Biomacromolecules最新文献

The microscopic state of polysaccharides in solution─whether dissolved, dispersed, or aggregated─directly dictates the macroscopic properties of the bulk fluid. However, the influence of their true state in solution and nanostructures on rheology is often overlooked. Here, using non-Newtonian shear-thickening fluids (STFs, SiO₂/poly(ethylene oxide)) as a model, we systematically investigate how xylan conformation and dispersion affect STFs' rheology. Xylan nanocrystals (XNCs) and water-soluble xylan ethers with distinct dispersibility (well-dispersed vs aggregate) and solubility (room-temperature-soluble vs high-temperature-soluble) are synthesized. Among those, well-dispersed XNCs and room-temperature-soluble xylan ethers exhibit a pronounced thickening effect in STFs, reducing the critical shear rate by 2 orders of magnitude and increasing peak viscosity by 880%. This work demonstrates that polysaccharide conformation and dispersion behavior exert pronounced effects on STF rheology, providing a new avenue for leveraging polysaccharides as fluid additives.

Small interfering RNAs (siRNAs) offer considerable promise as anticancer therapeutics because they enable the precise silencing of disease-related gene expression. However, its clinical potential is limited by rapid degradation and possible off-target toxicity, necessitating the development of an effective targeted delivery system. Bioengineered silk, a biocompatible and biodegradable material, can be tailored with functional peptides to enable nucleic acid binding and receptor-specific targeting. We developed five MS1 silk-based proteins that target VEGFR-1 or VEGFR-2, which are receptors that are frequently overexpressed in the tumor microenvironment (TME), including both endothelial and cancer cells. These were blended with MS2KN silk, which binds nucleic acids, to generate hybrid nanospheres. The resulting carriers exhibited high siRNA loading efficiency, selective binding to VEGFR-overexpressing endothelial and nonsmall cell lung cancer (NSCLC) cells, and efficient cellular uptake. Delivery of siRNA via these nanospheres led to a significant reduction in target gene expression. Our platform has strong potential for targeted siRNA delivery to VEGFR-overexpressing cells within the TME.

Inspired by mussel adhesion mechanisms and the structural advantages of double network (DN) hydrogels, this study developed a catechol- and polyphosphate-modified natural biomacromolecular-based DN hydrogel to tackle critical wound healing challenges, including persistent inflammation, oxidative stress, and impaired angiogenesis. The hydrogel exhibits tailored mechanical adaptability to wound microenvironments, ensuring conformal coverage under high-glucose conditions. Its inherent hemostatic capacity stems from rapid interfacial adhesion and coagulation activation, addressing the bleeding complications commonly observed in wounds. Furthermore, the hydrogel actively modulates pathological microenvironments via ROS scavenging and anti-inflammatory effects while facilitating sustained release of bioactive components to synergistically promote angiogenesis, collagen deposition, and epithelial regeneration. In summary, this mussel-inspired glycosyl cyclic hydrogel integrated multifunctional therapeutic advantages including microenvironment regulation, dynamic adaptability, and pro-regenerative signaling into a single platform, demonstrating great potential as a next-generation dressing for refractory diabetic wound management.

The need for multifunctional polymers in cellular environments arises from their potential applications in cancer treatment, drug delivery, gene delivery, imaging, sensing of different biomolecules, environmental and cellular engineering, etc. However, due to certain limitations, the direct polymerization of multifunctional polymers within cells is not feasible, as it faces many challenges. Therefore, this study emphasizes the synthesis of functionalized molecules outside the cells and subsequent modification of the polymers inside the cells through intracellular postpolymerization modification (iPPM). We investigate Förster resonance energy transfer (FRET) as a technique for confirming the occurrence of postpolymerization reactions in cells in real time without the need for extraction or purification. The FRET reaction consists of 7-nitrobenz-2-oxa-1,3-diazole (NBD) as the FRET donor, integrated as a segment in the polymer backbone, and rhodamine B-polyethylene glycol-dibenzocyclooctyne (RhB-PEG-DBCO) as the FRET acceptor. A copper-free click chemistry method is used as a postpolymerization reaction within cells by the reaction between the azide group on the polymer backbone and DBCO in the FRET acceptor. By employing FRET and a targeted approach, this technique contributes to the development of multifunctional polymers for diverse applications in cellular environments.

Thermosetting polymers are widely used due to their excellent thermal stability, mechanical performance and chemical resistance. A major challenge, however, is the recyclability related to their cross-linked nature. Consequently, they are often discarded by incineration or landfilling. The incorporation of dynamic linkages within thermosets offers a promising route toward the complete recycling of cross-linked polymers. Covalent adaptable networks such as vitrimers exhibit properties comparable to those of thermosets during operation but are still reprocessable at elevated temperatures. The use of renewable carbon feedstocks for their manufacturing is key for further reducing the environmental impact of this new class of materials. To explore the complete range of sustainable vitrimer materials, the discussion on renewable carbon includes both the use of biomass and end-of-life plastics as feedstock. Using the gathered knowledge, a perspective is presented on the impact of vitrimer materials from both an environmental and economic point of view.

Recent advancements in bioconjugation chemistry have increasingly focused on thiol-based strategies, offering reversible and stimuli-responsive mechanisms, particularly suited for biomedical applications. This review aims to provide a critical overview of the latest developments in thiol-containing linkers, such as disulfide bonds and photocleavable groups, emphasizing their role in enabling controllable and often reversible conjugation of biomolecules. The review will explore several applications, including peptide synthesis and peptide-stapling strategies, antibody-drug conjugates (ADCs), and responsive biomaterials, categorize key classes of cleavable thiol-based linkers, and analyze their mechanisms. Covering the literature from the past 15 years, focusing on innovations until 2024, this review addresses the chemical foundations and practical implementations of these systems, identifying current limitations and proposing future directions for designing selective, biocompatible, and functionally dynamic conjugation platforms.

This publication constitutes a comparison of two apparently different communities, namely, synthetic polymer self-assemblies and amyloid aggregates, to cross-fertilize each other. The starting point is shared recognized issues in the reproducibility of the fabrication of the aggregates for each community. Based on this, this publication compares the underlying mechanistic principles of self-assembly, the methods for the preparation of assemblies, and the techniques used for their characterization. This highlights some common practices, while also revealing notable differences. Interestingly, some techniques may be used by both communities but with different perspectives and aims, whereas others are preferably employed by one community. The article finally suggests possible cross-advice for each one.

Degree of circular polarization (DOCP) of reflected light is an intriguing optical phenomenon of chiral photonic materials; however, it remains underexploited. This is especially the case with cellulose nanocrystals (CNCs), despite the fact that their angle-dependent structural color has been overwhelmingly attended to. Herein, CNC-based chiral photonic materials capable of dual actuation are constructed by vacuum-assisted self-assembly. Leveraging femtosecond laser machining, complex structural color 3D shapes, and crawling robotic devices are produced from these materials. The incident angle-incident lasing wavelength-reflected light DOCP correlation and DOCP-based ternary code are established, based on which a secure and efficient robotic information transmission strategy is presented, where a message is simply synthesized from structural color photos using a single-use key and the encryption security increases with photo numbers by power law. Our work unleashes the hidden potential of CNC-based soft actuators and enables them for secure and efficient robotic data transmission.

Injectable hydrogels offer promising alternatives for scaffold-based tissue engineering due to their minimally invasive delivery and in situ forming capability. In this study, we reported the first development of an injectable hydrogel scaffold combining carboxymethyl cellulose (CMC), poly(ethylene glycol) (PEG), and poly(ε-caprolactone) (PCL) into a single system. This novel approach integrated the biocompatibility of CMC, tunable responsiveness of PEG, and mechanical robustness/degradability of PCL, which had not been previously reported. A pH- and temperature-responsive carboxymethyl cellulose (CMC) grafted with a methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) [CMC-g-(mPEG-b-PCL)] system was synthesized. The diblock copolymers were first prepared by ring-opening polymerization of ε-caprolactone using a poly(ethylene glycol) methyl ether (mPEG) in combination with a stannous octoate initiator, followed by grafting onto the pH-responsive CMC backbone using simple 1-ethyl-3-(3-(dimethylamino)propyl carbodiimide)/N-hydroxysuccinimide (EDC/NHS) coupling chemistry in N,N-dimethylformamide (DMF). Structural characterization by ¹H NMR and FTIR spectroscopy confirmed the presence of characteristic functional groups from both CMC and mPEG-b-PCL. Aqueous CMC-g-(mPEG-b-PCL) hydrogels were subsequently formulated, with 32 wt % CMC-g-(mPEG₁₇-b-PCL₁₂) showing the most favorable sol-gel phase-transition behavior based on the test tube inversion. Rheological analysis demonstrated that the hydrogel remained injectable in the sol state and formed a stable gel under physiological conditions, with the range of storage moduli comparable to that of early stage cartilage tissue. In addition, the hydrogel exhibited an interconnected porous structure, as observed by scanning electron microscopy. Cytocompatibility was validated through MTT and live/dead staining assays using L929 fibroblasts and MG63 osteoblast-like cells. The results showed that the cell morphology was preserved, and the cell viability was stable throughout 5 days of incubation. These findings support the cytocompatibility of the synthesized CMC-g-(mPEG-b-PCL) graft copolymer and suggest its potential for further investigation as an injectable hydrogel scaffold for bone and cartilage tissue engineering applications.

We employ cationized human serum albumin as a scaffold for attaching poly(ethylene glycol) (PEG) chains at precise locations along the protein backbone. Subsequent denaturation unfolds the protein backbone, resulting in brush polymers with a well-defined, monodisperse, polypeptide backbone with PEG side chains. The defined variation of PEG chain number allows for a systematic investigation of the impact of PEGylation on the protein secondary structure, protein backbone and PEG dynamics, as well as PEG crystallization. Strikingly, PEG side chains in the polypeptide-PEG hybrids can crystallize even at low grafting density. As a result, crystallization is embedded in the hybrids, evident from the low degree of crystallinity, reduced melting temperature, and superslow spherulitic growth rates. The crystallization temperature in the hybrids approaches the homogeneous nucleation limit of PEG, only accessible via confinement (e.g., in nanopores). Our findings underscore the unique crystallization characteristics of PEG side chains in polypeptide-PEG hybrids.