Search Results (70)

This study consisted of the injection molding simulation of polycaprolactone (PCL)-based nanocomposites reinforced with multi-walled carbon nanotubes (MWCNTs) for biomedical implant manufacturing. The simulation was additionally supported by experimental validation. The influence of varying MWCNT concentrations (0.5%, 5%, and 10% by weight) on key injection molding parameters, i.e., melt flow behavior, pressure distribution, temperature profiles, and fiber orientation, was analyzed with SolidWorks Plastics software. The results proved the low CNT content (0.5 wt.%) to be endowed with stable filling times, complete mold cavity filling, and minimal frozen regions. Thus, this formulation produced defect-free modular filament sticks suitable for subsequent 3D printing. In contrast, higher CNT loadings (particularly 10 wt.%) led to longer fill times, incomplete cavity filling, and early solidification due to increased melt viscosity and thermal conductivity. Experimental molding trials with the 0.5 wt.% CNT composites confirmed the simulation findings. Following minor adjustments to processing parameters, high-quality, defect-free sticks were produced. Overall, the PCL/MWCNT composites with 0.5 wt.% nanotube content exhibited optimal injection molding performance and functional properties, supporting their application in modular, patient-specific biomedical 3D printing. Full article

As the global plastic pollution problem intensifies and the environmental hazards of traditional petroleum-based plastics become increasingly significant, the development of sustainable alternative materials has become an urgent need. This paper systematically reviews the research progress, application status and future trends of new generation bioplastics in the field of food packaging. Bioplastics are categorized into three main groups according to their sources and degradability: biobased biodegradable materials (e.g., polylactic acid PLA, polyhydroxy fatty acid ester PHA, chitosan, and cellulose-based materials); biobased non-biodegradable materials (e.g., Bio-PE, Bio-PET); and non-biobased biodegradable materials (e.g., PBAT, PCL, PBS). Different processing technologies, such as thermoforming, injection molding, extrusion molding and coating technologies, can optimize the mechanical properties, barrier properties and freshness retention of bioplastics and promote their application in scenarios such as food containers, films and smart packaging. Although bioplastics still face challenges in terms of cost, degradation conditions and industrial support, promising future directions are found in the development of the large-scale utilization of non-food raw materials (e.g., agricultural waste, algae), nano-composite technology to enhance the performance, and the development of intelligent packaging functions. Through technological innovation and industry chain integration, bioplastics are expected to transform from an environmentally friendly alternative to a mainstream packaging material, helping to realize the goal of global carbon neutrality. Full article

Water contamination due to microbial proliferation remains a critical global challenge, especially with increasing urbanization, industrial activities, and the use of agrochemicals, and it requires the development of innovative methods for their purification that are not harmful to the environment and humans. In this study, innovative antibacterial nanocomposite coatings, composed of zirconia and silver nanocluster, were developed and deposited via eco-friendly co-sputtering physical vapor deposition (PVD) method onto electrospun polymeric membranes (PCL and PAN-PCL) for water filtration applications. Structural and morphological analyses, including XRD and UV-Vis spectroscopy, confirmed the deposition of a composite coating, consisting of an amorphous zirconia matrix embedding silver nanoclusters, homogeneously distributed on one side of the polymeric fibers. Wettability evaluations showed an increase in hydrophobicity after coating, particularly affecting the filtration performance of the PCL membranes. Antibacterial tests revealed strong inhibition against Staphylococcus epidermidis (Gram-positive) and partial efficacy against Escherichia coli (Gram-negative). Filtration tests of contaminated solutions revealed a 99% reduction in Bacillus subtilis, significant inhibition of Listeria monocytogenes, and limited effect on E. coli, with no bacterial proliferation observed on the coated membranes. These results underscore the effectiveness of ZrO₂/Ag nanocomposites in enhancing microbial control and suggest a promising, scalable strategy for sustainable and safe water purification systems. Full article

When it comes to the disposal of paperboard and cardboard packaging waste to reduce their environmental impact, recycling is one of the most desirable options. With innovations and development of biopolymer coatings and their application in packaging materials, new paper-based packaging solutions are expected on the market. Besides evaluating their mechanical and barrier properties, it is essential to assess their environmental impact. Therefore, this study investigated the impact of biodegradable polycaprolactone (PCL) polymer coating, as well as PCL modified with SiO₂, Al₂O₃, and ZnO nanoparticles, on the recycling behavior of paperboard. The coating samples were prepared by dissolving PCL polymer in ethyl acetate and nanoparticle dispersion. Paperboard (230 g/m²) was printed by offset printing process and then coated with PCL and PCL nanocomposite coatings. Recycling was performed under controlled laboratory conditions following a standardized method. Deinkability was assessed by evaluating the optical properties and using an image analysis system. From the obtained results, it can be concluded that the use of PCL coatings and PCL coating modified with SiO₂, Al₂O₃, and ZnO nanoparticles do not significantly impact the optical properties of the recycled pulp, thereby not restricting the implementation in paperboard production and waste management. Full article

Background/Objectives: Peripheral nerve injuries (PNIs) are a debilitating problem, resulting in diminished quality of life due to the continued presence of both chronic and acute pain. The current standard of practice for the repair of PNIs larger than 10 mm is the use of autologous nerve grafts. Autologous nerve grafts have limitations that often result in outcomes that are not sufficient to remove motor and sensory impairments. Bio-mimetic nanocomposite scaffolds combined with mesenchymal stem cells (MSCs) represent a promising approach for PNIs. In this study, we investigated the potential of an electrospun wrap of polycaprolactone (PCL) + graphene oxide (GO), with and without xenogeneic human adipose tissue-derived MSCs (hADMSCs) to use as a platform for neural tissue engineering. Methods: We evaluated, in vitro and in vivo, the potential of the nerve wrap in providing support for axonal growth. To establish the rat sciatic nerve defect model, a 10 mm long limiting defect was created in the rat sciatic nerve of 18 Lewis rats. Rats treated with the nanocomposites were compared with autograft-treated defects. Gait, histological, and muscle analyses were performed after sacrifice at 12 weeks post-surgery. Results: Our findings demonstrate that hADMSCs had the potential to transdifferentiate into neural lineage and that the nanocomposite successfully delivered hADMSCs to the injury site. Histologically, we show that the PCL + GO nanocomposite with hADMSCs is comparable to the autologous nerve graft, to support and guide axonal growth. Conclusions: The novel PCL + GO nerve wrap and hADMSCs used in this study provide a foundation on which to build upon and generate future strategies for PNI repair. Full article

Nanocomposites prepared with a terpolymer of poly(L–lactide) (PLLA)–poly(ε–caprolactone) (PCL)–poly(ethylene glycol) (PEG) and partially oxidized carbon nanotubes (CNTs_po) were synthesized and characterized to evaluate their ability to act as an effective nanocarrier of the anticancer drug methotrexate. The homopolymers of PLLA and PCL were synthesized through ring-opening polymerization (ROP) and characterized through gel permeation chromatography (GPC). The PLLA–PCL–PEG terpolymers were synthesized through a four-step chemical route using oxalyl chloride as a linker agent and analyzed with ¹H–NMR, ¹³C–NMR, and FTIR spectroscopies. Additionally, the nanocomposites were characterized through FTIR, and X-ray photoelectron spectroscopy (XPS), as well as the differential scanning calorimetry (DSC) technique. XPS analysis revealed that PLLA–PCL–PEG terpolymer chains are grafted onto CNTs_po. Moreover, evaluations through FTIR and DSC strongly suggest that the PCL-rich domains are preferentially oriented toward CNTs_po. The release tests exhibited a “burst effect” profile, which was more evident in the terpolymers than in the nanocomposites. Five models were used to assess methotrexate’s in vitro release. For the nanocomposites, the best fit to the experimental data was obtained using the first-order model, whereas the results obtained from the Korsmeyer–Peppas model indicated that Fickian diffusion drives methotrexate’s release. Full article

Chronic wounds often result in multiple infections with various kinds of bacteria and uncontrolled wound exudate, resulting in several healthcare issues. Advanced medicated nanofibres prepared by electrospinning have gained much attention for their topical application on infected chronic wounds. The objective of this work is to enhance the critical variables of ciprofloxacin-loaded polycaprolactone-silk sericin (PCL/SS-PVA-CIP) nanofibre production via the process of electrospinning. To examine the antibacterial effectiveness of PCL/SS-PVA-CIP nanocomposites, the material was tested against P. aeruginosa and S. aureus. The combination of PCL/SS-PVA-CIP exhibited potent inhibitory properties, with the most effective concentrations of ciprofloxacin (CIP) being 3 μg/g and 7.0 μg/g for each bacterium, respectively. The biocompatibility was evaluated by conducting cell reduction and proliferation studies using the human epidermal keratinocyte (HaCaT) cells and human gingival fibroblasts (HGFs) in vitro cell lines. The PCL/SS-PVA-CIP showed good cell compatibility with HaCaT and HGF cells, with effective proliferation even at antibiotic doses of up to 7.0 μg/g. The drug release effectiveness of the nanocomposites was assessed at various concentrations of CIP, resulting in a maximum cumulative release of 76.5% and 74.4% after 72 h for CIP concentrations of 3 μg/g and 7 μg/g, respectively. In summary, our study emphasizes the possibility of combining silk sericin (SS) and polycaprolactone (PCL) loading with CIP nanocomposite for wound management. Full article

Bone regeneration poses a significant challenge in the field of tissue engineering, prompting ongoing research to explore innovative strategies for effective bone healing. The integration of stem cells and nanomaterial scaffolds has emerged as a promising approach, offering the potential to enhance regenerative outcomes. This study focuses on the application of a stem cell-laden nanomaterial scaffold designed for bone regeneration in rabbits. The in vivo study was conducted on thirty-six healthy skeletally mature New Zealand white rabbits that were randomly allocated into six groups. Group A was considered the control, wherein a 15 mm critical-sized defect was created and left as such without any treatment. In group B, this defect was filled with a polycaprolactone–hydroxyapatite (PCL + HAP) scaffold, whereas in group C, a PCL + HAP-carboxylated multiwalled carbon nanotube (PCL + HAP + MWCNT-COOH) scaffold was used. In group D, a PCL + HAP + MWCNT-COOH scaffold was used with local injection of bone morphogenetic protein-2 (BMP-2) on postoperative days 30, 45, and 60. The rabbit bone marrow-derived mesenchymal stem cells (rBMSCs) were seeded onto the PCL + HAP + MWCNT-COOH scaffold by the centrifugal method. In group E, an rBMSC-seeded PCL + HAP + MWCNT-COOH scaffold was used along with the local injection of rBMSC on postoperative days 7, 14, and 21. For group F, in addition to the treatment given to group E, BMP-2 was administered locally on postoperative days 30, 45, and 60. Gross observations, radiological observation, scanning electron microscopic assessment, and histological evaluation study showed that group F displayed the best healing properties, followed by group E, group D, group C, and B. Group A showed no healing with ends blunting minimal fibrous tissue. Incorporating growth factor BMP-2 in tissue-engineered rBMSC-loaded nanocomposite PCL + HAP + MWCNT-COOH construct can augment the osteoinductive and osteoconductive properties, thereby enhancing the healing in a critical-sized bone defect. This novel stem cell composite could prove worthy in the treatment of non-union and delayed union fractures in the near future. Full article

A combined computational and experimental study of 3D-printed scaffolds made from hybrid nanocomposite materials for potential applications in bone tissue engineering is presented. Polycaprolactone (PCL) and polylactic acid (PLA), enhanced with chitosan (CS) and multiwalled carbon nanotubes (MWCNTs), were investigated in respect of their mechanical characteristics and responses in fluidic environments. A novel scaffold geometry was designed, considering the requirements of cellular proliferation and mechanical properties. Specimens with the same dimensions and porosity of 45% were studied to fully describe and understand the yielding behavior. Mechanical testing indicated higher apparent moduli in the PLA-based scaffolds, while compressive strength decreased with CS/MWCNTs reinforcement due to nanoscale challenges in 3D printing. Mechanical modeling revealed lower stresses in the PLA scaffolds, attributed to the molecular mass of the filler. Despite modeling challenges, adjustments improved simulation accuracy, aligning well with experimental values. Material and reinforcement choices significantly influenced responses to mechanical loads, emphasizing optimal structural robustness. Computational fluid dynamics emphasized the significance of scaffold permeability and wall shear stress in influencing bone tissue growth. For an inlet velocity of 0.1 mm/s, the permeability value was estimated at 4.41 × 10⁻⁹ m², which is in the acceptable range close to human natural bone permeability. The average wall shear stress (WSS) value that indicates the mechanical stimuli produced by cells was calculated to be 2.48 mPa, which is within the range of the reported literature values for promoting a higher proliferation rate and improving osteogenic differentiation. Overall, a holistic approach was utilized to achieve a delicate balance between structural robustness and optimal fluidic conditions, in order to enhance the overall performance of scaffolds in tissue engineering applications. Full article

Polymer-based nanocomposites such as polycaprolactone/graphene oxide (PCL/GO) have emerged as alternatives for bone tissue engineering (BTE) applications. The objective of this research was to investigate the impact of a gelatin (Gt) coating on the degradability and different properties of PCL nanofibrous scaffolds fabricated by an electrospinning technique with 1 and 2 wt% GO. Uniform PCL/GO fibers were obtained with a beadless structure and rough surface. PCL/GO scaffolds exhibited an increase in their crystallization temperature (Tc), attributed to GO, which acted as a nucleation agent. Young’s modulus increased by 32 and 63% for the incorporation of 1 and 2 wt% GO, respectively, in comparison with neat PCL. A homogeneous Gt coating was further applied to these fibers, with incorporations as high as 24.7 wt%. The introduction of the Gt coating improved the hydrophilicity and degradability of the scaffolds. Bioactivity analysis revealed that the hydroxyapatite crystals were deposited on the Gt-coated scaffolds, which made them different from their uncoated counterparts. Our results showed the synergic effect of Gt and GO in enhancing the multifunctionality of the PCL, in particular the degradability rate, bioactivity, and cell adhesion and proliferation of hGMSC cells, making it an interesting biomaterial for BTE. Full article

The aim of this research is to develop new nanocomposite membranes (NMs) for guided bone regeneration from polycaprolactone (PCL), with different concentrations of gentamicin sulfate (GEN) and nano-hydroxyapatite (nHAP) through electrospinning. The obtained NMs were characterized for structure through SEM and AFM, which revealed the influence of GEN and nHAP on the fiber diameter. The addition of GEN lowered the fiber diameter, and the addition of nHAP increased the diameter of the fibers. The NMs demonstrated antibacterial properties against P. aeruginosa, S. aureus, B. cereus, and E. coli depending on the drug concentration, while being negligibly affected by the nHAP content. NM cytotoxicity assessment, performed once using the MTT assay, revealed no cytotoxicity. The developed NMs could be a promising alternative for guided bone regeneration. Full article

This study investigated the relationship between the structure and mechanical properties of polycaprolactone (PCL) nanocomposites reinforced with baghdadite, a newly introduced bioactive agent. The baghdadite nanoparticles were synthesised using the sol–gel method and incorporated into PCL films using the solvent casting technique. The results showed that adding baghdadite to PCL improved the nanocomposites’ tensile strength and elastic modulus, consistent with the results obtained from the prediction models of mechanical properties. The tensile strength increased from 16 to 21 MPa, and the elastic modulus enhanced from 149 to 194 MPa with fillers compared to test specimens without fillers. The thermal properties of the nanocomposites were also improved, with the degradation temperature increasing from 388 °C to 402 °C when 10% baghdadite was added to PCL. Furthermore, it was found that the nanocomposites containing baghdadite showed an apatite-like layer on their surfaces when exposed to simulated body solution (SBF) for 28 days, especially in the film containing 20% nanoparticles (PB20), which exhibited higher apatite density. The addition of baghdadite nanoparticles into pure PCL also improved the viability of MG63 cells, increasing the viability percentage on day five from 103 in PCL to 136 in PB20. Additionally, PB20 showed a favourable degradation rate in PBS solution, increasing mass loss from 2.63 to 4.08 per cent over four weeks. Overall, this study provides valuable insights into the structure–property relationships of biodegradable-bioactive nanocomposites, particularly those reinforced with new bioactive agents. Full article

The increasing demand for non-invasive biocompatible materials in biomedical applications, driven by accidents and diseases like cancer, has led to the development of sustainable biomaterials. Here, we report the synthesis of four block formulations using polycaprolactone (PCL), polylactic acid (PLA), and zinc oxide nanoparticles (ZnO-NPs) for subdermal tissue regeneration. Characterization by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) confirmed the composition of the composites. Additionally, the interaction of ZnO-NPs mainly occurred with the C=O groups of PCL occurring at 1724 cm⁻¹, which disappears for F4, as evidenced in the FT-IR analysis. Likewise, this interaction evidenced the decrease in the crystallinity of the composites as they act as crosslinking points between the polymer backbones, inducing gaps between them and weakening the strength of the intermolecular bonds. Thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyses confirmed that the ZnO-NPs bind to the carbonyl groups of the polymer, acting as weak points in the polymer backbone from where the different fragmentations occur. Scanning electron microscopy (SEM) showed that the increase in ZnO-NPs facilitated a more compact surface due to the excellent dispersion and homogeneous accumulation between the polymeric chains, facilitating this morphology. The in vivo studies using the nanocomposites demonstrated the degradation/resorption of the blocks in a ZnO-NP-dependant mode. After degradation, collagen fibers (Type I), blood vessels, and inflammatory cells continue the resorption of the implanted material. The results reported here demonstrate the relevance and potential impact of the ZnO-NP-based scaffolds in soft tissue regeneration. Full article

The multiple roles of organic nanofillers in biodegradable nanocomposites (NC) with a blend-based matrix is not yet fully understood. This work highlights combination of reinforcing and structure-directing effects of chitin nanowhiskers (CNW) with different degrees of deacetylation (DA), i.e., content of primary or secondary amines on their surface, in the nanocomposite with the PCL/PLA 1:1 matrix. Of importance is the fact that aminolysis with CNW leading to chain scission of both polyesters, especially of PLA, is practically independent of DA. DA also does not influence thermal stability. At the same time, the more marked chain scission/CNW grafting for PLA in comparison to PCL, causing changes in rheological parameters of components and related structural alterations, has crucial effects on mechanical properties in systems with a bicontinuous structure. Favourable combinations of multiple effects of CNW leads to enhanced mechanical performance at low 1% content only, whereas negative effects of structural changes, particularly of changed continuity, may eliminate the reinforcing effects of CNW at higher contents. The explanation of both synergistic and antagonistic effects of structures formed is based on the correspondence of experimental results with respective basic model calculations. Full article

This work analyzes on nanoscale spatial domains the mechanical features of electrospun membranes of Polycaprolactone (PCL) loaded with Functionalized Magnetite Nanoparticles (FMNs) produced via an electrospinning process. Thermal and structural analyses demonstrate that FMNs affect the PCL crystallinity and its melting temperature. HarmoniX-Atomic Force Microscopy (H-AFM), a modality suitable to map the elastic modulus on nanometric domains of the sample surface, evidences that the FMNs affect the local mechanical properties of the membranes. The mechanical modulus increases when the tip reveals the magnetite nanoparticles. That allows accurate mapping of the FMNs distribution along the nanofibers mat through the analysis of a mechanical parameter. Local mechanical modulus values are also affected by the crystallinity degree of PCL influenced by the filler content. The crystallinity increases for a low filler percentage (<5 wt.%), while, higher magnetite amounts tend to hinder the crystallization of the polymer, which manifests a lower crystallinity. H-AFM analysis confirms this trend, showing that the distribution of local mechanical values is a function of the filler amount and crystallinity of the fibers hosting the filler. The bulk mechanical properties of the membranes, evaluated through tensile tests, are strictly related to the nanometric features of the complex nanocomposite system. Full article