Biomacromolecules最新文献

A cheap and easy-to-recycle solvent, namely, aqueous NaOH with no additives, was used to dissolve cellulose and make cross-linker-free materials with varying porosity, testing them as drug delivery devices. Cellulose solutions were gelled, coagulated in a nonsolvent (water, ethanol), and dried either using supercritical CO₂ (aerogels) or low-vacuum evaporation (named "xerogels"). Aerogels had densities of around 0.1 g/cm³ and specific surface areas (SSAs) of 200-400 m²/g. A significant influence of the first nonsolvent and drying mode on material properties was recorded: when the first nonsolvent was ethanol and low-vacuum drying was performed from ethanol, aerogel-like xerogels were obtained with densities of around 0.2 g/cm³ and SSAs of 200-260 m²/g. Other conditions (under evaporative drying) resulted in cellulose with much lower porosity and SSA. All materials were evaluated as drug delivery devices in simulated gastrointestinal fluids; theophylline was used as a model drug. Materials of high porosity exhibited shrinking and rapid drug release, whereas denser materials swelled and showed slower release. Two release mechanisms were suggested: diffusion through aqueous media in pores and diffusion through swollen pore walls. The results demonstrate a large spectrum of options for tuning the properties of porous cellulose materials for drug release applications.

Despite the increasing interest in cellulose-derived materials in biomedical research, there remains a significant gap in comprehensive in vivo analyses of cellulosic materials obtained from various sources and processing methods. To explore durable alternatives to synthetic medical meshes, we evaluated the in vivo biocompatibility of bacterial nanocellulose, regenerated cellulose, and cellulose nanofibrils in a subcutaneous transplantation model, alongside incumbent polypropylene and polydioxanone. Notably, this study demonstrates the in vivo biocompatibility of regenerated cellulose obtained through alkali dissolution and subsequent regeneration. All cellulose-derived implants triggered the expected foreign body response in the host tissue, characterized predominantly by macrophages and foreign body giant cells. Porous materials promoted cell ingrowth and biointegration. Our results highlight the potential of bacterial nanocellulose and regenerated cellulose as safe alternatives to commercial polypropylene meshes. However, the in vivo fragmentation observed for cellulose nanofibril meshes suggests the need for measures to optimize their processing and preparation.

Identification of bacterial lectins offers an attractive route to the development of new diagnostics, but the design of specific sensors is complicated by the low selectivity of carbohydrate-lectin interactions. Here we describe a glycopolymer-based sensor array which can identify a selection of lectins with similar carbohydrate recognition preferences through a pattern-based approach. Receptors were generated using a polymer scaffold functionalized with an environmentally sensitive fluorophore, along with simple carbohydrate motifs. Exposure to lectins induced changes in the emission profiles of the receptors, enabling the discrimination of analytes using linear discriminant analysis. The resultant algorithm was used for lectin identification across a range of concentrations and within complex mixtures of proteins. The sensor array was shown to discriminate different strains of pathogenic bacteria, demonstrating its potential application as a rapid diagnostic tool to characterize bacterial infections and identify bacterial virulence factors such as production of adhesins and antibiotic resistance.

Bacterial infections in chronic wounds, such as bedsores and diabetic ulcers, present significant healthcare challenges. Excessive antibiotic use leads to drug resistance and lacks precision for targeted wound treatment. Our study introduces an innovative solution: a near-infrared (NIR) and pH dual-responsive hydrogel patch incorporating regenerated silk fibroin (RSF) and molybdenum dioxide (MoO₂) nanoparticles (NPs), offering enhanced mechanical properties, precise drug release, and superior antibacterial efficacy. The dual-responsive hydrogel patch allows for precise control over antibiotic release triggered by NIR light and pH fluctuations, enabling tailored treatment for infected wounds. First, the pH-responsive characteristic matches the alkaline environment of the infected wound, ensuring on-demand antibiotic release. Second, NIR exposure accelerates antibiotic release, enhancing wound healing and providing additional antibacterial effects. Additionally, the patch further blocks bacterial infection, promotes wound repair, and degrades in sync with the healing process, further bolstering the efficacy against wound infections.

Chemodynamic therapy (CDT) has been limited by the tumor microenvironment, such as the low concentration of hydrogen peroxide (H₂O₂). The combination of therapeutic strategies that increase H₂O₂ with CDT can synergistically enhance the therapeutic effect. Herein, a novel supramolecular PEG-DNA-ferrocene nanogel that can codeliver glucose oxidase (GOx) and the hypoxia-activable prodrug tirapazamine (TPZ) was developed to synergistically amplify CDT via cascade reactions. The DNA nanogel was size-controllable and DNase I-responsive and exhibited good biocompatibility. Induced by oxygen consumption and H₂O₂ generation in the catalytic reaction of GOx, the drugs TPZ and ferrocene in the nanogel underwent the hypoxia-based reaction and the Fenton reaction, respectively. The vitro model tests, intracellular ROS test, MTT experiments, and DNA damage assay demonstrated that the H₂O₂-based cascade Fenton reaction and the hypoxia-based cascade reaction obviously increased ·OH generation and promoted the apoptosis of cancer cells. This cascade supramolecular nanoplatform provided a promising therapeutic strategy to synergistically amplify CDT.

Natural materials exhibit exceptional properties due to their hierarchical structures spanning from the nano- to the macroscale. Replicating these intricate spatial arrangements in synthetic materials presents a significant challenge as it requires precise control of nanometric features within large-scale structures. Addressing this challenge depends on developing methods that integrate assembly techniques across multiple length scales to construct multiscale-structured synthetic materials in practical, bulk forms. Polymers and polymer-hybrid nanoparticles, with their tunable composition and structural versatility, are promising candidates for creating hierarchically organized materials. This review highlights advances in scalable techniques for nanoscale organization of polymer-based building blocks within macroscopic structures, including block copolymer self-assembly with additive manufacturing, polymer brush nanoparticles capable of self-assembling into larger, ordered structures, and direct-write colloidal assembly. These techniques offer promising pathways toward the scalable fabrication of materials with emergent properties suited for advanced applications such as bioelectronic interfaces, artificial muscles, and other biomaterials.

Nanotherapeutic techniques are becoming increasingly important in the treatment of bone disorders owing to their targeted drug delivery. This study formulates zein nano coop composites containing chimeric antioxidants (ascorbic acid, luteolin, resveratrol, and coenzyme Q) (AZN) and evaluates its application in bone regeneration using osteoblasts and a Zebrafish osteoporosis model. In vitro experiments with human osteoblast-like MG63 cells showed enhancement of bone mineralization and regeneration. It further exhibited high biocompatibility in Zebrafish larvae, with increased calcium/phosphorus deposition and upregulation of osteogenic genes. The study has unequivocally demonstrated the potential of AZN in bone regeneration and fracture healing in both normal and osteoporosis models, underscoring the significance of this research. Further investigations using higher animal models are warranted to expand on these findings. The impact of this research seems far-reaching, with the possible development of new, effective, and safe treatment options for osteoporosis, addressing the limitations of the currently available treatments.

Elastomers based on the resilin protein confer exceptional mechanical resilience in nature, but it remains elusive to recover the remarkable properties of these materials when they are made in the laboratory. This is possibly due to preorganized conformations of resilin in its natural setting, facilitating Tyr-based cross-linking. Here, resilin-like peptides (RLPs) are conjugated with a graphene-binding peptide, P1, to produce P1/RLP conjugates, in which the P1 domain may provide favorable preorganization on a graphene surface. Experiments using quartz crystal microbalance analysis and atomic force microscopy identified that the parent RLPs demonstrate negligible graphene binding; however, integration of the P1 with the RLPs resulted in the formation of dense, patterned bioligand overlayers on graphene. To complement this, molecular simulations revealed a notable difference in binding mode of the conjugates compared with typical materials binding peptides. Specifically, the adsorption of the P1/RLP conjugates did not focus on a few strongly bound "anchor" residues, but instead supported a more diffuse mode of binding, with many more participating residues featuring moderate contact. Analysis of the number of available Tyr residues (i.e., those not adsorbed at the surface) indicate that the RLP2-based conjugates will provide greater opportunity for cross-linking when adsorbed on graphene, providing a framework to generate patterned elastomeric materials.

COVID-19 made apparent the devastating impact viral pandemics have had on global health and order. Development of broad-spectrum antivirals to provide early protection upon the inevitable emergence of new viral pandemics is critical. In this work, antiviral polymers are discovered using a combination of high-throughput polymer synthesis and antiviral screening, enabling diverse polymer compositions to be explored. Amphipathic polymers, with ionizable tertiary amine groups, are the most potent antivirals, effective against influenza virus and SARS-CoV-2, with minimal cytotoxicity. It is hypothesized that these polymers interact with the viral membrane as they showed no activity against a nonenveloped virus (rhinovirus). The switchable chemistry of the polymers during endosomal acidification was evaluated using lipid monolayers, indicating that a complex synergy between hydrophobicity and ionization drives polymer-membrane interactions. This new high-throughput methodology can be adapted to continue to engineer the potency of the lead candidates or develop antiviral polymers against other emerging viral classes.

The healing of infected wounds is challenging for patients. In this paper, a hybrid hydrogel with strong tissue adhesion, self-healing, and antibiosis without antibiotics was developed as a dressing to promote the healing of infected chronic wounds. Acrylamide (PAM) was polymerized with N,N-methylene bis(acrylamide) (BIS) as the substrate, and self-assembled nanoparticles of carboxymethyl chitosan and chlorin e6 (CMCS/Ce6 NPs) trapped with magnesium (Mg²⁺) ions were dispersed in the hydrogel substrate. CMCS/Ce6 NPs provided favorable photodynamic antibiosis via the production of reactive oxygen species (ROS) under NIR irradiation. The hybrid hydrogels exhibited excellent self-healing properties, diverse adhesion, and biocompatibility. The in vivo results indicated that the hybrid hydrogel accelerated wound healing significantly via comprehensive factors of photodynamic antibiosis of CMCS/Ce6 NPs, cell proliferation promotion by Mg²⁺, good bioadhesion, and moisture retention of the PAM hydrogel, which promoted collagen deposition and blood vessel maturation.