Macromolecular Materials and Engineering最新文献

The potential of aminoterminated hyperbranched polyglycerol (hPG-NH₂) crosslinked by polyethylene glycol dialdehyde (DA) hydrogel as a bone adhesive is presented in this proof-of-concept study. The hydrogel system, crosslinked by Schiff base bonds, is designed to degrade hydrolytically when applied internally. To elaborate the relationship between the crosslinker length and the material properties, three different DAs with different molecular masses were used, as well as glutaraldehyde, and also blends of those components. It was shown that the hydrogel's properties could be adjusted by application of these aldehydes and their mixtures. In general, the gelation time decreases with lower molecular mass of the dialdehyde crosslinker, whereas the gel strength increases. The hydrogel model adhesives lead to a bond strength of up to 800 kPA on bone substrates.

This study investigates the impact of curcumin-adsorbed ZnO nanoparticles (C-ZnO NPs) on the physical, mechanical, and antibacterial properties of kappa (κ)-carrageenan hydrogels, focusing on their potential as biocompatible materials. Microstructure analysis revealed that ZnO NPs formed needle-like structures, providing a large surface area for curcumin adsorption, with an average length of 377.24 nm and a width of 46.09 nm. Functional group analysis indicated successful adsorption of curcumin, a bioactive compound, onto ZnO NPs. Crystallographic analysis showed no significant impact of curcumin on the crystallinity of ZnO NPs. Optical absorbance analysis confirmed the formation of NPs with characteristic absorption peaks. Swelling analysis revealed that κ-carrageenan hydrogels exhibited a swelling rate of 1987.05 ± 8.28%, while C-ZnO-loaded hydrogels showed a comparable swelling rate of 1705.01 ± 2.5%. The water retention capacity analysis indicated that C-ZnO loaded hydrogels also had a comparable water retention capacity to those without NPs. Mechanical strength tests showed that C-ZnO-loaded hydrogels had a significantly higher Young's modulus (0.25353 MPa) compared to κ-carrageenan hydrogels (0.07157 MPa). Drug release kinetic modeling using the Hixson Crowell and Korsmeyer-Peppas models best described the release behavior of C-ZnO from the hydrogels across various pH levels. Cell viability studies showed high viability for both hydrogel types, indicating their potential as biocompatible materials. Antibacterial tests demonstrated the effective bacteriostatic ability of C-ZnO loaded hydrogels against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). These findings highlight the potential of curcumin-adsorbed ZnO nanoparticles incorporated into κ-carrageenan hydrogels as multifunctional biomaterials for drug delivery and therapeutic applications.

Effective recycling of polymers into valuable resources is the basis for establishing a circular economy. Whereas mechanical recycling often leads to downcycling, the concept of recycling-on-demand (ROD) has high promise. The aim is to design next-generation polymer materials that combine good material properties during use with convenient recycling abilities into higher-value building blocks at the end of use. This work targets oligomers as desired degradation products to enhance energy efficiency in degradation and re-polymerization steps. Therefore, selectively cleavable bonds are implemented into polyesters to degrade them by application of certain triggers. Poly(ester-co-acetal)s (PEAs) with model character are synthesized in a solution-based sustainable process utilizing organo-catalysis. In this approach, OH-terminated oligoesters (OEs) are bridged by acid-labile acetal groups, yielding polymeric materials that provide excellent recyclability. Two degradation-repolymerization cycles by formation and cleavage of the acetal bonds were verified by nuclear magnetic resonance spectroscopy. At the same time, size exclusion chromatography confirms the effective polymerization and selective degradation of the acetals under full retention of the polyester oligomers. Additionally, the OH number of the degraded materials is determined to ensure good stoichiometry for effective repolymerization. These combined efforts result in an impressive proof of concept for the proposed ROD principle.

Aramid fibers such as Kevlar are frequently used in protective applications due to their mechanical strength and thermal stability. However, the low surface reactivity of aramid has limited its functional modifications, particularly for enhancing water resistance, an increasingly important requirement in protective textiles. This study presents a surface functionalization approach that imparts durable hydrophobicity to Kevlar fabric. Polyacrylic acid (PAA) was used as a coupling agent to improve the adhesion of nanodiamonds (ND), including detonation (DND) and hydroxylated forms (ND-OH), to the fiber surface. Subsequent treatment with n-dodecyl tri-methoxy silane generated a robust hydrophobic finish. The PAA-DND-silane system exhibited the highest water contact angle and retained its performance after repeated washing and abrasion cycles. The enhancement in hydrophobicity was attributed to nanostructured roughness promoting a Cassie-Baxter wetting regime. Crucially, the modification did not compromise the fabric's flexibility, although it reduced the air permeability 50%. This scalable strategy offers a pathway to multifunctional aramid textiles that meet the stringent demands of modern protective gear.

Developing sustainable 3D printable materials that confer competitive mechanical properties as well as advanced properties such as shape memory has remained a challenge. To address these issues, this work investigated the incorporation of economically accessible microcrystalline cellulose reinforcing particles with itaconate surface grafting within itaconated castor oil monomer and isobornyl (meth)acrylate (IBO(M)A) reactive diluent formulations. Using itaconate surface grafted microcrystalline cellulose particles tolerated high reinforcement loading up to 10 wt.%, and yielded improved mechanical properties compared to unmodified particles. Varying the reinforcing particle loading achieved tailorable mechanical properties, while the choice of reactive diluent also led to differing mechanical properties (IBOA: E of 0.86–1.59 GPa, UTS of 14.8–24.7 MPa and IBOMA: E of 1.01–1.39 GPa, UTS of 21–27.7 MPa). Formulations up to 5 wt.% particle loading were 3D printed using masked stereolithography, achieving detailed features and intricate structures with low polymerization shrinkage. The 3D printed polymers displayed efficient shape memory behavior with thermal actuation at 100°C. This work highlights the efficacy of microcrystalline cellulose and its ease of surface modification, the potential to use itaconic acid as a sustainable source of reactive unsaturation in vat photopolymerization additive manufacturing, and that 3D printed materials with a high biobased carbon content that were also mechanically competitive and displayed shape memory capabilities could be readily achieved through facile synthetic pathways.

The United Kingdom continues to play a leading role in macromolecular materials science and engineering, where deep-rooted expertise in polymer chemistry, manufacturing, and biomedical engineering converge with urgent global needs. With increasing demand for sustainable, biocompatible, multifunctional, and digitally engineered polymeric systems, UK researchers are advancing both the theoretical foundations and applied innovations of macromolecular materials. This special collection of Macromolecular Materials and Engineering, titled “Macromolecular Materials in the UK,” brings together 19 rigorously peer-reviewed research articles and reviews authored by teams across the UK and their international collaboration partners. Each contribution represents major advances in synthesis, characterization, functionalization, and application of polymer-based materials.

Several contributions demonstrate the UK's focus on bio-based, degradable, and circular materials. Rehman et al. [mame.202400418] investigated the knife stab resistance of Bombyx mori silk cocoons, comparing entire cocoons (EC) with cocoon wall segments (CWS) through static and dynamic testing. Findings showed that ECs dissipate 95% of the kinetic energy during penetration, exhibit anisotropic and auxetic behavior, and provide greater stab resistance with smaller damage footprints than CWS. Lalegani Dezaki et al. [mame.202400276] fabricated PLA-based composites with wheat and mussel bio-fillers, exhibiting flame retardancy and shape-memory effects for 3D/4D printing applications. Kacem et al. [mame.202500067] highlighted the effective use of sulfuric acid and sodium hydroxide treatments to significantly enhance the tensile, compressive, and bending properties of yucca fibres and their epoxy-based bio-composites. Treated fibres showed improved surface morphology, crystallinity, and interfacial bonding. Bakhtiari et al. [mame.202500108] highlighted how processing sequence and compatibilization with Joncryl significantly influence the performance of PLA/PBAT blends. A two-step blending method improved interfacial adhesion, mechanical strength, and flexibility, offering promising applications in biodegradable packaging and films. Harley et al. [mame.202500129] reported the development of PA36,10, a novel biobased and recyclable thermoplastic elastomer synthesized from Priamine 1075 and sebacic acid without harmful solvents. Exhibiting excellent elasticity (1636% elongation at break), mechanical robustness, and foamability using a common blowing agent, PA36,10 offers a promising sustainable alternative for applications traditionally dominated by fossil fuel-based elastomers. Krumins et al. [mame.202500176] introduced monoperillyl maleate (PeryMal), a novel terpene-derived, photocurable monomer synthesized using green chemistry principles for sustainable stereolithography 3D printing. Blended with ACMO or bio-based iBoMA, PeryMal-based formul

Traditional wound dressings lack advanced wound-healing functionalities, with added difficulties of frequent replacements. Electrospinning is an exciting avenue for fabricating biomedical dressings with improved performance. This study presents the development of a novel electrospun nanocomposite scaffold composed of sodium alginate (SA) and polyethylene oxide (PEO), crosslinked with calcium ions and subsequently coated with bacterial cellulose (BC) for prospective wound dressing applications. A post-electrospinning dip-coating strategy was employed to preserve the structural integrity of both SA and BC, addressing limitations of traditional BC-polymer composites. SEM analysis revealed uniform, bead-free nanofibers with interconnected porosity, promoting breathability and moisture exchange. FTIR confirmed functional group retention post-coating, while DSC indicated thermal stability above physiological temperatures. Mechanical testing showed a Young's modulus of 1.99 MPa and strain-at-break of 2.27%, comparable to commercial dressings such as Aquacel Extra and Kaltostat. Coating consistency was validated through thickness analysis, with over 92% retention after aqueous immersion. Solubility tests demonstrated hydrolytic responsiveness and coating stability under moist conditions. These results highlight the scaffold's mechanical resilience, structural compatibility, and process scalability. The developed SA/PEO–BC composite presents a promising, cost-effective platform for wound care. Future investigations will explore its biological activity, antibacterial performance, and in vivo efficacy for clinical translation.

Diabetes is characterized by inadequate insulin secretion and elevated blood glucose levels, and patients require continuous insulin infusion and continuous glucose monitoring. Self-regulating insulin delivery systems, which use glucose-sensitive materials for dynamic and automatic insulin release, have been considered as a solution to alleviate these problems. In this study, poly(propylene imine) dendrimers functionalized with phenolboronic acid (PBA) are synthesized and modified to develop a glucose-sensitive system with a suitable pK_a under physiological conditions. The results showed that the pK_a of PBA decreased from ∼8 to 7.35 after attachment to the dendrimer due to the effect of the amino groups and increased acidity. Also, the equilibrium binding constant (K_eq-tet) for PBA-attached G4 dendrimer (HB-CBA) was determined to be 79 m⁻¹ by the spectral method. Dynamic light scattering (DLS) analysis confirmed the sensitivity of the system to glucose; the particle size of HB-CBA at pH 7.5 increased from 179 nm without glucose to 192 and 246 nm in the presence of 1 and 3 mg/mL glucose. The encapsulation efficiency (EE) and loading capacity (LC) were 92% and 2.3%, respectively. Insulin release was observed in a glucose-dependent manner: about 82% at 3 mg/mL, about 48% at 1 mg/mL, and 26% in glucose-free medium. These results indicate that HB-CBA is a smart and glucose-sensitive carrier that can regulate insulin release based on the glucose level and provide effective performance in self-regulating drug delivery.

The rising demand for sustainable, plant-based proteins has accelerated the development of advanced processing technologies to enhance their functionality and applicability. Among these, electrohydrodynamic (EHD) techniques—particularly electrospinning have emerged as promising tools for structuring plant proteins into nanofibers with tailored physicochemical properties. This review provides a comprehensive overview of electrospinning as applied to plant proteins, focusing on its principles, challenges, and recent advancements. The unique structural complexities of plant proteins, such as limited solubility, low chain entanglement, and globular conformations, hinder their direct electrospinnability. To address these limitations, several strategies have been explored, including the use of solvents to unfold protein structures, incorporation of carrier polymers to enhance molecular entanglements, addition of surfactants to lower surface tension, and various denaturation methods ranging from thermal and pH treatments to green technologies like high hydrostatic pressure and ultrasound. Furthermore, synergistic approaches combining these techniques have demonstrated improved fiber formation and morphology. Despite promising laboratory-scale results, significant challenges remain regarding the scalability, reproducibility, and mechanical performance of electrospun plant protein fibers. Future research ought to focus on optimizing formulations and process parameters to enable large-scale production and expand their use in food, packaging, and biomedical applications.

Front Cover: Imagine microscopic architects harnessing the sun's energy stored in our fields and kitchens to construct the foundations of future medicine. The cover of the Research Article (DOI: 2500074) by Emmanuel Asare, Ipsita Roy, and co-workers reveals a narrative of sustainable creation, featuring bacteria that convert renewable resources into highly biocompatible polymers. These materials are woven into intricate nanofiber scaffolds that support cellular growth and guide the delicate extensions of neuronal networks. Join us in exploring the intersection of nature's ingenuity and advanced tissue engineering, paving a greener path to healing.