Colloids and Surfaces B: Biointerfaces最新文献

Ethephon (2-chloroethylphosphonic acid), a widely used ethylene-releasing agrochemical, raises concerns regarding its potential interactions with biological membranes. To address this, we investigated the effects of ethephon on model phosphatidylcholine membranes with different degrees of unsaturation, employing giant unilamellar vesicles (GUVs) as bilayer systems and Langmuir films as complementary monolayer models. GUVs revealed a clear dependence of membrane response on lipid composition. Saturated DPPC vesicles displayed limited morphological alterations upon exposure to ethephon, whereas unsaturated systems were markedly more sensitive. POPC bilayers showed the strongest response, with rapid onset of structural damage, loss of phase contrast, and vesicle rupture within minutes of exposure. DOPC vesicles were also affected, though to a lesser extent, predominantly through loss of contrast and minor shape deformations. Langmuir film experiments supported these findings, indicating that ethephon preferentially interacts with the polar headgroups of unsaturated lipids and induces disorder in their hydrocarbon chains, as revealed by PM-IRRAS. The combined evidence demonstrates that lipid unsaturation plays a critical role in modulating the susceptibility of membranes to ethephon, with POPC bilayers being the most vulnerable. These results highlight potential molecular mechanisms underlying the impact of this agrochemical on cell membranes and may provide insights into its toxicological effects at the biomembrane level.

Although drug nanocrystals have attracted considerable interest within the pharmaceutical industry, there remain issues with the production of nanocrystals with a size below 100 nm. The aim of the present study is to develop a stable, reproducible Canagliflozin (CFZ) sub-100 nm nanosuspension system using microfluidic nanoprecipitation and Quality by Design (QbD) techniques. By means of the circumscribed central composite design (CCCD), critical parameters of the microfluidic nanoprecipitation process and nanosuspension formulation components were optimised. Optimal CFZ nanosuspension with Z-average of 89.52 ± 3.30 nm, PDI of 0.12 ± 0.01 and drug content of 92.49 ± 0.03 % was successfully fabricated using Soluplus as a stabiliser. An increase in saturation solubility corresponding to approximately 250 times the value of the pure CFZ in water was noted. The optimised CFZ nanosuspension was solidified by freeze-drying and electrospraying. Overall, the study has demonstrated that by using a combination of microfluidics and QbD it is promising to generate stable sub-100 nm nanocrystals with high yield, and narrow size distribution and favourable stability.

In the present study, the effect of in situ cross-linking of Ca²⁺ of pectin-tragacanth gum active packaging films with succinic acid on the properties and storage of fresh Easy Rock raspberries was investigated. The introduction of CaCl₂ and Ca₃(C₆H₅O₇)₂ into the polysaccharide matrix at a concentration of 0.125 % (w/w) resulted in an increase (p < 0.05) in film strength. TS was 45.58 MPa (0.125CLF) and 44.66 MPa (0.125 F), respectively. CaCl₂ cross-linked films again showed significantly better barrier performance compared to films treated with calcium citrate. Oxygen permeance similarly declined with increasing cross-linker concentration, with the most substantial improvement occurring between 0.25 % and 0.5 % Ca²⁺. In unpackaged fruit, the amount of anthocyanins increased rapidly after 4 and 7 days. After 7 days of storage, the greatest colour stability and the smallest differences in brightness (L*) were observed in fruit packaged in CaCl₂ cross-linked films, suggesting that calcium more effectively protected the cellular structure of raspberries. Fruit packaged in film with added citrate retained its red colour intensity, but with slightly greater anthocyanin variability, which may be due to greater susceptibility to oxidation with pH changes.

As novel anticancer treatment, phototherapy has recently shown promising immunotherapy effect. However, photodynamic (PDT) or photothermal (PTT) alone is not sufficient to achieve satisfactory anticancer immunities. Certain polysaccharides can stimulate immune responses, but its application as an adjuvant in anticancer phototherapy has not been clearly studied. In this study, we established PLGA nanoparticles (PPS-ICG@PLGA NPs), loading polysaccharides from Poria cocos (PPS) as adjuvant, and using ICG as phototherapeutic molecule to study its anticancer immunities. The PPS was proved to enhance the ICD and immunomodulatory activity of the nanoparticle. Following intravenous injection, the PPS-ICG@PLGA NPs can accumulate in tumor site up to 24 h. Under NIR laser irradiation, the PTT/PDT associated with PPS induced cascade anticancer effects to activate cytotoxic T lymphocytes (CTLs). In vivo antitumor studies confirmed that the administration of PPS-ICG@PLGA NPs increased the ratio of CD4⁺ and CD8⁺ T cells in both tumor and spleen, enhanced DCs maturation in tumor and reversed the intratumor infiltration of regulatory T cells (Tregs) in tumor. These results demonstrate the application potential of PPS in promoting the immunotherapy efficacy of phototherapy, and also propose PPS-ICG@PLGA as a promising nanosystem for photoimmunotherapy.

The pathological microenvironment in diabetes mellitus (DM) patients is marked by local hyperglycemia, elevated oxidative stress, and increased susceptibility to infection, all of which commonly impair the osseointegration of titanium (Ti) implants. To address this clinical challenge, we developed a metal-polyphenol network (CGA/Sr coating) formed by chelating chlorogenic acid with strontium ions, which was anchored to the Ti surface via aminoethylaminopropyltrimethoxysilane (AEAPTMS). The CGA/Sr coating successfully suppressed the biological activity of S. aureus and E. coli, decreased the generation of reactive oxygen species (ROS), and enhanced mitochondrial function. Cell experiments have shown that the coating promotes the proliferation, differentiation and mineralization of osteoblasts, and up-regulates osteogenic markers (Runx2, OSX, OCN). This osteoinductive effect is mediated through the promotion of the Wnt/β-catenin pathway. The involvement of this pathway was further confirmed using a specific inhibitor (FH535). In a type 2 diabetic rat model, Ti rods coated with CGA/Sr exhibited enhanced osteogenesis and osseointegration, as confirmed by micro-CT scanning and histological evaluation. In conclusion, the CGA/Sr coating represents a promising biomaterial strategy for enhancing the osseointegration of Ti implants in DM patients.

The development of a quantitative electrochemical method for H₂O₂ detection is crucial as it enables the real-time assessment of both bleaching agent residues in food and oxidative stress in cancer cells. The single-atom Co catalyst Co SAs@ZIF-NC was prepared using a bimetallic ZIF-8-67 precursor via a template-confined synthesis strategy. Successful synthesis was confirmed through comprehensive characterization of its structure and morphology using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller method, and X-ray absorption near edge structure. The as-synthesized Co SAs@ZIF-NC was immobilized on the surface of a pencil-lead graphite electrode, enabling the electrochemical detection of H₂O₂. The H₂O₂ sensor showed excellent analytical performance for H₂O₂ detection, with a linear range of 1-12000 μM, a detection limit of 0.21 μM, and a sensitivity of 2395.54 μA·mM^-1·cm^-2 (S/N = 3), alongside reliable selectivity, stability, and reproducibility. It was successfully applied to determine H₂O₂ residues in food and monitor extracellular H₂O₂ levels in A549 cells. Therefore, this paper proposes a novel material design strategy for single-atom catalysts for electrochemical H₂O₂ sensing.

Tumor immunotherapy demonstrates considerable promise in activating the body's immune system. Nonetheless, the tumor microenvironment presents a significant challenge to the efficacy of this therapy. Metal-organic framework compounds (MOFs) possess substantial potential for clinical application in tumor immunotherapy, attributed to their high porosity, extensive surface area, adjustable structures, and responsiveness to light and sound. Researchers have developed various MOF-based drug delivery systems designed to modulate the tumor microenvironment (TME) by leveraging these properties as drug carriers. This study begins with a thorough overview of the fundamental characteristics of MOFs, including their structural attributes and synthesis methods. It subsequently provides an in-depth discussion on the mechanisms by which MOF-based drug delivery systems can influence the tumor microenvironment, focusing on the therapeutic targets of tumor immunotherapy and the synergistic application of immunotherapy alongside other therapy modalities (chemotherapy, radiotherapy, photodynamic therapy, sonodynamic therapy, chemodynamic therapy, photothermal therapy, and microwave therapy). Finally, the study addresses the numerous challenges MOF-based immunotherapy encounters in clinical settings.

Highly adaptable pressure sensors are gaining significant interest due to their potential applications in areas, such as artificial skin for wearables, health tracking, and human-machine interface. Here, a new strategy for the fabrication of a flexible wearable pressure sensor based on tissue paper coated with MXene/Bi is reported. Leveraging the inherent flexibility and 3D porous structure of cotton fabric, the sensor demonstrates exceptional performance with high sensitivity (2.73 kPa⁻¹ within 0-20 kPa), a wide detection range (0-1200 kPa), fast response/recovery times (210/100 ms), and long-term durability (3000 cycles). The developed sensor is versatile and suitable for diverse pressure detection, including finger pressing, wrist pulse monitoring, handwriting, and speech recognition. Importantly, tactile sensor array is also designed for the recognition of different tactile stimuli, showcasing significant potential for use in advanced sensor technologies and next-generation wearable electronics.

Repairing large segmental bone defects remains a significant clinical challenge due to the limited self-healing capacity of bone tissue. Although autologous bone grafting is still the clinical standard, it is limited by donor-site complications and availability. Three-dimensional (3D) printed scaffolds offer customizable architectures but often lack bioactivity. Human dental follicle stem cell-derived conditioned medium (hDFSC-CM) is enriched in osteogenic factors but suffers from rapid clearance at defect sites. Here, we engineered a bioactive composite scaffold by integrating a 3D-printed polycaprolactone (PCL) framework with a gelatin methacrylate (GelMA) hydrogel loaded with hDFSC-CM (PCL/GelMA@hDFSC-CM). This design leverages the mechanical strength of PCL and the bio-interfacial properties of GelMA to achieve sustained release of bioactive factors. In vitro, PCL/GelMA@hDFSC-CM significantly enhanced cell adhesion, proliferation, and osteogenic differentiation compared with PCL or PCL/GelMA controls. In vivo, it promoted defect bridging, mineral deposition, and bone regeneration in a rat tibial defect model. Mechanistically, RNA sequencing and functional validation revealed that these pro-osteogenic effects were mediated, at least in part, by activation of the JAK2/STAT3 signaling pathway. These findings demonstrate that functionalizing polymeric scaffolds with a hydrogel-based delivery system effectively harnesses the regenerative potential of stem cell secretomes, offering a promising cell-free strategy for bone tissue engineering.