Search Results (797)

The development of 3D printing high-impact denture bases is challenging, as materials exhibiting both high flexural strength/modulus and fracture toughness are required. Nowadays, most of the commercially available 3D printing denture bases contain significant amounts of crosslinking monomers and therefore behave as brittle materials. In this contribution, urethane dimethacrylate DMA1/(octahydro-4,7-methano-1H-indenyl)methyl acrylate (OMIMA) 1/1 (wt/wt) formulations containing a poly(ε-caprolactone)-polydimethylsiloxane-poly(ε-caprolactone) (PCL-PDMS-PCL) triblock copolymer (BCP1) and fumed silica SiO₂-NPs were evaluated for DLP 3D printing of fracture-tough denture bases. The post-curing step was performed at various temperatures (RT, 60 °C, 80 °C, 100 °C and 120 °C). This parameter was shown to strongly influence the T_g and mechanical properties of 3D printed materials. A post-curing temperature of 100 °C was found to be ideal. Under these conditions, 3D printed materials exhibiting excellent mechanical properties were successfully obtained. Furthermore, the amounts of BCP1 and SiO₂-NPs were varied. The formulation containing 8.0 wt% of BCP1 and 10.0 wt% of SiO₂-NPs (FS = 67.5 ± 1.3 MPa, FM = 2450 ± 71 MPa, K_max = 2.11 ± 0.06 MPa m^1/2, W_f = 1109 ± 19 J m⁻²) was able to fulfill the ISO 20795-1:2013 requirements in terms of flexural strength (FS)/modulus (FM) and fracture toughness for denture bases with improved impact resistance (FS > 65 MPa, FM > 2000 MPa, K_max > 1.9 MPa m^1/2, W_f > 900 J m⁻²). This material showed better performance than the commercially available formulations Printodent^® GR-14.2 denture HI (FS = 69.2 ± 1.8 MPa, FM = 2153 ± 76 MPa, K_max = 0.82 ± 0.04 MPa m^1/2, W_f = 79 ± 10 J m⁻²) and Lucitone Digital Print^TM 3D denture base (FS = 56.7 ± 1.9 MPa, FM = 2144 ± 12 MPa, K_max = 1.92 ± 0.09 MPa m^1/2, W_f = 1272 ± 177 J m⁻²). Full article

Hydrophilic surface modification is widely investigated as a strategy to improve the hemocompatibility of small-diameter vascular grafts. We previously developed a polyvinyl alcohol-coated poly-ε-caprolactone nanofiber graft (PVA–PCL graft) and showed that the PVA coating improved graft hydrophilicity and mechanical properties. However, whether this coating provides an in vivo advantage over uncoated PCL grafts remains unclear. In addition, the influence of pre-implantation surface hydration on the function of hydrophilic grafts has not been fully examined. In this study, we first compared PVA–PCL and uncoated PCL grafts in a rat abdominal aorta implantation model and found no statistically significant difference in patency rate between the graft types. We then examined whether pre-wetting enhanced the anti-fouling function of the PVA coating. In vitro whole-blood flushing assays demonstrated that pre-wetting markedly reduced blood component deposition on PVA–PCL grafts, but this effect did not translate into detectable improvements in patency or tissue regeneration in the rat model. These findings indicate that pre-wetting effectively enhances the in vitro anti-fouling behavior of PVA–PCL grafts and may serve as a simple strategy to optimize the functional surface state of hydrophilic coatings. Further studies are needed to determine whether this in vitro improvement can be translated into meaningful enhancement in graft performance in vivo. Full article

Diabetic chronic wounds are often accompanied by excessive wound exudate maceration, which prolongs the inflammatory phase and increases the risk of infection. Such a complex wound microenvironment imposes more stringent requirements on multifunctional wound dressings. A multifunctional Cur Janus nanofibrous dressing is developed by integrating an electrospun poly(ε-caprolactone)/gelatin hydrophilic layer with a curcumin (Cur)-loaded PCL hydrophobic layer. Janus structure with asymmetric wettability, which exhibited unidirectional liquid transport properties both in vitro and in vivo. Its unique structure also makes it possible to carry both hydrophilic and hydrophobic drugs at the same time. The incorporation of curcumin endows the dressing with antibacterial and antioxidant functionalities, offering the potential to modulate the inflammatory microenvironment of diabetic chronic wounds. Furthermore, the wound healing ability and anti-inflammatory effects of Cur Janus nanofibers were evaluated in a diabetic mouse model. The results showed that Cur Janus nanofibers significantly reduced wound area, increased the proportion of pro-healing M2 macrophages, shortened the inflammatory phase, and ultimately accelerated diabetic wound healing. This work provides a multifunctional and scalable platform for advanced wound dressing design. Its excellent antibacterial, antioxidant (ROS scavenging) and anti-inflammatory (macrophage phenotype M1 to M2) properties, combined with the unidirectional fluid transport and dual-release potential of hydrophilic and hydrophobic drugs, demonstrate broad prospects in the management of diabetic wounds. Full article

Poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) copolymer micelles have emerged as promising drug delivery systems for enhancing the solubility and bioavailability of poorly water-soluble benzimidazole drugs. In this study, we prepared and characterized PEG-b-PCL micelles to encapsulate poorly water-soluble anthelmintics such as albendazole (ABZ) and fenbendazole (FBZ), with a focus on comparing their encapsulation behaviour, release profiles, and biological activity in cancer therapy. Drug-loaded micelles were analysed using dynamic light scattering (DLS), which revealed uniform nanosized micelles with a narrow polydispersity index (PDI). The morphology and size of both empty and drug-loaded micelles were examined using transmission electron microscopy (TEM), confirming that the micelles were spherical and consistent in size. Both drugs were efficiently encapsulated within the micellar core, demonstrating a high loading capacity. The release profiles of PEG-b-PCL micelles containing albendazole (ABZ) and fenbendazole (FBZ) at pH 7.4 were also evaluated. FBZ exhibited slower release kinetics compared to ABZ, likely due to its higher lipophilicity and stronger interactions with the hydrophobic PCL core, resulting in enhanced retention within the micelles. In contrast, ABZ had faster release kinetics. Finally, the in vitro MTT assays performed on the highly invasive triple-negative breast cancer (TNBC) cell line revealed the potential of these micelles as effective drug delivery systems. Full article

This study aims to develop sustainable conductive nanocomposites based on poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL) blends reinforced with multi-walled carbon nanotubes (MWCNT) and graphene nanoplatelets (G), focusing on their multifunctional performance. The novelty lies in the production of hybrid nanocomposites based on PLA/PCL blends with MWCNT/G using conventional industrial processing techniques, enabling the development of eco-friendly nanocomposites with tailored electrical, mechanical, and electromagnetic properties. The nanocomposites were prepared by twin-screw extrusion followed by injection molding. Rheological, scanning electron microscopy (SEM), mechanical, thermal, thermomechanical, electrical conductivity, and electromagnetic shielding properties were systematically evaluated. From a rheological perspective, the PLA/PCL/MWCNT and PLA/PCL/MWCNT/G nanocomposites exhibited a plateau at low frequencies, associated with the formation of a percolated network. This was confirmed by the significant increase in electrical conductivity and electromagnetic shielding response. The morphology observed by SEM showed a refinement of the PCL phase in the PLA matrix with the incorporation of MWCNT. The PLA/PCL/MWCNT/G (4/2 parts per hundred resin, phr) nanocomposite showed a 309% increase in impact strength compared to neat PLA, while maintaining the heat deflection temperature (HDT). The elastic modulus exceeded 2300 MPa and accelerated the crystallization process by more than 15 °C compared to PLA, which makes it important to reduce injection molding time. Additionally, it exhibited the highest electrical conductivity level, around 6.79 × 10⁻⁵ S/cm, which resulted in improved electromagnetic shielding performance in the 8.2–18 GHz range, highlighting the synergistic effect between 1D and 2D fillers. The developed PLA/PCL/MWCNT and PLA/PCL/MWCNT/G nanocomposites demonstrate potential for antistatic applications, combining sustainability with multifunctional performance and industrial scalability. Full article

Poly(ε-caprolactone) (PCL) is a biodegradable aliphatic polyester with applications in many areas. Lipase B from Moesziomyces antarcticus (CALB, previously known as Candida antarctica lipase B) is a well-characterize enzyme capable of hydrolysing several polyesters. In this study, the codon-optimized gene encoding CALB was cloned into the yeast Yarrowia lipolytica to enhance its natural capabilities toward polyesters biodegradation. PCL films biodegradation was conducted directly in the medium using the engineered yeast at 28 °C. Process optimization employing baffled flasks significantly improved degradation efficiency and reduced time to 24 h. This study showed that the engineered yeast Y. lipolytica is a promising host for polyester biodegradation. Full article

Bone grafting remains limited, and the strategies to design even more structurally complex scaffolds—able to reproduce the hierarchical architecture of bone extracellular matrix—are rapidly growing. In this study, we report the fabrication of a hierarchically structured scaffold produced by layering poly(ε-caprolactone)/gelatin (PCL/Gt) or poly(lactic acid)/gelatin (PLA/Gt) electrospun nanofibers via coaxial electrospinning onto 3D-printed poly(lactic acid) (PLA) scaffolds via fused deposition modeling (FDM). After the printing process, PLA disks (10 × 1 mm, 20% infill, ~80% porosity, pore size ~1.57 mm) were coated with core/shell (PCL/Gt, PLA/Gt) fibers to investigate the in vitro interfacial response of osteoblasts in comparison with monocomponent fibrous coatings (PCL, PLA, Gt). SEM and TEM confirmed that core/shell fibers exhibited bead-free morphologies, with a significant reduction in fiber diameter (≈287–316 nm) and higher interfibrillar porosity compared to monocomponent fibers. FTIR and thermogravimetric analyses indicated the presence of hydrogen bonding between the polyester and gelatin, and the absence of residual solvent after deposition. At the same time, water contact angle measurements confirmed an increase in hydrophilic properties from 80–86° to 120° ascribable to the presence of gelatin. Accordingly, in vitro response of human fetal osteoblasts (hFOB 1.19) exhibited an evident improvement in the case of Gt-based fibrous coatings (i.e., PCL/Gt and PLA/Gt) in terms of early adhesion (4–24 h) and metabolic activity from 3 to 21 days, cell spreading into star-shaped morphologies, formation of extracellular matrix, and mineral phase deposition. In more detail, a remarkable increase in alkaline phosphatase activity was observed in Gt-based coaxial coatings from day 7 onward, with the highest values recorded for PLA/Gt. Overall, we demonstrated that the Gt-based coaxial fibrous coating provided a mix of topological and biochemical cues that synergistically promoted key osteoblast activities at the interface, supporting the regeneration of new bone tissue in highly tailored 3D-printed scaffolds, thus suggesting a promising strategy for personalized regenerative medicine. Full article

The microstructure of semicrystalline bioresorbable polymers is central to their biomedical performance because the crystalline content influences both the mechanical stability and the degradation behaviour. Experimental studies have shown that crystallinity evolves concurrently with mass loss during enzymatic degradation. However, most existing models represent the material as a single homogeneous structure, preventing them from capturing this microstructural evolution or the state-selective mechanisms that drive it. We present a one-dimensional partial differential equation model for the enzymatic degradation of thin films, which treats the crystalline and amorphous states as distinct reactive components. Calibrated to poly($\epsilon$-caprolactone) (PCL) degraded by Candida antarctica lipase in vitro, the model accurately reproduces both the observed weight-loss profile and the concurrent decline in crystallinity. Parameter uncertainty analysis indicates that while there are varying degrees of confidence in individual parameter values, the overall model predictive uncertainty is well constrained. Parameter sensitivity analysis shows that the amorphous catalytic rate (the rate at which the enzyme degrades the amorphous region) is the dominant driver of degradation dynamics. The identified model parameters are used to explore the role of film thickness on the rates of mass and crystallinity loss. It was found that thin films remain largely reaction-limited, whereas thicker specimens become increasingly transport-influenced, with slower degradation and delayed structural evolution in the material interior. The model provides a useful tool to explore the effect of changing PCL film thickness on degradation rate and crystallinity-related properties without extensive experimentation. Full article

Sodium-ion-based polymer electrolytes have emerged as an essential technology for the next generation of solid-state batteries, offering the possibility of greater safety and mechanical flexibility. This work aimed to prepare eco-friendly ormolytes based on a biohybrid host matrix, which were doped, for the first time, with a wide range of NaTFSI concentrations. The matrix consists of short poly(ε-caprolactone) segments covalently bonded to siliceous domains via urethane linkages. The samples obtained were thin and transparent films. They were characterized by means of thermogravimetric analysis (TGA) and X-ray diffraction (XRD), and the films exhibited an amorphous character over the entire composition range. Ionic conductivity measurements were performed, and at room temperature for n = 10, the ionic conductivity was 2.44 × 10⁻³ mS.cm⁻¹. The highest ionic conductivity value of 1.78 × 10⁻² mS.cm⁻¹ (n = 10) was obtained at 62.0 °C. To access the cation/urethane interactions, Fourier transform infrared (FT-IR) spectroscopy was employed, and it was noted that the global profile was slightly altered with the incorporation of salt, in which more interactions were observed for the more concentrated samples. Thus, the proposed material may be promising in the development of more sustainable and environmentally friendly electrochemical devices with Na ions. Full article

Background/Objectives: An ideal bone scaffold should promote bone cell growth and functional vascularization, hence the importance of imbuing biomaterials with pro-angiogenic cues. In this work, silica-based bioactive glasses, either pristine (SBA3) or doped with copper (SBA3_Cu), were embedded in poly(ε-caprolactone) (PCL), which was also used as a control. Methods: In vitro co-cultures of adipose-derived mesenchymal stem/stromal cells (ASCs) and human microvascular endothelial cells (HMEC-1s) were kept in α-MEM, MCDB131, and EndoGRO media to test the biomaterials. The co-cultures were visualized by immunofluorescence and SEM, while flow cytometry was performed to characterize cellular immunophenotype. The angiogenic potential was evaluated using conditioned media of co-cultures to perform a tubulogenesis assay and VEGF-A quantification. Results: Immunophenotypic analysis showed a significant decrease in the endothelial CD31+ cellular subset, whereas the OB-like cellular subset expressing CD105, CD73, CD90, and ALP increased in all culture media over time. In α-MEM, HMEC-1s were unable to form a capillary network independent of the substrates. A more organized network was visible when co-cultures were plated on PCL, in MCDB131 and EndoGRO, or if they were kept in EndoGRO on PCL/SBA3_Cu. The VEGF-A concentrations were similar in the conditioned media from co-cultures grown on PCL/SBA_Cu, in EndoGRO, and on PCL and PCL/SBA3, in MCDB131. Conclusions: The presence of copper did not promote the angiogenic potential of HMEC-1, likely due to the low concentration of released copper ions and the predominant osteoinductive effect of the other ions released by the bioglass. A re-evaluation of formulation and structure of bioglass scaffold could enhance the angiogenic potential. Full article

Bone tissue has a remarkable regenerative capacity; however, advanced strategies are needed to support the repair process for critical-sized defects. While autografts and allografts remain the gold standard, their limitations have stimulated alternative approaches in bone tissue engineering, in search of scaffolds capable of mimicking native bone properties to promote effective regeneration. In this study, silk fibroin (SF)-based composite scaffolds incorporating β-tricalcium phosphate (β-TCP) and poly-ε-caprolactone (PCL) were synthesized using a simple and innovative cryogenic foaming method. The proposed fabrication technique overcomes many limitations of current synthesis methods, such as long processing times, the use of solvents, and reliance on complex, energy-intensive equipment. The composites were characterized using infrared spectroscopy to confirm the incorporation of all three components and their chemical bond arrangements. µ-CT, SEM, and ESEM analyses revealed that SF/β-TCP/PCL scaffolds exhibited great porosity and dynamic interaction with water while preserving pore morphology in wet environments. Swelling behavior, indirect cytotoxicity, and cell proliferation tests recognized the greater performance of SF/β-TCP/PCL scaffolds in promoting long-term cell proliferation, maintaining superior mechanical properties. These findings indicate that the proposed original, simple, and relatively low-cost manufacturing approach enabled the fabrication of scaffolds with excellent mechanical performances, controlled and stable porosity under both dry and physiological-like conditions, and high biocompatibility. The resulting constructs demonstrated promising results for cell proliferation and osteoconductive behavior, supporting their potential suitability as artificial bone substitutes. Full article

Biodegradable materials offer promising alternatives to petroleum-based polymers. This study investigates poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) nanocomposites reinforced with 1, 3 and 5 wt.% cellulose nanocrystals (CNCs) extracted from sugarcane bagasse via melt blending. The thermal, structural, morphological and biodegradation properties were evaluated using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray scattering (WAXS/SAXS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and biodegradation tests. SEM results revealed uniform dispersion of CNCs at low concentrations, whereas agglomeration occurred at higher concentrations for both PCL and PLA. At 1 wt.% CNCs, there was minimal impact on the biodegradation rates of both polymers, despite achieving uniform dispersion. However, significant acceleration in biodegradation was observed at 5 wt.% CNCs, attributed to the enhanced hydrophilic nature of the nanocomposites. CNCs acted as nucleating agents in PCL crystallization, while reducing the crystallization rate of PLA. This led to a mass loss of 36.4% for PCL and 82.2% for PLA, correlating with increased and decreased crystallinities, respectively. The study concludes that the hydrophilic–hydrophobic balance has a more significant influence on biodegradation rates than crystallinity or CNC dispersion. Full article

Electrospun poly(ε-caprolactone) (PCL) membranes incorporating Triticum vulgare extract (TVE) were developed as biomimetic scaffolds for periodontal regeneration. Using a ternary solvent system, two experimental formulations (µF-P10 and µF-P10T1) were fabricated and compared against a commercial dermal matrix. SEM analysis revealed bimodal fiber distributions (0.77–1.74 µm) and a surface porosity of 29.86% for TVE-loaded membranes, significantly higher than that of the commercial control (25.26%). FT-IR confirmed that the PCL chemical integrity was preserved, while mechanical testing showed that extract incorporation reinforced the matrix, increasing the Young’s modulus from 2.90 × 10³ Pa to 3.54 × 10³ Pa. UHPLC–MS identified ferulic acid as the primary bioactive component (90%), with release kinetics following a first-order model (R² = 0.998) over 48 h. Biological assays with human gingival fibroblasts (HGF) confirmed non-cytotoxicity (>70% viability). While both membranes supported healing, the µF-P10 formulation showed superior performance, with 80.2% proliferation and 60.6% wound closure, approaching control levels. These findings demonstrate that PCL-TVE electrospun scaffolds effectively combine favorable morphology and controlled release, offering a promising alternative for subepithelial connective tissue regeneration. Full article

Intranasal administration is a promising drug delivery route enabling precise and rapid central nervous system targeting. In our previous work, twelve hybrid colloidal dispersions were developed, consisting of synthetic poly(ethylene-oxide)-b-poly(ε-caprolactone) (PEO-b-PCL) block copolymers with an increasing proportion of the hydrophobic PCL segment, Tween 80 (Tw80) and β-cyclodextrin derivatives (βCD), either methyl-β-CD (MβCD) or hydroxy-propyl-β-CD (HPβCD) for IN delivery of ropinirole hydrochloride (RH). Colloidal dispersions were prepared at different weight ratios (system/RH equal to 10:1 and 10:5), characterized and evaluated in vitro. The aim of this study is to evaluate the ex vivo permeation through rabbit nasal mucosa and determine the pharmacokinetic parameters of RH, when administered intranasally as a colloidal dispersion, compared with oral and intranasal RH solutions in C57BL/6J mice. Ex vivo permeation studies showed that all formulations significantly enhanced RH permeation compared to the pure RH solution (0.5 mg/mL, pH 5.6). Among them, F4 [(PEO-b-PCL₁/Tw80/HPβCD)/RH 10:5] was selected for further investigation. Pharmacokinetic analysis showed that F4 significantly enhanced both systemic and brain exposure of RH, achieving higher serum AUC and C_max values, despite a 3-fold lower administered dose compared to the oral dose. It showed high systemic (F_rel(Serum) = 1815%) and brain (F_rel(Brain) = 363%) relative bioavailability compared with oral administration, underscoring its potential as an intranasal delivery system for efficient CNS targeting. Full article

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg²⁺) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg₂P₂O₇) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine. Full article