Fibrous Scaffolds Research Articles

Quaternized chitosan/PVA/natural bioactive agent electrospun wound scaffolds: production, characterization, and investigation of release kinetics.

Quaternized chitosan (HTCC) was synthesized and characterized to increase chitosan solubility. Then HTCC was electrospun with poly (vinyl alcohol) (PVA) and prepared natural bioactive agent (Calendula officinalis) extract was loaded onto fibers for wound scaffold applications. Morphological, structural, and mechanical characterization of the produced wound scaffolds was performed and their in vitro bioactive component release behavior was investigated. As a result, it was observed that the degree of quaternization of chitosan was 0.89, and synthesized HTCC was soluble in acidic, basic, alkaline media and could be electrospun with PVA in the presence of a natural bioactive agent. The presence of HTCC increased Young's modulus and the tensile strength of the PVA scaffolds, while the presence of bioactive extract caused a decrease in Young's modulus and an increase in tensile strength. Calendula officinalis is released in a controlled and slow manner from the scaffolds within approximately 55 h. The release behavior was consistent with the Higuchi kinetic model. In this study, the effect of PVA cooperator on HTCC nanofiber production in the presence of a bioactive component was investigated for the first time. HTCC and Calendula officinalis extract were also used together for the first time in the composition of a fiber scaffold. The mechanical properties and release kinetics of these scaffolds were also investigated for the first time. According to the results, it is thought that the wound scaffolds produced have the potential to be used as a new treatment tool, especially for chronic wounds.

Plant-Derived Zein as an Alternative to Animal-Derived Gelatin for Use as a Tissue Engineering Scaffold.

Natural biomaterials are commonly used as tissue engineering scaffolds due to their biocompatibility and biodegradability. Plant-derived materials have also gained significant interest due to their abundance and as a sustainable resource. This study evaluates the corn-derived protein zein as a plant-derived substitute for animal-derived gelatin, which is widely used for its favorable cell adhesion properties. Limited studies exist evaluating pure zein for tissue engineering. Herein, fibrous zein scaffolds are evaluated in vitro for cell adhesion, growth, and infiltration into the scaffold in comparison to gelatin scaffolds and are further studied in a subcutaneous model in vivo. Human mesenchymal stem cells (MSCs) on zein scaffolds express focal adhesion kinase and integrins such as αvβ3, α4, and β1 similar to gelatin scaffolds. MSCs also infiltrate zein scaffolds with a greater penetration depth than cells on gelatin scaffolds. Cells loaded onto zein scaffolds in vivo show higher cell proliferation and CD31 expression, as an indicator of blood vessel formation. Findings also demonstrate the capability of zein scaffolds to maintain the multipotent capability of MSCs. Overall, findings demonstrate plant-derived zein may be a suitable alternative to the animalderived gelatin and demonstrates zein's potential as a scaffold for tissue engineering.

Adhesion of Escherichia coli and Lactobacillus fermentum to Films and Electrospun Fibrous Scaffolds from Composites of Poly(3-hydroxybutyrate) with Magnetic Nanoparticles in a Low-Frequency Magnetic Field.

The ability of materials to adhere bacteria on their surface is one of the most important aspects of their development and application in bioengineering. In this work, the effect of the properties of films and electrospun scaffolds made of composite materials based on biosynthetic poly(3-hydroxybutyrate) (PHB) with the addition of magnetite nanoparticles (MNP) and their complex with graphene oxide (MNP/GO) on the adhesion of E. coli and L. fermentum under the influence of a low-frequency magnetic field and without it was investigated. The physicochemical properties (crystallinity; surface hydrophilicity) of the materials were investigated by X-ray structural analysis, differential scanning calorimetry and "drop deposition" methods, and their surface topography was studied by scanning electron and atomic force microscopy. Crystal violet staining made it possible to reveal differences in the surface charge value and to study the adhesion of bacteria to it. It was shown that the differences in physicochemical properties of materials and the manifestation of magnetoactive properties of materials have a multidirectional effect on the adhesion of model microorganisms. Compared to pure PHB, the adhesion of E. coli to PHB-MNP/GO, and for L. fermentum to both composite materials, was higher. In the magnetic field, the adhesion of E. coli increased markedly compared to PHB-MNP/GO, whereas the effect on the adhesion of L. fermentum was reversed and was only evident in samples with PHB-MNP. Thus, the resultant factors enhancing and impairing the substrate binding of Gram-negative E. coli and Gram-positive L. fermentum turned out to be multidirectional, as they probably have different sensitivity to them. The results obtained will allow for the development of materials with externally controlled adhesion of bacteria to them for biotechnology and medicine.

Development of a thick and functional human adipose-derived stem cell tissue sheet for myocardial infarction repair in rat hearts

BackgroundHeart failure (HF) is a major cause of death worldwide. The most effective treatment for HF is heart transplantation, but its use is limited by the scarcity of donor hearts. Recently, stem cell-based therapy has emerged as a promising approach for treating myocardial infarction. Our research group has been investigating the use of human induced pluripotent stem cell-derived cardiomyocyte patches as a potential therapeutic candidate. We have successfully conducted eight cases of clinical trials and demonstrated the safety and effectiveness of this approach. However, further advancements are necessary to overcome immune rejection and enhance therapeutic efficacy. In this study, we propose a novel and efficient technique for constructing mesenchymal stem cell (MSC) tissue sheets, which can be transplanted effectively for treating myocardial infarction repair.MethodsWe applied a one-step method to construct the human adipose-derived mesenchymal stem cell (hADSC) tissue sheet on a poly(lactic-co-glycolic acid) fiber scaffold. Histology, immunofluorescence, and paracrine profile assessment were used to determine the organization and function of the hADSC tissue sheet. Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function, fibrosis area, angiogenesis, and left ventricular remodeling.ResultsIn vitro, the hADSC tissue sheet showed great organization, abundant ECM expression, and increased paracrine secretion than single cells. In vivo, the hADSC tissue sheet group demonstrated improved cardiac functional recovery, less ventricular remodeling, decreased fibrosis, and enhanced angiogenesis than the MI group.ConclusionsWe developed thick and functional hADSC tissue sheets via the one-step strategy. The hADSC tissue sheet showed excellent performance in treating myocardial infarction in the rat model.Graphical

Improving properties of platelet-rich fibrin scaffold with tannic acid for wound healing.

Platelet-rich fibrin (PRF), which is the rich source of growth factors, has been used as an efficient scaffold in tissue engineering and wound healing. In this study, tannic acid as a green cross-linker with different concentrations (0.5%, 1%, 5% and 10%) was used to improve the properties of PRF. The cross-linked gel scaffolds were evaluated by analyses such as scanning electron microscopy, Fourier transform infrared spectroscopy, swelling and degradation, mechanical strength, cell toxicity, cell adhesion and antibacterial test. The results showed that the scaffold structure changes by increasing cross-linker concentration. The swelling rate decreased from 49% to 5% for the samples without the cross-linker and with tannic acid (10%), respectively. The degradation percentage for the cross-linked samples was 8%, which showed a lower degradation rate than the non-cross-linked samples (63%). The mechanical strength of the scaffold with the cross-linker increased up to three times (Young's modulus for the non-cross linked and the cross-linked samples: 0.01 and 0.6 MPa, respectively). Cytotoxicity was not observed up to 10% cross-linker concentration. The cells proliferated well on the cross-linked scaffolds and also showed a good antibacterial effect. In general, tannic acid can improve the physical and mechanical properties of PRF without negatively affecting its biological properties.

Melt electrowritten scaffold architectures to mimic tissue mechanics and guide neo-tissue orientation

All human tissues present with unique mechanical properties critical to their function. This is achieved in part through the specific architecture of the extracellular matrix (ECM) fibres within each tissue. An example of this is seen in the walls of the vasculature where each layer presents with a unique ECM orientation critical to its functions. Current adopted vascular grafts to bypass a stenosed/damaged vessel fail to recapitulate this unique mechanical behaviour, particularly in the case of small diameter vessels (<6 mm), leading to failure. Therefore, in this study, melt-electrowriting (MEW) was adopted to produce a range of fibrous scaffolds to mimic the extracellular matrix (ECM) architecture of the tunica media of the vasculature, in an attempt to match the mechanical and biological behaviour of the native porcine tissue. Initially, the range of collagen architectures within the native vessel was determined, and subsequently replicated using MEW (winding angles (WA) 45°, 26.5°, 18.4°, 11.3°). These scaffolds recapitulated the anisotropic, non-linear mechanical behaviour of native carotid blood vessels. Moreover, these grafts facilitated human mesenchymal stem cell (hMSC) infiltration, differentiation, and ECM deposition that was independent of WA. The bioinspired MEW fibre architecture promoted cell alignment and preferential neo-tissue orientation in a manner similar to that seen in native tissue, particularly for WA 18.4° and 11.3°, which is a mandatory requirement for long-term survival of the regenerated tissue post-scaffold degradation. Lastly, the WA 18.4° was translated to a tubular graft and was shown to mirror the mechanical behaviour of small diameter vessels within physiological strain. Taken together, this study demonstrates the capacity to use MEW to fabricate bioinspired scaffolds to mimic the tunica media of vessels and recapitulate vascular mechanics which could act as a framework for small diameter graft development to guide tissue regeneration and orientation.

Biocompatible neuronal stimulant-embedded poly(γ-benzyl-L-glutamate) peptide-based scaffolds promote differentiation, growth and functional maturation of human induced pluripotent stem cell-derived retinal ganglion cells

BackgroundTo culture human induced pluripotent stem cells(hiPSCs)- derived retinal ganglion cells (RGCs) with appropriate structure and functionality is critical for cell therapy of optic nerve degeneration. In this study, we aimed to assess the effectiveness of three biocompatible scaffolds -poly(γ-benzyl-L-glutamate) (PBG)-based three-dimensional fibrous scaffolds in promoting the structural and functional maturation of hiPSC-derived RGCs. MethodsThe study investigated three scaffolds (1) PBG, (2) PBG with glutamic acid (PBGA20), and (3) PBGA20 with sodium salt (PBGA20-Na). The biocompatibility was evaluated in vivo with C57BL/6 mice. Neurite outgrowth was assessed using immunostaining for axon markers, while fluorescence-based Ca2+ imaging and patch-clamp technique were employed to measure neuronal calcium signaling and electrophysiological activity, respectively. Significant findingsAll three PBG-based scaffolds exhibited excellent biocompatibility in vivo and effectively supported the directional outgrowth of neurites from hiPSC-derived RGCs while the PBGA20-Na group demonstrated the most favorable outcomes. The presence of glutamic acid in PBGA20 and PBGA20-Na scaffolds led to an increase in calcium signaling within hiPSC-derived RGCs. HiPSC-derived RGCs cultured on PBGA20 and PBGA20-Na scaffolds exhibited an earlier onset of electrophysiological activities with lower thresholds. These promising results provide a foundation for potential sheet transplantation of hiPSC-derived RGCs as cell therapy for optic nerve regeneration.

Self-organizing behaviors of cardiovascular cells on synthetic nanofiber scaffolds.

In tissues and organs, the extracellular matrix (ECM) helps maintain inter- and intracellular architectures that sustain the structure-function relationships defining physiological homeostasis. Combining fiber scaffolds and cells to form engineered tissues is a means of replicating these relationships. Engineered tissues' fiber scaffolds are designed to mimic the topology and chemical composition of the ECM network. Here, we asked how cells found in the heart compare in their propensity to align their cytoskeleton and self-organize in response to topological cues in fibrous scaffolds. We studied cardiomyocytes, valvular interstitial cells, and vascular endothelial cells as they adapted their inter- and intracellular architectures to the extracellular space. We used focused rotary jet spinning to manufacture aligned fibrous scaffolds to mimic the length scale and three-dimensional (3D) nature of the native ECM in the muscular, valvular, and vascular tissues of the heart. The representative cardiovascular cell types were seeded onto fiber scaffolds and infiltrated the fibrous network. We measured different cell types' propensity for cytoskeletal alignment in response to fiber scaffolds with differing levels of anisotropy. The results indicated that valvular interstitial cells on moderately anisotropic substrates have a higher propensity for cytoskeletal alignment than cardiomyocytes and vascular endothelial cells. However, all cell types displayed similar levels of alignment on more extreme (isotropic and highly anisotropic) fiber scaffold organizations. These data suggest that in the hierarchy of signals that dictate the spatiotemporal organization of a tissue, geometric cues within the ECM and cellular networks may homogenize behaviors across cell populations and demographics.

Modification of hydrophobic electrospun polyurethane fibers for efficient wound healing activity

The intricate process of wound healing demands an atmosphere that is conducive to quick healing. In this situation, creating biocompatible and antibacterial fibers may be a good choice. In this study, the unmodified polyurethane and polyurethane modified with cellulose acetate and rosemary oil were electrospun into fibers. These fibers were subsequently adsorbed using silver nanoparticles. The FE-SEM was used to characterize the fibers, revealing their defect-free morphology and the presence of nanoparticles on them. Additionally, the XRD findings demonstrated that silver nanoparticles were successfully incorporated into the spun fiber mats. The contact angle measurements indicated a decreasing behavior starting from 100.4±1° to 28.4±3° in the case of unmodified polyurethane and modified fibers. The antibacterial assay revealed that although unmodified fiber mats have negligible antibacterial action, the modified fibers exhibited considerable antibacterial activity against E. coli and S. aureus. In-vitro studies revealed that Human embryonic kidney 293T (HEK 293T) cell proliferation was enhanced on the surface of modified fibers compared to unmodified fibers. In conclusion, our research presents unique multifunctional fibrous scaffolds that are appropriate and optimal for wound healing applications.

Shish-kebab structure fiber with nano and micro diameter regulate macrophage polarization for anti-inflammatory and bone differentiation

Biopolymer grafts often have limited biocompatibility, triggering excessive inflammatory responses similar to foreign bodies. Macrophage phenotype shifts are pivotal in the inflammatory response and graft success. The effects of the morphology and physical attributes of the material itself on macrophage polarization should be the focus. In this study, we prepared electrospun fibers with diverse diameters and formed a shish-kebab (SK) structure on the material surface by solution-induced crystallization, forming electrospun fiber scaffolds with diverse pore sizes and roughness. In vitro cell culture experiments demonstrated that SK structure fibers could regulate macrophage differentiation toward M2 phenotype, and the results of in vitro simulation of in vivo tissue reconstruction by the microenvironment demonstrated that the paracrine role of M2 phenotype macrophages could promote bone marrow mesenchymal stem cells (BMSCs) to differentiate into osteoblasts. In rats implanted with a subcutaneous SK-structured fiber scaffold, the large-pore size and low-stiffness SK fiber scaffolds demonstrated superior immune performance, less macrophage aggregation, and easier differentiation to the anti-inflammatory M2 phenotype. Large pore sizes and low-stiffness SK fiber scaffolds guide the morphological design of biological scaffolds implanted in vivo, which is expected to be an effective strategy for reducing inflammation when applied to graft materials in clinical settings.

Edible electrospun zein nanofibrous scaffolds close the gaps in biofilm formation ability between microorganisms

Biofilm is an important survival mode of microorganisms in nature. Biofilm culture is supposed to be a way of learning from nature to endow microorganisms with a strong tolerance. However, microorganisms possess different biofilm formation abilities, and universal scaffolds, especially edible scaffolds, suitable for fast biofilm formation are not found yet. Zein is a hydrophobic and biocompatible prolamine-rich protein from corn and is one of the most used biomacromolecules now. In this work, natural zein was utilized to produce electrospun zein nanofibrous biomaterial. The results demonstrate that edible electrospun zein nanofibrous scaffolds significantly enhance biofilm formation, where bacterial probiotics and yeasts are 0.9–1.4 Log cfu/cm2 (8–25 × ) and 1.7–3.3 Log cfu/cm2 (50–2000 × ) higher than the values on polystyrene plates and zein films, respectively. Gaps in biofilm formation abilities between bacteria and yeasts are narrowed from 1.7–1.8 Log cfu/cm2 (50–63 × ) to 0.5–0.6 Log cfu/cm2 (3–4 × ), respectively. Biofilms quickly formed on electrospun zein nanofibrous scaffolds before the occurrence of serious swelling deformation of the scaffolds. This is the first attempt to use edible electrospun fibrous scaffolds based on natural biomacromolecules for enhancing biofilm formation, crucially important for the application of probiotics and yeast in food and medical industries. Electrospun zein nanofibrous scaffolds can serve as powerful tools to enhance the biofilm formation of valuable food microorganisms and close the huge gaps in biofilm formation abilities between microorganisms, providing a convenient and universal strategy to produce biofilm-phenotyped probiotics and yeasts.

Piezoelectrically induced augmented functionality of primary cultured hippocampal neurons on electrospun PVDF-(Na, K) NbO3 composite fibers

Owing to the risk of permanent disability of the associated tissue/organ, peripheral nerve injuries present one of the major concerns. As growth and regeneration of axons are sensitive towards electrical activity of substrate, polyvinylidene difluoride (PVDF)−10 vol% sodium potassium niobate (NKN) piezoelectric composite fibers were electrospun and corona poled at 17 kV. Electrospun PVDF-NKN fibrous scaffolds show remarkable increase in the average number of dendrites per neuron and mean soma area of primary cultured hippocampal neurons of embryonic mice which further increases after polarization (∼ 1.3 and 1.6 times of unpoled PVDF, respectively). The developed composite can be suggested as a potential candidate for peripheral nerve regeneration.

Composite of bacterial cellulose and gelatin: A versatile biocompatible scaffold for tissue engineering

Synthesis of 0.4 ± 0.03 g/L per day of pure and porous bacterial cellulose (BC) scaffolds (scaffBC) and BC scaffolds modified with gelatin (scaffBC/Gel) was carried out using the Medusomyces gisevii Sa-28 bacterial strain. FT-IR spectroscopy and X-ray diffraction analysis showed that the scaffolds largely consist of crystalline cellulose I (Iα, Iß). Heating of BC with gelatin to 60 °C with subsequent lyophilization led to its modification by adsorption and binding of low-molecular fractions of gelatin and the formation of small pores between the fibers, which increased the biocompatibility and solubility of BC. The solubility of scaffBC and scaffBC/Gel was 20.8 % and 44.4 %, respectively, which enhances degradation in vivo. Light microscopy, scanning electron microscopy, and microcomputed tomography showed a uniform distribution of pores with a diameter of 100–500 μm. The chicken chorioallantoic membrane (CAM) model and subcutaneous implantation in rats confirmed low immunogenicity and intense formation of collagen fibers in both scaffolds and active germination of new blood vessels in scaffBC and scaffBC/Gel. The proliferative cellular activity of fibroblasts confirmed the safety of scaffolds. Taken together, the results obtained show that scaffBC/Gel can be used for the engineering of hard and soft tissues, which opens opportunities for further research.

Cell-Derived Extracellular Matrix Fiber Scaffolds Improve Recovery from Volumetric Muscle Loss.

There are currently no surgical procedures that effectively address the treatment of volumetric muscle loss (VML) injuries that has motivated the development of implantable scaffolding. In this study, the effectiveness of an allogenic scaffold fabricated using fibers built from the extracellular matrix (ECM) collected from muscle fibroblast cells during growth in culture was explored using a hindlimb VML injury (tibialis anterior muscle) in a rat model. Recovery outcomes (8 weeks) were explored in comparison with unrepaired controls as well previously examined allogenic scaffolds prepared from decellularized skeletal muscle (DSM) tissue (n = 9/sample group). At 8-week follow-up, we found that the repair of VML injuries using ECM fiber scaffolds in combination with an autogenic mince muscle (MM) paste significantly improved the recovery of peak contractile torque (79% ± 13% of uninjured contralateral muscle) when compared with unrepaired VML controls (57% ± 13%). Similar significant improvements were measured for muscle mass restoration (93% ± 10%) in response to ECM fiber+MM repair when compared with unrepaired VML controls (73% ± 13%). Of note, mass and contractile strength recovery outcomes for ECM fiber scaffolds were not significantly different from DSM+MM repair controls. These in vivo findings support the further exploration of cell-derived ECM fiber scaffolds as a promising strategy for the repair of VML injury with recovery outcomes that compare favorably with current tissue-sourced ECM scaffolds. Furthermore, although the therapeutic potential of ECM fibers as a treatment strategy for muscle injury was explored in this study, they could be adapted for high-throughput fabrication methods developed and routinely used by the textile industry to create a broad range of woven implants (e.g., hernia meshes) for even greater clinical impact.

Where Do CABs Exist? Verification of a specific region containing concave Actin Bundles (CABs) in a 3-Dimensional confocal image.

CABs (Concave Actin Bundles) are oriented against the scaffold transversally in a manner different from traditional longitudinal F-actin bundles. CABs are present in a specific area, and do not exist in random areas. Biologically, CABs are developed to attach cells to fibers firmly so that CABs are found near cells. Based on this knowledge, we closely examined 3D confocal microcopy images containing fiber scaffolds, actin, and cells. Then, we assumed that the areas containing high values of compactness of fiber, compactness of actin, and density of cells would have many numbers of CABs.In this research, we wanted to prove this assumption. We first incorporated a two-point correlation function to define a measure of compactness. Then, we used the Bayes' theorem to prove the above assumption. As the assumption, our results verified that CABs exist in an area of high compactness of a fiber network, high compactness of actin distribution, and high density of cells. Thus, we concluded that CABs are developed to attach cells to a fibrillar scaffold firmly. This finding may be further verified mathematically in future studies.

A scaffold containing zinc oxide for Schwann cell-mediated axon growth

Objective. Schwann cells (SCs) transplanted in damaged nervous tissue promote axon growth, which may support the recovery of function lost after injury. However, SC transplant-mediated axon growth is often limited and lacks direction. Approach. We have developed a zinc oxide (ZnO) containing fibrous scaffold consisting of aligned fibers of polycaprolactone (PCL) with embedded ZnO nanoparticles as a biodegradable, bifunctional scaffold for promoting and guiding axon growth. This scaffold has bifunctional properties wherein zinc is released providing bioactivity and ZnO has well-known piezoelectric properties where piezoelectric materials generate electrical activity in response to minute deformations. In this study, SC growth, SC-mediated axon extension, and the presence of myelin basic protein (MBP), as an indicator of myelination, were evaluated on the scaffolds containing varying concentrations of ZnO in vitro. SCs and dorsal root ganglion (DRG) neurons were cultured, either alone or in co-culture, on the scaffolds. Main results. Findings demonstrated that scaffolds with 1 wt.% ZnO promoted the greatest SC growth and SC-mediated axon extension. The presence of brain-derived neurotrophic factor (BDNF) was also determined. BDNF increased in co-cultures for all scaffolds as compared to SCs or DRGs cultured alone on all scaffolds. For co-cultures, cells on scaffolds with low levels of ZnO (0.5 wt.% ZnO) had the highest amount of BDNF as compared to cells on higher ZnO-containing scaffolds (1 and 2 wt.%). MBP immunostaining was only detected in co-cultures on PCL control scaffolds (without ZnO). Significance. The results of this study demonstrate the potential of the ZnO-containing scaffolds for SC-mediated axon growth and its potential for use in nervous tissue repair.

Antibacterial, anti-inflammatory, rapid hemostasis, and accelerated repair by multifunctional metal–organic frameworks fibrous scaffolds for diabetic wounds

Excessive inflammation, bacterial infection, persistent bleeding, and wound exudate accumulation are common in diabetic wounds, impeding cell proliferation and disturbing tissue remodeling, making it difficult for diabetic wounds to heal. The rapid hemostasis and reduction of bacterial infection, as well as the excessive infiltration of inflammatory factors, serve as key strategies for diabetic wound healing. In this study, Taxifolin (TAX) was loaded onto cyclodextrin metal–organic frameworks (CD-MOFs), which were subsequently loaded into polycaprolactone (PCL) scaffolds via electrostatic spinning to construct multifunctional electrospun fibrous membranes (EFMs) with antimicrobial, anti-inflammatory, hemostatic, and wound exudate-absorbent properties. The resulting EFMs exhibited a hydrophilic surface, which facilitated wound adhesion and enhanced its hemostatic properties. By aggregating the wound exudate and triggering a cascade release of TAX, bacterial infection in the wound was reduced, decreasing the expression of inflammatory factors. This also promoted collagen deposition, vascular regeneration, and myofibroblast contraction and migration and facilitated the remodeling and repair of the wound tissue. These results demonstrated that designed fibrous scaffolds could effectively accelerate the repair process of diabetic mice, providing a new strategy for the treatment of diabetic wounds.

GelMA/TCP nanocomposite scaffold for vital pulp therapy

Pulp capping is a necessary procedure for preserving the vitality and health of the dental pulp, playing a crucial role in preventing the need for root canal treatment or tooth extraction. Here, we developed an electrospun gelatin methacryloyl (GelMA) fibrous scaffold incorporating beta-tricalcium phosphate (TCP) particles for pulp capping. A comprehensive morphological, physical-chemical, and mechanical characterization of the engineered fibrous scaffolds was performed. In vitro bioactivity, cell compatibility, and odontogenic differentiation potential of the scaffolds in dental pulp stem cells (DPSCs) were also evaluated. A pre-clinical in vivo model was used to determine the therapeutic role of the GelMA/TCP scaffolds in promoting hard tissue formation. Morphological, chemical, and thermal analyses confirmed effective TCP incorporation in the GelMA nanofibers. The GelMA+20%TCP nanofibrous scaffold exhibited bead-free morphology and suitable mechanical and degradation properties. In vitro, GelMA+20%TCP scaffolds supported apatite-like formation, improved cell spreading, and increased deposition of mineralization nodules. Gene expression analysis revealed upregulation of ALPL, RUNX2, COL1A1, and DMP1 in the presence of TCP-laden scaffolds. In vivo, analyses showed mild inflammatory reaction upon scaffolds’ contact while supporting mineralized tissue formation. Although the levels of Nestin and DMP1 proteins did not exceed those associated with the clinical reference treatment (i.e., mineral trioxide aggregate), the GelMA+20%TCP scaffold exhibited comparable levels, thus suggesting the emergence of differentiated odontoblast-like cells capable of dentin matrix secretion. Our innovative GelMA/TCP scaffold represents a simplified and efficient alternative to conventional pulp-capping biomaterials. Statement of significanceVital pulp therapy (VPT) aims to preserve dental pulp vitality and avoid root canal treatment. Biomaterials that bolster mineralized tissue regeneration with ease of use are still lacking. We successfully engineered gelatin methacryloyl (GelMA) electrospun scaffolds incorporated with beta-tricalcium phosphate (TCP) for VPT. Notably, electrospun GelMA-based scaffolds containing 20% (w/v) of TCP exhibited favorable mechanical properties and degradation, cytocompatibility, and mineralization potential indicated by apatite-like structures in vitro and mineralized tissue deposition in vivo, although not surpassing those associated with the standard of care. Collectively, our innovative GelMA/TCP scaffold represents a simplified alternative to conventional pulp capping materials such as MTA and Biodentine™ since it is a ready-to-use biomaterial, requires no setting time, and is therapeutically effective.

Electrospinning and nanofibre applications: fundamentals and recent status

A field that is constantly growing is the bio fabrication of biomimetic materials for tissue engineering applications. Particularly intriguing are the mechanical and structural features that nano fibrous scales can emulate (e.g., collagen fibres). This review provides a broad overview of the production of nanofibers with a focus on the creation and use of electrospun nano fibrous scaffolds. Electrospinning allows for the creation of mats with precise fibre arrangements and structural integrity using a variety of biodegradable biopolymers. This review also lists some production process benefits and drawbacks. Also, the characteristics of the nanofibers that can be created using each process are illustrated together with the electrospinning techniques for producing nanofibers.

COMPARISION OF THE GLIO-PROTECTIVE EFFECTS OF BIOPOLYMER COATED ELECTROSPUN SCAFFOLDS

Gliosis is a condition that plays a negative role in various neurological pathologies. In this study, it was aimed to obtain and compare the glio-protective effects of electrospun fibrous scaffolds coated by different biopolymers. First, in vitro gliosis model was obtained by inducing U-87 MG cells with LPS and IFN-γ. The optimized model was applied to U-87 MG cells grown on polycaprolactone (PCL), hyaluronic acid (HA) coated, gelatin coated, and collagen coated PCL scaffolds. Immunofluorescent (IF) staining was performed with glial fibrillary acidic protein (GFAP) antibody to determine the level of gliosis. It was found that 5µg/mL LPS concentration induced gliosis and hyaluronic acid-coated PCL scaffolds have shown a protective effect on gliosis.