Name: synthesis of decellularized cartilage extracellular matrix hydrogels
Uploaded: 2023-07-21T14:10:00
Description: Watch this Scientific Journal Video about Synthesis of Decellularized Cartilage Extracellular Matrix Hydrogels at JoVE.com

This work was sponsored by the Medicine and Health Technology Plan of Zhejiang Province (2019KY050), the Traditional Chinese Medicine Science and Technology Plan of Zhejiang Province (2019ZA026), the Key Research and Development Plan in Zhejiang Province (Grant No.2020C03043), the Traditional Chinese Medicine Science and Technology Plan of Zhejiang Province (2021ZQ021), and the Zhejiang Provincial Natural Science Foundation of China (LQ22H060007).

This study was approved by the Ethics Committee of Tongde Hospital of Zhejiang Province.
1. Preparation of the DC-ECM hydrogel
NOTE: In this study, the cartilage was obtained from the knee joints of 12 month old Bama miniature pigs, avoiding the collection of bone tissue.
<ol>
	<li>Take the collected cartilage, and block and chop it into 1-2 mm3 pieces with a scalpel.</li>
	<li>Place 20 g of the minced cartilage in a 50 mL centrifuge tu...

<ol>
	<li>Vega, S. L., Kwon, M. Y., Burdick, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+hydrogels+for+cartilage+tissue+engineering.">Recent advances in hydrogels for cartilage tissue engineering.</a> European Cells &amp; Materials. 33, 59-75 (2017).</li><li>Yang, J., Zhang, Y. S., Yue, K., Khademhosseini, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-laden+hydrogels+for+osteochondral+and+cartilage+tissue+engineering.">Cell-laden hydrogels for osteochondral and cartilage tissue engineering.</a> Acta Biomaterialia. 57, 1-25 (2017).</li><li>Bejleri, D., Davis, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decellularized+extracellular+matrix+materials+for+cardiac+repair+and+regeneration.">Decellularized extracellular matrix materials for cardiac repair and regeneration.</a> Advanced Healthcare Materials. 8 (5), e1801217 (2019).</li><li>Brown, M., Li, J., Moraes, C., Tabrizian, M., Li-Jessen, N. Y. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decellularized+extracellular+matrix:+New+promising+and+challenging+biomaterials+for+regenerative+medicine.">Decellularized extracellular matrix: New promising and challenging biomaterials for regenerative medicine.</a> Biomaterials. 289, 121786 (2022).</li><li>Barbulescu, G. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decellularized+extracellular+matrix+scaffolds+for+cardiovascular+tissue+engineering:+Current+techniques+and+challenges.">Decellularized extracellular matrix scaffolds for cardiovascular tissue engineering: Current techniques and challenges.</a> International Journal of Molecular Sciences. 23 (21), 13040 (2022).</li><li>Zhang, W., Du, A., Liu, S., Lv, M., Chen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Research+progress+in+decellularized+extracellular+matrix-derived+hydrogels.">Research progress in decellularized extracellular matrix-derived hydrogels.</a> Regenerative Therapy. 18, 88-96 (2021).</li><li>Zhu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-derived+decellularized+extracellular+matrix+scaffolds+for+articular+cartilage+repair.">Cell-derived decellularized extracellular matrix scaffolds for articular cartilage repair.</a> International Journal of Artificial Organs. 44 (4), 269-281 (2021).</li><li>Li, T., Javed, R., Ao, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xenogeneic+decellularized+extracellular+matrix-based+biomaterials+for+peripheral+nerve+repair+and+regeneration.">Xenogeneic decellularized extracellular matrix-based biomaterials for peripheral nerve repair and regeneration.</a> Current Neuropharmacology. 19 (12), 2152-2163 (2021).</li><li>Xia, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decellularized+cartilage+as+a+prospective+scaffold+for+cartilage+repair.">Decellularized cartilage as a prospective scaffold for cartilage repair.</a> Materials Science &amp; Engineering C-Materials for Biological Applications. 101, 588-595 (2019).</li><li>Chen, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Desktop-stereolithography+3D+printing+of+a+radially+oriented+extracellular+matrix/mesenchymal+stem+cell+exosome+bioink+for+osteochondral+defect+regeneration.">Desktop-stereolithography 3D printing of a radially oriented extracellular matrix/mesenchymal stem cell exosome bioink for osteochondral defect regeneration.</a> Theranostics. 9 (9), 2439-2459 (2019).</li><li>Saldin, L. T., Cramer, M. C., Velankar, S. S., White, L. J., Badylak, S. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+matrix+hydrogels+from+decellularized+tissues:+Structure+and+function.">Extracellular matrix hydrogels from decellularized tissues: Structure and function.</a> Acta Biomaterialia. 49, 1-15 (2017).</li><li>Yuan, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell+delivery+in+tissue-specific+hydrogel+enabled+meniscal+repair+in+an+orthotopic+rat+model.">Stem cell delivery in tissue-specific hydrogel enabled meniscal repair in an orthotopic rat model.</a> Biomaterials. 132, 59-71 (2017).</li><li>Zheng, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intensified+stiffness+and+photodynamic+provocation+in+a+collagen-based+composite+hydrogel+drive+chondrogenesis.">Intensified stiffness and photodynamic provocation in a collagen-based composite hydrogel drive chondrogenesis.</a> Advanced Science. 6 (16), 1900099 (2019).</li><li>Young, J. L., Holle, A. W., Spatz, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=P.Nanoscale+and+mechanical+properties+of+the+physiological+cell-ECM+microenvironment.">P.Nanoscale and mechanical properties of the physiological cell-ECM microenvironment.</a> Experimental Cell Research. 343 (1), 3-6 (2016).</li><li>Abdolghafoorian, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+heart+valve+decellularization+on+xenograft+rejection.">Effect of heart valve decellularization on xenograft rejection.</a> Experimental and Clinical Transplantation. 15 (3), 329-336 (2017).</li></ol>

This protocol provides a systematic approach for the preparation of decellularized cartilage extracellular matrix hydrogels that closely mimic the native ECM of cartilage tissue. The protocol involves a combination of physical, chemical, and enzymatic disruption to remove cellular material while preserving the structure and composition of the ECM. The protocol's critical steps include adjusting the decellularization time and methods and ensuring complete decellularization.
Compared to other ex...

Cartilage tissue engineering is a rapidly developing field that seeks to regenerate damaged or diseased cartilage tissue1. One key challenge in this field is the development of biomimetic scaffolds that can support the growth and differentiation of chondrocytes, the cells responsible for producing cartilage2. The ECM of cartilage tissue plays a critical role in regulating the behavior of chondrocytes. DC-ECM is an effective scaffold for tissue engineering applications3.
A number of techniques have been developed to produce DC-ECM from cartilage tissue, including chemical, enzymatic, and physical methods. However, these methods often result in the generation of ECM hydrogels that are insufficiently biomimetic, which limits their potential for use in tissue engineering applications4,5. Thus, there is a need for a more effective method for producing DC-ECM hydrogels.
The development of this technique is important because it can advance the field of tissue engineering by providing a new approach for creating biomimetic scaffolds that can support tissue regeneration and repair. Furthermore, this technique could be easily adapted to produce ECM hydrogels from other tissues, thereby expanding its potential applications.
In the broader body of literature, there has been growing interest in using DC-ECM as a scaffold for tissue engineering applications6. Numerous studies have demonstrated the effectiveness of DC-ECM hydrogels in promoting cell growth and differentiation in various tissues, including cartilage7,8. Therefore, the development of a protocol for producing DC-ECM hydrogels that closely mimic the natural ECM of cartilage tissue is a significant contribution to the field.
The protocol presented in this paper addresses this need by providing a novel method for producing DC-ECM hydrogels that closely mimic the natural ECM of cartilage tissue. The protocol involves decellularizing cartilage tissue, isolating the resulting ECM, and creating a hydrogel by cross-linking the ECM with a biocompatible polymer. The resulting hydrogel has shown promising results in supporting the growth and differentiation of chondrocytes.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1 M Tris-HCl, pH7.6</td>
			<td>Beyotime</td>
			<td>ST776-100 mL</td>
			<td></td>
		</tr>
		<tr>
			<td>1 M Tris-HCl, pH8.0</td>
			<td>Beyotime</td>
			<td>ST780-500 mL</td>
			<td></td>
		</tr>
		<tr>
			<td>-80 &#176;C Freezer</td>
			<td>Eppendorf</td>
			<td>F440340034</td>
			<td></td>
		</tr>
		<tr>
			<td>Deoxyribonuclease</td>
			<td>Aladdin</td>
			<td>D128600-80KU</td>
			<td></td>
		</tr>
		<tr>
			<td>DNEasy Blood &#38;Tissue Kit</td>
			<td>Qiagen</td>
			<td>No. 69506</td>
			<td></td>
		</tr>
		<tr>
			<td>GAG colorimetric quantitative detection kit</td>
			<td>Shanghai Haling</td>
			<td>HL19236.2</td>
			<td></td>
		</tr>
		<tr>
			<td>HCP-2 dryer&#160;</td>
			<td>Hitachi</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Nanodrop8000</td>
			<td>Thermo Fisher</td>
			<td>N/A</td>
			<td>Spectrophotometer</td>
		</tr>
		<tr>
			<td>PBS (10x)</td>
			<td>Gibco</td>
			<td>70011044</td>
			<td></td>
		</tr>
		<tr>
			<td>Ribonuclease</td>
			<td>Aladdin</td>
			<td>R341325-100 mg</td>
			<td></td>
		</tr>
		<tr>
			<td>Sigma500</td>
			<td>ZIESS</td>
			<td>N/A</td>
			<td>Scanning electron microscope</td>
		</tr>
		<tr>
			<td>Spectra S</td>
			<td>Thermo Fisher</td>
			<td>N/A</td>
			<td>Transmission electron microscope</td>
		</tr>
		<tr>
			<td>Stainless steel sieve</td>
			<td>SHXB-Z-1</td>
			<td>Shanghai Xinbu</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Beyotime</td>
			<td>P0096-500 mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin&#160;</td>
			<td>Gibco</td>
			<td>15050065</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultraviolet lamp</td>
			<td>Omnicure 2000</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Vitamin B2</td>
			<td>Gibco</td>
			<td>R4500-5G</td>
			<td></td>
		</tr>
		<tr>
			<td>Vortex mixer</td>
			<td>Shanghai Qiasen</td>
			<td>78HW-1&#160;</td>
			<td></td>
		</tr>
	</tbody>
</table>

synthesis of decellularized cartilage extracellular matrix hydrogels

Decellularized cartilage extracellular matrix (DC-ECM) hydrogels are promising biomaterials for tissue engineering and regenerative medicine due to their biocompatibility and ability to mimic natural tissue properties. This protocol aims to produce DC-ECM hydrogels that closely mimic the native ECM of cartilage tissue. The protocol involves a combination of physical and chemical disruption and enzymatic digestion to remove the cellular material while preserving the structure and composition of the ECM. The DC-ECM is cross-linked using a chemical agent to form a stable and biologically active hydrogel. The DC-ECM hydrogel has excellent biological activity, spatial structure, and biological induction function, as well as low immunogenicity. These characteristics are beneficial in promoting cell adhesion, proliferation, differentiation, and migration and for creating a superior microenvironment for cell growth. This protocol provides a valuable resource for researchers and clinicians in the field of tissue engineering. Biomimetic hydrogels can potentially enhance the development of effective tissue engineering strategies for cartilage repair and regeneration.

To prepare a better DC-ECM cartilage hydrogel, we studied and reviewed the previous literature and compared the various decellularization protocols in terms of the decellularization ratio, immunogenicity, and mechanical functionality9.
On this basis, we prepared the DC-ECM cartilage hydrogel and explored the effect of a radially oriented extractive matrix/mesenchymal stem cell exosome bio-ink in treating osteochondral defects. The results showed that the DC-ECM cartilag...

Watch this Scientific Journal Video about Synthesis of Decellularized Cartilage Extracellular Matrix Hydrogels at JoVE.com

Synthesis of Decellularized Cartilage Extracellular Matrix Hydrogels

This paper introduces a new method for the synthesis of decellularized cartilage extracellular matrix (DC-ECM) hydrogels. DC-ECM hydrogels have excellent biocompatibility and provide a superior microenvironment for cell growth. Therefore, they can be ideal cell scaffolds and biological delivery systems.

Decellularized cartilage extracellular matrix (DC-ECM) hydrogels are promising biomaterials for tissue engineering and regenerative medicine due to their ...

Our protocol is significant as it enables the creation of disease in hydrogels that closely resemble the nature of cartilage tissue. The main advantage of this technique is ability to produce disease in hydrogels with evident biological activity in spatial structure, low immunogenicity, and biological industrial function. To begin, chop the collected cartilage using a scalpel into pieces of one to two cubic millimeters in size.In a 50-millimeter centrifuge tube, submerge 20 grams of the minced cartilage in 20 milliliters of hypotonic Tris-hydrochloride buffer. Place the tube at 80 degrees Celsius for three hours, and then in the oven at 37 degrees Celsius for three hours. Vortex the centrifuge tube for 30 seconds at 1000 RPM.Then filter the decellularized cartilage using a plastic sieve placed on a 50-milliliter centrifuge tube. Wash the cartilage thrice with sterile PBS before collecting it. Add 10 milliliters of trypsin solution to the collected cartilage and incubate it on a shaker at 37 degrees Celsius for 24 hours, replacing the trypsin every four hours.After filtering the suspension, wash the trypsinized cartilage with hypertonic buffer. Once the cartilage is preserved, add 10 milliliters of nuclease solution and place it on a shaker at 37 degrees Celsius for four hours. After washing with sterile PBS, add hypertonic Tris-hydrochloride solution to the cartilage and place it on the shaker as demonstrated.Once washed with sterile PBS, submerge the tissue in 1%Triton X-100 solution for 24 hours. After removing the Triton X-100, rinse the decellularized cartilage with distilled water for three days, changing the water every 12 hours. After three days, add peracetic acid solution to the cartilage and soak it for four hours.Once washed with PBS, collect the cartilage using a plastic sieve as previously demonstrated. Using liquid nitrogen, prepare decellularized cartilage powder. Add 80 milliliters of 0.5 molar acetic acid and 20 milligrams of pepsin to two grams of cartilage powder, and digest the mixture for 24 hours at 37 degrees Celsius.After digestion, centrifuge the suspension at 400 G for 10 minutes and collect the supernatant, which is now called DC-ECM solution For storing the DC-ECM solution, add one milliliter of the solution to each well of a six-well plate and place it in a lyophilizer. Once the solution is freeze dried, transfer it to a centrifuge tube. To form a hydrogel, dissolve 20 milligrams of freeze dried DC-ECM solution in one milliliter of sterile distilled water.Once vortexed, add one milligram of vitamin B2 to the DC-ECM solution. After incubation, irradiate it with UV light for three minutes. Add buffer GTL and proteinase K to 20 milligrams of DC-ECM cartilage powder, and mix thoroughly using vortex oscillation.For complete cartilage dissolution, incubate the mixture at 56 degrees Celsius for four hours. Once vortexed, add 200 microliters of buffer GTL followed by anhydrous ethanol. After vortexing, centrifuge the sample at 6000 G for one minute at four degrees Celsius.Then collect and quantify the DNA as described in the manuscript. For analyzing collagen, acidify five milligrams of DC-ECM powder in hydrochloric acid at 100 degrees Celsius for 20 minutes. Then neutralize it with five milliliters of six molar sodium hydroxide solution.Calculate the hydroxyproline content of the neutralized sample using absorbance at 570 nanometers against the hydroxyproline standard. Add 500 microliters of reagent A to 200 milligrams of DC-ECM powder after mixing. Incubate the sample at four degrees Celsius for 16 hours.Once centrifuged, collect 50 microliters of sample solution and add 50 microliters of reagent B, followed by reagent C.After incubating the sample for 10 minutes, add 750 microliters of reagent D and incubate for 30 minutes in the dark. After centrifugation, add one microliter of reagent E to the pellet and mix well before centrifuging. Then dissociate the sample before GAG content measurement.In the prepared DC-ECM cartilage, the DNA content was significantly eliminated. However, the collagen and GAG content were retained compared to the native cartilage. The SEM and TEM analysis demonstrated the ultra structure of the prepared DC-ECM.The prepared hydrogel in the inverted tube did not flow to the bottom, thus demonstrating gelation. Further, compared to the DC-ECM only solution, the addition of vitamin B2 reduced the gelation time due to the induced crosslinking during the DC-ECM hydrogel formation. The DC-ECM hydrogel viscosity was higher than the solution viscosity and increased shear rates decreased the solution viscosity.Moreover, the high storage modulus of the DC-ECM solution and hydrogel indicated that they both had gel rather than liquid properties. The SEM analysis demonstrated that the pore size of the DC-ECM solution was significantly decreased in the hydrogel form after crosslinking and freeze drying. The protocol involves a combination of physical and chemical disruption and enzymatic digestion to remove cellular material while preserving the structure and the conversation of the ECM.

synthesis-of-decellularized-cartilage-extracellular-matrix-hydrogels

Research

JoVE Journal

Bioengineering

The Synthesis of RGD-functionalized Hydrogels as a Tool for Therapeutic Applications

The use of polymers as biomaterials has provided significant advantages in therapeutic applications. In particular, the possibility to modify and functionalize polymer chains with compounds that are able to improve biocompatibility, mechanical properties, or cell viability allows the design of novel materials to meet new challenges in the biomedical field. With the polymer functionalization strategies, click chemistry is a powerful tool to improve cell-compatibility and drug delivery properties of polymeric devices. Similarly, the fundamental need of biomedicine to use sterile tools to avoid potential adverse-side effects, such as toxicity or contamination of the biological environment, gives rise to increasing interest in the microwave-assisted strategy.
The combination of click chemistry and the microwave-assisted method is suitable to produce biocompatible hydrogels with desired functionalities and improved performances in biomedical applications. This work aims to synthesize RGD-functionalized hydrogels. RGD (arginylglycylaspartic acid) is a tripeptide that can mimic cell adhesion proteins and bind to cell-surface receptors, creating a hospitable microenvironment for cells within the 3D polymeric network of the hydrogels. RGD functionalization occurs through Huisgen 1,3-dipolar cycloaddition. Some PAA carboxyl groups are modified with an alkyne moiety, whereas RGD is functionalized with azido acid as the terminal residue of the peptide sequence. Finally, both products are used in a copper catalyzed click reaction to permanently link the peptide to PAA. This modified polymer is used with carbomer, agarose and polyethylene glycol (PEG) to synthesize a hydrogel matrix. The 3D structure is formed due to an esterification reaction involving carboxyl groups from PAA and carbomer and hydroxyl groups from agarose and PEG through microwave-assisted polycondensation. The efficiency of the gelation mechanism ensures a high degree of RGD functionalization. In addition, the procedure to load therapeutic compounds or biological tools within this functionalized network is very simple and reproducible.

We present a protocol for the synthesis of RGD-functionalized hydrogels as devices for cell and drug delivery. The procedure involves copper catalyzed alkyne-azide cycloaddition (CuAAC) between alkyne-modified polyacrylic acid (PAA) and a RGD-azide derivative. The hydrogels are formed using microwave-assisted polycondensation and their physicochemical properties are investigated.

The use of polymers as biomaterials has provided significant advantages in therapeutic applications. In particular, the possibility to modify and ...

Preparation of Extracellular Matrix Protein Fibers for Brillouin Spectroscopy

Brillouin spectroscopy is an emerging technique in the biomedical field. It probes the mechanical properties of a sample through the interaction of visible light with thermally induced acoustic waves or phonons propagating at a speed of a few km/sec. Information on the elasticity and structure of the material is obtained in a nondestructive contactless manner, hence opening the way to in vivo applications and potential diagnosis of pathology. This work describes the application of Brillouin spectroscopy to the study of biomechanics in elastin and trypsin-digested type I collagen fibers of the extracellular matrix. Fibrous proteins of the extracellular matrix are the building blocks of biological tissues and investigating their mechanical and physical behavior is key to establishing structure-function relationships in normal tissues and the changes which occur in disease. The procedures of sample preparation followed by measurement of Brillouin spectra using a reflective substrate are presented together with details of the optical system and methods of spectral data analysis.

We present a protocol for the application of Brillouin light scattering spectroscopy to elastin and trypsin-purified type I collagen fibers of the extracellular matrix to extract their full elastic properties.

Brillouin spectroscopy is an emerging technique in the biomedical field. It probes the mechanical properties of a sample through the interaction of ...

Tunable Hydrogels from Pulmonary Extracellular Matrix for 3D Cell Culture

Here we present a method for establishing multiple component cell culture hydrogels for in vitro lung cell culture. Beginning with healthy en bloc lung tissue from porcine, rat, or mouse, the tissue is perfused and submerged in subsequent chemical detergents to remove the cellular debris. Histological comparison of the tissue before and after processing confirms removal of over 95% of double stranded DNA and alpha galactosidase staining suggests the majority of cellular debris is removed. After decellularization, the tissue is lyophilized and then cryomilled into a powder. The matrix powder is digested for 48 hr in an acidic pepsin digestion solution and then neutralized to form the pregel solution. Gelation of the pregel solution can be induced by incubation at 37 &#176;C and can be used immediately following neutralization or stored at 4 &#176;C for up to two weeks. Coatings can be formed using the pregel solution on a non-treated plate for cell attachment. Cells can be suspended in the pregel prior to self-assembly to achieve a 3D culture, plated on the surface of a formed gel from which the cells can migrate through the scaffold, or plated on the coatings. Alterations to the strategy presented can impact gelation temperature, strength, or protein fragment sizes. Beyond hydrogel formation, the hydrogel stiffness may be increased using genipin.

This is a method to create a 3-dimensional cell culture scaffold from pulmonary extracellular matrix. Intact lung is processed into hydrogels that can support the growth of cells in three-dimensions.

Here we present a method for establishing multiple component cell culture hydrogels for in vitro lung cell culture. Beginning with healthy en bloc lung ...

Fabricating a Kidney Cortex Extracellular Matrix-Derived Hydrogel

Extracellular matrix (ECM) provides important biophysical and biochemical cues to maintain tissue homeostasis. Current synthetic hydrogels offer robust mechanical support for in vitro cell culture but lack the necessary protein and ligand composition to elicit physiological behavior from cells. This manuscript describes a fabrication method for a kidney cortex ECM-derived hydrogel with proper mechanical robustness and supportive biochemical composition. The hydrogel is fabricated by mechanically homogenizing and solubilizing decellularized human kidney cortex ECM. The matrix preserves native kidney cortex ECM protein ratios while also enabling gelation to physiological mechanical stiffnesses. The hydrogel serves as a substrate upon which kidney cortex-derived cells can be maintained under physiological conditions. Furthermore, the hydrogel composition can be manipulated to model a diseased environment which enables the future study of kidney diseases.

Here we present a protocol to fabricate a kidney cortex extracellular matrix-derived hydrogel to retain the native kidney extracellular matrix (ECM) structural and biochemical composition. The fabrication process and its applications are described. Finally, a perspective on using this hydrogel to support kidney-specific cellular and tissue regeneration and bioengineering is discussed.

Extracellular matrix (ECM) provides important biophysical and biochemical cues to maintain tissue homeostasis. Current synthetic hydrogels offer robust ...

Fabrication of Decellularized Cartilage-derived Matrix Scaffolds

Osteochondral defects lack sufficient intrinsic repair capacity to regenerate functionally sound bone and cartilage tissue. To this extent, cartilage research has focused on the development of regenerative scaffolds. This article describes the development of scaffolds that are completely derived from natural cartilage extracellular matrix, coming from an equine donor. Potential applications of the scaffolds include producing allografts for cartilage repair, serving as a scaffold for osteochondral tissue engineering, and providing in vitro models to study tissue formation. By decellularizing the tissue, the donor cells are removed, but many of the natural bioactive cues are thought to be retained. The main advantage of using such a natural scaffold in comparison to a synthetically produced scaffold is that no further functionalization of polymers is required to drive osteochondral tissue regeneration. The cartilage-derived matrix scaffolds can be used for bone and cartilage tissue regeneration in both in vivo and in vitro settings.

Decellularized cartilage-derived scaffolds can be used as a scaffold to guide cartilage repair and as a means to regenerate osteochondral tissue. This paper describes the decellularization process in detail and provides suggestions to use these scaffolds in in vitro settings.

Osteochondral defects lack sufficient intrinsic repair capacity to regenerate functionally sound bone and cartilage tissue. To this extent, cartilage ...

Measuring Global Cellular Matrix Metalloproteinase and Metabolic Activity in 3D Hydrogels

Three-dimensional (3D) cell culture systems often more closely recapitulate in vivo cellular responses and functions than traditional two-dimensional (2D) culture systems. However, measurement of cell function in 3D culture is often more challenging. Many biological assays require retrieval of cellular material which can be difficult in 3D cultures. One way to address this challenge is to develop new materials that enable measurement of cell function within the material. Here, a method is presented for measurement of cellular matrix metalloproteinase (MMP) activity in 3D hydrogels in a 96-well format. In this system, a poly(ethylene glycol) (PEG) hydrogel is functionalized with a fluorogenic MMP cleavable sensor. Cellular MMP activity is proportional to fluorescence intensity and can be measured with a standard microplate reader. Miniaturization of this assay to a 96-well format reduced the time required for experimental set up by 50% and reagent usage by 80% per condition as compared to the previous 24-well version of the assay. This assay is also compatible with other measurements of cellular function. For example, a metabolic activity assay is demonstrated here, which can be conducted simultaneously with MMP activity measurements within the same hydrogel. The assay is demonstrated with human melanoma cells encapsulated across a range of cell seeding densities to determine the appropriate encapsulation density for the working range of the assay. After 24 h of cell encapsulation, MMP and metabolic activity readouts were proportional to cell seeding density. While the assay is demonstrated here with one fluorogenic degradable substrate, the assay and methodology could be adapted for a wide variety of hydrogel systems and other fluorescent sensors. Such an assay provides a practical, efficient and easily accessible 3D culturing platform for a wide variety of applications.

Here, a protocol is presented for encapsulating and culturing cells in poly(ethylene glycol) (PEG) hydrogels functionalized with a fluorogenic matrix metalloproteinase (MMP)-degradable peptide. Cellular MMP and metabolic activity are measured directly from the hydrogel cultures using a standard microplate reader.

Three-dimensional (3D) cell culture systems often more closely recapitulate in vivo cellular responses and functions than traditional two-dimensional (2D) ...

Labeling of Extracellular Vesicles for Monitoring Migration and Uptake in Cartilage Explants

Extracellular vesicles (EVs) are used in different studies to prove their potential as a cell-free treatment due to their cargo derived from their cellular source, such as platelet lysate (PL). When used as treatment, EVs are expected to enter the target cells and effect a response from these. In this research, PL-derived EVs have been studied as a cell-free treatment for osteoarthritis (OA). Thus, a method was set up to label EVs and test their uptake on cartilage explants. PL-derived EVs are labeled with the lipophilic dye PKH26, washed twice through a column, and then tested in an in vitro inflammation-driven&#160;OA model for 5 h after particle quantification by nanoparticle tracking analysis (NTA). Hourly, cartilage explants are fixed, paraffined, cut into 6 &#181;m sections to mount on slides, and observed under a confocal microscope. This allows verification of whether EVs enter the target cells (chondrocytes) during this period and analyze their direct effect.

Here, we present a protocol to label platelet lysate-derived extracellular vesicles to monitor their migration and uptake in cartilage explants used as a model for osteoarthritis.

Extracellular vesicles (EVs) are used in different studies to prove their potential as a cell-free treatment due to their cargo derived from their ...

Fabrication and Characterization of Layer-By-Layer Janus Base Nano-Matrix to Promote Cartilage Regeneration

Various biomaterial scaffolds have been developed to guide cell adhesion and proliferation in hopes to promote specific functions for in vitro and in vivo uses. The addition of growth factors into these biomaterial scaffolds is generally done to provide an optimal cell culture environment, mediating cell differentiation and its subsequent functions. However, the growth factors in a conventional biomaterial scaffold are typically designed to be released upon implantation, which could result in unintended side effects on surrounding tissue or cells. Here, the DNA-inspired Janus base nano-matrix (JBNm) has successfully achieved a highly localized microenvironment with a layer-by-layer structure for self-sustainable cartilage tissue constructs. JBNms are self-assembled from Janus base nanotubes (JBNts), matrilin-3, and transforming growth factor beta-1 (TGF-&#946;1) via bioaffinity. The JBNm was assembled at a TGF-&#946;1:matrilin-3:JBNt ratio of 1:4:10, as this has been the determined ratio at which proper assembly into the layer-by-layer structure could occur. First, the TGF-&#946;1 solution was added to the matrilin-3 solution. Then, this mixture was pipetted several times to ensure sufficient homogeneity before the addition of the JBNt solution. This formed the layer-by-layer JBNm, after pipetting several times again. A variety of experiments were performed to characterize the layer-by-layer JBNm structure, JBNts alone, matrilin-3 alone, and TGF-&#946;1 alone. The formation of JBNm was studied with UV-Vis absorption spectra, and the structure of the JBNm was observed with transmission electron microscopy (TEM). As the innovative layer-by-layer JBNm scaffold is formed on a molecular scale, the fluorescent dye-labeled JBNm could be observed. The TGF-&#946;1 is confined within the inner layer of the injectable JBNm, which can prevent the release of growth factors to surrounding areas, promote localized chondrogenesis, and promote an anti-hypertrophic microenvironment.

This protocol describes the assembly of a layer-by-layer Janus base nano-matrix (JBNm) scaffold by adding Janus base nanotubes (JBNts), matrilin-3, and Transforming Growth Factor Beta-1 (TGF-&#946;1) sequentially. The JBNm was fabricated and characterized; additionally, it displayed excellent bioactivity, encouraging cell functions such as adhesion, proliferation, and differentiation.

Various biomaterial scaffolds have been developed to guide cell adhesion and proliferation in hopes to promote specific functions for in vitro and in vivo ...

Comparative Study of Decellularization Techniques for Bovine Lung ECM Hydrogels

Development and Characterization of Decellularized Lung Extracellular Matrix Hydrogels

The use of extracellular matrix (ECM)-derived hydrogels in tissue engineering has become increasingly popular, as they can mimic cells&#39; natural environment in vitro. However, maintaining the native biochemical content of the ECM, achieving mechanical stability, and comprehending the impact of the decellularization process on the mechanical properties of the ECM hydrogels are challenging. Here, a pipeline for decellularization of bovine lung tissue using two different protocols, downstream characterization of the effectiveness of decellularization, fabrication of reconstituted decellularized lung ECM hydrogels and assessment of their mechanical and cytocompatibility properties were described. Decellularization of the bovine lung was pursued using a physical (freeze-thaw cycles) or chemical (detergent-based) method. Hematoxylin and Eosin staining was performed to validate the decellularization and retention of major ECM components. For the evaluation of residual collagen and sulfated glycosaminoglycan (sGAG) content within the decellularized samples, Sirius red and Alcian blue staining techniques were employed, respectively. Mechanical properties of the decellularized lung ECM hydrogels were characterized by oscillatory rheology. The results suggest that decellularized bovine lung hydrogels can provide a reliable organotypic<span style="font-size: 11pt; font-family: Calibri, sans-serif; color: black; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">&#160;alternative to commercial ECM products by retaining most native ECM components. Furthermore, these findings reveal that the decellularization method of choice significantly affects gelation kinetics as well as the stiffness and viscoelastic properties of resulting hydrogels.

Author Spotlight: Optimizing Bovine Lung Decellularization for Organotypic Hydrogels

The protocol elucidates two distinct decellularization methodologies applied to native bovine pulmonary tissues, providing a comprehensive account of their respective characterizations.

The use of extracellular matrix (ECM)-derived hydrogels in tissue engineering has become increasingly popular, as they can mimic cells&#39; natural ...

Decellularized Rat Spleen Matrix Preparation for Liver Tissue Engineering

Fabrication of Decellularized Spleen Matrix Derived from Rats

Liver transplantation is the primary treatment for end-stage liver disease. However, the shortage and inadequate quality of donor organs necessitate the development of alternative therapies. Bioartificial livers (BALs) utilizing decellularized liver matrix (DLM) have emerged as promising solutions. However, sourcing suitable DLMs remains challenging. The use of a decellularized spleen matrix (DSM) has been explored as a foundation for BALs, offering a readily available alternative. In this study, rat spleens were harvested and decellularized using a combination of freeze-thaw cycles and perfusion with decellularization reagents. The protocol preserved the microstructures and components of the extracellular matrix (ECM) within the DSM. The complete decellularization process took approximately 11 h, resulting in an intact ECM within the DSM. Histological analysis confirmed the removal of cellular components while retaining the ECM's structure and composition. The presented protocol provides a comprehensive method for obtaining DSM, offering potential applications in liver tissue engineering and cell therapy. These findings contribute to the development of alternative approaches for the treatment of end-stage liver disease.

Author Spotlight: Utilization of Decellularized Spleen Matrix for Bioartificial Livers

The decellularized spleen matrix (DSM) holds promising applications in the field of liver tissue engineering. This protocol outlines the procedure for preparing rat DSM, which includes harvesting rat spleens, decellularizing them through perfusion, and evaluating the resulting DSM to confirm its characteristics.

Liver transplantation is the primary treatment for end-stage liver disease. However, the shortage and inadequate quality of donor organs necessitate the ...