Biomacromolecules最新文献

Modification of plant mitochondria has attracted increasing attention as a strategy for developing highly productive crops, driving efforts to achieve efficient mitochondrial delivery of cargos. Mitochondria-targeting gene carriers with a strong cell-penetrating ability have been shown to deliver plasmid DNA into plant mitochondria, but this ability can reduce mitochondrial selectivity through nonspecific interaction with intracellular membranes. Herein, we developed a fusion peptide in which a mitochondria-targeting peptide was linked to a cell-penetrating peptide via an ultraviolet (UV)-cleavable linker, enabling regulation of cell-penetrating function after cellular uptake by UV irradiation. As a result, mitochondrial localization of the fusion peptide was significantly enhanced in Arabidopsis thaliana. Furthermore, UV irradiation improved the mitochondrial gene delivery efficiency and selectivity of gene carriers modified with the fusion peptide compared with nonirradiated conditions. Overall, these findings demonstrate that controlled release of the cell-penetrating peptide suppresses off-target effects and enables selective mitochondrial gene delivery in plant cells.

Complex coacervation is a type of associative liquid−liquid phase separation driven by the electrostatic complexation of oppositely-charged macromolecules. Coacervate materials have shown significant potential for the formulation of proteins and viruses with improved thermal stability. We leveraged a combination of experiments and simulations to investigate how the presence of both proteins and small-molecule excipients common in stabilizing formulations would affect the partitioning of both protein and excipient in the coacervate phase. Although electrostatic interactions tend to dominate the incorporation of proteins into coacervates, our study highlights the balance of protein-water-excipient interactions as a critical parameter for understanding partitioning trends in these multi-component formulations. This work provides insight into the design of multi-component formulations that take advantage of complex coacervation and could serve as a basis for product design in the future.

Protein delivery nanosystems must balance stable loading, barrier navigation, and targeted, controlled release. Herein, a pH/ROS dual-responsive nanogel (PRNG) was constructed by forming dynamic boronic ester crosslinkers between PEGylated hyaluronic acid bearing diethylenetriamine-grafted-catechol groups (PEG-HA-Dien-CA) and hyaluronic acid-conjugated phenylboronic acid (HA-PBA) for cytoplasmic cytochrome c (CC) delivery. This pioneering conceptual design not only facilitates the formation of stable nanocarriers with a high CC loading capacity, but also presents a distinctive mechanism for dual-responsive protein release. Confocal imaging confirmed that CC-loaded PRNG was efficiently internalized by A549 cells through CD44-dependent endocytosis, rapidly released from the endo/lysosomal compartments, and effectively delivered CC into the cytoplasm, and subsequently induced cell apoptosis in the acidic tumor microenvironment (TME) rich in H₂O₂. In mice bearing human lung tumors, CC-loaded PRNGs preferentially accumulate at tumor sites and effectively inhibit growth with minimal systemic toxicity, demonstrating a versatile nanoplatform for lung cancer therapy.

Hydrogel-based sensors face two persistent challenges: freeze-induced performance failure at sub-zero temperatures and an inherent trade-off between mechanical robustness and electrical conductivity. To address these issues, a triple-network hydrogel composed of polyacrylamide, gelatin, and carboxymethyl cellulose was designed, synergistically integrated with LiCl, CaCl₂, and glycerol. In this design, glycerol serves as the primary cryoprotectant, Li⁺ ions provide ionic conduction, and Ca²⁺ crosslinks reinforce the polymer network. The optimized hydrogel achieves high tensile strength (576 kPa), ultra-high stretchability (938%), outstanding toughness (233.4 kJ/m³), and high conductivity (2.95 S/m), while completely suppressing ice crystallization down to −80 °C. As a strain sensor, it delivers a gauge factor of 3.53 after freezing; as a bioelectrode, it records high-quality EMG, ECG, EOG, and EEG signals comparable to or surpassing commercial Ag/AgCl electrodes, and maintains reliable performance over 24 h at −20 °C. This work demonstrates a durable material candidate for long-term wearable sensing and biopotential recording in sub-zero environments.

The environmental impact of synthetic textiles has prompted the need for sustainable and re-processable alternatives. Here, we correlated the growth conditions used to produce kombucha-derived cellulose non-woven mats with their mechanical performance as a function of post-processing. Exploration into fermentation variables revealed that after 14 days, thick, uniform cellulose non-wovens were obtained under mildly acidic conditions at 30 °C with moderate inoculum and carbon-source loading. Next, the mechanical properties of thin and thick wet, as well as lyophilized and oven-dried non-wovens, were investigated using uniaxial tensile testing and rheology. Interestingly, lyophilized mats that were re-hydrated exhibited the highest ultimate tensile strength. Finally, in a proof-of-concept experiment, we explored if kombucha-grown clothing could be enzymatically degraded and re-processed using electrospinning into new nanofiber mats. Together, these results provide insight into the biomanufacturing of mechanically robust textiles that can be enzymatically degraded and then re-processed into next-generation textiles.

Inspired by the DNA-cleaving potency of natural enediynes such as calicheamicin, we report the design and synthesis of maleimide−enediyne conjugates integrated into poly(ε-caprolactone) (PCL) as a next-generation platform for anticancer drug delivery. Maleimide-based enediynes typically suffer from poor aqueous solubility and nonspecific toxicity, addressed here by covalently incorporating enediyne groups into amphiphilic PCL block copolymers via post-polymerization functionalization. The resulting polymers form ∼120 nm spherical micelles with a critical micelle concentration of 9.1 × 10⁻⁴ mg mL⁻¹, enhancing enediyne solubility, promoting tumor accumulation through the EPR effect, and enabling encapsulation of hydrophobic drugs such as doxorubicin. Electron paramagnetic resonance confirmed radical formation and Bergman cyclization under physiological conditions. Cell viability assays showed enediyne-induced death in MDA-MB-231 breast cancer cells, and the functionalized PCL exhibited in vitro DNA cleaving activity, demonstrating that maleimide−enediyne-functionalized PCL micelles are promising platforms for cancer chemotherapy.

Existing research of single polymer systems has primarily focused on the modification and optimization, with limited systematic comparisons of the performance evolution and gene transfection differences between branched polyethyleneimine (bPEI) and dendritic polyamide-amine (PAMAM) after fluorination modification. In this study, a series of fluorinated polymers were prepared by fluorinating 25 kDa bPEI and PAMAM G4 using heptafluorobutyric anhydride. The pEGFP plasmid was employed as a model gene. The gene transfection efficiencies of both types of materials before and after fluorination were systematically compared and evaluated using fluorescence analysis, flow cytometry, and in vivo imaging techniques. The results demonstrated that fluorination significantly enhanced transfection efficiency under serum-containing conditions. PAMAM G4-F7₇₃ in particular exhibited superior performance compared to fluorinated bPEI and the commercial Lipofectamine 2000 transfection reagent. This study represents the first systematic comparison of transfection performance between these two types of fluorinated polymers, providing crucial insights for rational design of gene delivery vectors.

Hydrogel coatings are promising candidates for biomedical surface functionalization. However, developing multifunctional hydrogel coatings that simultaneously integrate robust lubrication, effective antibacterial capacity, and stable interfacial adhesion remains challenging. Herein, a simple, substrate-independent in situ interfacial polymerization strategy was proposed to construct multifunctional hydrogel coatings, which is driven by a catechol−Fe³⁺ dual self-catalytic system. The pre-coated polydopamine adhesive coating captures Fe³⁺ ions from monomer solution and forms redox pairs with intrinsic catechol moieties, which spontaneously triggers interfacial radical polymerization and enables precise control of hydrogel coating thickness. Zwitterionic monomer and aminoglycoside antibiotic are incorporated synergistically to endow the hydrogel coatings with significant hydrophilicity, excellent lubrication, and antibacterial performance. The obtained hydrogel coatings exhibit steady low friction coefficients over 12,000 reciprocating cycles and high antibacterial efficacy against Escherichia coli and Staphylococcus aureus. This versatile method is compatible with diverse engineering materials and medical catheters, establishing a practical pathway toward biomedical hydrogel coatings.

The mechanical response of silk fibers is commonly associated with β-sheet crystallinity and molecular orientation, yet how these molecular descriptors are transmitted across the fibrillar hierarchy remains less clear. Here, we compare Hyphantria cunea silk with Bombyx mori silk to examine how nanofibril-level load-transfer descriptors are associated with deformation when β-sheet fraction and axial orientation are comparable. Peptide profiling and single-fiber synchrotron infrared microspectroscopy show that H. cunea silk contains β-sheet-compatible sequence motifs and reaches β-sheet content and axial orientation comparable to those of B. mori silk. Despite this similarity, H. cunea silk exhibits a high-strength, near-linear tensile response, whereas B. mori silk follows a yielding−extension−hardening pathway. AFM-based fibrillar analysis and topology-constrained load-transfer modeling identify systematic differences in ex situ contour characteristics, effective coupling, and characteristic load-transfer descriptors that are consistent with the observed mechanical divergence. These results identify nanofibril coupling topology as a structural descriptor for programming silk fiber deformation beyond β-sheet order.

Drug delivery to the brain involves challenging transportation across multiple biological barriers. Despite the great tunability of polymeric nanoparticles, the synthetic challenge of varying the physical property of a nanoparticle without varying its chemical formulation only adds to our limited understanding of this transport. Here, we introduce a method for tuning the rigidity of poly(lactic-co-glycolic acid) (PLGA) nanoparticles without altering the chemical formulation by using UV irradiation to control the crosslinking chemistry. Using atomic force microscopy (AFM), we were able to show that Young’s modulus of nanoparticles increased with UV exposure time. Crosslinked nanoparticles with greater rigidity were found to have greater diffusive ability through the brain parenchyma than their non-crosslinked counterparts. However, even with identical chemical formulations, minor differences in the chemical structure of crosslinked and non-crosslinked particles were found to influence transport, highlighting the importance of decoupling the physical properties of nanoparticles from their chemistry.