Biomacromolecules最新文献

This study presents a novel approach to harnessing the underutilized resource of livestock blood plasma proteins to produce bioplastic films based on amyloid fibrils. Upon acidic heating, a 20-h incubation period resulted in mature, semiflexible fibrils with an average length of 0.65 μm and a persistence length of 261 nm. Characterization using Thioflavin T intensity, circular dichroism, and FTIR spectroscopy revealed a cross-β-sheet structure stabilized by hydrogen bonding. The integration of plasma protein amyloid fibrils with poly(vinyl alcohol) (PVA) or methyl cellulose (MC) yielded bioplastic films that exhibit smooth and homogeneous micromorphology, enhanced toughness, and water stability, with PVA-based films demonstrating an exceptional elongation of ∼300%, suitable for food packaging applications. Compared to petroleum-based plastics, plasma amyloid fibril-incorporated films demonstrated a superior sustainability footprint (∼92%). This work underscores the potential of plasma protein amyloid fibrils in bioplastic applications, aligning with the global imperative for eco-friendly waste management and a circular economy.

During the course of evolution, distinct mucin subtypes have evolved, that predominantly occur in specific mucus variants of the body. A loss of this clear regional assignment is often associated with pathophysiological conditions such as asthma or gastric cancer. We here reconstitute mucus from different mucin subtypes to elucidate the influence of MUC5B/MUC2 contaminations on physiologically relevant properties of acidic MUC5AC gels as found in the stomach. Our findings indicate that these properties may be critically altered by the presence of an atypical mucin species. A weak integration of a contaminating mucin subtype into the host network yields weak viscoelastic gels with increased barrier capabilities. Unravelling the complex properties of mucosal barriers under disease conditions is crucial for the understanding of mucosal disease progression and for developing drug-carriers to traverse this biological barrier. Here, our results provide useful insights into mechanistic principles governing the physical properties of gastro-intestinal mucus.

Intracellular protein therapy is a promising strategy in biologics, including vaccine development, gene editing, and cancer therapeutics. However, protein-based drug delivery remains a significant challenge, particularly in penetrating cell barriers to reach intracellular targets. Inspired by transport adjuvants, we designed a series of polymeric vectors to achieve efficient functional protein trafficking with low cytotoxicity. With an adequate combination of guanidinium and fluorocarbon functionalities, a synergistic improvement of intracellular delivery is achieved in terms of both high intracellular transport and low cellular toxicity. The observed synergistic outcomes highlight new opportunities for delivery vehicle optimizations of intracellular biologics.

The knowledge of the molecular properties and arrangements of biopolymers in both solid and solution state are essential in the design of sustainable materials and biomedicine as they are decisive for mechanical strength, flexibility, and biodegradability. However, the structure of most biopolymers at charged interfaces can vary considerably, and their time-dependent visualization in liquid-state still remains challenging. In this work, we employed high-speed atomic force microscopy (HS-AFM) to visualize single xylan macromolecules from alkali-extracted birch and beechwood. On negatively charged mica surfaces, they appeared as individual macromolecules but assembled into aggregates on 3-aminopropyltriethoxysilane (APTES) surfaces (AP-mica). Hence, we further investigated the susceptibility to enzymatic degradation using an endoxylanase, which showed that the individual xylan macromolecules remained intact, while larger assemblies on AP-mica degraded over time. We demonstrate that HS-AFM is a powerful tool for understanding the molecular properties and degradation mechanisms of biopolymers. Moreover, by identifying alignment-dependent binding sites, strategies can be developed to ensure the biodegradability of composite materials by intelligent interface design.

The present study demonstrates that the change in the degree of xylan acetylation significantly alters the 2-fold screw population that effectively interacts with the (100) hydrophobic cellulose, while such effects are less prominent for the (110) hydrophilic surface. All of the acetylated xylans reveal an ≈10-40% higher 2-fold population on the hydrophobic cellulose due to higher xylan-cellulose contacts. Deviations from periodic acetylation result in much lower 2-fold conformations, despite a comparable number of xylan-cellulose hydrogen bonds and contacts. Thus, it can be hypothesized that a specific and unique set of xylan: cellulose interactions mediate the formation of 2-fold xylan to interact with cellulose, which is also a 2-fold screw. Highly acetylated xylans desorb from cellulose, while low acetylated xylans show dependence on the topology of the cellulose surface. These findings provide additional insights into plant cell wall microstructure dynamics and inform future strategies for efficient biomass deconstruction in biofuel production.

Psoriasis is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation, oxidative stress, and immune dysregulation. In this study, we developed a multifunctional, double-network hydrogel, composed of chitosan and poly(acrylic acid), embedded with cerium oxide nanoparticles (CeNPs) and betamethasone. The hydrogel harnesses the redox-catalytic properties of CeNPs to scavenge reactive oxygen species (ROS) while ensuring sustained betamethasone release for antibacterial and anti-inflammatory effects. Its mechanical stability and high water retention make it suitable for long-term skin application. In vitro, the hydrogel enhanced keratinocyte viability under oxidative stress and showed significant antibacterial activity against Escherichia coli. In a psoriasis-induced mouse model, the hydrogel significantly reduced epidermal hyperplasia, suppressed keratinocyte proliferation, and lowered inflammatory cytokine levels. The combination of antioxidant, antibacterial, and anti-inflammatory properties suggests that this hydrogel offers a promising therapeutic strategy for psoriasis, addressing both oxidative stress and inflammation for effective treatment.

The biological application of gold nanospheres (AuNSs) is often constrained by their stability and cytotoxicity. We present a greener synthetic approach that gives a simple and more environmentally friendly route to synthesizing AuNSs for biomedical applications. In this study, we detail a novel one-step, green synthesis of poly(2-alkyl-2-oxazoline) (POx)-coated AuNSs, which eliminates the need for additional reducing and stabilizing agents. The impact of the polymer structure on the nanoparticle formulation kinetics and nanoparticle characteristics is thoroughly investigated, revealing that the terminal functional group and the alkyl side chain significantly influence the reduction and stabilization process of AuNSs. Finally, POx-coated AuNSs were tested in vitro against F98 glioblastoma cells and proved to be usable without significant toxicity up to 75 μM. Herein, the outlined rapid and efficient method of the preparation of POx-coated AuNSs serves as a foundation for advancing the development of complex AuNSs tailored for biomedical applications.

In this study, we have screened out an effective triphenylphosphine-derived initiator (2-TMOPP) for efficient ring-opening polymerization of α-amino acid N-carboxyanhydrides (NCA ROP) and demonstrated the potential of the prepared helical polypeptide as an efficient ion channel. By optimizing polymerization conditions, 2-TMOPP exhibited precise control over the molecular weight and polydispersity index for the prepared polypeptides, the universality for different NCA monomers, and the ability to form α-helical secondary structures. By further incorporating ion binding groups and regulating the molecular length, α-helical polypeptide PLCE was capable of inserting into lipid bilayers and possessing the function of ion transport (H⁺/K⁺ antiport) via a channel mechanism (EC₅₀ = 12.75 ± 1.58 μg mL^-1). PLCE also showed anticancer activity toward HeLa cells, with an IC₅₀ value of approximately 69.67 ± 1.20 μg mL^-1 after 20 h coculture, showing the possibility for future practical application in biomedical fields.

Control over network chemistry and connectivity of hydrogels is critical for the generation of tunable material properties, including material degradation for applications such as tissue scaffolding and drug delivery. Here, the degradation of hydrogels employing different hydrolytically cleavable groups including benzamide and syringic acid-derived carbamates, kojic acid-derived carbonates, and kojic acid-derived esters under physiological conditions was studied. Tunability of the hydrogel network degradation was demonstrated by varying the hydrolytically degradable moiety, macromer functionality, and copolymerization with hydrolytically stable macromers. These hydrolytically labile macromers were introduced and cross-linked intracellularly to induce transient cellular quiescence in MCF10A cells, resulting in a highly tunable degradation mechanism that is shown to be capable of inducing reversible biostasis of cells with 60% of cells treated with the carbonate macromer returning to their proliferative state and rebounding in translational activity after 72 h, while the biological activity of the carbamate macromer-treated cells remained suppressed.

Enzymatic degradation of plastics is a sustainable approach to address the growing issue of plastic accumulation. Here, we demonstrate the degradation of aliphatic polyesters using enzyme-displaying bacterial spores and the fabrication of self-degradable spore-containing plastics. The degradation proceeds without nutrient-dependent spore germination into living cells. Engineered spores completely degrade aliphatic polyesters into small molecules, retain activity through multiple cycles, and regain full activity through germination and sporulation. We also found that the interplay between the glass transition temperature and melting temperature of polyester substrates affects heterogeneous biocatalytic degradation by engineered spores. Directly incorporating spores into polyesters results in robust materials that are completely degradable. Our study offers a straightforward and sustainable biocatalytic approach to plastic degradation.