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This study evaluated the biocompatibility of dense and porous forms of Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), Poly(ε-caprolactone) (PCL), and their 75/25 blend for bone tissue engineering applications. The biomaterials were characterized morphologically using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and the thickness and porosity of the scaffolds were determined. Functional assessments of mesenchymal stem cells (MSCs) included the MTT assay, alkaline phosphatase (ALP) production, and morphological and cytochemical analyses. Moreover, these polymers were implanted into rats to evaluate their in vivo performance. The morphology and FTIR spectra of the scaffolds were consistent with the expected results. Porous polymers were thicker than dense polymers, and porosity was higher than 92% in all samples. The cells exhibited good viability, activity, and growth on the scaffolds. A higher number of cells was observed on dense polymers, likely due to their smaller surface area. ALP production occurred in all samples, but enzyme activity was more intense in PCL samples. The scaffolds did not interfere with the osteogenic capacity of MSCs, and mineralized nodules were present in all samples. Histological analysis revealed new bone formation in all samples, although pure PHBV exhibited lower results compared to the other blends. In vivo results indicated that dense PCL and the dense 75/25 blend were the best materials tested, with PCL tending to improve the performance of PHBV in vivo. [ABSTRACT FROM AUTHOR]

AbstractThis study aims to evaluated the impact of poly(ε-caprolactone) (PCL) microspheres on the pharmacokinetics and pharmacodynamics (PopPK/PD) of 6-methylcoumarin (6MC). For this, PCL microspheres loaded with 6MC were prepared using the emulsification-evaporation method. Particle size, zeta potential, drug loading, and entrapment efficiency were characterised by dynamic light scattering and UV spectrophotometry. In vitro release and pharmacokinetics in Wistar rats were assessed for free and encapsulated 6MC. Anti-inflammatory activity was evaluated using the carrageenan-induced paw edoema model, with PopPK and PopPK/PD models developed. Microspheres showed diameters between 2.9 and 7.1 µm, zeta potentials of −10 to −15 mV, and drug loading of 0.24 mg/mg. Encapsulation efficiency was 45.5% to 75.9%. PopPK models showed enhanced absorption and distribution, with increased anti-inflammatory potency of encapsulated 6MC. PCL microspheres significantly improved the pharmacokinetic and pharmacodynamic profiles of 6MC, enhancing its therapeutic potential for lipophilic drugs. [ABSTRACT FROM AUTHOR]

Obtaining a polymer nanocomposite with optimum viscoelastic, thermal, and biocompatibility properties is the main objective when designing nanocomposite systems with potential applications in tissue engineering. For this purpose, a blend of Polycaprolactone (PCL) and Polyvinylidene fluoride (PVDF) in an 85/15 weight ratio, along with a nanocomposite reinforced by nanohydroxyapatite (nHA) particles, is fabricated using a solution casting method in a mold. The impact of nHA content on crystallinity, viscoelastic properties, thermal stability, and the properties–structure relationship of nanocomposites is evaluated using scanning electron microscopy (SEM). Dynamic mechanical thermal (DMTA) analysis is used to determine the William–Landel–Ferry (WLF) constants and the effect of nHA on the nanocomposite's viscoelastic behavior. The PCL/15PVDF/0.5 wt% nHA exhibits the maximum thermal stability (40% residual char value) and 95% increase in storage modulus at 90 °C (rubbery region) in comparison with PCL/15PVDF blend. Water contact angle (WCA) and biocompatibility tests are conducted on the PCL/15PVDF blend and nanocomposite scaffolds to design appropriate nanocomposite systems with potential applications in tissue engineering. The high hydrophilic properties are assigned to PCL/15PVDF/0.5 wt% nHA with a WCA of 67.5°. Finally, in vitro cell culture confirmed 0.5 wt% nHA significantly improves cell adhesion and cytotoxicity with MG‐63 cells. [ABSTRACT FROM AUTHOR]

Poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL), two biodegradable and biocompatible polymers that are commonly used for biomedical applications, are, respectively, the result of the ring-opening polymerization of LA and ε-CL, cyclic esters, which can be produced according to several mechanisms (cationic, monomer-activated cationic, anionic, and coordination-insertion), except for L-lactide, which is polymerized only by anionic, cationic, or coordination-insertion polymerization. A series of well-defined PLLA-b-PCL block copolymers have been obtained starting from the same PLLA homopolymer, having a molar mass of 2500 g·mol−1, and being synthesized by coordination-insertion in the presence of tin octoate. PCL blocks were obtained via a cationic-activated monomer mechanism to limit transesterification reactions, and their molar masses varied from 1800 to 18,500 g·mol−1. The physicochemical properties of the copolymers were determined by 1H NMR, SEC, and DSC. Moreover, a series of nanoparticles (NPs) were prepared starting from these polyester-based copolymers by an emulsification/evaporation method. The sizes of the obtained NPs varied between 140 and 150 nm, as a function of the molar mass of the copolymers. Monomodal distribution curves with PDI values under 0.1 were obtained by Dynamic Light Scattering (DLS) and their spherical shape was confirmed by TEM. The increase in the temperature from 25 to 37 °C induced only a very slight decrease in the NP sizes. The results obtained in this preliminary study indicate that NPs have a temperature stability, allowing us to consider their use as drug-loaded nanocarriers for biomedical applications. [ABSTRACT FROM AUTHOR]

Few studies have investigated the biodegradation of microplastics in marine environments. Microorganisms that can degrade microplastics in high-salinity conditions are sought after. Therefore, we aimed to isolate a halotolerant poly(ε-caprolactone) (PCL)-degrading bacterium for applications in biotechnology. The bacterium isolated from seaside soil was identified as Bacillus gibsonii via phylogenetic analysis based on 16S rRNA gene sequences and designated as KRICT-1. We tested whether the KRICT-1 strain showed halotolerance by determining the sodium chloride (NaCl) tolerance at various concentrations. The KRICT-1 strain showed growth at up to 10% NaCl on Luria–Bertani (LB) medium agar plates and 10% NaCl in liquid LB medium, indicating that KRICT-1 can grow and produce a PCL-depolymerizing enzyme under high-salt conditions. The KRICT-1 strain could depolymerize PCL with a PCL film weight loss of 2.82% at up to 10% NaCl concentration after cultivation of 7 weeks. KRICT-1 is the first strain of B. gibsonii which shows PCL-depolymerizing activity. Scanning electron microscopy and water contact angle results confirmed the degradation of PCL by the KRICT-1 strain. The extracellular enzyme produced by the KRICT-1 strain was stable over a wide range of temperatures (15–40 °C) and pH (7.0–9.5). This halotolerant PCL-degrading bacterium can be used in the degradation of biodegradable plastics present in saline soils, saline water, and wastewater. [ABSTRACT FROM AUTHOR]

Nanocomposites prepared with a terpolymer of poly(L–lactide) (PLLA)–poly(ε–caprolactone) (PCL)–poly(ethylene glycol) (PEG) and partially oxidized carbon nanotubes (CNTspo) 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 CNTspo. Moreover, evaluations through FTIR and DSC strongly suggest that the PCL-rich domains are preferentially oriented toward CNTspo. 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. [ABSTRACT FROM AUTHOR]

The improvement of the mucosal sealing around the implant represents a challenge, one that prompted research into novel materials. To this purpose, a printable poly(ε-caprolactone) (PCL)-based composite loaded with alumina-toughened zirconia (ATZ) at increasing rates of 10, 20, and 40 wt.% was prepared, using a solvent casting method with chloroform. Disks were produced by 3D printing; surface roughness, free energy and optical contact angle were measured. Oral fibroblasts (PF) and epithelial cell (SG) tests were utilized to determine the biocompatibility of the materials through cell viability assay and adhesion and spreading evaluations. The highest level of ATZ resulted in an increase in the average roughness (Sa), while the maximum height (Sz) was higher for all composites than that of the unmixed PCL, regardless of their ATZ content. Surface free energy was significantly lower on PCL/ATZ 80/20 and PCL/ATZ 60/40, compared to PCL and PCL/ATZ 90/10. The contact angle was inversely related to the quantity of ATZ in the material. PF grew without variations among the different specimens at 1 and 3 days. After 7 days, PF grew significantly less on PCL/ATZ 60/40 and PCL/ATZ 80/20 compared to unmixed PCL and PCL 90/10. Conversely, ATZ affected and improved the growth of SG. By increasing the filler amount, PF cell adhesion and spreading augmented, while PCL/ATZ 80/20 was the best for SG adhesion. Overall, PCL/ATZ 80/20 emerged as the best composite for both cell types; hence, it is a promising candidate for the manufacture of custom made transmucosal dental implant components. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop multifunctional magnetic poly(ε‐caprolactone) (PCL) mats with antibacterial properties for bone tissue engineering and osteosarcoma prevention. To provide good dispersion of magnetic iron oxide nanoparticles (IONs), they were first grafted with PCL using a novel three‐step approach. Then, a series of PCL‐based mats containing a fixed amount of ION@PCL particles and an increasing content of ascorbic acid (AA) was prepared by electrospinning. AA is known for increasing osteoblast activity and suppressing osteosarcoma cells. Composites were characterized in terms of morphology, mechanical properties, hydrolytic stability, antibacterial performance, and biocompatibility. AA affected both the fiber diameter and the mechanical properties of the nanocomposites. All produced mats were nontoxic to rat bone marrow‐derived mesenchymal cells; however, a composite with 5 wt.% of AA suppressed the initial proliferation of SAOS‐2 osteoblast‐like cells. Moreover, AA improved antibacterial properties against Staphylococcus aureus and Escherichia coli compared to PCL. Overall, these magnetic composites, reported for the very first time, can be used as scaffolds for both tissue regeneration and osteosarcoma prevention. [ABSTRACT FROM AUTHOR]

This study investigates the development and characterization of UV‐curable Poly(ε‐caprolactone) (PCL), Acrylated Epoxidized Soybean Oil (AESO), and Carbon Nanotubes (CNT) nanocomposites for biomedical engineering applications. The PCL/AESO blends were prepared in various ratios, and CNTs were incorporated at concentrations of 0.5, 1.0, and 1.5 wt% to enhance mechanical properties. The UV‐curable formulations aimed to leverage rapid curing times, precise control over material properties, and the ability to fabricate complex structures. Results indicated that the incorporation of CNTs improved the tensile strength, modulus, and toughness of the composites. The PCL/AESO/CNT nanocomposites exhibited a tensile strength increase of 25%, a modulus improvement of 30%, and a toughness enhancement of 20% compared to pure PCL. Thermal analysis showed an increase in crystallization temperature and thermal stability, with a crystallinity degree of 63.31% and a maximum degradation temperature of 407°C for the B/C 50/50/1.5 sample. Biocompatibility assessments using L929 fibroblast cells revealed that the composites supported cell viability and proliferation over 7 days with negligible cytotoxicity. Cell attachment studies indicated favorable morphology and adherence, suggesting a conducive environment for cell growth and differentiation. Hydrolytic biodegradation studies demonstrated adjustable degradation rates, making these composites suitable for various biomedical applications requiring controlled biodegradation. [ABSTRACT FROM AUTHOR]

AbstractA series of photoluminescent nanocomposite polyurethane adhesives were elaborated from a chemoenzymatic prepared diol of caprolactone (PCL-diol) and ethylene glycol with an excess of two different isocyanates: i) hexamethylene (HDI) and (ii) isophorone (IPDI)) diisocyanates. Adhesive formulations were filled with functionalized poly(amido-amine) (PAMAM) carbon nanotubes (f-MWNTs) and carbon quantum dots (CQDTs). Dry swine gut was used as substrate and mechanical tests were performed to explore the performance of the adhesives. The obtained materials were characterized by infrared spectroscopy (FT-IR), energy surface by contact angle, differential scanning calorimetry (DSC), hydrolytic degradation, and mechanical testing under tension, lap shear, T-peel, wound closure, and burst pressure. Among the main results were the formation of covalent bonds between the substrate and the adhesive, and the fact that the mechanical strength of the nanocomposite adhesives was superior to that of the unfilled adhesives. Compatibility of nanocomposites with the substrate was achieved by increasing wettability by the incorporation of both nanofillers. Also, adhesives filled with only CQDTs and with MWNTs-CDQTs combined showed photoluminescence activity under ultraviolet light. [ABSTRACT FROM AUTHOR]

Electrospun nanofiber scaffolds mimic the structure of the natural extracellular matrix, making them promising for application in tissue engineering. Based on this, the biopolymers poly(ε-caprolactone) (PCL) and gelatin, with good mechanical and biological properties, respectively, were electrospun with acetic acid as the only solvent, without the crosslinking process in order to reduce the cytotoxic effects of commonly used solvents. This study evaluated the influence of scaffold thicknesses on the physicochemical properties. Scaffolds with 4 different thicknesses were produced by increasing the electrospinning time (A = 1 h, B = 1.5 h, C = 2 h and D = 3 h). Thicker scaffolds (B, C and D, 0.142 ± 0.029 to 0.306 ± 0.053 nm) were manipulated easily, presented higher mechanical strength (from 156.21 to 178.53%) and smaller diameter fibers (approximately 300.0 nm). On the other hand, the longer the processing time, the less uniform the fibers and more melting regions between fibers, which may hinder the use of the scaffold and should be considered. Only the thickest scaffold (D) showed higher wettability (contact angle 31.1° ± 3°). Intermediate thickness scaffolds showed less beads and fiber irregularities. Cell adhesion was good due to gelatin, though cell proliferation remained constant for the thicker scaffold indicating that longer processing time may not be advantageous for cell application. Results showed that intermediate thickness scaffolds of PCL/gelatin (0.142 ± 0.029 to 0.195 ± 0.034 nm) assure good physicochemical properties to be applied for different cell types. [ABSTRACT FROM AUTHOR]

Biodegradable polymers for food applications have emerged as a sustainable alternative to reduce plastic waste. In this work, compostable films based on blends of poly(ε-caprolactone) (PCL) and thermoplastic gliadins (TPG) were developed for packaging applications. Firstly, gliadins were extracted from wheat gluten and plasticized with glycerol. Then, PCL/TPG films were prepared by cast-extrusion processing at pilot scale and samples were characterized in terms of their structural, morphological, thermal, mechanical, barrier and optical properties. The addition of TPG increased the glass transition temperature (Tg) of PCL, reduced the oxygen permeability at 0% and 50% relative humidity values, and improved the seal strength properties of the films, having a minimal effect on the thermal stability, transparency, and the high stretchability characteristic of PCL. On the other hand, the presence of gliadins led to more water sensitive materials, resulting in a slight increase in the water vapor permeability. Finally, the home-compostability assessment of the films revealed that the presence of gliadins accelerated the aerobic biodegradation and the disintegration with respect to pristine PCL film, thus, showing the potential interest of the developed materials for sustainable packaging applications. [ABSTRACT FROM AUTHOR]

A quantitative analysis of the morphology, as well as an analysis of the distribution of components and surface/interfacial properties in poly(lactic acid)(PLA) InegoTM 3251D, poly(ε-caprolactone) (PCL) Capa 6800 and nano-silica (SiO2) Aerosil®200 blends, was conducted in this research. The study aimed to improve the understanding of how PLA, PCL, and nano-SiO2 interact, resulting in the specific morphology and surface properties of the blends. Samples were produced by varying the concentration of all three components. They were analyzed using SEM, EDS mapping, water contact angle measurements, surface free energy calculation, adhesion parameter measurements, and FTIR-ATR spectroscopy. The results showed that the addition of SiO2 nanoparticles led to an increase in the contact angle of water, making the surface more hydrophobic. SEM images of the blends showed that increasing the PCL content reduced the size of spherical PCL elements in the blends. FTIR-ATR analysis showed that SiO2 nanoparticles influenced the structure ordering of PLA in the blend with equal portions of PLA and PCL. In the samples with a higher PCL content, the spherical elements present in the samples with a higher PLA/PCL ratio have been reduced, indicating better interactions at the interface between PLA, PCL, and SiO2. SEM-EDS mapping of the PLA/PCL 100/0 blend surfaces revealed the presence of SiO2 clusters and the silicon (Si) concentration reaching up to ten times higher than the nominal concentration of SiO2. However, with the addition of 3% SiO2 to the blend containing PCL, the structure became more granular. Specifically, Si protrusions in the sample PLA/PCL 90/10 with 3% SiO2 displayed 29.25% of Si, and the sample PLA/PCL 70/30 with 3% SiO2 displayed an average of 10.61% of Si at the protrusion locations. The results confirmed the affinity of SiO2 to be encapsulated by PCL. A better understanding of the interactions between the materials in the presented blends and the quantitative analysis of their morphology could improve the understanding of their properties and allow the optimization of their application for different purposes. [ABSTRACT FROM AUTHOR]

This work focuses on the study and comparison of two mixing methods for the dispersion of Alumina-Toughened Zirconia (ATZ) within the polymer matrix of Poly(ε-caprolactone) (PCL). The dry-mixing method using solvent-free impact milling (M) and the solvent casting method with chloroform (SC) were investigated. Samples were produced by 3D printing, and specimens were printed at increasing ATZ loadings (namely, 10, 20, and 40 wt.%). The chemico-physical, mechanical, and cell interaction characteristics of the materials prepared with both mixing methods were studied. Solvent mixing allowed better dispersion of the ATZ in the polymer matrix with respect to dry mixing. In addition, dry mixing affected the molecular weight of the PCL/ATZ composites much more than the solvent casting method. For these reasons, materials obtained by solid mixing exhibited the worst mechanical performance with respect to those obtained by solvent casting, which showed increased Young's moduli with increasing ATZ amounts. The in vitro biological response elicited in a mesenchymal stem cell model seemed to be influenced by the mixing method, with a preference for the composites obtained through solvent mixing and containing 20 or 40 wt.% of ATZ. [ABSTRACT FROM AUTHOR]

Abstract Obtaining a polymer nanocomposite with optimum viscoelastic, thermal, and biocompatibility properties is the main objective when designing nanocomposite systems with potential applications in tissue engineering. For this purpose, a blend of Polycaprolactone (PCL) and Polyvinylidene fluoride (PVDF) in an 85/15 weight ratio, along with a nanocomposite reinforced by nanohydroxyapatite (nHA) particles, is fabricated using a solution casting method in a mold. The impact of nHA content on crystallinity, viscoelastic properties, thermal stability, and the properties–structure relationship of nanocomposites is evaluated using scanning electron microscopy (SEM). Dynamic mechanical thermal (DMTA) analysis is used to determine the William–Landel–Ferry (WLF) constants and the effect of nHA on the nanocomposite's viscoelastic behavior. The PCL/15PVDF/0.5 wt% nHA exhibits the maximum thermal stability (40% residual char value) and 95% increase in storage modulus at 90 °C (rubbery region) in comparison with PCL/15PVDF blend. Water contact angle (WCA) and biocompatibility tests are conducted on the PCL/15PVDF blend and nanocomposite scaffolds to design appropriate nanocomposite systems with potential applications in tissue engineering. The high hydrophilic properties are assigned to PCL/15PVDF/0.5 wt% nHA with a WCA of 67.5°. Finally, in vitro cell culture confirmed 0.5 wt% nHA significantly improves cell adhesion and cytotoxicity with MG‐63 cells.

This research aimed to fabricate and evaluate Poly(lactic acid)/poly(ε-caprolactone)/graphene (PLA/PCL/G) nanocomposite scaffolds for peripheral nerve tissue engineering. To achieve this goal, scaffolds were fabricated using the fused deposition modeling (FDM) 3D printing method with the following compositions: 50 wt% PLA-50 wt% PCL (PLA-PCL), 98.5 wt% PLA-1.5 wt% G (PLA-G), 98.5 wt% PCL-1.5 wt% G (PCL-G), and 50 wt% PLA-48.5 wt% PCL-1.5 wt% G (PLA-PCL-G). The microstructure and chemical composition of the scaffolds were characterized using SEM, XRD, and FTIR. SEM images revealed that the PLA-PCL-G scaffold exhibited a more regular and uniform morphology compared to the others, with the PLA-PCL scaffold displaying the least regularity. The porosity percentage and pore size of the scaffolds ranged from 50 % to 86 % and 300 to 500 µm, respectively. Mechanical properties were assessed via compression testing, indicating that the elastic modulus of the PLA-PCL-G scaffold was approximately 22.36 MPa, suitable for peripheral nerve tissue applications. Electrical conductivity testing showed that PLA-PCL-G had a conductivity of about 8.2E-5 S/cm, similar to PLA-G. Biodegradability was evaluated by immersing samples in phosphate-buffered saline (PBS), revealing that PLA-PCL-G exhibited a weight loss of approximately 1.3 % and a degradation rate of 0.14 mm/day over four weeks, closely matching peripheral nerve tissue regeneration rates. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay results confirmed that PLA-PCL-G scaffolds were non-cytotoxic to PC12 cells. Overall, these findings suggest that the 50 wt% PLA-48.5 wt% PCL-1.5 wt% G scaffold holds promise for peripheral nerve tissue engineering applications.

[Display omitted] • Utilization of brewers' spent grain (BSG), spent hops (SH) and spent yeast (SY). • BSG, SH, and SY applied as fillers for poly(ε-caprolactone) (PCL)-based composites. • The first direct connection between SH or SY and the polymer technology. • Composites' oxidative resistance enhanced by SY incorporation. • Compatibility of PCL-based composites enhanced by SY application. Beer is among the most popular beverages in the world, with the production distributed uniformly between the biggest continents, so the utilization of brewing by-products is essential on a global scale. Among their potential recipients, the plastics industry offers extensive range of potential products. Herein, the presented study investigated the application of currently underutilized solid brewing by-products (brewers' spent grain, spent hops, spent yeast) as fillers for highly-filled poly(ε-caprolactone)-based composites, providing the first direct connection between spent hops or spent yeast and the polymer composites. Comprehensive by-product characterization revealed differences in chemical composition. The elemental C:O ratio, protein content, and Trolox equivalent antioxidant capacity varied from 1.40 to 1.89, 12.9 to 32.4 wt%, and 2.41 to 10.24 mg/g, respectively, which was mirrored in the composites' structure and performance. Morphological analysis pointed to the composition-driven hydrophilicity gap limiting interfacial adhesion for high shares of brewers' spent grain and spent hops, due to high hydrophilicity induced by carbohydrate content. Phytochemicals and other components of applied by-products stimulated composites' oxidative resistance, shifting oxidation onset temperature from 261 °C for matrix over 360 °C for high spent yeast shares. Simultaneously, spent yeast also provided compatibilizing effects for poly(ε-caprolactone)-based composites, reducing complex viscosity compared to other fillers and indicating its highest affinity to poly(ε-caprolactone)due to the lowest hydrophilicity gap. The presented results indicate that the proper selection of brewing by-products and adjustment of their shares creates an exciting possibility of engineering composites' structure and performance, which can be transferred to other polymers differing with hydrophilicity. [ABSTRACT FROM AUTHOR]

Oral bone defects occur as a result of trauma, cancer, infections, periodontal diseases, and caries. Autogenic and allogenic grafts are the gold standard used to treat and regenerate damaged or defective bone segments. However, these materials do not possess the antimicrobial properties necessary to inhibit the invasion of the numerous deleterious pathogens present in the oral microbiota. In the present study, poly(ε-caprolactone) (PCL), nano-hydroxyapatite (nHAp), and a commercial extract of Humulus lupulus L. (hops) were electrospun into polymeric matrices to assess their potential for drug delivery and bone regeneration. The fabricated matrices were analyzed using scanning electron microscopy (SEM), tensile analysis, thermogravimetric analysis (TGA), FTIR assay, and in vitro hydrolytic degradation. The antimicrobial properties were evaluated against the oral pathogens Streptococcus mutans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. The cytocompatibility was proved using the MTT assay. SEM analysis established the nanostructured matrices present in the three-dimensional interconnected network. The present research provides new information about the interaction of natural compounds with ceramic and polymeric biomaterials. The hop extract and other natural or synthetic medicinal agents can be effectively loaded into PCL fibers and have the potential to be used in oral applications. [ABSTRACT FROM AUTHOR]

Polymer network materials are interesting alternatives to thermoplastic polymers. Here, the preparation of polymer capsules is investigated, which are made from poly(ε‐caprolactone) (PCL) networks and are compartmentalized in a crosslinked PCL shell and a core that is suitable to enclose payloads of interest. Aided by microfluidic templating, PCL network capsules with a narrow size distribution (176 ± 5 µm) and thin shells (≈7.5 µm) are formed from 4‐arm star‐shaped 12 kDa PCL precursors by photoinitiator‐free UV light‐induced radical polymerization of methacrylate end‐groups. FITC‐BSA is encapsulated as a model protein. The physicochemical characterization of the capsules indicated a partial crosslinking of methacrylate endgroups into netpoints. Microscopy revealed a fraction of collapsed capsules that are discussed in the context of network stability and mechanical stress created at the capsule interfaces during solvent removal. The incubation of particles with human embryonic kidney (HEK) cells showed good cell compatibility, suggesting their potential use in biosciences and beyond. [ABSTRACT FROM AUTHOR]

Recycled duck bones (DBs) and fish shells were processed into natural derivatives. Through innovative design, these natural derivatives were then combined with biocompatible polymer to create a new type of ecofriendly filament suitable for three-dimensional (3D) printing of scaffolds for bone regeneration. The DBs and fish shells were thermally processed to produce DB-derived hydroxyapatite (HA) and fish shell-derived Ca(OH)2 (TAS), respectively. Poly(ε-caprolactone) (PCL), HA, and TAS were combined and fabricated into new composite filaments, which were then transformed into scaffolds using 3D printing technology. The structure and antibacterial behaviors of the obtained composite scaffolds were studied. Alone, PCL showed no bacterial inhibition. MHA (a mix of 4, 8, 12, 16 wt%-HA and 0.8 wt% TAS) was added to PCL to form a PCL/MHA composite material, which significantly improved the functional properties of PCL and enhanced cell attachment and proliferation. The Ca(OH)2 content of TAS was responsible for the antibacterial effect. The PCL/MHA composites were porous and displayed enhanced osteoblast proliferation in vitro. The osteoblast cell population do not affected when cultured on the PCL/HA and PCL/MHA series composites according to cell cycle distribution analysis. The surfaces of the various PCL/HA and PCL/MHA composites showed elevated levels of calcium and phosphorus compounds when exposed to simulated body fluids. Calcium and phosphate ions were rapidly deposited on PCL/HA and PCL/MHA composite scaffolds in osteoblasts according to the cell mineralization assay. Our findings suggest great potential of the PCL/HA and PCL/MHA composite scaffolds in bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

In order to study the effect of nanoparticle dimensions on the thermodynamic properties of PHBV and PHBV blends, one-dimensional cellulose nanocrystals (CNC), two-dimensional graphene, and zero-dimensional hydrophobic nano-silica were selected to regulate the crystallization and mechanical properties of poly(β-hydroxybutyrate-co-valerate) (PHBV) and PHBV blends. The morphology, crystallization process, mechanical property and rheological response of PHBV nanomaterials were analyzed. Experimental results show that the three selected nanomaterials all hinder the crystallization process of PHBV, among which two-dimensional graphene exhibits the most obvious hindrance. At the same time, two-dimensional graphene can improve the tensile strength and impact strength of PHBV. However, in the rheological response of PHBV nanocomposites, zero-dimensional hydrophobic nano-silica and one-dimensional cellulose nanocrystals show more obvious regulatory effects than two-dimensional graphene. [ABSTRACT FROM AUTHOR]

Dermal substitutes bear a high clinical demand because of their ability to promote the healing process of cutaneous wounds by reducing the healing time the appearance and improving the functionality of the repaired tissue. Despite the increasing development of dermal substitutes, most of them are only composed of biological or biosynthetic matrices. This demonstrates the need for new developments focused on using scaffolds with cells (tissue construct) that promote the production of factors for biological signaling, wound coverage, and general support of the tissue repair process. Here, we fabricate by electrospinning two scaffolds: poly(ε-caprolactone) (PCL) as a control and poly(ε-caprolactone)/collagen type I (PCol) in a ratio lower collagen than previously reported, 19:1, respectively. Then, characterize their physicochemical and mechanical properties. As we bear in mind the creation of a biologically functional construct, we characterize and assess in vitro the implications of seeding human Wharton's jelly mesenchymal stromal cells (hWJ-MSCs) on both scaffolds. Finally, to determine the potential functionality of the constructs in vivo, their efficiency was evaluated in a porcine biomodel. Our findings demonstrated that collagen incorporation in the scaffolds produces fibers with similar diameters to those in the human native extracellular matrix, increases wettability, and enhances the presence of nitrogen on the scaffold surface, improving cell adhesion and proliferation. These synthetic scaffolds improved the secretion of factors by hWJ-MSCs involved in skin repair processes such as b-FGF and Angiopoietin I and induced its differentiation towards epithelial lineage, as shown by the increased expression of Involucrin and JUP. In vivo experiments confirmed that lesions treated with the PCol/hWJ-MSCs constructs might reproduce a morphological organization that seems relatively equivalent to normal skin. These results suggest that the PCol/hWJ-MSCs construct is a promising alternative for skin lesions repair in the clinic.

Background/Objectives: Hydrophobic semi-solid or liquid biodegradable polymers have shown unique advantages as injectable matrices for sustained release of a wide range of drugs. Here we report the design, synthesis, and characterization of a new low-melt liquid copolymer based on poly(ε-caprolactone) (PCL) and establish its utility as a versatile delivery platform. Methods: The copolymer, mPA20, consisting of short PCL blocks connected via acid-labile acetal linkages, was synthesized using a one-pot reaction and its properties were comprehensively characterized. Results: mPA20 is an amorphous, injectable liquid at physiological temperature and can undergo pH-sensitive hydrolytic degradation. mPA20 bearing methacrylate end groups can be photo-crosslinked into solid matrices with tunable mechanical properties. A hydrophobic fluorophore, Nile Red (NR), was solubilized in mPA20 without any solvent. Sustained release of NR into aqueous medium was achieved using mPA20, either as an injectable liquid depot or a photo-crosslinked solid matrix. Further, mPA20 self-emulsified in water to form nanodroplets, which were subsequently photo-crosslinked into nanogels. Both the nanodroplets and nanogels mediated efficient intracellular delivery of NR with no cytotoxicity. Conclusions: mPA20, a new photo-crosslinkable, hydrophobic liquid copolymer with pH-sensitive degradability, is highly adaptable as either an injectable or implantable depot or nanoscale carrier for the controlled release and intracellular delivery of poorly soluble drugs.

In recent years, the issue related to electronic waste production has been gaining prominence. One of the approaches considered to limit the impact of e-waste on the environment involves the development of biodegradable electronic devices or devices that dissolve in the environment at the end of their life cycle. In this study, we present the preliminary results related to the creation of a sensor that could meet both criteria. The device was constructed using a composite material obtained by impregnating a membrane of polycaprolactone (a biodegradable polymer) with 1-Ethyl-3-Methylimidazolium tetrafluoroborate (a water-soluble ionic liquid), which was coated with a conductive silver-based varnish. Leveraging the piezoionic effect, the device has been proven to function as a vibration sensor with a sensitivity of approximately 1.9 × 10−5 V/mm and a resolution of about 0.15 mm. [ABSTRACT FROM AUTHOR]

Poly(ε-caprolactone) (PCL) and poly(δ-valerolactone) (PVL) are aliphatic polyesters that can generally be used for basic medical materials such as bone and dental implant materials, drug delivery systems, and scaffolds in tissue engineering. PCL and PVL belong to the polylactone group which have superior properties such as good biocompatibility, nontoxicity, flexibility, thermoplastic and can be biodegraded in a controlled manner. These superior properties make it the main choice in producing medical materials. This study aims to determine the degree of polymerization of PCL and PVL catalyzed using a bis(β-diketonate)zirconium(IV) complex. In addition, analysis of the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) was also carried out on the catalyst complex. The ring-opening polymerization reaction (ROP) of ε-caprolactone (ε-CL) and δ-valerolactone (δ-VL) lasted for 4 h at 100 °C. The resulting PCL and PVL were then characterized for their chemical and thermal properties using FTIR, 1HNMR, XRD, DTA and TGA. Both PCL and PVL are semicrystalline. On the other hand, the resulting PCL has a melting point of 65.5 °C, with a degree of polymerization (DP) of 17. Meanwhile, the resulting PVL has a melting point of 63.4 °C with a DP of 8. [ABSTRACT FROM AUTHOR]

In this work, the effectiveness of seven commercial compatibilizers is tested in polylactide (PLA)/poly(ε‐caprolactone) (PCL) blends with different compositions to obtain a high‐impact PLA. None of the compatibilizers is effective for 90/10 and 80/20 PLA/PCL compositions, as no improvement of the impact strength is observed. For the 70/30 composition, compatibilizers having glycidyl methacrylate (GMA) and acrylate groups in their structure are proved the most effective, as the morphological change towards co‐continuity induced by them leads to significant impact strength improvements (of ≈345% and 90% with respect to the neat PLA and the noncompatibilized PLA/PCL 70/30 blend, respectively). The 70/30 PLA/PCL composition, as it shows the best balance of properties, and the best compatibilizer (ElvaloyPTW) are chosen to carry out the optimization of the compatibilizer content. It is found that adding 6 phr to the blend results in highly toughened and ductile blends while maintaining a high modulus and yield strength values. Larger compatibilizer contents lead to even higher impact strength values, but the low‐strain mechanical properties are notably reduced. Thus, in this work, a simple and easily scalable method to produce high‐impact PLA is shown, as it implies the compounding of three commercially available components without involving any toxic solvents. [ABSTRACT FROM AUTHOR]

The effect of hollow glass beads on poly(ε-caprolactone) (PCL) oxidative degradation has been evaluated by the non-isothermal chemiluminescence (CL) method and thermogravimetry analysis (TGA). The main goal of the research and this publication was to reduce the production costs associated with the materials for 3D printing, which would also have a low mass, excellent biocompatibility and suitable thermal properties. Experiments have clearly shown the dual effect of a filler and its extent in terms of poly(ε-caprolactone). The chosen methods demonstrate the superposition of both the pro-degradation and stabilization effects of hollow glass beads on the polymer. The former was evident above the load of 10 wt.% of filler. The non-isothermal TGA records were analyzed as being composed of three temperature-dependent processes of the first-order kinetics. A massive compensation effect between the so-called activation energy and the logarithm of pre-exponential factors for heating rates of 2.5, 5 and 10 °C/min has been shown to be typical for similar non-isothermal thermogravimetry evaluation. [ABSTRACT FROM AUTHOR]

The need for effective artificial skin as a substitute for damaged skin in chronic wound therapy is recently growing. Poly(ε-caprolactone) (PCL) has been identified as a potential material for artificial skin scaffolds due to its exceptional mechanical properties and biocompatibility. However, PCL lacks sufficient bioactivity, necessitating the introduction of bioactive molecules to scaffolds. Human umbilical cord blood serum (UCBS) and platelet-rich plasma (PRP), rich in bioactive molecules, are promising coating materials for PCL-based scaffolds. Therefore, this research aimed to investigate the effect of UCBS and PRP coatings on the mechanical properties, cytotoxicity, and cell attachment ability of PCL scaffolds. Scaffolds prepared through glutaraldehyde-mediated cross-linking of 20% (w/v) PCL followed by freeze-drying were immersed with UCBS or PRP overnight. Coating scaffolds with UCBS generated a significantly lower Young's modulus (0.20 MPa) compared to non-coated counterparts (0.27 MPa), while PRP-coated scaffolds showed no substantial change (0.24 MPa). Both UCBS and PRP coatings significantly increased (p < 0.05) the viability and attachment of primary human fibroblast cells on scaffolds, showing the potential to enhance PCL cytocompatibility for artificial skin. [ABSTRACT FROM AUTHOR]

In this study, the effects of poly(ε-caprolactone) (PCL) molecular weight and the type and presence of nanosilica on the non-isothermal crystallization behavior of PCL in the PCL/poly(styrene-co-acrylonitrile) (SAN)/nanosilica systems have been quantitatively investigated. The PCL/SAN system have been chosen as an ideal model system because of the special phase behavior of the blends, which include a lower-critical solution temperature (LCST) phase diagram over a virtual upper-critical solution temperature. By this choose, the great importance of phase separation, mutual phase dissolution and preferential nanoparticle migration to one of the polymeric phases on the crystallization behavior during a commercial production process has been highlighted. The addition of both hydrophilic (Si) and hydrophobic (SiR) silica nanoparticles to virgin PCLs with different molecular weights retards the crystallization process. However, the presence of these nanoparticles in PCL/SAN blends impacts the PCL crystallization kinetics in opposite ways, depending on the nanosilica type, PCL molecular weight and melt cooling rate. The reasons for the observed opposite trends are the changes in the LCST-type phase diagram position by altering the PCL molecular weight and nanosilica type, the selective migration of nanoparticles as well as the dispersion state of nanofillers. The presence of both Si and SiR nanosilicas increases the crystallization activation energy, respectively, by 4.2% and 2.4% for the PCL/SAN blend conatining the PCL with lower molecular weight. While the addition of both Si (11%) and SiR (6.7%) reduces this energy for the blend conatining the PCL with higher molecular weight.

Abstract In this work, the effectiveness of seven commercial compatibilizers is tested in polylactide (PLA)/poly(ε‐caprolactone) (PCL) blends with different compositions to obtain a high‐impact PLA. None of the compatibilizers is effective for 90/10 and 80/20 PLA/PCL compositions, as no improvement of the impact strength is observed. For the 70/30 composition, compatibilizers having glycidyl methacrylate (GMA) and acrylate groups in their structure are proved the most effective, as the morphological change towards co‐continuity induced by them leads to significant impact strength improvements (of ≈345% and 90% with respect to the neat PLA and the noncompatibilized PLA/PCL 70/30 blend, respectively). The 70/30 PLA/PCL composition, as it shows the best balance of properties, and the best compatibilizer (ElvaloyPTW) are chosen to carry out the optimization of the compatibilizer content. It is found that adding 6 phr to the blend results in highly toughened and ductile blends while maintaining a high modulus and yield strength values. Larger compatibilizer contents lead to even higher impact strength values, but the low‐strain mechanical properties are notably reduced. Thus, in this work, a simple and easily scalable method to produce high‐impact PLA is shown, as it implies the compounding of three commercially available components without involving any toxic solvents.

Despite their popularity and multiplicity of applications, wood–polymer composites (WPCs) still have to overcome particular issues related to their processing and properties. The main aspect is the compatibility with plant-based materials which affects the overall performance of the material. It can be enhanced by strengthening the interfacial adhesion resulting from physical and/or chemical interactions between the matrix and filler, which requires introducing a compatibilizer or a proper modification of one or both phases. Herein, the impact of cellulose filler modifications with varying contents (1–10 wt%) of hexamethylene diisocyanate (HDI) on the compatibility of Mater-Bi/poly(ε-caprolactone) (PCL)-based biocomposites was evaluated. An analysis of surface wettability revealed that the filler modification reduced the hydrophilicity gap between phases, suggesting compatibility enhancement. It was later confirmed via microscopic observation (scanning electron microscopy (SEM) and atomic force microscopy (AFM)), which pointed to the finer dispersion of modified particles and enhanced quality of the interface. The rheological analysis confirmed increased system homogeneity by the reduction in complex viscosity. In contrast, thermogravimetric analysis (TGA) indicated the efficient modification of filler and the presence of the chemical interactions at the interface by the shift of thermal decomposition onset and the changes in the degradation course. [ABSTRACT FROM AUTHOR]

Electrospun nanofibers have been applied as a new technology for gas indicators in food intelligent packaging. A poly(ε-caprolactone) (PCL)/red cabbage anthocyanin (RCA)-based nanofiber volatile amines gas indicator was developed by applying a bi-solvent of acetic acid (AA) and formic acid (FA) in electrospinning. The visibility of color change was improved from pink to blue, compared to blue to yellow-green, when using a single solvent of AA. The solutes of PCL (12.5, 15, 17.5, and 20%) and RCA (10, 20, 30, and 40%) and the solvents of AA/FA (9:1, 7:3, 5:5, 3:7, and 1:9) were applied in electrospinning under the condition of 12.5 cm, 1.0 mL/h, and 20 kV. The optimal microstructure with the thinnest fiber diameter and constant arrangement without forming NF beads appeared under the 7:3 FA/AA, 15% PCL, and 20% RCA condition. The indicator changed from pink to blue with the values of total color change (ΔE) of 10, 14, and 18 when exposed to the saturated gas of ammonia solutions of 8, 80, and 800 mM, respectively. The indicator was stable and unchanged in color for 28 days when exposed to light at room temperature. In the application to mackerel packaging, the built-in indicator changed from pink to purple regardless of storage temperature when the spoilage point was reached. [ABSTRACT FROM AUTHOR]

A common industrial byproduct known as hydrogen peroxide, which is an essential intermediate, is associated with oxidative damage to brain cells and a number of neurodegenerative disorders. Although catalases are enzymes capable of decomposing hydrogen peroxide into water and oxygen, the low stability of free enzymes limits their industrial use. In the current study, poly(ε‐caprolactone)/polyethyleneimine nanofibers were fabricated using the electrospinning process and catalase was subsequently immobilized via coordination of Cu2+ ions. The characterization of the catalase‐immobilized nanofibers and their catalytic activity for hydrogen peroxide decomposition was evaluated by comparing the free catalase. The studies conducted in the pH range of 5.0–8.5 revealed that the catalase‐immobilized nanofibers had their highest levels of enzyme activity at pH 7.0. When compared to free catalase, it was shown that the thermal stability and storage stability of catalase‐immobilized nanofibers were significantly improved. Catalase‐immobilized nanofibers showed significant reusability, where activity was maintained by around 60% after five repeating cycles. The findings showed that catalase‐immobilized PCL/PEI‐Cu2+ nanofibers had a high potential for various industrial applications as a substitute for the existing techniques. [ABSTRACT FROM AUTHOR]

Poly(ε-caprolactone) (PCL) is a hydrophobic, resorbable aliphatic polymer recognized for its low tenacity and extensive elongation at break, making it a popular choice for fabricating biodegradable tissue engineering scaffolds. PCL's slow degradation rate typically results in a complete resorption period of 2 to 3 years. While numerous studies have examined the degradation of PCL in various forms such as films and webs, no study to date has investigated its physiological degradation in multifilament yarn form. In this study, we subjected PCL multifilament yarn samples to physiological conditions in phosphate-buffered saline (PBS) maintained at a consistent temperature of 37 ± 2 °C and agitated at 45 rpm for a period of 32 weeks. We retrieved samples at five different intervals to analyze the degradation profile of the multifilament yarn. This allowed us to estimate the complete resorption time and rate under these in vitro conditions. Over the 32-week period, the multifilament yarn's mass decreased by 4.8%, its elongation at break declined by 42%, the tenacity dropped by 40%, and the peak load at break fell by 46.5%. Based on these findings, we predict that a scaffold structure incorporating PCL multifilament yarn would undergo complete resorption in approximately 14 months under physiological conditions, such as in PBS solution at a pH of approximately 7 and a temperature of 37 °C. [ABSTRACT FROM AUTHOR]

In this study, we report the development of a micellar system based on a poly(methacrylic acid)-b-poly(ε-caprolactone)-b-poly(methacrylic acid) triblock copolymer (PMAA16-b-PCL35-b-PMAA16) for the oral delivery of resveratrol. The micellar nanocarriers were designed to comprise a PCL core for solubilizing the poorly water-soluble drug and a hydrated PMAA corona with bioadhesive properties for providing better contact with the gastrointestinal mucosa. The micelles were first formed in an aqueous media via the solvent evaporation method and then loaded with resveratrol (72% encapsulation efficiency). Studies by transmission electron microscopy (TEM) and dynamic and electrophoretic light scattering (DLS and PALS) revealed a spherical shape, nanoscopic size (100 nm) and a negative surface charge (−30 mV) of the nanocarriers. Loading of the drug slightly decreased the hydrodynamic diameter (Dh) and increased the ƺ-potential of micelles. In vitro dissolution tests showed that 80% and 100% of resveratrol were released in 24 h in buffers with pH 1.2 and 6.8, respectively, whereas for the same time, not more than 10% of pure resveratrol was dissolved. A heat-induced albumin denaturation assay demonstrated the advantage of the aqueous micellar formulation of resveratrol, which possessed anti-inflammatory potential as high as that of the pure drug. Further, the micellar resveratrol (5 µM) exerted a strong protective effect and maintained viability of mucosa epithelial HT-29 cells in a co-cultural model, representing the production of inflammatory cytokines. For comparison, the pure resveratrol at the same concentration did not protect the damaged HT-29 cells at all. Thus, the present study revealed that the PMAA-b-PCL-b-PMAA copolymeric micelles might be considered appropriate nanocarriers for the oral delivery of resveratrol. [ABSTRACT FROM AUTHOR]

Due to their diverse and unique physical properties, miktoarm star copolymers (μ-SCPs) have garnered significant attention. In our study, we employed α-monobomoisobutyryl-terminated polydimethylsiloxane (PDMS-Br) to carry out styrenics-assisted atom transfer radical coupling (SA ATRC) in the presence of 4-vinylbenzyl alcohol (VBA) at 0 °C. By achieving high coupling efficiency (χc = 0.95), we obtained mid-chain functionalized PDMS-VBAm-PDMS polymers with benzylic alcohols. Interestingly, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis revealed the insertion of only two VBA coupling agents (m = 2). Subsequently, the PDMS-VBA2-PDMS products underwent mid-chain extensions using ε-caprolactone (ε-CL) through ring-opening polymerization (ROP) with an efficient organo-catalyst at 40 °C, resulting in the synthesis of novel (PDMS)2-μ-(PCL)2 μ-SCPs. Eventually, novel (PDMS)2-μ-(PCL)2 μ-SCPs were obtained. The obtained PDMS-μ-PCL μ-SCPs were further subjected to examination of their solid-state self-assembly through small-angle X-ray scattering (SAXS) experiments. Notably, various nanostructures, including lamellae and hexagonally packed cylinders, were observed with a periodic size of approximately 15 nm. As a result, we successfully developed a simple and effective reaction combination (Є) strategy (i.e., SA ATRC-Є-ROP) for the synthesis of well-defined PDMS-μ-PCL μ-SCPs. This approach may open up new possibilities for fabricating nanostructures from siloxane-based materials. [ABSTRACT FROM AUTHOR]

Hydrophilic chitosan (CHT) and hydrophobic polyε‐caprolactone (PCL) are well‐known biocompatible and biodegradable polymers that have many applications in the biomedical and pharmaceutical fields. But the mixtures of these two compounds are considered incompatible, which makes them not very interesting. To avoid this problem and to further extend the properties of these homopolymers, the synthesis of a new graft copolymer, the fully biodegradable amphiphilic poly(ε‐caprolactone‐g‐chitosan) (PCL‐g‐CHT) is described, with an unusual "reverse" structure formed by a PCL backbone with CHT grafts, unlike the "classic" CHT‐g‐PCL structure with a CHT main chain and PCL grafts. This copolymer is prepared via a copper‐catalyzed 1,3‐dipolar Huisgen cycloaddition between propargylated PCL (PCL‐yne) and a new azido‐chitosan (CHT‐N3). In order to obtain an amphiphilic copolymer regardless of the pH, chitosan oligomers, soluble at any pH, are prepared and used. The amphiphilic PCL‐g‐CHT copolymer spontaneously self‐assembles in water into nanomicelles that may incorporate hydrophobic drugs to give novel drug delivery systems. [ABSTRACT FROM AUTHOR]

The present study describes the development of novel block copolymer nanocarriers of the phytocannabinoid cannabidiol (CBD), designed to enhance the solubility of the drug in water while achieving high encapsulation efficiency and prolonged drug release. Firstly, a well-defined amphiphilic block copolymer consisting of two outer hydrophilic polyglycidol (PG) blocks and a middle hydrophobic block of poly(ε-caprolactone) bearing pendant cinnamyl moieties (P(CyCL-co-CL)) were synthesized by the click coupling reaction of PG-monoalkyne and P(CyCL-co-CL)-diazide functional macroreagents. A non-modified polyglycidol/poly(ε-caprolactone) amphiphilic block copolymer was obtained as a referent system. Micellar carriers based on the two block copolymers were formed via the solvent evaporation method and loaded with CBD following two different protocols—loading during micelle formation and loading into preformed micelles. The key parameters/characteristics of blank and CBD-loaded micelles such as size, size distribution, zeta potential, molar mass, critical micelle concentration, morphology, and encapsulation efficiency were determined by using dynamic and static multiangle and electrophoretic light scattering, transmission electron microscopy, and atomic force microscopy. Embedding CBD into the micellar carriers affected their hydrodynamic radii to some extent, while the spherical morphology of particles was not changed. The nanoformulation based on the copolymer bearing cinnamyl moieties possessed significantly higher encapsulation efficiency and a slower rate of drug release than the non-modified copolymer. The comparative assessment of the antiproliferative effect of micellar CBD vs. the free drug against the acute myeloid leukemia-derived HL-60 cell line and Sezary Syndrome HUT-78 demonstrated that the newly developed systems have pronounced antitumor activity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Composites of synthetic bone mineral substitutes (BMS) and biodegradable polyesters are of particular interest for bone surgery and orthopedics. Manufacturing of composite scaffolds commonly uses mixing of the BMS with polymer melts. Melt processing requires a high homogeneity of the mixing, and is complicated by BMS-promoted thermal degradation of polymers. In our work, poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL) composites reinforced by commercial β-tricalcium phosphate (βTCP) or synthesized carbonated hydroxyapatite with hexagonal and plate-like crystallite shapes (hCAp and pCAp, respectively) were fabricated using injection molding. pCAp-based composites showed advanced mechanical and thermal characteristics, and the best set of mechanical characteristics was observed for the PLLA-based composite containing 25 wt% of pCAp. To achieve compatibility of polyesters and pCAp, reactive block copolymers of PLLA or PCL with poly(tert-butyl ethylene phosphate) (C1 and C2, respectively) were introduced to the composite. The formation of a polyester-b-poly(ethylene phosphoric acid) (PEPA) compatibilizer during composite preparation, followed by chemical binding of PEPA with pCAp, have been proved experimentally. The presence of 5 wt% of the compatibilizer provided deeper homogenization of the composite, resulting in a marked increase in strength and moduli as well as a more pronounced nucleation effect during isothermal crystallization. The use of C1 increased the thermal stability of the PLLA-based composite, containing 25 wt% of pCAp. In view of positive impacts of polyester-b-PEPA on composite homogeneity, mechanical characteristics, and thermal stability, polyester-b-PEPA will find application in the further development of composite materials for bone surgery and orthopedics. [ABSTRACT FROM AUTHOR]

Styrene – glycidyl acrylate copolymer Joncryl ADR4368 (ADR) was employed as a compatibilizer in the immiscible blends of poly(lactic acid) (PLA) and poly(ε-caprolactone) (PCL). The morphology, crystallization behavior and mechanical properties were investigated. The compatibility between PLA and PCL was poor, thus leading to poor tensile properties for PLA/PCL blends. The addition of ADR reduced the size of PCL domains due to the formation of long chain branched copolymers in the interface, indicating the improved compatibility of PLA and PCL. PCL enhanced the cold crystallization ability of PLA, while ADR delayed the cold crystallization ability of PLA. Compared with PLA/PCL blends, PLA/PCL/ADR obtained a more uniform microcrystalline dispersion during cooling. Therefore, when the PCL content was 30 wt%, the elongation at break and impact strength of PLA/PCL/ADR were effectively improved at 1 wt% ADR. [ABSTRACT FROM AUTHOR]

Skin, as the largest and one of the most vital organs of the human body, which is subject to damage more than other tissues, consists of three main layers: epidermis, dermis, and hypodermis. Tissue engineering and biomaterials as cell support can be used to regenerate the damaged parts of skin. In the present study, a three-layer scaffold was made for biomimicking the native skin tissue and accelerating wound healing. Poly(ε-caprolactone)/zinc oxide nanoparticles as porous polymer nanocomposite containing 0, 5, 10 and 15 wt.% zinc oxide nanoparticles prepared in two layers using solvent casting/salt leaching method. The third layer of chitosan as the external membrane was added by sodium hydroxide cross-linking agent on the previous two layers. The phase structure, chemical functional group, and morphology of the prepared scaffolds were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), respectively. To evaluate the mechanical properties, the prepared scaffolds were subjected to compressive strength test. The obtained results showed that the porosity of the three-layered scaffolds was partially changed in a gradient behavior. The structural integrity, morphological cohesion, and compressive strength of the scaffolds with 5 wt.% zinc oxide nanoparticles in which the cross-linking agent was used to add the chitosan membrane were significantly higher than the other prepared scaffolds. [ABSTRACT FROM AUTHOR]

The development of new biodegradable biomaterials with osteoconductive properties for bone tissue regeneration is one of the urgent tasks of modern medicine. In this study, we proposed the pathway for graphene oxide (GO) modification with oligo/poly(glutamic acid) (oligo/poly(Glu)) possessing osteoconductive properties. The modification was confirmed by a number of methods such as Fourier-transform infrared spectroscopy, quantitative amino acid HPLC analysis, thermogravimetric analysis, scanning electron microscopy, and dynamic and electrophoretic light scattering. Modified GO was used as a filler for poly(ε-caprolactone) (PCL) in the fabrication of composite films. The mechanical properties of the biocomposites were compared with those obtained for the PCL/GO composites. An 18–27% increase in elastic modulus was found for all composites containing modified GO. No significant cytotoxicity of the GO and its derivatives in human osteosarcoma cells (MG-63) was revealed. Moreover, the developed composites stimulated the proliferation of human mesenchymal stem cells (hMSCs) adhered to the surface of the films in comparison with unfilled PCL material. The osteoconductive properties of the PCL-based composites filled with GO modified with oligo/poly(Glu) were confirmed via alkaline phosphatase assay as well as calcein and alizarin red S staining after osteogenic differentiation of hMSC in vitro. [ABSTRACT FROM AUTHOR]

Lung cancer ranks second position among the cancer-related deaths. Osimertinib mesylate (OSM) is a tyrosine-kinase-inhibitor which can effectively treat non-small cell lung cancer (NSCLC), but still there are certain limitations and side effects which could be circumvented by polymeric nanoparticles approach. Hence, this research was aimed to develop drug-loaded biodegradable polycaprolactone nanoparticles (PCL-NPs) such as OSM-loaded PCL-NPs (PCL-OSM-NPs) and chitosan fabricated OSM-loaded PCL-NPs (CS-PCL-OSM-NPs) to achieve active-targeting of OSM in the cancerous lung tissue. Thus, CS-PCL-OSM-NPs enhance the anticancer efficacy due to active targeting nature and thereby reduces off-target side effects of OSM in the NSCLC treatment. Blank PCL-NPs, PCL-OSM-NPs, and CS-PCL-OSM-NPs were prepared by nanoprecipitation method. Optimized blank PCL-NPs, PCL-OSM-NPs, and CS-PCL-OSM-NPs exhibited the mean particle size of 90.2 ± 4.7 nm, 167.7 ± 2.9 nm, and 233.7 ± 4.8 nm respectively. The encapsulation efficiency % (%EE) of PCL-OSM-NPs was found to be 68.4 ± 3.2%. In vitro drug release study demonstrated sustained release profile of 69.5 ± 5% and 65.7 ± 1.5% for OSM from both the PCL-OSM-NPs and CS-PCL-OSM-NPs, respectively. The PCL-OSM-NPs and CS-PCL-OSM-NPs demonstrated the inhibition of 82.2 ± 0.5% and 81.9 ± 0.2% in A549 cancer cells respectively which clearly signified the improved efficacy. Moreover, the PCL-OSM-NPs and CS-PCL-OSM-NPs exhibited significantly less hemolysis than OSM indicating safety of the formulation. These findings indicate that biohemocompatible CS-PCL-OSM-NPs is an attractive option to treat NSCLC with enhanced anticancer activity and reduced side effects. [ABSTRACT FROM AUTHOR]

In order to obtain the novel poly(ε-caprolactone) (PCL) cross-linked networks with good shape memory properties, the cross-linked networks of PCL with different molecular weights were prepared by thiol-ene click chemistry method, and its microstructure, thermal properties, mechanical properties and shape memory properties were characterized. The results show that the hydroxyl end of PCL was successfully converted to acrylate-terminated PCL, and almost all the samples show perfect cross-linked network, and the cross-linked polymer has a thermally induced shape memory effect; with the increase of the molecular weight of PCL diol, the melting temperature and crystallinity of the cross-linked network also show an upward trend; the molecular weight of PCL diol has a certain influence on its fixation ability, but regardless of the length of PCL diol, the shape recovery rate of all samples can reach more than 90%. The efficient thiol-ene click chemistry reaction ensures the uniform distribution of PCL chains between cross-linked nodes, the cross-linked network has good network structure, good mechanical and shape memory properties. The exploration of new PCL cross-linked network provides a feasible way for the end functionalization of polymers.

Carotid endarterectomy (CEA) with patch angioplasty is the most effective treatment for carotid artery stenosis. However, the use of existing vascular patches is often associated with thrombosis, restenosis, calcification and other complications.Objective: to develop biodegradable patches for arterial reconstruction, containing vascular endothelial growth factor (VEGF) or arginyl-glycyl-aspartic acid (RGD), and comparatively evaluate their biocompatibility and efficacy in in vitro experiments and during preclinical trials in large laboratory animal models.Materials and methods. Biodegradable patches, made from a mixture of poly(3-hydroxybutyrate-co-3- hydroxyvalerate (PHBV) and poly(ε-caprolactone) (PCL), were fabricated by electrospinning and modified with VEGF or the peptide sequence RGD in different configurations. In in vitro experiments, the surface structure, physicomechanical and hemocompatibility properties were evaluated. In in vivo experiments, we evaluated the effectiveness of the developed vascular patches for 6 months after implantation into the carotid artery of 12 sheep. The quality of remodeling was assessed using histological and immunofluorescence studies of explanted specimens.Results. The PHBV/PCL/VEGF patches had physicomechanical characteristics closer to those of native vessels and their biofunctionalization method resulted in the smallest drop in strength characteristics compared with their unmodified PHBV/PCL counterparts. Modification with RGD peptides reduced the strength of the polymer patches by a factor of 2 without affecting their stress-strain behavior. Incorporation of VEGF into polymer fibers reduced platelet aggregation upon contact with the surface of the PHBV/PCL/VEGF patches and did not increase erythrocyte hemolysis. At month 6 of implantation into the carotid artery of sheep, the PHBV/PCL/ VEGF patches formed a complete newly formed vascular tissue without signs of associated inflammation and calcification. This indicates the high efficiency of the VEGF incorporated into the patch. In contrast, the patches modified with different configurations of RGD peptides combined the presence of neointimal hyperplasia and chronic granulomatous inflammation present in the patch wall and developed during bioresorption of the polymer scaffold.Conclusion. PHBV/PCL/VEGF patches have better biocompatibility and are more suitable for vascular wall reconstruction than PHBV/PCL/RGD patches.