Search Results (1,043)

Cortical immature neurons (cINs) represent a unique population of prenatally generated, non-dividing neurons that maintain an immature phenotype, characterized by doublecortin (DCX) and polysialylated neural cell adhesion molecule (PSA-NCAM) expression, into adulthood. Unlike canonical adult neurogenesis involving continuous neuron generation from stem cell niches, cINs constitute a distinct form of structural plasticity termed “neurogenesis without division”. This review comprehensively examines the molecular markers, morphological diversity, developmental origins, and maturation trajectories of cINs across species. We highlight the striking inverse interspecies relationship between cIN abundance and canonical adult neurogenesis, reflecting distinct biophysical and structural shifts in neural plasticity mechanisms across mammalian lineages. Furthermore, we discuss factors modulating cIN phenotype, including neurotransmitter systems, stress, sensory experience, and aging. Clinical evidence implicating cIN alterations in temporal lobe epilepsy, traumatic brain injury, and stroke is evaluated, revealing potential roles in both pathological circuit remodeling and endogenous repair. Critical gaps remain regarding the molecular programs maintaining immaturity, differentiation triggers, and the functional consequences of circuit integration. Understanding cIN biology offers new perspectives on cortical plasticity and may inform therapeutic strategies targeting endogenous cellular reserves for brain repair. Full article

During development, neurexin-2 (NRXN2) is a cell adhesion molecule localized to presynaptic terminals as well as axonal shafts and immature neurites, where it participates in the regulation of neuronal cell morphogenesis. Given its critical role in early neuronal development, NRXN2 is considered a susceptibility gene product for neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD) and intellectual disability (ID). However, the intracellular signaling mechanisms linking NRXN2 deficiency to abnormal neuronal cell morphology remain unclear. Herein, we investigated the molecular basis of excessive cell morphogenesis induced by the knockdown of NRXN2 using the N1E-115 cell line, a model of neuronal morphogenesis characterized by neurite outgrowth. Silencing NRXN2 using the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas13 system resulted in a marked enhancement of process elongation. Mechanistically, we found that Girdin (also called GIV or CCDC88A), a non-receptor guanine nucleotide exchange factor for heterotrimeric G proteins, can mediate the excessive process length phenotype. Transfection of either the regulator of G protein signaling (RGS) domain of RGS3, a GTPase-activating protein for G proteins, or the G protein-binding domain of engulfment and cell motility 1 (ELMO1) rescued the excessive process formation. Similar results were obtained in primary cortical neurons. In addition, these interventions normalized downstream Rac1 activity in cells. Together, our findings elucidate Girdin signaling as a mediator of excessive neuronal process formation following NRXN2 knockdown, providing mechanistic insight into how the loss of function of NRXN2 leads to aberrant cell morphogenesis at least at the molecular and cellular levels. These results suggest that signaling through Girdin may contribute to the morphological abnormalities associated with NRXN2-related neurodevelopmental disorders. Full article

Given the urgent need to regulate oxidative stress microenvironments in chronic wound healing, hydrogel dressings that simultaneously integrate antioxidant, antibacterial, mechanically adaptive, and biocompatible properties are highly desirable. In this study, a natural polymer-based composite hydrogel dressing loaded with zinc-quercetin nanozyme (Zn-Q) was designed. The gel skeleton was constructed via a dual network of photocrosslinked methacrylated silk fibroin (SilMA) and mercaptolated hyaluronic acid (HA-SH) via thiol-ene click chemistry, with the catalase (CAT)-like Zn-Q nanozyme encapsulated in situ within the network, thereby achieving synergy between chemical crosslinking and dynamic metal-polyphenol coordination. Systematic characterization revealed that Zn-Q nanozyme adopted a stable octahedral coordination configuration, and its continuous porous structure exposed abundant catalytically active sites. The composite hydrogels exhibited a highly interconnected, three-dimensional (3D) porous morphology, with swelling ratios that increased significantly with Zn-Q nanozyme content (up to around 1082%). Rheological and mechanical tests demonstrated that although incorporating the nanozyme reduced the storage modulus, the reversible physical crosslinks formed via hydrogen bonding and coordination interactions endowed the material with excellent tensile toughness and energy-dissipation capacity, exhibiting typical Mullins softening behavior. Functional evaluation showed that Zn-Q nanozyme conferred superior free radical scavenging capability to the hydrogels and exerted dose-dependent inhibition against both Staphylococcus aureus and Escherichia coli. Furthermore, the hydrogels exhibited favorable adhesion to various wet organs and heterogeneous material surfaces, with hemolysis rates below 5% and cell viability exceeding 100% after 3 days of culturing with fibroblasts, confirming their excellent hemocompatibility and cytocompatibility. This study provides an experimental basis for developing a new type of wound repair materials that integrate antioxidant, anti-infective, and mechanically adaptive properties, holding significant application potential in oxidative stress-related tissue repair fields. Full article

Polyetheretherketone (PEEK) has emerged as a promising biomaterial for orthopedic and craniofacial implants due to its favorable mechanical properties and fatigue resistance; however, its inherent chemical inertness limits effective osseointegration. In this study, femtosecond laser surface modification is explored as a strategy to enhance the bioactivity of PEEK. Based on a previously performed parametric study, controlled micro- and nanoscale surface textures were fabricated using femtosecond laser processing, enabling precise tuning of surface roughness and wettability without the need for additional chemical treatment. The modified surfaces were systematically characterized in terms of morphology, composition, and topography using scanning electron microscopy (SEM), 3D profilometry, and water contact angle measurements. Four optimized femtosecond laser-generated surface architectures were selected for the present investigation and comprehensively characterized, followed by in vitro evaluation of dental pulp stem cell adhesion, morphology, and proliferation. The results indicate that laser-induced micro/nanostructuring enhances the surface properties of PEEK, while supporting cellular attachment and favorable cell–surface interaction. Differences in the biological response were observed among the optimized laser-textured surfaces. These findings highlight the feasibility of femtosecond laser texturing as a clean, reproducible, and scalable approach for the development of next-generation, personalized orthopedic implants. Full article

The adult mammalian heart exhibits limited regenerative capacity. Although the epicardium contributes to cardiac injury responses and remodeling, expandable adult human in vitro models for investigating epicardial activation and epithelial-to-mesenchymal (EMT)-associated cellular responses remain limited. Here, we isolated human epicardium-derived cells from the adult heart auricle, expressing WT1⁺/MSLN⁺/CRIP1⁺ and generated an expandable immortalized epicardium-derived cell (iEPDC) population, allowing the investigation of intercellular dynamics upon EMT activation. TGFβ signaling was modulated using SB431542 or TGFβ3. Morphological, immunocytochemical, transcriptomic and functional analyses were performed to investigate treatment-dependent responses. SB431542-treated iEPDCs displayed epithelial-like characteristics and elevated WT1, MSLN and CRIP1 expression, with CRIP1 detected at both transcript and protein levels. TGFβ3-treated cells expressed the mesenchymal markers VIM and CD105 and exhibited spindle-shaped morphology, increased migratory behavior and upregulation of mesenchymal- and remodeling-associated markers. Transcriptomic analyses revealed distinct treatment-dependent profiles, enrichment of ‘focal adhesion’, ‘ECM-receptor interaction’ and cytoskeleton-associated pathways in TGFβ3-treated iEPDCs and intermediate transcriptional characteristics in untreated cells. Together, these findings establish adult iEPDCs as an expandable in vitro model for investigating TGFβ-dependent epicardial activation and EMT-associated processes in the adult human heart. Furthermore, the integration of phenotypic, transcriptomic and functional findings revealed the treatment-responsive plasticity of adult human iEPDCs, supporting future studies of injury-associated epicardial activation. Full article

The development of reusable and biocompatible biomaterial-based culture substrates is increasingly relevant for improving sustainability in biomedical research workflows. In this study, polyethylene terephthalate glycol-modified (PETG) was evaluated as a potential alternative to conventional polystyrene (PS) for in vitro cell culture applications. PETG substrates were fabricated through laser cutting and tested for their ability to support cell adhesion, viability, proliferation, and lineage-specific differentiation across multiple human cell models, including calvarial mesenchymal stromal cells (CMSCs), bone marrow-derived mesenchymal stromal cells (hBM-MSCs), dermal fibroblasts, LHCN-M2 myoblasts, and SH-SY5Y neuroblastoma cells. Morphological and immunofluorescence analyses demonstrated that PETG supported cell attachment and focal adhesion formation, comparable to standard PS surfaces. Cell viability and proliferation assays confirmed metabolic activity and growth over time. Furthermore, PETG substrates supported osteogenic, adipogenic, myogenic, and neuronal differentiation, as demonstrated by histological staining, myotube formation, neurite outgrowth, and lineage-specific gene expression analyses. Finally, PETG maintained CMSC morphology and metabolic activity after repeated recovery, ethanol/UV treatment, and gelatin re-coating, with comparable results between new substrates and those reused for up to three cycles. These findings support PETG as a biocompatible culture substrate with preliminary short-term reuse potential and possible sustainability benefits for laboratory workflows. Full article

Chronic infected wounds are often characterized by persistent bacterial colonization, biofilm formation, excessive oxidative stress, and prolonged inflammation, which severely impair tissue regeneration. To address these challenges, a multifunctional wound dressing capable of antibacterial activity and microenvironment modulation was developed. In this study, amide-modified hyaluronic acid (HA-ADH) was used as the matrix, and a dynamic coordination network was constructed via Cu²⁺-hydrazide interactions to form an in situ HA-Cu hydrogel. Curcumin-loaded DSPE-PEG2000 micelles were further incorporated to obtain a pH-responsive composite hydrogel (HA-Cu/Cur). The prepared hydrogel exhibited a porous interconnected structure, along with favorable injectability, self-healing capability, tissue adhesiveness, moderate swelling, controllable degradability, and pH-responsive behavior under acidic conditions. In vitro antibacterial assays demonstrated that both HA-Cu and HA-Cu/Cur effectively inhibited the growth and biofilm formation of Escherichia coli and Staphylococcus aureus. The antibacterial activity was associated with disruption of bacterial morphology, depletion of intracellular ATP, and induction of reactive oxygen species, while HA-Cu/Cur showed enhanced performance in antibiofilm activity and oxidative stress-related effects compared with HA-Cu. Cytocompatibility studies revealed that the hydrogel extracts exhibited negligible cytotoxicity toward L929 fibroblasts and RAW 264.7 macrophages, while promoting fibroblast migration and significantly reducing the expression of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) in lipopolysaccharide-stimulated RAW 264.7 cells, with HA-Cu/Cur showing a more pronounced anti-inflammatory effect. In summary, the HA-Cu/Cur hydrogel integrates the antibacterial and pro-healing properties of Cu²⁺ with the antioxidant and anti-inflammatory activities of curcumin. The hydrogel effectively inhibited the growth and biofilm formation of both E. coli and S. aureus, reduced the expression of TNF-α, IL-6, and IL-1β in LPS-stimulated macrophages, and promoted fibroblast migration, demonstrating its potential as a multifunctional wound dressing for the management of infected wounds. Full article

Cell migration is a fundamental biological process regulated by interactions between cells and extracellular matrix. Although topographical cues are known to influence cell behaviors, directional migration across three-dimensional (3D) sloped steps remains poorly understood. Here, 3D sloped steps with patterned TiO_x surfaces were fabricated to investigate topography-guided cell migration in complex 3D microenvironments. The ultrathin TiO_x layers were patterned along the bottom, sidewall, and top regions of the steps, providing continuous guidance during cell migration up or down the steps. MC3T3-E1 cells were confined to the patterned regions and exhibited contact-guided migration along the asymmetrical arrowhead patterns. Forward and reverse arrowheads were introduced to evaluate the effect of geometrical asymmetry on cell migration directionality. Forward arrowheads preferentially guided cells from the bottom to the top of steps, whereas reverse arrowheads promoted migration down the steps, demonstrating reversible control of cell migration direction through arrowhead orientation. Analysis of cell morphology revealed that ultrathin TiO_x topographies influenced lamellipodia orientation and cell adhesion, providing mechanistic insights into geometry-mediated control of cell migration direction. These findings demonstrate that guiding pattern asymmetry can be used to regulate the speed and directionality of cell migration across sloped steps, which can be applied to control cell migration behaviors on engineered 3D platforms. Full article

Background: Degenerative joint diseases are a major cause of disability and drive the increasing demand for joint arthroplasty. Long-term prosthesis success depends on rapid and stable bone–implant integration, which is influenced by the osteo-inductive and osteo-conductive properties of implant materials. Chromium–cobalt (CrCo) and titanium (Ti) alloys are widely used in reconstructive orthopedics, but direct comparative data on their biological performance, particularly for trabecular titanium (T-Ti), remain limited. This study aimed to directly compare the biocompatibility and osteogenic potential of CrCo and T-Ti using human mesenchymal stromal cells (MSCs). Methods: Human MSCs were characterized by immunophenotyping and cultured on CrCo and T-Ti scaffolds under control and osteogenic conditions for up to 28 days. Cell adhesion and morphology were assessed by scanning electron microscopy. Proliferation and viability were quantified, and osteogenic differentiation was evaluated using alkaline phosphatase activity, calcium deposition assays, and gene expression profiling of osteogenic markers. Results: Both materials supported MSC adhesion and proliferation, confirming cytocompatibility. Under control conditions, T-Ti significantly increased alkaline phosphatase activity and osteogenic gene expression. Under osteogenic stimulation, T-Ti accelerated differentiation and mineralized matrix deposition. CrCo exhibited limited stimulation of the osteogenic-supportive microenvironment and delayed differentiation responses. Conclusions: Trabecular titanium, in terms of morphology and topology, provides a biologically active scaffold that both induces and conducts osteogenic differentiation of human MSCs, whereas CrCo acts primarily as a mechanically optimized but biologically passive material. These findings support the use of trabecular titanium at bone-contact interfaces in joint prostheses to enhance osteointegration and potentially improve long-term implant stability. Full article

Graphene oxide (GO)-based nanostructured biomaterials have emerged as promising platforms for tissue engineering due to their novel biointeractive properties. In this study, we developed polyamide 6 (PA6) scaffolds by electrospinning using the Nanospider technique. Unlike conventional laboratory-scale electrospinning systems, Nanospider™ employs a wire-based electrode coated with a thin layer of polymer solution, from which nanofibers are continuously generated under a high-voltage electric field, enabling the large-scale fabrication of scaffolds. The scaffolds were then nanostructured with GO to investigate the effect of surface modification on their physicochemical properties, and biological responses. Surface characterization demonstrated that GO incorporation altered the microtexture of PA6 scaffolds, leading to changes in topographical parameters and surface morphology. In vitro studies performed using human stromal HS-5 cells confirmed high cytocompatibility of both GO nanofilms and PA6-GO composites, with preserved metabolic activity and enhanced cell adhesion. Scanning electron microscopy revealed improved spreading, elongated morphology, and increased filopodia formation on GO-modified scaffolds. Gene expression analyses indicated modulation of mechanotransduction- and adhesion-related pathways, including differential regulation of FN1, FAK, and integrin-associated genes, suggesting that GO nanostructuring influences early cell–material interactions through combined effects on surface architecture and chemistry. Ex vivo studies using embryonic tissues derived from chicken embryo Gallus gallus demonstrated effective colonization of connective, cartilage, and bone tissues on GO-modified scaffolds. Collectively, these findings demonstrate that GO nanostructuring of electrospun PA6 scaffolds improves biointerface formation, supports mechanobiological adaptation, and promotes tissue development, highlighting the potential for regenerative medicine. Full article

Myogenic differentiation is a powerful mechanism for generating diverse cell types from fibroblasts. Here, we show that targeted suppression of β-actin by RNA interference in human fibroblasts triggers coordinated molecular and structural changes consistent with trans-differentiation toward SMC-like phenotype. This conversion is marked by upregulation of smooth muscle differentiation markers (α- and γ-smooth muscle actins, SM22, smooth muscle myosin, desmin, vinculin) at mRNA and protein levels, together with distinct morphological alterations: increased cell area, loss of polarity, and reorganization of the actin cytoskeleton. Notably, β-actin-downregulated fibroblasts exhibited a focal adhesion architecture that differed from parental fibroblasts. These findings indicate that β-actin downregulation may provide a novel in vitro method to induce SMC-like differentiation, with potential implications for vascular biology and tissue engineering. Full article

Implant surface optimization aims to reduce osteointegration process time and prevent failures. Here, we report a novel laser-assisted approach for incorporating hydroxyapatite into titanium implant surfaces and evaluate the resulting biological response. Titanium discs were fabricated by Nd:YVO4 laser texturing and coated with hydroxyapatite using either conventional or laser sintering, according to seven study groups: flat titanium (TiL), laser-textured titanium with 0.25 and 0.8 mm patterns (TiT025 and TiT08), and laser-textured titanium with 0.25 and 0.8 mm patterns plus bioactive coating using conventional sintering (TiT025CS and TiT08CS) or laser sintering (TiT025LS and TiT08LS). Human gingival fibroblasts (HGF hTERT) were cultured on discs to assess adhesion, morphology, viability, and cytokine secretion. Surface texturing alone did not significantly affect fibroblast viability over 7 days (p > 0.05). Hydroxyapatite coatings significantly reduced viability on both patterns when conventionally sintered (p < 0.05), whereas laser-sintered coatings did not cause a significant decrease; overall viability was higher in LS than in CS samples (p < 0.05). Scanning electron microscopy after 24 h showed adherent cells on all surfaces. IL-1β secretion was consistently lower than IL-10 secretion during the 3-day study period. When normalized to cell viability, these findings remained consistent. At day 1, IL-1β/viability and IL-10/viability ratios were similar across groups. By day 3, the IL-1β/viability ratio decreased in all groups, with TiT08 showing significantly lower values than TiT08CS (p < 0.05). In contrast, the IL-10/viability ratio increased in coated patterned samples (TiT025, TiT025CS, TiT025LS, TiT08, TiT08CS, and TiT08LS). In conclusion, the 0.25 mm laser-textured pattern combined with optimized hydroxyapatite sintering elicited a more favorable cytokine secretion profile compared to the 0.8 mm pattern, suggesting a reduced pro-inflammatory response. Full article

Pancreatic ductal adenocarcinoma frequently metastasises to the liver, although the mechanisms underlying hepatic pre-metastatic niche formation remain unclear. Small extracellular vesicles mediate tumour–host communication and may drive hepatic microenvironment reprogramming. This study investigated the effects of pancreatic ductal adenocarcinoma-derived small extracellular vesicles on extracellular matrix remodelling and epithelial–mesenchymal transition-related plasticity in hepatic cells. Small extracellular vesicles were isolated from pancreatic ductal adenocarcinoma cell lines (MIAPaCa-2, PANC-1) and from the serum of 25 patients, characterized, and administered to hepatic stellate (LX-2) and hepatocyte-like (HEPA-RG) cells. Cell viability and migration were evaluated by functional assays, morphology by scanning electron microscopy, and molecular changes by RT-PCR, Western blotting, and immunofluorescence. In LX-2 cells, small extracellular vesicles exposure increased metabolic activity, adhesion, and migration, while inducing morphological and molecular changes associated with extracellular matrix remodelling, including reduced collagen type I alpha 2 chain, vimentin, and E-cadherin expression. In HEPA-RG cells, viability was minimally affected, whereas migration and EMT-related plasticity were enhanced. Patient-derived small extracellular vesicles induced similar but less pronounced effects. Overall, pancreatic ductal adenocarcinoma-derived small extracellular vesicles induced early hepatic microenvironmental remodelling, supporting a potential role for tumour–liver crosstalk in pre-metastatic niche-associated processes, highlighting tumour–liver crosstalk as a potential therapeutic target. Full article

As the use of electronics and mobile devices increases, indium and its related compounds are increasingly prevalent in consumer products. However, the effects of the ionic form of indium on the mammalian renal cells are unclear. Understanding indium toxicity in these cells is important, as it relates to kidney health. Kidneys remove heavy metals, maintain electrolyte balance, and perform other vital functions. This in vitro study examines the effects of indium chloride (InCl₃) on Vero cells, focusing on cell morphology, viability, reactive oxygen species (ROS) production, and expression of key focal adhesion proteins. Cells were incubated in culture media with InCl₃ concentrations ranging from 0 to 3.2 mM for 24 h. Fluorescence confocal microscopy analyses revealed that concentrations above 0.8 mM caused the cells to become more compact and display decreased actin filament lengths, suggesting cellular degeneration, which was further supported by the AlamarBlue^® Cell Viability Reagent. Using a 2′,7′–dichlorofluorescin diacetate (DCFDA/H2DCFDA) assay, we show that ROS levels increase with InCl₃ concentration, accompanied by significant increases in focal adhesion kinase (FAK) and paxillin at InCl₃ concentrations above 0.8 mM. Interestingly, the level of α-actinin detected is not affected by exposure to InCl₃. Our findings demonstrate that InCl₃ has negative impacts on the growth and behaviour of Vero cells at concentrations exceeding 0.8 mM, underscoring the need for further investigation into the biological effects of indium-containing compounds. Full article

Methacrylate-based materials, widely used in dentistry, must possess high biocompatibility with oral cells and tissues. Currently, to improve the integration of orthodontic devices with the biological structures, laser-assisted polymer modification is actively employed. Importantly, functionalization is required only for the surface of the material that directly interacts with the oral tissues. This study presents approaches for laser modification of polymethacrylate materials and evaluates their influence on the proliferative activity of human spleen fibroblasts. Using laser radiation, two geometric patterns were obtained on the polymer surfaces. Cell morphology and proliferation on the experimental samples were assessed using scanning electron microscopy. It was found that the polymer with a groove-textured surface (pattern 1) promoted enhanced cell adhesion and reduced material toxicity. Additionally, the antibacterial properties of the polymers were evaluated. The sample with sparsely distributed surface craters (pattern 2) demonstrated an antifouling effect against Escherichia coli. Full article