Name: production of elastin-like protein hydrogels for encapsulation and immunostaining of cells in 3d
Uploaded: 2018-05-19T13:30:00
Description: Watch this Scientific Journal Video about Production of Elastin-like Protein Hydrogels for Encapsulation and Immunostaining of Cells in 3D at JoVE.com

The authors thank T. Palmer and H. Babu (Stanford Neurosurgery) for providing murine NPCs. Vector art in Figure 4 was used and adapted from Servier Medical Art under Creative Commons Attribution 3.0 Unported License (https://creativecommons.org/licenses/by/3.0/legalcode). Part of this work was performed at the Stanford Nano Shared Facilities (SNSF), supported by the National Science Foundation under award ECCS-1542152. N.A.S. acknowledges support from the National Institute of General Medical Sciences of the National Institutes of Health (32GM008412). C.M.M. acknowledges support from an NIH NRSA pre-doctoral fellowship (F31 EB020502) and the Siebel Scholars Program. S.C.H. acknowledges support from the National Institutes of Health (U19 AI116484 and R21 EB018407), National Science Foundation (DMR 1508006), and the California Institute for Regenerative Medicine (RT3-07948). This research received funding from the Alliance for Regenerative Rehabilitation Research &#38; Training (AR3T), which is supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institute of Neurological Disorders and Stroke (NINDS), and National Institute of Biomedical Imaging and Bioengineering (NIBIB) of the National Institutes of Health under Award Number P2CHD086843. The content is solely the responsibility of the authors and does not necessarily represent the views of the National Institutes of Health.

1. ELP Expression Protocol
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	<li>Day 1: Growing the starter colony
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		<li>Prepare ampicillin and chloramphenicol agar plates by autoclaving 25 g of Luria broth and 15 g of agar per 1 L of ultrapure water. Once the solution has cooled to ~60 &#176;C, add 1 mL of ampicillin stock (100 mg/mL in ultrapure water) and 1 mL of chloramphenicol stock (34 mg/mL in 70% ethanol) to 1 L of agar solution for final concentrations of 100 &#181;g/mL and 34 &#181;g/mL, respectively. Transfer 20 mL of final solu...

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A., Mrksich, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directing+Stem+Cell+Fate+by+Controlling+the+Affinity+and+Density+of+Ligand-Receptor+Interactions+at+the+Biomaterials+Interface.">Directing Stem Cell Fate by Controlling the Affinity and Density of Ligand-Receptor Interactions at the Biomaterials Interface.</a> Angewandte Chemie International Edition. 51 (20), 4891-4895 (2012).</li><li>Tse, J. R., Engler, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Hydrogel+Substrates+with+Tunable+Mechanical+Properties.">Preparation of Hydrogel Substrates with Tunable Mechanical Properties.</a> Current Protocols in Cell Biology. , 10.16.1-10.16.16 (2010).</li><li>Hughes, C. S., Postovit, L. M., Lajoie, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Matrigel:+A+complex+protein+mixture+required+for+optimal+growth+of+cell+culture.">Matrigel: A complex protein mixture required for optimal growth of cell culture.</a> Proteomics. 10 (9), 1886-1890 (2010).</li><li>DiMarco, R. L., Heilshorn, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multifunctional+Materials+through+Modular+Protein+Engineering.">Multifunctional Materials through Modular Protein Engineering.</a> Advanced Materials. 24 (29), 3923-3940 (2012).</li><li>Meyer, D. E., Chilkoti, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+recombinant+proteins+by+fusion+with+thermally-responsive+polypeptides.">Purification of recombinant proteins by fusion with thermally-responsive polypeptides.</a> Nature Biotechnology. 17 (11), 1112-1115 (1999).</li><li>Aladini, F., Araman, C., Becker, C. F. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+synthesis+and+characterization+of+elastin-like+polypeptides+(ELPs)+with+variable+guest+residues.">Chemical synthesis and characterization of elastin-like polypeptides (ELPs) with variable guest residues.</a> Journal of Peptide Science. 22 (5), 334-342 (2016).</li><li>McMillan, R. A., Caran, K. L., Apkarian, R. P., Conticello, V. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Resolution+Topographic+Imaging+of+Environmentally+Responsive,+Elastin-Mimetic+Hydrogels.">High-Resolution Topographic Imaging of Environmentally Responsive, Elastin-Mimetic Hydrogels.</a> Macromolecules. 32 (26), 9067-9070 (1999).</li><li>McMillan, R. A., Conticello, V. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+Characterization+of+Elastin-Mimetic+Protein+Gels+Derived+from+a+Well-Defined+Polypeptide+Precursor.">Synthesis and Characterization of Elastin-Mimetic Protein Gels Derived from a Well-Defined Polypeptide Precursor.</a> Macromolecules. 33 (13), 4809-4821 (2000).</li><li>Chung, C., Lampe, K. J., Heilshorn, S. 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Recombinant protein expression and purification is a powerful tool to synthesize biomaterials with high reproducibility. Owing largely to the advent of commercialized molecular cloning, custom recombinant plasmids can be purchased from several suppliers, which significantly reduces the time to work with materials like ELPs. Similarly, plasmids can be requested directly from the originating lab when the original work was supported by a federal contract and the future work will be for non-profit use. The full ELP amino aci...

Over the past century, two-dimensional (2D) tissue culture has developed into an integral toolset for studying fundamental cell biology in vitro. In addition, the relatively low-cost and simple protocols for 2D cell culture have led to its adoption across many biological and medical disciplines. However, past research has shown that traditional 2D platforms can lead to results that deviate markedly from those collected in vivo, causing precious time and funding wasted for clinically oriented research1,2,3. We and others hypothesize that this discrepancy may be attributed to the lack of native biochemical and biophysical cues provided to the cells cultured on 2D surfaces, which can be necessary for optimal proliferation and maturation of various cell types.
To address these limitations and help bridge the gap between 2D in vitro and in vivo studies, researchers have developed three-dimensional (3D) hydrogel platforms for cell-encapsulation1,4,5,6. Hydrogels are ideal materials to recapitulate the endogenous microenvironment of the extracellular matrix (ECM) in vivo due to their tissue-like mechanical properties and water-swollen structure that enables rapid transport of nutrients and signaling factors7,8. Furthermore, 3D hydrogels can be designed to have independent control over the mechanical and biochemical properties of the scaffold. Both matrix mechanics9,10,11,12 and cell-adhesive ligands13,14,15 are well-known to influence cell behavior in vitro and in vivo. Thus, 3D hydrogels with tunable properties offer a platform to study the causal relationships between cells and their microenvironment. Criteria for an ideal 3D hydrogel matrix include simple, non-cytotoxic cell-encapsulation as well as independent tunability of physiologically relevant mechanical properties and mimics of native cell-adhesive motifs.
Both synthetic (e.g., polyethylene glycol, polylactic acid, poly(glycolic acid)) and naturally-derived (e.g., alginate, collagen, Matrigel) hydrogels have advantages over 2D in vitro culture platforms; however, they also have significant shortcomings which limit their applicability. First, many synthetic and naturally-derived platforms require harsh crosslinking conditions that can be potentially toxic to mammalian cells, leading to decreased cell viability7. Additionally, many synthetic platforms lack native bioactivity and need to be functionalized through secondary chemical reactions, which can add increased cost and complexity16. Finally, while naturally-derived materials typically contain intrinsic bio-active domains, they are often plagued by high batch-to-batch variability and often are limited to forming relatively weak gels7,17.
Recombinant protein engineering presents a unique toolset for materials design by allowing explicit control over protein sequence and, by extension, the potential mechanical and biochemical properties of the final hydrogel scaffold18. Additionally, by leveraging the well-known biological machinery of Escherichia coli (E. coli) to express proteins, materials can be produced cost-effectively and consistently with limited inter- and intra-batch variability. The elastin-like protein (ELP) presented here has three engineered domains: (1) a T7 and His6 tag that allows for labeling via fluorescently tagged antibodies, (2) an &#39;elastin-like&#39; region that confers elastic mechanical properties and allows for chemical crosslinking, and (3) a &#39;bio-active&#39; region that encodes for cell-adhesive motifs.
Our elastin-like region is based on the canonical (Val-Pro-Gly-Xaa-Gly)5 elastin sequence where four of the &#39;Xaa&#39; amino acid sites are isoleucine (Ile), but could be designed to be any amino acid except proline. This sequence endows recombinant ELPs with lower critical solution temperature (LCST) behavior that can be exploited for simple purification post-expression via thermal cycling19,20. This LCST property can be tuned to thermally aggregate at different temperatures by modifying the guest &#39;Xaa&#39; residue21,22.
Here, the &#39;Xaa&#39; position on one of the five elastin-like repeats has been replaced with the amine-presenting lysine (Lys) amino acid, which is utilized for hydrogel crosslinking. Our previous work has shown non-cytotoxic and robust crosslinking via reaction with the amine-reactive crosslinker tetrakis(hydroxymethyl)phosphonium chloride (THPC)23. By varying overall protein content and crosslinker concentration, we are able to produce hydrogels that can be tuned to span a physiologically relevant stiffness range (~0.5-50 kPa)9,23,24. In addition to tuning mechanical properties, cell adhesion within the hydrogel results from the integration of canonical cell-adhesive domains within the backbone of the ELP protein. For example, the incorporation of the extended fibronectin-derived &#39;RGDS&#39; amino acid sequence allows for cell adhesion and conformational flexibility, while the scrambled, non-binding &#39;RDGS&#39; variant restricts cell-matrix adhesion24. By modulating the ratio of cell-adhesive to non-adhesive proteins as well as the total protein concentration, we are able to effectively produce hydrogels which span a wide range of ligand concentration. Resultantly, we have developed a hydrogel platform with decoupled biochemical and biophysical properties, which can be independently tuned for optimal 3D culture of various cell types.
In addition to matrix stiffness and adhesive ligand tunability, recombinant hydrogels offer the capability to design specific material degradation profiles, which is necessary for cell spreading, proliferation, and migration within a 3D context4,9. This degradation is afforded by cell secretion of proteases that specifically target either the extended &#39;RGDS&#39;9 or elastin-like sequence25. ELP hydrogels have also been shown to support the subsequent biochemical assays that are necessary for studying cell viability and function including immunocytochemistry as well as DNA/RNA/protein extraction for quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot9. ELP variants have also been used in a number of in vivo models and are known to be well tolerated by the immune system26.
Taken together, ELP as a material platform for cell-encapsulation studies boasts a wide variety of benefits compared to synthetic or naturally-derived material platforms, which often lack the same degree of biochemical and biophysical tunability and reproducibility. Additionally, ELP&#39;s simple and non-cytotoxic use with a wide variety of cell types (e.g., chick dorsal root ganglia14,24, murine neural progenitor cells9, human mesenchymal stem cells27, bovine neonatal chondrocytes28, human endothelial cells29,30) allows for a more physiologically relevant model of the endogenous 3D ECM compared to 2D cell culture. Herein, we present a protocol for the expression of recombinantly-derived, ELPs for the use as a tunable hydrogel platform for 3D cell encapsulation. We further present the methodology for down-stream fluorescent labeling and confocal microscopy of encapsulated cells.

<table border="0" cellpadding="0" cellspacing="0" width="904">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:355px;">Elastin-Like Protein Expression and Purification</td>
			<td style="width:260px;"></td>
			<td style="width:123px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10 cm Petri Dishes</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">FB0875713</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">70% Ethanol</td>
			<td>RICCA Chemical</td>
			<td style="width:123px;">2546.70-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ammonium Sulfate</td>
			<td>Sigma-Aldrich</td>
			<td style="width:123px;">A3920-500G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ampicillin</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">BP1760-25G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bacto Agar</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">9002-18-0&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BL21(DE3)pLysS Competent Cells</td>
			<td>Invitrogen</td>
			<td style="width:123px;">C606003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Chloramphenicol</td>
			<td style="width:260px;">Amresco</td>
			<td style="width:123px;">0230-100G&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Deoxyribonuclease I from bovine pancreas</td>
			<td>Sigma-Aldrich</td>
			<td style="width:123px;">DN25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EDTA disodium salt, dihydrate</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">O2793-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glycerol</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">BP229-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isopropanol</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">A451-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isopropyl &#946;-D-1-thiogalactopyranoside (IPTG)&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">BP1755-10G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Luria Broth</td>
			<td style="width:260px;">EMD Millipore</td>
			<td>1.10285.5007</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Parafilm</td>
			<td>VWR</td>
			<td style="width:123px;">52858-000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Phenylmethanesulfonyl fluoride (PMSF)</td>
			<td>MP Biomedicals</td>
			<td style="width:123px;">195381</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium Chloride</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">BP358-212</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sodium Hydroxide</td>
			<td>Sigma-Aldrich</td>
			<td style="width:123px;">S 8045-1KG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Syringe Filter Unit (0.22 &#956;m)</td>
			<td>Millipore</td>
			<td style="width:123px;">SLGP033RB</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Terrific Broth</td>
			<td style="width:260px;">Millipore</td>
			<td style="width:123px;">71754-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tris Base</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">BP152-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cell Encapsulation in 3D ELP Hydrogels</td>
			<td style="width:260px;"></td>
			<td style="width:123px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.22 &#956;m syringe filters</td>
			<td style="width:260px;">Millipore</td>
			<td style="width:123px;">SLGV004SL</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.5 mm thick silicone sheet</td>
			<td>Electron Microscopy Science</td>
			<td style="width:123px;">70338-05</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;">24-well tissue culture plates&#160;</td>
			<td>Corning</td>
			<td style="width:123px;">353047</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Disposable Biopsy Punch (2 mm)</td>
			<td>Integra Miltex</td>
			<td style="width:123px;">33-31</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Disposable Biopsy Punch (4 mm)</td>
			<td>Integra Miltex</td>
			<td style="width:123px;">33-34</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Disposable Biopsy Punch (5 mm)</td>
			<td>Integra Miltex</td>
			<td style="width:123px;">33-35</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dulbecco&#8217;s phosphate buffered saline (DPBS)&#160;</td>
			<td>Corning</td>
			<td style="width:123px;">21-031-CM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:355px;">No. 1 12 mm glass coverslips</td>
			<td>Thermo Fisher Scientific</td>
			<td style="width:123px;">12-545-80</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tetrakis(hydroxymethyl)phosphonium chloride (THPC)</td>
			<td>Sigma-Aldrich</td>
			<td style="width:123px;">404861-100ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.5% Tryspin/EDTA</td>
			<td>Thermo Fisher&#160;</td>
			<td style="width:123px;">15400054</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:355px;">Immunocytochemistry of Cells in 3D ELP Hydrogels</td>
			<td style="width:260px;"></td>
			<td style="width:123px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">16% (w/v) Paraformaldehyde (PFA)</td>
			<td style="width:260px;">Electron Microscopy Sciences</td>
			<td style="width:123px;">15701</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bovine Serum Albumin (BSA)</td>
			<td style="width:260px;">Roche</td>
			<td style="width:123px;">3116956001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DAPI (4&#39;,6-Diamidino-2-Phenylindole, Dihydrochloride)</td>
			<td>Molecular Probes</td>
			<td style="width:123px;">D1306&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Donkey Serum</td>
			<td style="width:260px;">Lampire Biological Labs</td>
			<td style="width:123px;">7332100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Goat anti-mouse Secondary Antibody (AF488)</td>
			<td style="width:260px;">Molecular Probes</td>
			<td style="width:123px;">A-11017</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Goat anti-rabbit Secondary Antibody (AF546)</td>
			<td style="width:260px;">Molecular Probes</td>
			<td style="width:123px;">A-11071</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Goat Serum</td>
			<td>Gibco</td>
			<td style="width:123px;">16210-072</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:355px;">Mouse Nestin Primary Antibody</td>
			<td style="width:260px;">BD Pharmingen</td>
			<td style="width:123px;">556309</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mouse Sox2 Primary Antibody</td>
			<td style="width:260px;">Cell Signaling Technology</td>
			<td style="width:123px;">23064S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:355px;">Nail Polish</td>
			<td style="width:260px;">Electron Microscopy Sciences</td>
			<td style="width:123px;">72180</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td style="width:123px;">X100-100ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vectashield Hardset Mounting Medium&#160;</td>
			<td style="width:260px;">Vector Labs</td>
			<td style="width:123px;">H-1400&#160;</td>
			<td></td>
		</tr>
	</tbody>
</table>

production of elastin-like protein hydrogels for encapsulation and immunostaining of cells in 3d

Two-dimensional (2D) tissue culture techniques have been essential for our understanding of fundamental cell biology. However, traditional 2D tissue culture systems lack a three-dimensional (3D) matrix, resulting in a significant disconnect between results collected in vitro and in vivo. To address this limitation, researchers have engineered 3D hydrogel tissue culture platforms that can mimic the biochemical and biophysical properties of the in vivo cell microenvironment. This research has motivated the need to develop material platforms that support 3D cell encapsulation and downstream biochemical assays. Recombinant protein engineering offers a unique toolset for 3D hydrogel material design and development by allowing for the specific control of protein sequence and therefore, by extension, the potential mechanical and biochemical properties of the resultant matrix. Here, we present a protocol for the expression of recombinantly-derived elastin-like protein (ELP), which can be used to form hydrogels with independently tunable mechanical properties and cell-adhesive ligand concentration. We further present a methodology for cell encapsulation within ELP hydrogels and subsequent immunofluorescent staining of embedded cells for downstream analysis and quantification.

The ELPs used in this protocol are comprised of five regions: a T7 tag, His6 tag, enterokinase (EK) cleavage site, a bio-active region, and an elastin-like region (Figure 1). The T7 and His6 tags allow for easy identification through standard Western blot techniques. Introduction of the EK cleavage site allows for the enzymatic removal of the tag region, if needed. The bio-active region encodes for the extended, fibronectin-derived cell-adhesive (&#39;RGDS&#3...

Watch this Scientific Journal Video about Production of Elastin-like Protein Hydrogels for Encapsulation and Immunostaining of Cells in 3D at JoVE.com

Production of Elastin-like Protein Hydrogels for Encapsulation and Immunostaining of Cells in 3D

Recombinant protein-engineered hydrogels are advantageous for 3D cell culture as they allow for complete tunability of the polymer backbone and therefore, the cell microenvironment. Here, we describe the process of recombinant elastin-like protein purification and its application in 3D hydrogel cell encapsulation.

Two-dimensional (2D) tissue culture techniques have been essential for our understanding of fundamental cell biology. However, traditional 2D tissue ...

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Bioengineering

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