Search Results (102)

Skeletal muscle diseases often exhibit fiber-type-specific characteristics and pose substantial clinical challenges, necessitating innovative therapies. The extracellular matrix (ECM) plays a pivotal role in muscle physiology and regeneration, influencing cell differentiation. However, its specific role and mechanisms influencing muscle fiber type specification remain insufficiently understood. In this study, C2C12^GFP myoblasts were differentiated into myofibers on plates coated with fibronectin, Collagen I, and Geltrex™. Differentiation occurred successfully across all ECM substrates, resulting in myofiber formation. Quantitative polymerase chain reaction (qPCR) analysis confirmed myogenic marker expression patterns, indicating decreased Pax7 and increased Myog levels by day 7. Protein analysis through Western blot and immunofluorescence assays along with transcriptomic profiling through RNA sequencing consistently indicated that Collagen I promoted slow-type fibers development, as evidenced by increased slow myofiber protein expression and the upregulation of slow fiber-associated genes, potentially mediated by pathways involving calcineurin/NFAT, MEF2, MYOD, AMPK, PI3K/AKT, and ERK1. In contrast, fibronectin and Geltrex™ led to fast-type fiber development, with elevated fast-type fiber protein levels and upregulation of fast fiber-associated genes, possibly through activation of HIF1A, FOXO1, NFKB, and ERK2. These findings elucidate ECM-mediated muscle fiber type differentiation mechanisms, informing future targeted therapies for muscle regeneration. Full article

Nanotopography refers to the intricate surface characteristics of materials at the sub-micron (<1000 nm) and nanometer (<100 nm) scales. These topographical surface features significantly influence the physical, chemical, and biological properties of biomaterials, affecting their interactions with cells and surrounding tissues. The development of nanostructured surfaces of polymeric nanocomposites has garnered increasing attention in the fields of tissue engineering and regenerative medicine due to their ability to modulate cellular responses and enhance tissue regeneration. Various top-down and bottom-up techniques, including nanolithography, etching, deposition, laser ablation, template-assisted synthesis, and nanografting techniques, are employed to create structured surfaces on biomaterials. Additionally, nanotopographies can be fabricated using polymeric nanocomposites, with or without the integration of organic and inorganic nanomaterials, through advanced methods such as using electrospinning, layer-by-layer (LbL) assembly, sol–gel processing, in situ polymerization, 3D printing, template-assisted methods, and spin coating. The surface topography of polymeric nanocomposite scaffolds can be tailored through the incorporation of organic nanomaterials (e.g., chitosan, dextran, alginate, collagen, polydopamine, cellulose, polypyrrole) and inorganic nanomaterials (e.g., silver, gold, titania, silica, zirconia, iron oxide). The choice of fabrication technique depends on the desired surface features, material properties, and specific biomedical applications. Nanotopographical modifications on biomaterials’ surface play a crucial role in regulating cell behavior, including adhesion, proliferation, differentiation, and migration, which are critical for tissue engineering and repair. For effective tissue regeneration, it is imperative that scaffolds closely mimic the native extracellular matrix (ECM), providing a mechanical framework and topographical cues that replicate matrix elasticity and nanoscale surface features. This ECM biomimicry is vital for responding to biochemical signaling cues, orchestrating cellular functions, metabolic processes, and subsequent tissue organization. The integration of nanotopography within scaffold matrices has emerged as a pivotal regulator in the development of next-generation biomaterials designed to regulate cellular responses for enhanced tissue repair and organization. Additionally, these scaffolds with specific surface topographies, such as grooves (linear channels that guide cell alignment), pillars (protrusions), holes/pits/dots (depressions), fibrous structures (mimicking ECM fibers), and tubular arrays (array of tubular structures), are crucial for regulating cell behavior and promoting tissue repair. This review presents recent advances in the fabrication methodologies used to engineer nanotopographical microenvironments in polymeric nanocomposite tissue scaffolds through the incorporation of nanomaterials and biomolecular functionalization. Furthermore, it discusses how these modifications influence cellular interactions and tissue regeneration. Finally, the review highlights the challenges and future perspectives in nanomaterial-mediated fabrication of nanotopographical polymeric scaffolds for tissue engineering and regenerative medicine. Full article

For organ-on-a-chip (OoC) engineering, the use of biocompatible coatings and materials is not only recommended but essential. Extracellular matrix (ECM) components are commonly used as coatings due to their effects on cell orientation, protein expression, differentiation, and adhesion. Among the most frequently used coatings are collagen, fibronectin, and Matrigel, according to the specific cell type and intended OoC application. Additionally, materials such as polydimethylsiloxane (PDMS), thermoplastics, chitosan, and alginate serve as scaffolding components due to their biomechanical properties and biocompatibility. Here, we discuss some of the most employed coating techniques, including SAMs, dip coating, spin coating, microcontact printing, and 3D bioprinting, each offering advantages and drawbacks. Current challenges comprise enhancing biocompatibility, exploring novel materials, and improving scalability and reproducibility. Full article

Traumatic spinal cord injury (SCI) initiates a cascade of events, including persistent inflammation, which contributes to secondary injury. At a molecular level, the lesion is characterized by an altered microenvironment with changes in extracellular matrix (ECM) composition and organization, identified as a potential obstacle for effective stem cell-based cell therapies. We investigated the interactions between decellularized intact and injured rat spinal cords and rat embryonic (RESCs) and neural stem cells (NSCs) at 2 and 47 days post-lesion (dpl). Decellularized ECM was used to generate 2D coating and 3D gel in vitro platforms for cell seeding. Results showed that the 2dpl 2D coating exerted a significant negative effect on the viability of both cell types, while the 47dpl 2D coating maintained RESC pluripotency. NSCs cultured on the 2dpl 2D coating for seven days showed a severe impairment in cell growth, while maintaining a cluster formation potential and differentiation marker expression comparable to normal ECM for astrocytic and oligodendroglial lineages. Notably, when NSCs are grown in 47dpl 3D gel, the lineage turns dramatically toward an astroglial lineage. These results clearly show the detrimental effects of the SCI ECM microenvironment on stem cells, advancing the understanding of potential timings suitable for effective SCI cell-based therapies. Full article

Understanding the diffusion mechanisms of nanocarriers in tumor tissues is crucial for enhancing drug delivery to target areas. This study developed a simulation method combining lattice gas automata and the lattice Boltzmann method to explore the diffusion behaviors of ligand-coated nanoparticles (NPs) in the extracellular matrix (ECM) and tumor tissues under the influence of external fields. We propose mathematical models to describe how the movement of NPs is affected by thermomagnetic effects and by their interactions with ECM fiber walls and cells, and to calculate the flow field and temperature distribution in tumor tissues containing interstitial fluids. The results show that reduced tissue porosity and increased ECM fiber and cell densities hinder NP transport. Conversely, degrading ECM collagen fibers with thermal or other energy forms significantly improved NP diffusion in treated tissues. Modifying the surface zeta potential of NPs allowed for the regulation of NP adhesion to ECM fibers and cell membranes based on their charged components. However, altering the charge on the NP surface did not further enhance diffusion once a certain charge level was reached. Increased temperatures from NP heat generation under external fields improved interstitial fluid flow, thereby enhancing NP diffusion. Additionally, a static magnetic field gradient considerably increased the penetration depth of magnetic NPs in the direction of the field, with minimal effects on diffusion in other directions and, in some cases, reducing diffusion. Full article

The inducible enzyme cyclooxygenase-2 (COX-2) and the subsequent synthesis of eicosanoids initiated by this enzyme are important molecular players in bone healing. In this pilot study, the suitability of a novel selective COX-2 inhibitor bearing a nitric oxide (NO)-releasing moiety was investigated as a modulator of healing a critical-size bone defect in rats. A 5 mm femoral defect was randomly filled with no material (negative control, NC), a mixture of collagen and autologous bone fragments (positive control, PC), or polycaprolactone-co-lactide (PCL)-scaffolds coated with two types of artificial extracellular matrix (aECM; collagen/chondroitin sulfate (Col/CS) or collagen/polysulfated hyaluronic acid (Col/sHA3)). Bone healing was monitored by a dual-tracer ([¹⁸F]FDG/[¹⁸F]fluoride) approach using PET/CT imaging in vivo. In addition, ex vivo µCT imaging as well as histological and immunohistochemical studies were performed 16 weeks post-surgery. A significant higher uptake of [¹⁸F]FDG, a surrogate marker for inflammatory infiltrate, but not of [¹⁸F]fluoride, representing bone mineralization, was observed in the implanted PCL-scaffolds coated with either Col/CS or Col/sHA3. Molecular targeting of COX-2 with NO-coxib had no significant effect on tracer uptake in any of the groups. Histological and immunohistochemical staining showed no evidence of a positive or negative influence of NO-coxib treatment on bone healing. Full article

During corneal wound healing, transforming growth factor-beta 1 (TGF-β1) causes differentiation of quiescent keratocytes into myofibroblasts. Decorin has been investigated as a promising anti-fibrotic therapeutic for corneal healing due to its interaction with TGF-β1, collagen, and cell surface receptors. In this study, a novel microfluidic method for coating aligned collagen fibrils with decorin was developed to mimic the presence of decorin within the corneal stroma. Decorin was found to bind selectively to collagen and remained bound for at least five days. To investigate the effects of decorin coatings on keratocyte activation, primary rabbit keratocytes were cultured in the presence of TGF-β1 for 5 days on substrates with or without decorin and stained for α-smooth muscle actin (α-SMA). The expression of α-SMA was reduced by similar amounts on monomeric collagen (40%), random collagen fibrils (32%), and aligned collagen fibrils (32%) coated with decorin as controls. However, α-SMA expression was differentially expressed between the collagen substrates not coated with decorin, with significantly lower expression on uncoated aligned collagen fibrils compared to uncoated collagen monomers. Addition of decorin directly to culture media, had a limited effect on reducing myofibroblast differentiation. Taken together, these results demonstrate the importance of topography and ECM composition on keratocyte activation. Full article

Corneal fibroblasts are central to normal and abnormal wound healing in the cornea. During the wound healing process, several biochemical and biophysical signals that are present in the extracellular matrix (ECM) play critical roles in regulating corneal fibroblast behavior. The translocation and activation of Yes-associated protein (YAP)—a main transcriptional factor in the Hippo signaling pathway—is one example of mechanotransduction involving these signals. However, how corneal fibroblasts integrate these simultaneous cues is unknown. In this study, we utilized well-defined micropatterns of aligned collagen fibrils and other ECM proteins to explore the effects of cell density, topography, geometric confinement, and ECM composition on the translocation of YAP in corneal fibroblasts. We observed that when human corneal fibroblasts (HTKs) were confined to narrow micropatterns (50 μm and 100 μm) of proteins, there was a high degree of cell alignment irrespective of cell seeding density. However, the location of YAP was dependent upon the cell seeding density, ECM composition, and topography. YAP was more nuclear-localized on substrates coated with aligned collagen fibrils or fibronectin as compared to substrates coated with monomeric collagen, random collagen fibrils, or poly-L-Lysine. In addition, we also observed that YAP nuclear localization was significantly reduced when HTKs were cultured on aligned collagen fibrils, monomeric collagen, or fibronectin in the presence of monoclonal blocking antibodies against α₅ or β₁ integrin subunits. Finally, we observed that HTK cells formed fibrillar fibronectin on both monomeric collagen and aligned collagen fibrils. These findings provide new insights into how simultaneous biochemical and biophysical cues affect YAP localization in corneal fibroblasts. Full article

The performance of an orthopedic procedure depends on several tandem functionalities. Such characteristics include materials’ surface properties and subsequent responses. Implant surfaces are typically roughened; this roughness can further be optimized to a specific morphology such as nanotubular roughness (ZrNTs) and the surfaces can further be used as static drug reservoirs. ZrNTs coatings are attracting interest due to their potential to improve the success rate of implant systems, by means of better physical affixation and also micro/nano physio-chemical interaction with the extracellular matrix (ECM). Effective control over the drug release properties from such coatings has been the subject of several published reports. In this study, a novel and simple approach to extending drug release time and limiting the undesirable burst release from zirconia nanotubes (ZrNTs) via structural modification was demonstrated. The latter involved fabricating a double-layered structure with a modulated diameter and was achieved by varying the voltage and time during electrochemical anodization. The structurally modified ZrNTs and their homogenous equivalents were characterized via SEM and ToF-SIMS, and their drug release properties were monitored and compared using UV–Vis spectroscopy. We report a significant reduction in the initial burst release phenomenon and enhanced overall release time. The simple structural modification of ZrNTs can successfully enhance drug release performance, allowing for flexibility in designing drug delivery coatings for specific implant challenges, and offering a new horizon for smart biomaterials based on metal oxide nanostructures. Full article

Induced pluripotent stem cell (iPSC)-derived neurons (iNs) have been widely used as models of neurodevelopment and neurodegenerative diseases. Coating cell culture vessels with extracellular matrixes (ECMs) gives structural support and facilitates cell communication and differentiation, ultimately enhances neuronal functions. However, the relevance of different ECMs to the natural environment and their impact on neuronal differentiation have not been fully characterized. In this study, we report the use of four commonly used extracellular matrixes, poly-D-lysine (PDL), poly-L-ornithine (PLO), Laminin and Matrigel, which we applied to compare the single-coating and double-coating conditions on iNs differentiation and maturation. Using the IncuCyte live-cell imaging system, we found that iNs cultured on single Matrigel- and Laminin-coated vessels have significantly higher density of neurite outgrowth and branch points than PLO or PDL but produce abnormal highly straight neurite outgrowth and larger cell body clumps. All the four double-coating conditions significantly reduced the clumping of neurons, in which the combination of PDL+Matrigel also enhanced neuronal purity. Double coating with PDL+Matrigel also tended to improve dendritic and axonal development and the distribution of pre and postsynaptic markers. These results demonstrate that the extracellular matrix contributes to the differentiation of cultured neurons and that double coating with PDL+Matrigel gives the best outcomes. Our study indicates that neuronal differentiation and maturation can be manipulated, to a certain extent, by adjusting the ECM recipe, and provides important technical guidance for the use of the ECM in neurological studies. Full article

Cultured meat produced using satellite cells has emerged to address issues such as overpopulation, the ethical conundrums associated with the breeding environment, and the methane gas emissions associated with factory farming. To date, however, the challenges of maintaining satellite cells in vitro and reducing the costs of the culture media are still substantial. Gelatin, collagen, and fibronectin are commonly used extracellular matrices (ECMs) that facilitate signal integration with the cells and promote cell adhesion. In this study, we compared the proliferation, cell cycle, immunocytochemistry, and expression levels of Pax7, Pax3, Myf5, MyoD1, and MyoG genes in bovine satellite cells (BSCs) cultured on gelatin-, collagen- and fibronectin-coated dishes as part of short- and long-term cultures. We observed that BSCs cultured on gelatin-coated dishes showed higher levels of Pax7 expression than BSCs cultured on collagen- and fibronectin-coated dishes in both short- and long-term cultures, indicating that BSCs cultured on gelatin effectively maintained the satellite cell population in both the short- and long-term cultures. Our study highlights that gelatin is an effective ECM for the maintenance of BSCs and the production of cultured meat. Full article

Tissue engineering of nervous tissue is a promising direction in the treatment of neurological diseases such as spinal cord injuries or neuropathies. Thanks to technological progress and scientific achievements; the use of cells; artificial scaffolds; and growth factors are becoming increasingly common. Despite challenges such as the complex structure of this tissue, regenerative medicine appears as a promising future approach to improve the quality of life of patients with nervous injuries. Until now; most functional biomaterials used for this purpose were based on decellularized extra cellular matrix (ECM) or nanofibrous materials, whereas current clinically verified ones in most cases do not exhibit bioactivity or the possibility for external stimulation. The aim of this research was to develop a new type of bioactive, chitosan-based 3D materials applicable as nerve guide conduits (NGCs) modified with poly(dopamine), Au/Pt coated with PVP nanoparticles, and cannabidiol. The NGCs were prepared under microwave-assisted conditions and their chemical structure was studied using the FT-IR method. Next, this study will discuss novel biomaterials for morphology and swelling abilities as well as susceptibility to biodegradation in the presence of collagenase and lysozyme. Finally, their potential in the field of nervous tissue engineering has been verified via a cytotoxicity study using the 1321N1 human astrocytoma cell line, which confirmed their biocompatibility in direct contact studies. Full article

Mechanotransduction, the process of how cells sense and convert mechanical stimuli into biochemical response, is crucial in the migration of leukocytes or cancer cells through the endothelium during inflammation or metastasis. Migrating cells exert forces on the endothelium through cell surface adhesion molecules, such as platelet endothelial adhesion molecule PECAM-1, and this is essential for a successful transmigration. To study PECAM-1-mediated mechanotransduction, we applied PECAM-1-antibody-coated magnetic beads and exerted about 40 pN force on the endothelial monolayer. We show that force increases cell–ECM adhesion in the cell center and is accompanied by the opening of cell–cell junctions. Upon depletion of the MEK/ERK kinase, BRAF force increases cell–ECM adhesion both at the cell periphery and in the cell center, but this does not result in the opening of cell–cell junctions. Decreasing cell–ECM adhesion in BRAF-depleted cells through FAK inhibition results in the remodeling of cell–cell junctions. Force-induced increase in cell–ECM adhesion in the cell center correlates with the activation of the transcriptional cofactor Yes-associated protein (YAP). Furthermore, the induced activation of YAP through LATS inhibition prevents junctional remodeling in control cells. Thus, the activation of YAP might determine the strength of cell–cell junctions during PECAM-1-mediated mechanotransduction. Full article

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterized by ongoing inflammation, impaired tissue repair, and aberrant interplay between airway epithelium and fibroblasts, resulting in an altered extracellular matrix (ECM) composition. The ECM is the three-dimensional (3D) scaffold that provides mechanical support and biochemical signals to cells, now recognized not only as a consequence but as a potential driver of disease progression. To elucidate how the ECM influences pathophysiological changes occurring in COPD, in vitro models are needed that incorporate the ECM. ECM hydrogels are a novel experimental tool for incorporating the ECM in experimental setups. We developed an airway wall model by combining lung-derived ECM hydrogels with a co-culture of primary human fibroblasts and epithelial cells at an air–liquid interface. Collagen IV and a mixture of collagen I, fibronectin, and bovine serum albumin were used as basement membrane-mimicking coatings. The model was initially assembled using porcine lung-derived ECM hydrogels and subsequently with COPD and non-COPD human lung-derived ECM hydrogels. The resulting 3D construct exhibited considerable contraction and supported co-culture, resulting in a differentiated epithelial layer. This multi-component 3D model allows the investigation of remodelling mechanisms, exploring ECM involvement in cellular crosstalk, and holds promise as a model for drug discovery studies exploring ECM involvement in cellular interactions. Full article

An ideal extracellular matrix (ECM) replacement scaffold in a three-dimensional cell (3D) culture should induce in vivo-like interactions between the ECM and cultured cells. Highly hydrophilic polyvinyl alcohol (PVA) nanofibers disintegrate upon contact with water, resulting in the loss of their fibrous morphology in cell cultures. This can be resolved by using chemical crosslinkers and post-crosslinking. A crosslinked, water-stable, porous, and optically transparent PVA nanofibrous membrane (NM) supports the 3D growth of various cell types. The binding of cells attached to the porous PVA NM is low, resulting in the aggregation of cultured cells in prolonged cultures. PVA NMs containing integrin-binding peptides of fibronectin and laminin were produced to retain the blended peptides as cell-binding substrates. These peptide-blended PVA NMs promote peptide-specific cell adherence and growth. Various cells, including epithelial cells, cultured on these PVA NMs form layers instead of cell aggregates and spheroids, and their growth patterns are similar to those of the cells cultured on an ECM-coated PVA NM. The peptide-retained PVA NMs are non-stimulatory to dendritic cells cultured on the membranes. These peptide-retaining PVA NMs can be used as an ECM replacement matrix by providing in vivo-like interactions between the matrix and cultured cells. Full article