control of surface properties of a biomaterial at the scale level of the components of the ECM has the potential to effectively modulate cell response. Ordered nanoscale silicon pillar arrays were fabricated using reverse micelles of block copolymers on full wafers, with standard deviations lower than 15%. Bioactive synthetic peptides were covalently grafted on nanoarrays to evaluate possible synergies between chemistry and topography on osteogenic differentiation of hMSCs. Functionalization with RGD (Arg-Gly-Asp) and BMP-2 (bone morphogenetic protein-2) mimetic peptides lead to an enhancement of osteogenic differentiation. Bare nanopillar arrays of reduced pitch were found to promote faster hMSC differentiation. These findings highlight the relevance of investigating possibilities of engineering in vitro systems which can be fine-tuned according to the envisaged cell response.


2011 ◽  
Vol 39 (1) ◽  
pp. 383-387 ◽  
Author(s):  
Raymond A.A. Smith ◽  
Kate Meade ◽  
Claire E. Pickford ◽  
Rebecca J. Holley ◽  
Catherine L.R. Merry

ES (embryonic stem) cell differentiation is dependent on the presence of HS (heparan sulfate). We have demonstrated that, during differentiation, the evolution of specific cell lineages is associated with particular patterns of GAG (glycosaminoglycan) expression. For example, different HS epitopes are synthesized during neural or mesodermal lineage formation. Cell lines mutant for various components of the HS biosynthetic pathway are selectively impaired in their differentiation, with lineage-specific effects observed for some lines. We have also observed that the addition of soluble GAG saccharides to cells, with or without cell-surface HS, can influence the pace and outcome of differentiation, again highlighting specific pattern requirements for particular lineages. We are combining this work with ongoing studies into the design of artificial cell environments where we have optimized three-dimensional scaffolds, generated by electrospinning or by the formation of hydrogels, for the culture of ES cells. By permeating these scaffolds with defined GAG oligosaccharides, we intend to control the mechanical environment of the cells (via the scaffold architecture) as well as their biological signalling environment (using the oligosaccharides). We predict that this will allow us to control ES cell pluripotency and differentiation in a three-dimensional setting, allowing the generation of differentiated cell types for use in drug discovery/testing or in therapeutics.


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