Macromolecular bioscience最新文献

Chemodynamic therapy (CDT) is an innovative cancer treatment strategy that leverages Fenton or Fenton-like reactions to convert hydrogen peroxide (H₂O₂) in the tumor microenvironment (TME) into highly cytotoxic hydroxyl radicals (•OH). However, the therapeutic efficacy of CDT against tumor cells is limited by two primary constraints: 1) insufficient H₂O₂ levels in the TME, which restricts •OH generation; and 2) elevated concentrations of reduced glutathione (GSH) in the TME, which neutralizes excess reactive oxygen species (ROS). To address these challenges, this study developed a nanoplatform based on mixed micelles composed of two distinct polycarbonate materials. One polycarbonate is conjugated with cinnamaldehyde (CA) via side chains to form a polymeric prodrug, enabling pH-responsive release of CA. The other polycarbonate chelates Fe³⁺ through side-chain carboxyl groups to initiate Fenton-like reactions. In the acidic TME, the mixed micelles release CA, which elevates intracellular H₂O₂ levels, thereby overcoming the limitation of inadequate H₂O₂ supply in tumor cells. Simultaneously, the Fe³⁺ complex within the micelles depletes GSH, reducing it to Fe²⁺, which triggers Fenton-like reactions that amplify ROS production, thus enhancing CDT efficacy. Additionally, pH-triggered disassembly of the micelles in the acidic TME releases encapsulated doxorubicin (DOX), which induces tumor cell apoptosis by damaging DNA, further augmenting antitumor therapeutic outcomes. The nanocarrier developed in this study integrates a synergistic strategy of “H₂O₂ elevation and Fenton-like reaction” with chemotherapy, significantly improving tumor cell eradication and demonstrating substantial potential for cancer treatment.

Biomass-derived gels offer benefits such as drug delivery and a moist environment, but they typically lack mechanical strength, therapeutic properties, monitoring capabilities, and autoclave resistance. Enhancing these attributes requires precise, cost-effective chemical modification of the biomass material. Herein, a chemical-free approach to transform biomass DNA from onion into DNA nanodots (DNA Dots) that serve as cross-linking cores, chemically bonded with polyethylene glycol diacrylate (PEGDA) through Michael addition, is presented. Using glycerol as the organic liquid phase, the DNA Dot-PEGDA conjugate is formulated into an organogel with exceptional mechanical strength to withstand autoclave sterilization, exhibits antifreeze properties, and sustainably delivers Insulin at the wound site to accelerate healing. Besides cross-linking, the DNA Dots’ rich photophysical properties enable fluorescent tracking of the organogel and generate reactive oxygen species (ROS) under visible light irradiation, maintaining antibiotic-free sterility. While controlled ROS generation inhibits bacterial growth, biocompatibility is not compromised. The newly formulated organogel expedites the healing process in normal and diabetic conditions as tested using HEKa cells. This represents the first example of converting biomass DNA into nanodots to develop a multifunctional organogel that is autoclavable, anti-freezing, trackable, and capable of delivering growth factor while simultaneously generating and scavenging ROS for potential wound healing applications.

The development of multifunctional scaffolds integrating mechanical robustness and bioactivity is crucial for bone tissue engineering. In this study, chitosan-based scaffolds reinforced with hydroxyapatite (HAP) and potassium sodium niobate (KNN) are fabricated via freeze-drying. Structural characterization confirmed crystalline phase purity, strong interfacial bonding, and uniform elemental distribution without secondary phases. Morphological analysis of the composites revealed interconnected porous networks with an average pore size of 95 ± 8 nm and porosity of 77%. Mechanical testing depicted marked improvement, with the Young's modulus of the composite reaching 4.14 MPa, nearly double that of chitosan. Bioactivity assays demonstrated dense apatite growth after 12 days in simulated body fluid, with a Ca/P ratio of 1.66, close to stoichiometric HAP. Swelling and enzymatic degradation studies indicated reduced fluid uptake and slower degradation of 11.9 ± 0.4% over 24 days for the composite, compared to pure chitosan and single-phase scaffolds, thereby confirming enhanced stability. Antioxidant analysis using an in vitro assay reported 48.6 ± 0.5% radical scavenging for the composite, notably higher than 36 ± 0.6% observed for chitosan, while protein adsorption increased to 20–27 µg/mL compared to 9 µg/mL. MG-63 osteoblasts exhibited > 90% viability at day 1 and sustained growth through day 5 with spreading and adhesion. These results highlight HAP-KNN reinforced chitosan scaffolds as promising multifunctional platforms for orthopedic applications.

Effective control of large and deep wounds with incompressible bleeding is essential for pre-hospital first aid. The development of rapid and effective emergency hemostatic materials could reduce the amount of blood loss, promote wound healing, and improve the survival rate. In this study, a carboxymethyl chitosan/ Panax notoginseng polysaccharide (CMCS&PNP) sponge with a layered porous structure was developed, which has high hemostatic and antibacterial effects. The unique bark-like layered porous structure was prepared by the rapid freezing method, which enabled CMCS&PNP to quickly adsorb the water from the bottom of the sponge to the upper layer (the water absorption rate within 3 min could reach 256.83 ± 2.04%). The smaller pores between the two layers allow red blood cells and fibrin to be trapped on the surface of the bottom of the sponge, thereby concentrating the tangible components of the blood and speeding up clotting. The pro-coagulant activity, pro-healing ability, and antibacterial properties of CMCS&PNP were confirmed by in vivo and in vitro experiments. This study not only developed a new composite sponge with high efficiency in hemostasis but also promoted healing. In addition, we also studied the effect of the layered porous structure prepared by rapid freezing on hemostasis and wound healing, providing a new perspective for the development of a composite hemostatic sponge.

The healing of skin wounds is a complex process, the outcome of which is determined by a combination of factors. Adverse factors, such as infection, chronic inflammatory infiltration, and poor vascularity, can impede the healing process, significantly reducing the quality of life. The primary method of promoting wound healing is pharmacotherapy; however, pharmacotherapy alone has several disadvantages, including poor release control, a short half-life, and low bioavailability. Therefore, designing materials with well-controlled release properties and increased bioavailability is important. In this study, ginsenoside Rg1 was incorporated into a photo-crosslinking (LAP/UV) and chemical cross-linking (EDC-mediated amide bond formation) hydrogel synthesized from hyaluronic acid methacrylamide and silk fibroin to enhance drug activity. The resulting composite hydrogel has good hydrophilicity, mechanical properties, and stability, enabling the slow release of Rg1 for up to 14 days. In addition, in vitro experiments revealed that the composite hydrogel exhibits good biocompatibility (Cell viability > 90%) and promotes angiogenesis and maturation. In subsequent in vivo experiments, the composite hydrogel showed a good ability to promote vascular regeneration (p < 0.0001) and collagen deposition. Finally, Western blotting and qPCR analysis of rat tissues showed that the drug-loaded composite hydrogel group possessed anti-inflammatory and tissue healing abilities. This suggests that the composite hydrogel developed shows great promise in promoting wound healing.