Colloids and Surfaces B: Biointerfaces最新文献

Minimally invasive methods for detecting glucose, cholesterol and hydrogen peroxide are crucial for monitoring the nutritional and health status of humans and animals. The peroxidase mimetic activity by nanozymes is one of the versatile methods for detecting glucose, cholesterol, hydrogen peroxide, and other biomolecules. However, the strict requirement of acidic pH limits their sensing and interfacing ability with natural enzymes. The present study developed bovine serum albumin (BSA) coated gold nanoclusters (AuNC) immobilized on paper fabric to enable single-step visual detection of glucose, cholesterol and hydrogen peroxide in complex biological fluids like serum and milk. The BSA-AuNC suspension and immobilized paper fabric synergistically interface with the natural oxidative enzymes, glucose oxidase or cholesterol oxidase, at physiological pH. The concomitant loss in the fluorescent intensity of BSA-AuNC-loaded paper fabric exposed to the generated hydrogen peroxide (glucose/glucose oxidase or cholesterol/cholesterol oxidase) was directly proportional to the concentration of glucose or cholesterol. These reactions enabled simple visual detection as well as quantification of hydrogen peroxide, glucose and cholesterol using Image-J software and common smartphone-based mobile applications. The detection ability of BSA-AuNC-embedded paper fabric is specific and remains unaltered in the presence of similar oxidase enzymes or similar substrate analogues. With these unique features, the BSA-AuNC embedded paper fabric stands out as a prominent analytical device with enormous potential as a simple, user-friendly detection tool for monitoring biomolecules that are important to health, nutrition, and environmental safeguarding.

Two-photon photodynamic therapy (TP-PDT) offers an innovative approach to cancer treatment that utilizes near-infrared light to activate photosensitizers and generate reactive oxygen species (ROS) for targeted cancer cell elimination. TiO₂-CUR-Sofast (TCS), which uses TiO₂ nanoparticles and Sofast cationic polymer to modify curcumin (CUR), has demonstrated potential as a photosensitizer under visible light irradiation, addressing the limitations of CUR's narrow spectral range and low bioavailability. This study explores the utility of the two-photon technique to activate TCS within the infrared spectrum, aiming to enhance ROS production and penetration depth compared to traditional CUR. TCS exhibits a significantly higher ROS production at 900 nm excitation wavelength, approximately 6-7 times that of CUR, signifying a substantial increase in efficiency. In TP-PDT, TCS showed significant phototoxicity against HeLa and T24 cell lines compared to CUR. Furthermore, TCS's photodynamic efficacy is further confirmed by cell apoptosis and necrosis studies, where approximately 89 % of cells treated with TCS under 900 nm light irradiation were observed in an apoptosis/necrosis state. And the TP-PDT effect in deep tissue was simulated using pig skin. It shows that the two-photon excitation has a significant penetration depth advantage over the single-photon excitation. These results indicate that the two-photon PDT scheme of TCS has greater potential than the single-photon PDT scheme in the treatment of cancer, and provides an experimental foundation for the effective treatment of deep lesions.

Wound healing is delayed due to the infection and biofilm formation of antibiotic-resistant species of gram-negative bacteria especially Pseudomonas aeruginosa and Escherichia coli. Antibacterial photodynamic therapy provides an efficient therapeutic strategy for overcoming drug resistance by producing reactive oxygen species (ROS) and reactive nitrogen species (RNS). Here, we have designed a low-cost light emitting diode (LED) based reusable and non-invasive titanium dioxide nanoparticles patch which is sandwiched between the thin polymer layers. The light-induced pore formation in the polymeric film due to the free radical, in turn, passes through the system and kills the bacteria rather than nanoparticles entering the system resulting in the reusability nature of the patch. The patch's in vitro antibacterial and antibiofilm activity and their mechanism (synergic ROS-induced RNS) were studied. In addition, the reusable antibacterial properties, biocompatibility and wound-healing properties of the patch were also successfully elucidated.

The misuse of antibiotics has led to the growing problem of multidrug-resistant (MDR) bacteria, and there is still a lack of effective antibacterial agents that can replace antibiotics. Therefore, the design and development of multifunctional nanomaterials with long-term inhibitory effects on drug-resistant bacteria are extremely challenging. In this study, a multifunctional biomimetic self-assembly system, BSA-ZnO&Quercetin, based on bovine serum albumin (BSA), ZnO, and quercetin, was established using a simple and controllable method. The prepared self-assembly system has high stability and biocompatibility, and could fully combine the performance advantages of each component. BSA-ZnO&Quercetin showed excellent broad-spectrum antibacterial activity without inducing bacterial resistance. The related antibacterial mechanism of BSA-ZnO&Quercetin primarily involves biofilm inhibition and destruction, and inducing the production of reactive oxygen species, resulting in the death of the bacteria. The biomimetic self-assembly system BSA-ZnO&Quercetin constructed in this research is expected to replace antibiotics for antibacterial application.

Landfill leachate, a complex mixture of pollutants, poses a significant environmental hazard. This study reports the synthesis and characterization of superabsorbent nanocomposites (SANs) designed for enhanced performance in waste management applications. SANs were prepared using carboxymethyl cellulose (CMC) and sodium polyacrylate (SPA) as the main components, carbon dots (CDs) to improve absorption, and Satureja Khuzestanica essential oil (SEO) for antibacterial performance. The results demonstrated that the addition of CDs significantly increased the absorption capacity and liquid retention of the samples, with a water absorption capacity reaching up to 8621 %. Furthermore, the samples exhibited high mechanical strength, with tensile strength improving by over 100 % in the presence of CDs. The inclusion of SEO provided strong antibacterial activity against Escherichia coli and Staphylococcus aureus, with inhibition zones measuring up to 26 mm. These SANs, with their high absorption capacity, mechanical robustness, and antibacterial properties, show great potential for improving waste management practices, particularly in leachate absorption strategies.