Search Results (226)

Pistacia lentiscus var. chia resin (Chios Mastic Gum—CMG) is a natural aromatic resin that has been utilized in traditional medicine for more than 2.5 millennia, as it exhibits a wide range of pharmacological properties. In this study, various quantities of Chios Mastic Gum (3.5, 6.5, and 10 wt%) were encapsulated in electrospun fibers of poly-ε-caprolactone (PCL) to develop functional fibrous mats with multiple potential applications. The morphological analysis of composite membranes was conducted through scanning electron microscopy (SEM), revealing the formation of uniform fibers and incremental diameter size in samples with a higher concentration of CMG. The encapsulation efficiency was assessed by UV-Vis spectrophotometry and showed an exceptionally high loading efficiency (87–88%). The cytotoxicity of CMG-loaded nanofibers was tested in human embryonic kidney cell line HEK293 and human hepatocarcinoma cell line HepG2 using the MTT assay. In both cases, a high concentration of encapsulated CMG led to a statistically significant reduction in cell viability. Full article

Extracellular vesicles (EVs) have emerged as promising acellular tools for modulating immune responses for tissue engineering applications. This study explores the potential of human fibroblast-derived EVs delivered within a three-dimensional (3D) injectable scaffold composed of polycaprolactone (PCL) nanofibers and collagen (PNCOL) to reprogram macrophage behavior and support scaffold integrity under inflammatory conditions. EVs were successfully isolated from human fibroblasts using ultracentrifugation and characterized for purity, size distribution and surface markers (CD63 and CD9). Macrophage-laden PNCOL scaffolds were prepared under three conditions: macrophage-only (MP), fibroblast co-encapsulated (F-MP), and EV-encapsulated (EV-MP) groups. Structural integrity was assessed via scanning electron microscopy and Masson’s trichrome staining, while immunomodulatory effects were evaluated through metabolic assays, gene expression profiling, and immunohistochemistry for macrophage polarization markers (CD80, CD206). When co-encapsulated with pro-inflammatory (M1) macrophages in PNCOL scaffolds, fibroblast-derived EVs preserved scaffold structure and significantly enhanced macrophage metabolic activity compared to the control (MP) and other experimental group (F-MP). The gene expression and immunohistochemistry data demonstrated substantial upregulation of anti-inflammatory markers (TGF-β, CD163, and CCL18) and surface protein CD206, indicating a phenotypic shift toward M2-like macrophages for EV-encapsulated scaffolds relative to the other groups. The findings of this study demonstrate that fibroblast-derived EVs integrated into injectable PCL–collagen scaffolds offer a viable, cell-free approach to modulate inflammation, preserve scaffold structure, and support regenerative healing. This strategy holds significant promise for advancing immuno-instructive platforms in regenerative medicine, particularly in settings where conventional cell therapies face limitations in survival, cost, or safety. Full article

Wound healing is a complex biological process that benefits from advanced biomaterials capable of modulating inflammation and promoting tissue regeneration. In this study, cerium oxide nanoparticles (CeO₂NPs) were green-synthesized using Hemerocallis citrina extract, which served as both a reducing and stabilizing agent. The CeO₂NPs exhibited a spherical morphology, a face-centered cubic crystalline structure, and an average size of 9.39 nm, as confirmed by UV-Vis spectroscopy, FTIR, XRD, and TEM analyses. These nanoparticles demonstrated no cytotoxicity and promoted fibroblast migration, while significantly suppressing the production of inflammatory mediators (TNF-α, IL-6, iNOS, NO, and ROS) in LPS-stimulated RAW264.7 macrophages. Gene expression analysis indicated M2 macrophage polarization, with upregulation of Arg-1, IL-10, IL-4, and TGF-β. Aligned polycaprolactone/polylactic acid (PCL/PLA) nanofibers embedded with CeO₂NPs were fabricated using electrospinning. The composite nanofibers exhibited desirable physicochemical properties, including porosity, mechanical strength, swelling behavior, and sustained cerium ions release. In a rat full-thickness wound model, the CeO₂ nanofiber-treated group showed a 22% enhancement in wound closure compared to the control on day 11. Histological evaluation revealed reduced inflammation, enhanced granulation tissue, neovascularization, and increased collagen deposition. These results highlight the therapeutic potential of CeO₂-incorporated nanofiber scaffolds for accelerated wound repair and inflammation modulation. Full article

Current hydrogels used for cartilage tissue engineering often lack the mechanical strength and structural integrity required to mimic native human cartilage. This study addresses this limitation by developing reinforced hydrogels based on a ternary polymer blend of poly(vinyl) alcohol (PVA), gelatin (GL), and chitosan (CH), with gentamicin sulfate (GS) as an antimicrobial agent and a crosslinker. The hydrogels were produced using two crosslinking methods, the freeze/thaw and heated cycles, and reinforced with forcespun polycaprolactone (PCL) nanofiber to improve mechanical performance. Chemical characterization revealed that GS forms weak hydrogen bonds with the ternary polymers, leading to esterification with PVA, and covalent bonds are formed as the result of the free amino group (-NH₂) of chitosan that reacts with the carboxylic acid group (-COOH) of gelatin. SEM images help us to see how the hydrogels are reinforced with polycaprolactone (PCL) fibers produced via force spinning technology, while mechanical properties were evaluated via uniaxial tensile and compressive tests. Water retention measurements were performed to examine the crosslinking process’s influence on the hydrogel’s water retention, while the hydrogel surface roughness was obtained via confocal microscopy images. A constitutive model based on non-Gaussian strain energy density was introduced to predict experimental mechanical behavior data of the hydrogel, considering a non-monotonous softening function. Loading and unloading tests demonstrated that GS enhanced crosslinking without compromising water retention or biocompatibility because of the reaction between the free amino group of CH and the carboxylic group of gelatin. The PCL-reinforced PVA/GL/CH hydrogel shows strong potential for cartilage repair and tissue engineering applications. Full article

The intrinsic trade-off among sensitivity, response speed, and measurement range continues to hinder the wider adoption of flexible pressure sensors in areas such as medical diagnostics and gesture recognition. In this work, we propose a grid-structured polycaprolactone/thermoplastic-polyurethane nanofiber pressure sensor decorated with multi-walled carbon nanotubes (PCL/TPU@MWCNTs). By introducing a gradient grid membrane, the strain distribution and reconstruction of the conductive network can be modulated, thereby alleviating the conflict between sensitivity, response speed, and operating range. First, static mechanical simulations were performed to compare the mechanical responses of planar and grid membranes, confirming that the grid architecture offers superior sensitivity. Next, PCL/TPU@MWCNT nanofiber membranes were fabricated via coaxial electrospinning followed by vacuum-filtration and assembled into three-layer planar and grid piezoresistive pressure sensors. Their sensing characteristics were evaluated by simple index-finger motions and slide the mouse wheel identified. Within 0–34 kPa, the sensitivities of the planar and grid sensors reached 1.80 kPa⁻¹ and 2.24 kPa⁻¹, respectively; in the 35–75 kPa range, they were 1.03 kPa⁻¹ and 1.27 kPa⁻¹. The rise/decay times of the output signals were 10.53 ms/11.20 ms for the planar sensor and 9.17 ms/9.65 ms for the grid sensor. Both sensors successfully distinguished active index-finger bending at 0–0.5 Hz. The dynamic range of the grid sensor during the extension motion of the index finger is 105 dB and, during the scrolling mouse motion, is 55 dB, affording higher measurement stability and a broader operating window, fully meeting the requirements for high-precision hand-motion recognition. Full article

Background/Objectives: Cirsium setosum (commonly known as thistle) is a traditional Chinese medicinal plant with significant therapeutic potential, exhibiting hemostatic, antioxidant, and wound-healing properties. Electrospinning offers a versatile platform for fabricating nanoscale scaffolds with tunable functionality, making them ideal for drug delivery and tissue engineering. Methods: In this study, a bioactive extract from thistle was obtained and incorporated into a thermosensitive triblock copolymer (PNNS) and polycaprolactone (PCL) to develop a multifunctional nanofibrous scaffold for enhanced wound healing. The prepared nanofibers were thoroughly characterized using Fourier-transform infrared spectroscopy (FTIR), contact angle measurements, thermogravimetric analysis (TGA), and tensile fracture testing to assess their physicochemical properties. Results: Notably, the inclusion of PNNS imparted temperature-responsive behavior to the scaffold, enabling controlled deformation in response to thermal stimuli—a feature that may facilitate wound contraction and improve scar remodeling. Specifically, the scaffold demonstrated rapid shrinkage at a physiological temperature (38 °C) within minutes while maintaining structural integrity at ambient conditions (20 °C). In vitro studies confirmed the thistle extract’s potent antioxidant activity, while in vivo experiments revealed their effective hemostatic performance in a liver bleeding model when delivered via the composite nanofibers. Thistle extract and skin temperature-responsive contraction reduced the inflammatory outbreak at the wound site and promoted collagen deposition, resulting in an ideal wound-healing rate of above 95% within 14 days. Conclusions: The integrated strategy that combines mechanical signals, natural extracts, and electrospinning nanotechnology offers a feasible design approach and significant technological advantages with enhanced therapeutic efficacy. Full article

The optimal parameters for the microwave-assisted extraction of Epimedium brevicornum Maxim. were determined by using response surface methodology (RSM), increasing the extraction of flavonoids by 1.79 times. The resulting extract facilitated the green synthesis of zinc oxide nanoparticles (ZnONPs) with a wurtzite structure through a reaction with zinc nitrate. These ZnONPs were then incorporated into polycaprolactone (PCL) by using an electrospinning technique to produce nanofibers. The incorporation of ZnONPs resulted in an increase in Young’s modulus, biodegradation rate, and swelling ratio while decreasing the diameter and water contact angle of the nanofibers, thereby improving the hydrophilicity of PCL. ZnO demonstrates excellent biocompatibility with periodontal ligament stem cells (PDLSCs), increasing cell proliferation and enhancing alkaline phosphatase activity by 56.9% (p < 0.05). Additionally, mineralization deposition increased by 119% (p < 0.01) in the presence of 1% ZnO and showed a concentration-dependent response. After inducing PDLSC cultures with PCL–1% ZnO for 21 days, the protein expression levels of Runx2 and OCN increased by 50% (p < 0.05) and 30% (p < 0.001), respectively. Additionally, Col-1, Runx2, BSP, and OCN gene expression levels increased by 2.18, 1.88, 1.8, and 1.7 times, respectively. This study confirms that biosynthesized ZnONPs improve the physical properties of PCL nanofibers and effectively induce the osteogenic differentiation of PDLSCs. Full article

Cellular infiltration into traditional electrospun nanofibers (NFs) is limited due to their dense structures. We were able to obtain polycaprolactone (PCL) NFs with variable and defined pore sizes and thicknesses by using a customized programmed NF collector that controls the moving speed during electrospinning. NFs obtained by this method were tested in vitro and have shown better cell proliferation within the NFs with larger pore sizes. This study investigated in vivo host cell migration and neovascularization within implanted porous PCL NF discs using a mouse pouch model. Four types of PCL NFs were prepared and classified based on the electrospinning speed: NF-zero (static control), NF-low (0.085 mm/min), NF-mid (0.158 mm/min) and NF-high (0.232 mm/min) groups. With the increase in the speed, we observed an increase in the pore area; NF-zero (11.6 ± 6.2 μm²), NF-low (37.4 ± 28.6 μm²), NF-mid (67.6 ± 54.8 μm²), and NF-high (292.3 ± 286.5 μm²) groups. The NFs were implanted into air pouches of BALB/cJ mice. Mice without NFs served as control. Animals were sacrificed at 7 and 28 days after the implantation. Pouch tissues with implanted NFs were collected for histology (n = three per group and time point). The efficiency of the tissue penetration into PCL NF sheets was closely linked to the pore size and area. NFs with the highest pore area had more efficient tissue migration and new blood vessel formation compared to those with a smaller pore area. No newly formed blood vessels were observed in NF-zero sheets up to 28 days. We believe that a porous NF scaffold with a controllable pore size and thickness has great potential for tissue repair/regeneration and for other healthcare applications. Full article

Tension-free hernioplasty has effectively reduced postoperative recurrence and mitigated complications by employing polymer patches. However, clinically used polymer patches often fall short in terms of the anti-deformation, anti-adhesion, and tissue integration functions, which can result in visceral adhesions and foreign body reactions after implantation. In this study, a Janus three-layer composite patch was developed for abdominal wall defect repair using a combination of 3D printing, electrospraying, and electrospinning technologies. On the visceral side, a dense electrospun polyvinyl alcohol/sodium hyaluronate (PVA/HA) scaffold was fabricated to inhibit cell adhesion. The middle layer, composed of polycaprolactone (PCL), provided mechanical support. On the muscle-facing side, a loose and porous electrospun nanofiber scaffold was created through electrospraying and electrospinning, promoting cell adhesion and migration to facilitate tissue regeneration. Mechanical testing demonstrated that the composite patch possessed excellent tensile strength (23.58 N/cm), surpassing the clinical standard (16 N/cm). Both in vitro and in vivo evaluations confirmed the patch’s outstanding biocompatibility. Compared with the control PCL patch, the Janus composite patch significantly reduced the visceral adhesion and enhanced the tissue repair in animal models. Collectively, this Janus composite patch integrated anti-deformation, anti-adhesion, and tissue-regenerative properties, providing a promising solution for effective abdominal wall defect repair. Full article

Severe skin damage poses a significant clinical challenge, as limited availability of skin donors, postoperative skin defects, and scarring often impair skin function. Traditional two-dimensional (2D) nanofibers exhibit small pore sizes that hinder cellular infiltration, unable to simulate the three-dimensional (3D) structure of the skin. To address these issues, we developed 3D porous nanofiber scaffolds composed of polycaprolactone–polylactic acid–mussel adhesive protein (PLGA-PCL-MAP) using low-temperature electrospinning combined with nano-spray technology. Meanwhile, this 3D scaffold features high porosity, enhanced water absorption, and improved air permeability. The incorporation of mussel adhesive protein (MAP) further increased the scaffold’s adhesive properties and biocompatibility. In vitro experiments demonstrated that the 3D nanofiber scaffolds significantly promoted the adhesion, proliferation, and migration of epidermal keratinocytes (HaCaTs) and human fibroblasts (HFBs), while providing ample space for inward cellular growth. Successful co-culture of HaCaT and HFBs within the scaffold revealed key functional outcomes: HaCaTs expressed keratinocyte differentiation markers CK10 and CK14, while HFBs actively secreted extracellular matrix components critical for wound healing, including collagen I, collagen III, and fibronectin. This skin substitute with a composite structure of epidermis and dermis based on three-dimensional nanofiber scaffolds can be used as an ideal skin replacement and is expected to be applied in wound repair in the future. Full article

Zone II flexor digitorum profundus (FDP) tendon injuries are complex, and present significant challenges in hand surgery, due to the need to balance strength and flexibility during repair. Traditional suture techniques often lead to complications such as adhesions or tendon rupture, prompting the exploration of novel strategies to improve outcomes. This review investigates the use of flexor digitorum superficialis (FDS) tendon autografts to reinforce FDP repairs, alongside the integration of biomaterials to enhance mechanical strength without sacrificing FDS tissue. Key biomaterials, including collagen–polycaprolactone (PCL) composites, are evaluated for their biocompatibility, mechanical integrity, and controlled degradation properties. Collagen-PCL emerges as a leading candidate, offering the potential to reduce adhesions and promote tendon healing. Although nanomaterials such as nanofibers and nanoparticles show promise in preventing adhesions and supporting cellular proliferation, their application remains limited by manufacturing challenges. By combining advanced repair techniques with biomaterials like collagen-PCL, this approach aims to improve surgical outcomes and minimize complications. Future research will focus on validating these findings in biological models, assessing tendon healing through imaging, and comparing the cost-effectiveness of biomaterial-enhanced repairs with traditional methods. This review underscores the potential for biomaterial-based approaches to transform FDP tendon repair. Full article

Microcapsules provide a microenvironment by improving the protection and delivery of cells and drugs to specific tissue areas, promoting cell integration and tissue regeneration. Effective microcapsules must not only be permeable for micronutrient diffusion but mechanically stable. Alginate hydrogel is one of the commonly used biomaterials for fabricating microcapsules due to its gel-forming ability and low toxicity. However, its mechanical instability, inertness, and excessive porosity have impeded its use. Embedding nanofibrils in the alginate hydrogel microcapsules improves their biological and mechanical properties. In this research, electrospun composite nanofibers of PCL–gelatin (PG) were first fabricated, characterized, and cryoground. The filtered and cryoground powder solution was mixed with the alginate solution and through electrospray, fabricated into microcapsules. Parameters such as flow rate, voltage, and hydrogel composition, which are critical in the electrostatic encapsulation process, were optimized. The microcapsules were further immersed in different solvent environments (DI water, complete media, and PBS), which were observed and compared for their morphology, size distribution, and mechanical stability properties. The average diameters of the PG nanofibers ranged between 0.2 and 2 μm, with an average porosity between 58 and 73%. The average size of the microcapsules varied between 300 and 900 μm, depending on the solvent environment. Overall, results showed an improved alginate 3D hydrogel network suitable for biomedical applications. Full article

Neuromimetic in vitro models, simulating in vivo architecture/organization, are urgently needed to reduce experimental reliance on live animals. Our group recently reported a novel brain tissue derivation protocol, simultaneously deriving all major cortical cell types (including immune cells) in a facile protocol, generating a network of neurons in a single growth medium, which was interfaced with nanomaterials. This represents a significant advance, as tissue engineers overwhelmingly use diverse methods to derive and combine individual brain cells for materials-interfacing. However, this multicellular model lacked cellular directionality/structural organization (unlike the highly organized cortical circuits in vivo). Synthetic nanofiber constructs are of high value in tissue engineering, providing directional cues for cells. Most neuro-nanofiber studies employ simple monocultures of astrocytes/neurons and commonly use peripheral neurons rather than central nervous system populations. Here, we have interfaced our complex brain model (neurons/astrocytes derived simultaneously) with randomly oriented or aligned polycaprolactone (PCL) fiber meshes. Both cell types showed targeted extension along aligned fibers versus coverslips or random fibers. A new analysis method developed in-house demonstrated that peak orientations for astrocytes and neurons correlated with aligned nanofibers. Our data support the concept that nanofiber scaffolds can achieve organized growth of mixed cortical neural cell populations, mimicking neural architecture. Full article

Complex wounds pose a significant healthcare challenge due to their susceptibility to infections and delayed healing. This study focuses on developing electrospun polycaprolactone (PCL) nanofiber membranes coated with Type I collagen derived from bovine skin and functionalized with silver nanoparticles (AgNPs) to address these issues. The collagen coating enhances biocompatibility, while AgNPs synthesized through chemical reduction with sodium citrate provide broad-spectrum antimicrobial properties. The physical properties of the membranes were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results showed the formation of nanofibers without defects and the uniform distribution of AgNPs. A swelling test and contact angle measurements confirmed that the membranes provided an optimal environment for wound healing. In vitro biological assays with murine 3T3 fibroblasts revealed statistically significant (p ≤ 0.05) differences in cell viability among the membranes at 24 h (p = 0.0002) and 72 h (p = 0.022), demonstrating the biocompatibility of collagen-coated membranes and the minimal cytotoxicity of AgNPs. Antibacterial efficacy was evaluated against Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Vancomycin-resistant Enterococcus (VRE), with the significant inhibition of biofilm formation observed for VRE (p = 0.006). Overall, this novel combination of collagen-coated electrospun PCL nanofibers with AgNPs offers a promising strategy for advanced wound dressings, providing antimicrobial benefits. Future in vivo studies are warranted to further validate its clinical and regenerative potential. Full article

We compared the applicability of 3D fibrous scaffolds, produced by our patented centrifugal spinning technology, in soft tissue engineering. The scaffolds were prepared from four different biocompatible and biodegradable thermoplastics, namely, polylactide (PLA), polycaprolactone (PCL), poly(3-hydroxybutyrate) (PHB), and poly(1,4-butylene succinate) (PBS) and their blends. The combined results of SEM and BET analyses revealed an internal hierarchically organized porosity of the polymeric micro/nanofibers. Both nanoporosity and capillary effect are crucial for the water retention capacity of scaffolds designed for tissue engineering. The increased surface area provided by nanoporosity enhances water retention, while the capillary effect facilitates the movement of water and nutrients within the scaffolds. When the scaffolds were seeded with adipose-derived stem cells (ASCs), the ingrowth of these cells was the deepest in the PLA/PCL 13.5/4 (w/w) composite scaffolds. This result is consistent with the relatively large pore size in the fibrous networks, the high internal porosity, and the large specific surface area found in these scaffolds, which may therefore be best suited as a component of adipose tissue substitutes that could reduce postoperative tissue atrophy. Adipose tissue constructs produced in this way could be used in the future instead of conventional fat grafts, for example, in breast reconstruction following cancer ablation. Full article