Patterning and transferring hydrogel-encapsulated bacterial cells for quantitative analysis of synthetically engineered genetic circuits

Choi, Woon Sun; Kim, Minseok; Park, Seongyong; Lee, Sung Kuk; Kim, Taesung

doi:10.1016/j.biomaterials.2011.09.069

Cited by 13 publications

(16 citation statements)

References 41 publications

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“…Adipogenesis is believed to occur in two stages [28]. The first stage is commitment of MSCs to pre-adipocytic differentiation which can be regulated by biophysical and biochemical cues such as matrix elasticity [29], cell shape [23,30], and matrix ligand [24,26] while the second stage is terminal differentiation to mature adipocytes through activation of peroxisome proliferator-activated receptor-γ (PPAR γ) [28]. MSCs that adopt characteristics of neuronal cells [31,32], demonstrate high expression of neurogenic markers such as neuroepithelial stem cell intermediate filament (NESTIN), microtubule associated protein 2 (MAP2), and ß3 tubulin [33–35].…”

Section: Introductionmentioning

confidence: 99%

Matrix directed adipogenesis and neurogenesis of mesenchymal stem cells derived from adipose tissue and bone marrow

et al. 2016

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Mesenchymal stem cells (MSCs) can differentiate into multiple lineages through guidance from the biophysical and biochemical properties of the extracellular matrix. In this work we conduct a combinatorial study of matrix properties that influence adipogenesis and neurogenesis including: adhesion proteins, stiffness, and cell geometry, for mesenchymal stem cells derived from adipose tissue (AT-MSCs) and bone marrow (BM-MSCs). We uncover distinct differences in integrin expression, the magnitude of traction stress, and lineage specification to adipocytes and neuron-like cells between cell sources. In the absence of media supplements, adipogenesis in AT-MSCs is not significantly influenced by matrix properties, while the converse is true in BM-MSCs. Both cell types show changes in the expression of neurogenesis markers as matrix cues are varied. When cultured on laminin conjugated microislands of the same adhesive area, BM-MSCs display elevated adipogenesis markers, while AT-MSCs display elevated neurogenesis markers; integrin analysis suggests neurogenesis in AT-MSCs is guided by adhesion through integrin αvβ3. Overall, the properties of the extracellular matrix guides MSC adhesion and lineage specification to different degrees and outcomes, in spite of their similarities in general characteristics. This work will help guide the selection of MSCs and matrix components for applications where high fidelity of differentiation outcome is desired.

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Section: Introductionmentioning

confidence: 99%

Matrix directed adipogenesis and neurogenesis of mesenchymal stem cells derived from adipose tissue and bone marrow

et al. 2016

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“…16 For a dual induction study, the same stain was transformed with plasmid pZBRG producing both red fluorescent proteins (RFPs) and GFPs in the presence of 40 mM arabinose and 10 μM tetracycline, respectively. 23 The same culture and preparation protocols as those used in our previous protocols 5, 24 were used for all the Analytical Chemistry Article DOI: 10.1021/acs.analchem.5b02028…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Crack-Photolithography for Membrane-Free Diffusion-Based Micro/Nanofluidic Devices

Kim

2015

Anal. Chem.

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Recent advances in controlling the cracking phenomena established a novel unconventional fabrication technique to generate mixed-scale patterns/structures with resolution and accuracy comparable to conventional nanofabrication techniques. Here, we adapt our previous cracking-assisted nanofabrication technique (called "crack-photolithography") relying on only the standard photolithography to develop micro/nanofluidic devices with greatly reduced time and cost. The crack-photolithography makes it possible not only to simultaneously produce micropatterns and nanopatterns with various dimensions but also to replicate both of the mixed-scale patterns in a high-throughput manner. Therefore, a microfluidic channel network can easily be fabricated with a nanochannel array that can function as a nanoporous membrane wherever necessary, which basically plays a key role in diffusion-allowed but convection-suppressed microfluidic devices. In addition, the nanochannel array can manipulate the transport of small molecules by adjusting its dimension and/or number at will, so that nanochannel-array-integrated micro/nanofluidic devices prove even more robust and accurate in diffusion control than conventional membrane-integrated microfluidic devices. As an application of such micro/nanofluidic devices, we employed synthetic bacterial cells and found that their genetic induction and expression are dominated by extracellular diffusive microenvironments that were completely engineered using the nanochannel array. Hence, the crack-photolithography could provide innovative fabrication techniques for unprecedented micro/nanofluidic devices that show substantial potential for a wide range of biological and chemical applications.

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“…The E. coli was transformed with plasmids that contain a constitutive promoter (pLtetO-1) and green fluorescent protein (GFP) genes to quantitatively analyze the bacterial population. For a dual induction study, the same stain was transformed with plasmid pZBRG, producing both red fluorescent proteins (RFPs) and GFPs in the presence of 4 mM arabinose and 50 nM tetracycline, respectively . We also used a DH10B strain having kanamycin resistance to test the selective growth with respect to antibiotic chemical conditions.…”

Section: Experimental Sectionmentioning

confidence: 99%

Nanoscale Hydrodynamic Film for Diffusive Mass Transport Control in Compartmentalized Microfluidic Chambers

et al. 2017

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A compartmentalized microfluidic chamber array that offers not only separate cell culture environments but also independent control of the diffusion of small molecules provides an extremely useful platform for cell cultivations and versatile cellular assays. However, it is challenging to incorporate both cell compartmentalization and active diffusion control in real-time and precise manners. Here, we present a novel nanoscale hydrodynamic film (NHF) that is formed between a solid substrate and a polydimethylsiloxane (PDMS) surface. The thickness of the NHF can be adjusted by varying the pressure applied between them so that the mass transfer through the NHF can also be controlled. These novel phenomena are characterized and applied to develop a compartmentalized microchamber array with diffusion-tunable and solution-switchable chemostat-like versatile bacterial assays. The NHF-based compartmentalization technique is ideal for not only continuous bacterial cultivation by consistently refreshing various nutrient sources but also various diffusion-based microbial assays such as chemical induction of synthetically engineered bacterial cells and selective growth of a specific bacterial strain with respect to chemical environments. In addition, we show that tight compartmentalization protects cells in the chambers, while biofilm formation and nutrient contamination are eliminated by loading a lysis buffer, which typically hinders long-term continuous cultures and accurate microbial assays on a chip. Therefore, we ensure that the NHF-based compartmentalization platform proposed in this work will facilitate not only fundamental studies in microbiology but also various practical applications of microbes for production of valuable metabolites and byproducts in a high-throughput and highly efficient format.

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Patterning and transferring hydrogel-encapsulated bacterial cells for quantitative analysis of synthetically engineered genetic circuits

Cited by 13 publications

References 41 publications

Matrix directed adipogenesis and neurogenesis of mesenchymal stem cells derived from adipose tissue and bone marrow

Matrix directed adipogenesis and neurogenesis of mesenchymal stem cells derived from adipose tissue and bone marrow

Crack-Photolithography for Membrane-Free Diffusion-Based Micro/Nanofluidic Devices

Nanoscale Hydrodynamic Film for Diffusive Mass Transport Control in Compartmentalized Microfluidic Chambers

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