Natural Polysaccharide Film-Based Triboelectric Sensor for Fruit Transportation Collision Monitoring.

Transportation-induced damage to fresh produce is a big challenge in logistics. Current acceleration and pressure sensors for collision monitoring face issues of power dependency, high cost, and environmental concerns. Here, a self-powered and environmentally friendly triboelectric sensor has been developed to monitor fruit collisions in transportation packaging. Microcrystalline cellulose/chitosan and sodium alginate films were prepared as positive and negative tribo-layers to assemble a natural polysaccharide film-based triboelectric nanogenerator (NP-TENG). The NP-TENG's electrical output was proportional to the structure parameters (contact surface roughness and separation gap of the tribo-layers) and the vibration factors (force and frequency) and exhibited excellent stability and durability (over 100,000 cycles under 13 N at 10 Hz). The high mechanical-to-electrical conversion efficiency (instantaneous areal power density of 9.6 mW/m2) and force sensitivity (2.2 V/N) enabled the NP-TENG to be a potential sensor for monitoring fresh produce collisions in packaging during logistics. Transportation simulation measurements of kiwifruits verified that the sensor's electrical outputs increased with the vibration frequency and stacking layer while varying at different packaging locations. This study suggests that the NP-TENG can effectively monitor collision damage during fruit transportation, providing new insights into developing intelligent food packaging systems to reduce postharvest supply chain losses.

Borneol serves as an adjuvant agent to promote the cellular uptake of curcumin for enhancing its photodynamic fungicidal efficacy against Candida albicans.

Candida albicans (C. albicans), a major opportunistic pathogenic fungus, is known to cause superficial skin infections. Unfortunately, the misuse of antibiotics has led to the emergence of drug resistance in fungi. Antimicrobial photodynamic therapy (aPDT), a non-antibiotic alternative, has shown potential in treating drug-resistant fungal infections. Curcumin is a photodynamically active phytochemical whose photodynamic fungicidal efficacy is largely dependent on its intracellular accumulation. However, curcumin faces challenges in penetrating the cytoplasm due to its poor water solubility and the fungal cell wall. Borneol, another monoterpenoid phytochemical, is known for its ability to enhance drug absorption. In this study, we showed that borneol improved the cellular uptake of curcumin, thereby enhancing its photodynamic fungicidal efficacy against C. albicans. This effect was attributed to borneol's ability to increase cell permeability. Transcriptomic analysis further confirmed that borneol disrupted the normal structure and function of the C. albicans cell wall and membrane, resulting in dysregulated mRNA expression of related genes and ultimately increased cell permeability. As a result, the excessive accumulation of curcumin in C. albicans triggered the overproduction of intracellular ROS upon exposure to blue light. These excessive intracellular ROS disrupted various cellular structures, interfered with essential cellular processes, inhibited biofilm formation and reduced virulence. Remarkably, borneol was also found to enhance curcumin uptake by C. albicans within biofilms, further enhancing the anti-biofilm efficacy of curcumin-mediated aPDT (Cur-aPDT). In conclusion, the results of this study strongly support the potential of borneol as an adjuvant agent to Cur-aPDT in treating superficial cutaneous fungal infections.