Search Results (952)

(1) Background: The extracellular matrix (ECM) is a natural scaffold for cells, creating a three-dimensional architecture composed of fibrous proteins (mainly collagen) and proteoglycans, which are synthesized by resident cells. In this study, a physiological hypoxic environment was utilized to enhance ECM production by human mesenchymal stem cells (hMSCs), a process relevant to tissue engineering and regenerative medicine. (2) Methods: hMSCs were treated with deferoxamine (DFO), a pharmaceutical hypoxia-mimetic agent that induces cellular responses similar to low-oxygen conditions through stabilization of hypoxia inducible factor-1α (HIF-1α). The time points 0 h 24 h, 3 h 24 h, and 24 h 24 h refer to DFO being added immediately after cell seeding (before cells adhesion), 3 h after cell seeding (during initial cells attachment), and 24 h after cell seeding (after focal adhesions formation and actin organization), respectively, to evaluate the influence of cell adhesion on ECM deposition. hMSCs incubated in culture media were subsequently exposed to DFO for 24 h. Samples were then subjected to cell viability tests, scanning electron microscopy (SEM), atomic force microscopy (AFM) and laser scanning confocal microscopy (CLSM) assessments. (3) Results: Viability tests indicated that DFO concentrations in the range of 0–300 µM were non-toxic over 24 h. The presence of collagen fibers in the DFO-derived ECM was confirmed with anti-collagen antibodies under CLSM. Increased ECM secretion was observed under the following conditions: 3 μM DFO (24 h 24 h), 100 μM DFO (0 h 24 h) and 300 μM DFO (3 h 24 h). SEM and AFM images revealed the morphology of various stages of collagen formation with both collagen fibrils and fibers identified. (4) Conclusions: Our preliminary study demonstrated enhanced ECM secretion by hMSC treated with DFO at concentrations of 3, 100, and 300 µM within a short cultivation period of 24–48 h without significant affecting cell viability. By mimicking physiological processes, it may be possible to stimulate endogenous tissue regeneration, for example, at an injury site. Full article

Cell-mediated extracellular matrix (ECM) self-assembly provides a biologically relevant approach for developing near-physiological tissue-engineered constructs by utilizing stromal cells to secrete and assemble ECM components in the presence of ascorbic acid. Despite its unique advantages, this method often results in scaffolds with limited mechanical properties, depending on the cell type. This research aimed to enhance the mechanical properties of these constructs by culturing cells derived from various sources, including skin, bladder, urethra, vagina, and adipose tissue, on electrospun scaffolds composed of polycaprolactone and collagen (PCLCOL). The hybrid scaffolds were evaluated using various in vitro assays to assess their structural and functional properties. Results showed that different stromal cells could deposit ECM on the PCLCOL with distinct composition compared to the ECM that was self-assembled on tissue culture plates (TCP). Additionally, cells cultured on PCLCOL exhibited a different growth factor secretion profile compared to those on TCP. Mechanical testing demonstrated that the hybrid scaffolds exhibited high mechanical properties and superior manipulability. These findings suggest that PCLCOL could be a promising platform for developing biomimetic scaffolds that combine enhanced mechanical strength with integrated biological cues for tissue repair. Full article

Pulmonary fibrosis (PF) is a progressive and fatal lung disease characterized by irreversible alveolar destruction and pathological extracellular matrix (ECM) deposition. Currently approved agents (pirfenidone and nintedanib) slow functional decline but do not reverse established fibrosis or restore functional alveoli. Multifunctional bioscaffolds present a promising therapeutic strategy through targeted modulation of critical cellular processes, including proliferation, migration, and differentiation. This review synthesizes recent advances in scaffold-based interventions for PF, with a focus on their dual mechano-epigenetic regulatory functions. We delineate how scaffold properties (elastic modulus, stiffness gradients, dynamic mechanical cues) direct cell fate decisions via mechanotransduction pathways, exemplified by focal adhesion–cytoskeleton coupling. Critically, we highlight how pathological mechanical inputs establish and perpetuate self-reinforcing epigenetic barriers to regeneration through aberrant chromatin states. Furthermore, we examine scaffolds as platforms for precision epigenetic drug delivery, particularly controlled release of inhibitors targeting DNA methyltransferases (DNMTi) and histone deacetylases (HDACi) to disrupt this mechano-reinforced barrier. Evidence from PF murine models and ex vivo lung slice cultures demonstrate scaffold-mediated remodeling of the fibrotic niche, with key studies reporting substantial reductions in collagen deposition and significant increases in alveolar epithelial cell markers following intervention. These quantitative outcomes highlight enhanced alveolar epithelial plasticity and upregulating antifibrotic gene networks. Emerging integration of stimuli-responsive biomaterials, CRISPR/dCas9-based epigenetic editors, and AI-driven design to enhance scaffold functionality is discussed. Collectively, multifunctional bioscaffolds hold significant potential for clinical translation by uniquely co-targeting mechanotransduction and epigenetic reprogramming. Future work will need to resolve persistent challenges, including the erasure of pathological mechanical memory and precise spatiotemporal control of epigenetic modifiers in vivo, to unlock their full therapeutic potential. Full article

The intervertebral disc (IVD) is a biphasic tissue in which the extracellular matrix (ECM) acts as a structural scaffold and regulates hydration and solute transport. The influence of hydration on the swelling and mechanical properties of the IVD, particularly the annulus fibrosus (AF), is not fully described in the literature. Hydration is assumed to affect inter- and intramolecular hydrogen bonding and hydrophilic interactions, thereby modulating tissue mechanics. This study aimed to assess the effect of hydration time on free swelling of AF and its impact on mechanical performance. AF specimens were divided into five groups, hydrated for 0, 10, 20, 30, or 40 min and subjected to uniaxial tensile testing until failure. Swelling-related geometric changes were correlated with tensile properties. Results demonstrated that hydration duration significantly influenced AF’s structural and mechanical characteristics in anterior and posterior IVD regions. Hydration increases rapidly within 10–20 min, causing cross-sections to swell, stress capacity to decrease, and stiffness to remain unchanged. However, after 40 min, the tissue becomes swollen beyond physiological balance. These findings identify hydration duration as a critical factor regulating AF function and provide important insights for experimental standardization, numerical modeling, and hydrogels designed for intervertebral disc regeneration. Full article

Glottic insufficiency, often caused by laryngeal nerve injury, impairs voice quality and breathing. Current treatments, such as hyaluronic acid injection, require frequent reapplication every 3–6 months. This study aimed to investigate the therapeutic potential of small extracellular vesicles (sEVs) derived from Wharton’s Jelly mesenchymal stem cells (WJMSCs) incorporated into genipin-crosslinked gelatin hydrogels (GCGHs) for promoting vocal fold fibroblast (VFFs) regeneration in vitro. WJMSCs were isolated from umbilical cords, expanded to passage 4, and used for sEV isolation via tangential flow filtration (TFF). The sEVs (585.89 ± 298.93 µg/mL) were characterized using bicinchoninic acid assay (BCA), nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and Western blot. Seven concentrations of sEVs were tested on VFFs to evaluate cytotoxicity and proliferation, identifying 75 µg/mL as the optimal dose. GCGHs were then combined with WJMSCs and sEVs and evaluated for physicochemical properties, degradation, biocompatibility, and immune response. The hydrogels were injectable within 20 min and degraded in approximately 42 ± 0.72 days. The optimal sEV concentration significantly enhanced VFFs proliferation (166.59% ± 28.11) and cell viability (86.16% ± 8.55, p < 0.05). GCGH-MSCs showed the highest VFFs viability (82.04% ± 10.51) and matrix contraction (85.98% ± 1.25) compared to other groups. All hydrogel variants demonstrated minimal immune response when co-cultured with peripheral blood mononuclear cells (PBMCs). GCGH is a promising scaffold for delivering WJMSCs and sEVs to support VFF regeneration, with demonstrated biocompatibility and regenerative potential. Further in vivo studies are warranted to validate these findings. Full article

This study presents the development of an advanced three-dimensional (3D) bioprinted skin scaffold integrating sodium alginate (SA), gelatin (Gel), human skin-derived decellularized extracellular matrix (dECM), and microbiota-derived postbiotics. To ensure a biocompatible and functional ECM source, human skin samples collected during elective aesthetic surgical procedures were utilized. Following enzymatic treatment, the dermal layer was carefully separated from the epidermis and subjected to four different decellularization protocols. Among them, Protocol IV emerged as the most suitable, achieving significant DNA removal while maintaining the structural and biochemical integrity of the ECM, as confirmed by Fourier-transform infrared spectroscopy. Building on this optimized dECM-4, microbiota-derived postbiotics from Limosilactobacillus reuteri EIR/Spx-2 were incorporated to further enhance the scaffold’s bioactivity. Hybrid scaffolds were then fabricated using 7% Gel, 2% SA, 1% dECM-4, and 40 mg/mL postbiotics in five-layered grid structures via 3D bioprinting technology. Although this composition resulted in reduced mechanical strength, it exhibited improved hydrophilicity and biodegradability. Moreover, antimicrobial assays demonstrated inhibition zones of 16 mm and 13 mm against methicillin-resistant Staphylococcus aureus (MRSA, ATCC 43300) and Pseudomonas aeruginosa (ATCC 27853), respectively. Importantly, biocompatibility was confirmed through in vitro studies using human keratinocyte (HaCaT) cells, which adhered, proliferated, and maintained normal morphology over a 7-day culture period. Taken together, these findings suggest that the engineered hybrid scaffold provides both regenerative support and antimicrobial protection, making it a strong candidate for clinical applications, particularly in the management of chronic wounds. Full article

Background: Necrotizing enterocolitis (NEC) is a life-threatening condition characterized by necrosis of the gastrointestinal tract caused by hypoperfusion and hypoxia-induced inflammation. Surgical treatment often requires resection, with high morbidity and mortality. Intestinal tissue engineering using absorbable biomaterials represents a potential alternative. Small intestinal submucosa (SIS) is a biodegradable extracellular matrix (ECM) scaffold that may facilitate regeneration of the native tissue. Objectives: The aim of our study is to investigate the regenerative potential of SIS in a rat model with multiple gastrointestinal defects. Methods: In rats, after a midline laparotomy, an approximately 1 cm full-thickness incision was performed on the anterior gastric wall, on the antimesenteric side of the small and large intestine, each covered with an SIS patch. After three weeks, the graft sites and adjacent fragments were harvested and fixed in 10% neutral buffered formalin. Cross-sections of the grafted area were processed and stained with hematoxylin and eosin for histologic analysis. Results: Among the fifteen Wistar rats used in the study, the survival rate was 80% (12/15). Macroscopic examination of the abdominal cavity after the second surgery showed no complications. Adhesions were present in 92% (11/12). Histological examination demonstrated complete mucosal coverage in all stomach samples, nine of the small intestine, and ten of the large intestine. Mild fibrosis with minimal inflammatory infiltrates predominated. Ulceration with granulation tissue replacement was observed in three small intestine samples. Foreign body reactions were restricted to suture sites. Conclusions: In this multifocal injury model, SIS integrated effectively and supported early regenerative healing across gastric, small-intestinal, and colonic sites at 3 weeks. These data support further studies with longer follow-up, quantitative histology and functional assessment, and evaluation in neonatal-relevant large animal models to determine translational potential for NEC surgery. Full article

Background/Objectives: The design of scaffolds that mimic the extracellular matrix has gained increasing attention in regenerative medicine. This study aims to develop and characterize electrospun nanofibrous scaffolds based on pullulan blended with either gelatin or gliadin and doped with selenium nanoparticles (Se NPs), to assess the influence of protein type and Se NP doping on scaffold performance and regenerative potential. Methods: Se NPs were synthesized via redox reaction and stabilized using pullulan. Electrospun scaffolds were then prepared by blending pullulan-stabilized Se NPs with either gelatin or gliadin. The resulting fibers were characterized using a multidisciplinary approach, including physicochemical (morphology, fiber dimension, swelling capacity, surface zeta potential, mechanical properties) and preclinical properties (antioxidant properties, fibroblast adhesion and proliferation, collagen expression). Results: Protein type influenced fiber morphology and dimensions, as well as mechanical behavior, with gelatin-based scaffolds demonstrating smaller fiber diameters and higher mechanical properties. The doping with Se NPs enhanced scaffold antioxidant properties without affecting fiber formation. Moreover, all scaffolds supported fibroblast proliferation, but those containing Se NPs showed enhanced modulation of ECM gene expression. Conclusions: The results show that scaffolds doped with Se NPs exhibited superior performance compared to the undoped counterparts, offering promising platforms for chronic wound reparation. Full article

Neural tissue injuries, including spinal cord damage and neurodegenerative diseases, pose a major clinical challenge due to the central nervous system’s limited regenerative capacity. Current treatments focus on stabilization and symptom management rather than functional restoration. Tissue engineering offers new therapeutic perspectives, particularly through the combination of electrospun nanofibrous scaffolds and mesenchymal stem cells (MSCs). Electrospun fibers mimic the neural extracellular matrix, providing topographical and mechanical cues that enhance MSC adhesion, viability, and neural differentiation. MSCs are multipotent stem cells with robust paracrine and immunomodulatory activity, capable of supporting regeneration and, under proper stimuli, acquiring neural-like phenotypes. This systematic review, following the PRISMA 2020 method, analyzes 77 selected articles from the last ten years to assess the potential of electrospun biopolymer scaffolds for MSC-mediated neural repair. We critically examine the scaffold’s composition (synthetic and natural polymers), fiber architecture (alignment and diameter), structural and mechanical properties (porosity and stiffness), and biofunctionalization strategies. The influence of MSC tissue sources (bone marrow, adipose, and dental pulp) on neural differentiation outcomes is also discussed. The results of a literature search show both in vitro and in vivo enhanced neural marker expression, neurite extension, and functional recovery when MSCs are seeded onto optimized electrospun scaffolds. Therefore, integrating stem cell therapy with advanced biomaterials offers a promising route to bridge the gap between neural injury and functional regeneration. Full article

Bone regeneration depends on a delicate balance between osteoblast-driven bone formation and osteoclast-mediated resorption, coordinated by complex biochemical cues. Magnesium (Mg²⁺) is known to modulate these processes. However, despite extensive research, its ability to simultaneously enhance osteogenesis and inhibit osteoclast activity remains unclear. In this study, we first investigated the effect of extracellular Mg²⁺ (0, 5, 10, 25, 50 mM) on osteoblast and osteoclast differentiation in 2D culture to determine whether a single Mg²⁺ dosing regimen can simultaneously promote osteogenesis while inhibiting osteoclast differentiation and maturation. A concentration dependent effect of Mg²⁺ was observed on both cell types, with increasing Mg²⁺ concentrations up to 25 mM significantly reducing osteoclast formation yet concurrently inhibiting osteogenic differentiation. At 50 mM, Mg²⁺ exhibited cytotoxic effects on both cell types. We then leveraged the osteogenic properties of biomimetic collagen/nano-hydroxyapatite (Coll/nHA) scaffolds by incorporating Mg²⁺ into the nHA phase to enable localised, controlled delivery. At a scaffold-loaded equivalent of 25 mM Mg²⁺, we observed enhanced bone matrix deposition alongside reduced osteoclast maturation, indicating a synergistic effect between Mg²⁺ and nHA in promoting osteogenesis. While no optimal synergistic dose was identified in 2D culture, these findings demonstrate that Coll-nHA scaffolds offer a promising strategy for localised Mg²⁺ delivery to enhance osteogenesis and suppress osteoclastogenesis. Importantly, the ease of scaffold modification opens the door to incorporating additional bioactive molecules, further advancing their potential in bone tissue engineering applications and the development of next-generation biomaterials for bone regeneration. Full article

The development of physiologically relevant three-dimensional (3D) culture systems is essential for modeling tumor complexity and improving the translational impact of cancer research. We established a 3D in vitro model of human hepatocellular carcinoma (HCC) using a marine collagen peptide-based (MCP-B) biomimetic hydrogel scaffold optimized for multicellular spheroid growth. Compared with conventional two-dimensional (2D) cultures, the MCP-B hydrogel more accurately recapitulated native tumor biology while offering simplicity, reproducibility, bioactivity, and cost efficiency. HCC cells cultured in MCP-B hydrogel displayed tumor-associated behaviors, including enhanced proliferation, colony formation, migration, invasion, and chemoresistance, and enriched cancer stem cell (CSC) populations. Molecular analyses revealed upregulated expression of genes associated with multidrug resistance; stemness regulation and markers; epithelial–mesenchymal transition (EMT) transcription factors, markers, and effectors; growth factors and their receptors; and cancer progression. The spheroids also retained liver-specific functions, suppressed apoptotic signaling, and exhibited extracellular matrix remodeling signatures. Collectively, these findings demonstrate that the 3D HCC model using MCP-B hydrogel recapitulates key hallmarks of tumor biology and provides a robust, physiologically relevant platform for mechanistic studies of HCC and CSC biology. This model further holds translational value for preclinical drug screening and the development of novel anti-HCC and anti-CSC therapeutics. Full article

Hydrogels with protein–polysaccharide combinations are widely used in the field of tissue engineering, as they can mimic the in vivo environments of native tissues, specifically the extracellular matrix (ECM). However, achieving stability and mechanical properties comparable to those of tissues by employing natural polymers remains a challenge due to their weak structural characteristics. In this work, we optimized the fabrication strategy of a hydrogel composite, comprising gelatin and sodium alginate (Gel-SA), by varying reaction parameters. Magnetite (Fe₃O₄) nanoparticles were incorporated to enhance the mechanical stability and structural integrity of the scaffold. The changes in hydrogel stiffness and viscoelastic properties due to variations in polymer mixing ratio, crosslinking time, and heating cycle, both before and after nanoparticle incorporation, were compared. FTIR spectra of crosslinked hydrogels confirmed physical interactions of Gel-SA, metal coordination bonds of alginate with Ca²⁺, and magnetite nanoparticles. Tensile and rheology tests confirmed that even at low magnetite concentration, the Gel-SA-Fe₃O₄ hydrogel exhibits mechanical properties comparable to soft tissues. This work has demonstrated enhanced resilience of magnetite-incorporated Gel-SA hydrogels during the heating cycle, compared to Gel-SA gel, as thermal stability is a significant concern for hydrogels containing gelatin. The interactions of thermoreversible gelatin, anionic alginate, and nanoparticles result in dynamic hydrogels, facilitating their use as viscoelastic acellular matrices. Full article

Hernia repair is among the most frequent procedures in general surgery, traditionally performed with synthetic meshes such as polypropylene. While effective in reducing recurrence, these materials are biologically inert and often trigger chronic inflammation, fibrosis, pain, and impaired abdominal wall function, with a significant impact on long-term quality of life. A comprehensive literature search was conducted in PubMed, Web of Science, and Scopus databases, and relevant preclinical, clinical, and review articles were synthesized within a narrative review framework. Recent advances in tissue engineering propose a shift from passive reinforcement to regenerative strategies based on biomimetic scaffolds, nanomaterials, and nanocomposites that replicate the extracellular matrix, enhance cell integration, and provide controlled drug delivery. Nanotechnology enables localized release of anti-inflammatory, antimicrobial, and pro-angiogenic agents, while electrospun nanofibers and composite scaffolds improve strength and elasticity. In parallel, 3D printing allows for patient-specific implants with tailored architecture and regenerative potential. Although preclinical studies show encouraging results, clinical translation remains limited by cost, regulatory constraints, and long-term safety uncertainties. Overall, these innovations highlight a transition toward personalized and regenerative hernia repair, aiming to improve durability, function, and patient quality of life. Full article

Background: Hypoxia is a hallmark of solid tumors, including hepatocellular carcinoma (HCC), where it drives oxidative stress and extracellular matrix (ECM) remodeling, promoting tumor invasion and metastasis. Investigating these mechanisms in patients remains challenging due to the complexity of the tumor microenvironment. Methods: We developed a scaffold-free three-dimensional (3D) spheroid model of HCC using human hepatocellular carcinoma HepG2 cells (ATCC HB-8065). To characterize hypoxia-driven processes, a multiparametric approach combining MTT assays for metabolic activity, confocal microscopy for viability and ECM organization, flow cytometry for apoptosis and ROS detection, qRT-PCR for gene expression, and FTIR spectroscopy for biochemical profiling were performed. Results: The 3D model exhibited progressive ROS accumulation, stabilization of HIF-1α, and metabolic reprogramming toward aerobic glycolysis. In parallel, ECM remodeling was evident, with increased expression of SPARC and FN1 and collagen fiber alignment, reflecting an invasive tumor phenotype. Conclusions: This scaffold-free 3D HCC model recapitulates key physiopathological features of tumor progression, providing a robust and physiologically relevant platform to investigate the hypoxia–ROS–ECM relationship and to support preclinical evaluation of targeted therapeutic strategies. Full article

In this study, promising compositions of cross-linked gelatin-based scaffolds were tested in vitro and in vivo. Our aim was to utilize a solid matrix that is suitable for medical applications, and to be regulated as a medical device as a soft tissue implant. Three different cross-linkers were used in vitro, and the optimal composition was chosen for in vivo testing. The surfaces of the scaffolds were observed with SEM, and, in the case of divinyl sulfone (DVS), small cracks appeared, and the structure was rigid. With the use of poly(ethylene glycol) diglycidyl ether (PEGDE), the surface was found to be uneven, but generally, the appearance was similar in each case. The optimal scaffold contained 5 v/v % 1,4-butanediol diglycidyl ether (BDDE), and was implanted for either one month or three months in the back of BL6 mice. The explants were assessed using analytical techniques, including microscopic imaging and histological analysis, and it was found that cells, connective tissue, and extracellular matrix (ECM) were all able to successfully infiltrate the scaffolds and did not induce any inflammation. In summary, these novel implants seem to promote blood vessel formation and support the adherence of adipose tissue, as confirmed by optical microscopy and histological evaluations. Full article