Search Results (135)

Bioabsorbable scaffolds from synthetic polyesters are widely used in the field of tissue engineering. However, their hydrophobic surface and lack of suitable functional groups are the main limitations related to cell attachment. The aim of this research was to modify the surface of polycaprolactone (PCL) scaffolds using a bioactive coating containing heparin bound via albumin spacer and platelet lysate over heparin. Porous scaffolds were produced by electrospinning from 10% PCL (w/w) solution in methylene chloride (25 kV voltage, 100 mm distance between electrodes and 4 mL/h feedrate), which demonstrated 5.5 ± 1.1 MPa Young’s modulus, 2.5 ± 0.4 MPa tensile strength and 321 ± 29% elongation at break. Bioactive coating does not change the structure and mechanical properties of the scaffolds. Treated scaffolds are biocompatible and have no cytotoxic effect in direct contact with cells. Functionalization also promotes the in vitro adhesion and proliferation of human adipose mesenchymal stromal cells. After 7 days of incubation, the PCL scaffold modified with the heparin–platelet lysate complex had a cell density of 185.6 ± 15.7 cells/mm² compared to 79.5 ± 7.8 cells/mm² for nontreated control. The intramuscular implantation of scaffolds revealed that immobilization of heparin alone prolongs the acute phase of the inflammatory reaction. However, subsequent treatment with platelet lysate minimizes the inflammatory reaction, slows the rate of implant absorption, and accelerates vascularization. The results obtained show that the developed bioactive coating improves the cellular properties of PCL electrospun scaffolds and can be used to form in vivo tissue-engineered constructs. Full article

The utilization of encapsulated biopharmaceuticals, including peptides and proteins, has grown substantially in recent years. In this study, the influence of aliphatic polyester physicochemical properties, specifically crystallinity and hydrophobicity, on the development of protein-loaded microparticles was investigated. A series of polyesters, namely amorphous PDLLA and semicrystalline PLLA, PCL, and PPDL, were synthesized via chemical and enzymatic ring-opening polymerization. Bovine serum albumin (BSA)-loaded microparticles were fabricated using a water-in-oil-in-water (w/o/w) double emulsion solvent evaporation method. The size of microparticles obtained was determined by scanning electron microscopy and dynamic light scattering methods. The enzymatic degradation of the polymer microparticles was assessed through incubation in a lipase-containing buffer solution. BSA and α-chymotrypsin (ACHT) were used as model proteins for the preparation of encapsulated polymer microspheres and comparison of their characteristics and properties. Protein encapsulation efficacy, release rate, and enzyme activity retained after encapsulation were evaluated and compared for selected aliphatic polyesters. The release profiles were processed with the use of various mathematical models to reveal the possible mechanism(s) of protein release. Full article

A chemical platform for post-polymerization methods was developed, starting from the ecodesign and enzymatic synthesis of safe and sustainable bio-based polyesters containing discrete units of itaconic acid. This unsaturated bio-based monomer enables the covalent linkage of molecules that can impart desired properties such as hydrophilicity, flexibility, permeability, or affinity for biological targets. Molecular descriptor-based computational methods, which are generally used for modeling the pharmacokinetic properties of drugs (ADME), were employed to predict in silico the hydrophobicity (LogP), permeability, and flexibility of virtual terpolymers composed of different polyols (1,4-butanediol, glycerol, 1,3-propanediol, and 1,2-ethanediol) with adipic acid and itaconic acid. Itaconic acid, with its reactive vinyl group, acts as a chemical platform for various post-polymerization functionalizations. Poly(glycerol adipate itaconate) was selected because of its higher hydrophilicity and synthetized via solvent-free enzymatic polycondensation at 50 °C to prevent the isomerization or crosslinking of itaconic acid. The ecotoxicity and marine biodegradability of the resulting oligoester were assessed experimentally in order to verify its compliance with safety and sustainability criteria. Finally, the viability of the covalent linkage of biomolecules via Michael addition to the vinyl pendant of the oligoesters was verified using four molecules bearing thiol and amine nucleophilic groups: N-acetylcysteine, N-Ac-Phe-ε-Lys-OtBu, Lys-Lys-Lys, and glucosamine. Full article

Agricultural and food by-products offer valuable opportunities for circular and bio-based innovation across sectors. In the textile industry, replacing fossil-based coatings with sustainable alternatives is increasingly urgent. This study evaluates the performance of a textile coating based on coffee silverskin (CS)—an abundant by-product of coffee roasting—applied to four natural fibre substrates: cotton, lyocell, wool, and silk. A formulation combining 60% CS sludge (8% solids), treated by wet ball milling, with an aliphatic polyester-polyurethane dispersion was applied via knife coating. Standardised tests assessed mechanical resistance, air permeability, colour fastness, moisture management, and water repellency, including contact angle and drop absorption analyses. Results revealed that all substrates were compatible with the CS-based coating, which reduced air permeability and increased hydrophobicity. Notably, silk showed the most significant functional enhancement, transitioning from hydrophilic to waterproof with increased durability—indicating strong potential for technical applications such as outerwear and performance textiles. Given the renewable origin of both the substrate and coating, this study highlights the feasibility of valorising agri-food waste in high-performance, bio-based textile systems. These findings demonstrate the potential of CS as a bio-based coating for technical textiles, supporting the development of high-performance and sustainable materials within the textile industry. Full article

This study investigates the surface properties of bio-based unsaturated polyester resin (b-UPR) nanocomposites reinforced with biosilica nanoparticles derived from rice husk. The b-UPR matrix was synthesized from recycled polyethylene terephthalate (PET) and renewable monomers, providing a sustainable alternative to conventional polyester resins. Unmodified and modified biosilica particles with silanes: (3-trimethoxysilylpropyl methacrylate—MEMO, trimethoxyvinylsilane—VYNIL, and 3-aminopropyltrimethoxysilane with biodiesel—AMBD) were incorporated in different amounts to evaluate their influence on the wettability, topography, and viscoelastic behavior of the composites. Contact angle measurements revealed that the addition of modified biosilica significantly improved the hydrophobicity of the b-UPR surface. The greatest increase in the wetting angle, amounting to 79.9% compared to composites with unmodified silica, was observed in the composites containing 5 wt.% SiO₂-AMBD. Atomic force microscopy (AFM) analysis indicated enhanced surface roughness and uniform dispersion of the nanoparticles. For the composite containing 1 wt.% of silica particles, the surface roughness increased by 25.5% with the AMBD modification and by 84.2% with the MEMO modification, compared to the unmodified system. Creep testing demonstrated that the reinforced nanocomposites exhibited improved dimensional stability under sustained load compared to the neat resin. These findings confirm that the integration of surface-modified biosilica not only enhances the mechanical properties but also optimizes the surface characteristics of bio-based polyester composites, broadening their potential for high-performance and sustainable applications. Full article

This study investigates the adsorption behavior of 4-methylbenzylidene camphor (4-MBC), a persistent ultraviolet filter, onto microplastic fibers (MPFs) released from domestic textiles, under environmentally relevant conditions. Two types of MPFs were used: MPF A, a heterogeneous blend of synthetic and natural fibers, and MPF B, a uniform polyester source. Adsorption experiments were conducted in municipal wastewater, Danube River surface water, and laundry effluent. Kinetic data best fit the pseudo-second-order model (R² > 0.95), and the Elovich model indicated chemisorption involving heterogeneous binding sites. MPF A exhibited superior adsorption capacities (qₑ = 85.4–90.1 µg/g) compared to MPF B (58.8–66.8 µg/g). Langmuir isotherms yielded maximum adsorption capacities of 204.9 µg/g for MPF A and 116.7 µg/g for MPF B (R² = 0.929–0.977), while D–R isotherm energies (12.0–21.7 kJ/mol) confirmed specific interactions, such as π–π stacking and hydrogen bonding. Adsorption efficiency was highest in municipal wastewater (total organic carbon—TOC = 13.12 mg/L, electrical conductivity—EC = 1152 µS/cm), followed by laundry and surface waters. These findings emphasize the critical role of polymer composition and matrix complexity in pollutant transport, suggesting MPFs are effective transporters of hydrophobic micropollutants in aquatic systems. Full article

The excellent moisture transport properties of yarns play a crucial role in improving the liquid moisture transfer behavior within textiles and maintaining their thermal-wet comfort. However, the current research on the moisture management performance of fabrics made from yarns with excellent liquid transport properties primarily compares the wicking results, without considering the varying requirements of testing conditions due to differences in human sweating rates during daily activities. Moreover, the understanding of moisture transport mechanisms in yarns within fabrics under different testing conditions remains insufficient. In this study, two types of twisted combination yarns, composed of hydrophobic profiled polyester filaments and hydrophilic spun yarns to form a hydrophobic-hydrophilic gradient along the axial direction of the yarn, were developed and compared with profiled polyester filaments to understand the liquid migration behaviors in the knitted fabrics formed by these yarns. Results showed that hydrophobic profiled polyester filament yarn demonstrated superior liquid transport performance with infinite saturated liquid supply (vertical wicking test). In contrast, the twisted combination yarns exhibited better moisture diffusion properties under limited liquid droplet supply conditions (droplet diffusion test and moisture management test). These contradictory findings indicated that the amount of liquid moisture supply in testing conditions significantly affected the moisture transport performance of yarns within fabrics. It was revealed that the liquid moisture in the twisted combination yarns migrated through capillary wicking for moisture transfer. Under an infinite saturated liquid supply condition, the higher the content of hydrophilic fibers in the spun yarns, the greater the amount of moisture transferred, demonstrating an excellent liquid transport performance. Under the limited liquid droplet supply conditions, both the volume of liquid water and the moisture absorption capacity of the yarn jointly influence internal moisture migration within the yarn. It provided a theoretical reference for testing the internal moisture wicking performance of fabrics under different states of human sweating. Full article

The inherent hydrophobic nature of PVDF material renders it challenging to establish a stable aqueous hydration layer, thereby limiting its suitability as a substrate for the preparation of nanofiltration (NF) membranes. In this study, we developed a novel modification approach that effectively enhances the hydrophilicity of PVDF substrates through the incorporation of sulfonic acid-doped polyaniline (SPANI) and hyperbranched polyester (HPE) into the PVDF casting solution, followed by cross-linking with trimesoyl chloride (TMC). The introduction of SPANI and HPE, which contain reactive polar amino and hydroxyl groups, improved the hydrophilicity of the substrate, while the subsequent cross-linking with TMC effectively anchored these components within the substrate through the covalent linking between TMC and the reactive sites. Additionally, the hydrolysis of TMC yielded non-reactive carboxyl groups, which further enhanced the hydrophilicity of the substrate. As a result, the modified PVDF substrate exhibited improved hydrophilicity, facilitating the construction of an intact polyamide layer. In addition, the fabricated TFC NF membrane demonstrated excellent performance in the advanced treatment of tap water, achieving a total dissolved solid removal rate of 57.9% and a total organic carbon removal rate of 85.3%. This work provides a facile and effective route to modify PVDF substrates for NF membrane fabrication. Full article

This paper proposes a new functionalized oligosiloxane as a comonomer for polyester, designed to provide hydrophobic surface properties and enhance low-temperature impact resistance. The functionalization of polymer resin itself has attracted attention in the context of monomaterialization. Chemically designing the primary structure of not only polymers but also monomers is crucial for enhancing the intrinsic performance of the resin. However, little is known about oligosiloxane monomers for polyester that can provide oligosiloxane-like properties such as hydrophobicity and flexibility at low temperatures. Here, we report the functional design of a polyester material through silicone copolymerization. A novel comonomer was designed and synthesized to optimize both the molecular structure and the compatibility of the silicone segments, promoting uniform copolymer formation. Incorporating silicone into the polymer matrix reduced surface energy, thereby improving water repellency. Furthermore, the flexibility imparted by the silicone components effectively mitigated the brittleness of polyester at sub-zero temperatures, resulting in superior impact resistance. Structural analysis, contact angle measurements, and low-temperature impact tests were conducted on the copolymers. The results confirmed that optimizing comonomer design enables significant enhancement of both hydrophobicity and impact durability, contributing to the development of high-performance polyester materials suitable for demanding environments. Full article

This review article focuses on providing an accumulated knowledge on state-of-the-art composite polymer coating technologies that are studied for corrosion protection. A specific focus has been given to epoxy resin-based composite systems, considering their wide use due to remarkable chemical resistance, excellent adhesion to substrate, thermal stability, and mechanical strength. The addition of various functional polymers to the epoxy matrix has spurred significant advancements in the prevention of corrosion. Light has been shed on the epoxy resin composite systems that are produced by blending with functional polymers like conductive polymers, hydrophobic polymers, etc., and nanofillers. In many cases, the formation of a passive layer at the metal/polymer interface was aided by the addition of such a functional polymer and nanofiller to the epoxy matrix. As a result, corrosive ions are prevented from penetrating by the physical barrier that composite coatings provide. Comparable blends of epoxy and polyamide, epoxy and polyester, and epoxy/poly(vinyl alcohol) and epoxy/polyurethane have superior adhesion, wear, barrier, and anticorrosion properties due to the fine dispersion of nanocarbon and inorganic nanoparticles. The several strategies used to prevent metals from corroding are covered in this review article. Full article

Common antibiotic therapies to treat bacterial infections are associated with systemic side effects and the development of resistance, directly connected to duration and dosage. Local drug delivery systems (DDSs) offer an alternative by localising antibiotics and thereby limiting their side effects while reducing the dosage necessary. A biodegradable polyester polycaprolactone (PCL)-based DDS was thus produced, containing various clinically relevant drugs. It was shown that the incorporation of four distinct antibiotic classes (amoxicillin, doxycycline, metronidazole and rifampicin), with very high mass fractions ranging up to 20 wt%, was feasible within the PCL matrix. This DDS showed the capacity for effective and sustained release. The release kinetics over 14 days were proven, showing a significant decrease in cytotoxicity with smooth muscle cells as well as an antibacterial effect on (1) aerobic, (2) anaerobic, (3) Gram-positive and (4) Gram-negative pathogens in vitro. The DDS demonstrated a markedly diminished cytotoxic impact owing to sustained release in comparison to pure antibiotics, while simultaneously maintaining their antibacterial efficacy. In conclusion, DDSs are a more tolerable form of antibiotics administration due to the hydrophobic PCL matrix causing a slower diffusion-controlled release, proven as a release mechanism via the Peppa–Sahlin model. Full article

Two recombinant cutinases, AfCutA and AfCutB, derived from Aspergillus fumigatus, were heterologously expressed in Pichia pastoris and systematically characterized for their biochemical properties and polyester-degrading capabilities. AfCutA demonstrated superior catalytic performance compared with AfCutB, displaying higher optimal pH (8.0–9.0 vs. 7.0–8.0), higher optimal temperature (60 °C vs. 50 °C), and greater thermostability. AfCutA exhibited increased hydrolytic activity toward p-nitrophenyl esters (C4–C16) and synthetic polyesters. Additionally, AfCutA released approximately 3.2-fold more acetic acid from polyvinyl acetate (PVAc) hydrolysis than AfCutB. Quartz crystal microbalance with dissipation monitoring (QCM-D) revealed rapid adsorption of both enzymes onto polyester films. However, their adsorption capacity on poly (ε-caprolactone) (PCL) films was significantly higher than on polybutylene succinate (PBS) films, and was influenced by pH. Comparative modeling of catalytic domains identified distinct structural differences between the two cutinases. AfCutA possesses a shallower substrate-binding cleft, fewer acidic residues, and more extensive hydrophobic regions around the active site, potentially explaining its enhanced interfacial activation and catalytic efficiency toward synthetic polyester substrates. The notably superior performance of AfCutA suggests its potential as a biocatalyst in industrial applications, particularly in polyester waste bioremediation and sustainable polymer processing. Full article

The preparation of superhydrophobic functional materials is of great significance for applications in oil pollution control. However, the materials synthesized by traditional post-modification methods usually suffer from problems of limited active sites, uneven distribution, and susceptibility of the surface structure to external factors, which may significantly affect their superhydrophobic properties. In this study, the superhydrophobic porous organic polymer LNU-32 was successfully prepared via in situ polymerization with the introduction of green, low-surface-energy, long-alkyl-chain functional groups into the pores, which formed a “brush-like” structure on the pore surface of the polymer and effectively enhanced its hydrophobicity. The LNU-32 material exhibits excellent superhydrophobicity, with a water contact angle of more than 151°. In addition, the superhydrophobic polyester fabric prepared from LNU-32 has an oil–water separation efficiency of more than 90%. The adsorption capacity of the superhydrophobic fabric for dimethicone also reached 7.37 times its own weight. The study shows that the LNU-32 material exhibits good application potential in the field of oil–water separation, especially in the treatment of oily wastewater and oil spills. Full article

In this research, the structure, morphology, hydrophobicity and swelling behavior of a polyurethane (PU) network and its composites (PUCs) were examined. PUCs were synthesized by the incorporation of different percentages (0.5, 1 and 2 wt.%) of unmodified or surface-modified TiO₂ nanoparticles into a PU network based on polycaprolactone, aliphatic hyperbranched polyester and isophorone diisocyanate. In order to improve interfacial interactions, the surface of the TiO₂ nanoparticles was chemically modified with lauryl gallate. The impact of the presence and content of unmodified or surface-modified TiO₂ nanoparticles on the cross-sectional and surface morphology, swelling behavior and hydrophobicity of the PU network was assessed by different experiments. The obtained findings revealed that the incorporation of TiO₂ nanoparticles brought a more pronounced irregular cross-sectional and rougher surface morphology, better microphase separation, higher values of the equilibrium swelling degree in tetrahydrofuran and toluene, and altered water contact angles compared to the neat PU. Based on the collected results, the practical applicability of the prepared PUCs may be in the area of protective coatings. Full article

The growing interest in developing antibacterial textiles using natural functional agents is largely driven by their sustainable and eco-friendly attributes. Lignin, a highly available biopolymer with a polyphenolic structure, has drawn attention due to its potential as a bioactive antibacterial agent. However, its inherent heterogeneity poses challenges, particularly regarding its antibacterial efficacy. In this study, unmodified kraft lignin sourced directly from the paper industry was applied to cotton and polyester fabrics, using a knife-coating technique with varying concentrations (0%, 5%, 10%, 20%, and 30% w/v), to assess its potential as an antibacterial coating. The lignin-coated fabrics demonstrated hydrophobic properties, with water contact angles reaching up to 110.3° and 112.6°, for polyester and cotton fabrics, respectively, alongside significantly reduced air permeability and water vapor permeability indexes, regardless of lignin concentration. Antibacterial evaluations also revealed that lignin-based coatings, with at least 10% w/v concentration, allowed cotton fabrics with a bacterial reduction surpassing 96%, according to ASTM E2149-2013, particularly for Gram-positive S. aureus, highlighting the potential of lignin as an antibacterial agent. Despite their limited resistance to domestic washing, the lignin-coated fabrics demonstrated exceptional stability under hot-pressing conditions. Therefore, this stability, combined with the hydrophobic and antibacterial properties observed, particularly on coated cotton fabrics, highlights the potential application of lignin-based coatings for the development of antibacterial and water-repellent textiles, with these coatings being particularly suited for single-use applications or scenarios where washing resistance is not a requirement. This approach offers a sustainable and efficient method for producing functional textiles while enabling value-added utilization of lignin, showcasing its potential as an eco-friendly solution in textile functionalization. Full article