Native Extracellular Matrix Composition Research Articles

Gelatin-Based Scaffolds with Carrageenan and Chitosan for Soft Tissue Regeneration.

Motivated by the enormous potential of hydrogels in regenerative medicine, new biocompatible gelatin-based hybrid hydrogels were developed through a green process using poly(ethylene glycol) diglycidyl ether as a cross-linking agent, adding carrageenan and chitosan polysaccharides to the network to better mimic the hybrid composition of native extracellular matrix. Overall, the hydrogels show suitable structural stability, high porosity and pore interconnectivity, good swellability, and finally, biocompatibility. Their mechanical behavior, investigated by tensile and compression tests, appears to be characterized by nonlinear elasticity with high compliance values, fast stress-relaxation, and good strain reversibility with no sign of mechanical failure for compressive loading-unloading cycles at relatively high deformation levels of 50%. Degradation tests confirm the hydrogel bioresorbability by gradual hydrolysis, during which the structural integrity of both materials is maintained, while their mechanical behavior becomes more and more compliant. Human Umbilical Cord-derived Mesenchymal Stem Cells (hUC-MSCs) were used to test the hydrogels as potential carriers for cell delivery in tissue engineering. hUC-MSCs cultured inside the hydrogels show a homogenous distribution and maintain their growth and viability for at least 21 days of culture, with an increasing proliferation trend. Hence, this study contributes to a further understanding of the potential use of hybrid hydrogels and hUC-MSCs for a wide range of biomedical applications, particularly in soft tissue engineering.

Developing Bovine Brain-Derived Extracellular Matrix Hydrogels: a Screen of Decellularization Methods for Their Impact on Biochemical and Mechanical Properties.

Tissue models that recapitulate the key biochemical and physical aspects of the brain have been highly pursued in neural tissue engineering. Decellularization of native organs offers the advantage of preserving the composition of native extracellular matrix (ECM). Brain ECM has distinct features which play a major role in neural cell behavior. Cell instructive ligands and mechanical properties take part in the regulation of cellular processes in homeostasis and diseases. One of the main challenges in decellularization is maintaining mechanical integrity in reconstituted hydrogels and achieving physiologically relevant stiffness. The effect of the decellularization process on different mechanical aspects, particularly the viscoelasticity of brain-derived hydrogels, has not been addressed. In this study, we developed bovine brain-derived hydrogels for the first time. We pursued seven protocols for decellularization and screened their effect on biochemical content, hydrogel formation, and mechanical characteristics. We show that bovine brain offers an easily accessible alternative for in vitro brain tissue modeling. Our data demonstrate that the choice of decellularization method strongly alters gelation as well as the stiffness and viscoelasticity of the resulting hydrogels. Lastly, we investigated the cytocompatibility of brain ECM hydrogels and the effect of modulated mechanical properties on the growth and morphological features of neuroblastoma cells.

Decellularized Human Lung Scaffolds as Complex Three-Dimensional Tissue Culture Models to Study Functional Behavior of Fibroblasts.

In vitro culturing of cells in two-dimensional (2D) environments is a widespread used methodology in biomedical research. Most commonly, cells are cultured on artificial plastic dish surfaces, which lead to abnormal functional behaviors, as plastic does not reflect the native microenvironment found in vivo or in situ. Therefore, a multitude of three-dimensional (3D) cell culture systems were developed in the past years, which aim to bridge the gap between 2D cell culture dishes and the in vivo situation. One of the more recent development in the field, the generation of viable precision-cut tissue slices from various organs emerged as an exciting approach to study complex interactions and biological processes ex vivo in 3D. Decellularization of such tissue slices leads to the removal of all functional cells, and leaves behind a scaffold of extracellular matrix (ECM), which closely recapitulates the molecular composition, mechanical properties, topology, and microarchitecture of native ECM. Subsequently, decellularized precision-cut lung slices (PCLS), also called 3D lung tissue culture (3D-LTCs), can be successfully reseeded with a variety of cell types, including fibroblasts, which attach to and engraft into the matrix. Here, we describe the generation of PCLS from resected human lung tissue and their decellularization and recellularization with primary human fibroblasts. This novel 3D tissue culture model allows for various functional studies of fibroblast behavior on native ECM composition and topology.

Engineering of a collagen-based extracellular matrix mimetic scaffold via electrospinning

Event Abstract Back to Event Engineering of a collagen-based extracellular matrix mimetic scaffold via electrospinning Jorge Almodovar1 and David Castilla1 1 University of Puerto Rico Mayaguez, Department of Chemical Engineering, Puerto Rico Nanofibrous scaffolds have been extensively used in tissue engineering due to its resemblance to native extracellular matrix (ECM) in scale, orientation, and geometry. Collagen is one of the biological polymers more suitable to be used in the fabrication of scaffolds. Collagen is the most abundant protein in the human body, providing strength and structure to tissues. Electrospun collagen nanofibrous scaffolds have been previously investigated using harsh solvents that disrupt collagen’s secondary structure and limits its applications as implantable devices. Our work focuses on the generation of a nanofibrous structure that mimics the morphology, organization, nanoscale and composition of native ECM. Type II collagen from cow tendon, was used to fabricate a nanofibrous structure via the electrospinning technique using a mild aqueous solvent. Scanning Electron Microscope (SEM) was used to confirm the morphology of the nanofibrous structure. SEM revelead that it was possible to fabricate an aligned or randomly oriented nanofibrous structure of type II collagen, with a range of diameters between from 36 to 130 nm. To utilize the collagen membranes in aqueous environment, crosslinking was performed by: 1) immersion in a 25% glutaraldehyde solution and 2) exposure to glutaraldehyde vapor. The chemical composition of the nanofibers was assessed using Fourier transform infrared spectroscopy (FT-IR). Secondary structure determination was based on the amide I band (1700–1600 cm-1), which is commonly used to study the secondary structure proteins. FTIR confirms that the secondary structure of collagen is preserved after the electrospinning process and after crosslinking. Un-crosslinked and crosslinked type II collagen membranes were mechanically tested with an Instron ElectroPuls model E3000 in tension mode at a constant displacement of 1.0 mm/s. Measurements for the un-crosslinked samples were performed in air at room temperature whereas the crosslinked samples were submerged in deionized water and tested at 37 degrees C using a BioPlus Temperature Controlled Bath. The crosslinking process allows for the fabrication of collagen scaffolds with mechanical properties in the range of soft tissues such as cartilage, and stable in water environments at body temperature. Young's Moduli (MPa) of 12.2 ± 3.3 for un-crosslinked nanofibers, 4.1 ± 0.5, for crosslinked - by immersion and 2.7 ± 0.7 for crosslinked – vapor were obtained. In conclusion, we developed a nanofibrous scaffold of type II collagen that preserves its chemical and secondary structure. Nanofibrous membranes were obtained with morphological and mechanical features similar to that found in soft tissues in the human body, which may be suitable as scaffolds for tissue regeneration. Keywords: Extracellular Matrix, biomaterial, nanofiber, material design Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: General Session Oral Topic: Electrospinning and related technologies Citation: Almodovar J and Castilla D (2016). Engineering of a collagen-based extracellular matrix mimetic scaffold via electrospinning. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00762 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jorge Almodovar David Castilla Google Jorge Almodovar David Castilla Google Scholar Jorge Almodovar David Castilla PubMed Jorge Almodovar David Castilla Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.