Introduction: In the previous study, nanoparticles coated with trimethyl chitosan (TMC) derivatives (PPTT-NPs) could promote the oral bioavailability of panax notoginseng saponins (PNS). Herein, we chose PPTT-NPs as a model drug to study the property and mechanism of intestinal absorption in vitro and in vivo. Methods: The stability of PPTT-NPs was evaluated using simulated gastric fluid and simulated intestinal fluid. The uptake and transport of PPTT-NPs were investigated in Caco-2 and Caco-2&HT29 co-culture cells. The biosafety, intestinal permeability, adhesion, and absorption mechanism of PPTT-NPs were investigated using SD rats in vivo. The live imaging and biodistribution of PPTT-NPs were observed by IVIS. Furthermore, the effects on CYP3A4 of PPTT-NPs were investigated using testosterone as the probe substrate. Results: The results of the stability assay showed that PPTT-NPs had a strong tolerance to the pH and digestive enzymes in the gastrointestinal environment. In vitro cell experiments showed that the uptake of drugs exhibited a time-dependent. When the ratio of TMC-VB₁₂ and TMC-Cys was 1:3, the uptake capacity of PPTT-NPs was the highest. PPTT-NPs could enhance the paracellular transport of drugs by reversibly opening a tight junction. Animal experiments demonstrated that PPTT-NPs have good biological safety. PPTT-NPs had good adhesion and permeability to small intestinal mucosa. Meanwhile, PPTT-NPs needed energy and various protein to participate in the uptake of drugs. The live imaging of NPs illustrated that PPTT-NPs could prolong the residence time in the intestine. Moreover, TMC-VB₁₂ and TMC-Cys could reduce the metabolism of drugs by inhibiting CYP3A4 to a certain extent. Conclusion: The results show that TMC-VB₁₂ and TMC-Cys are effective in the transport of PPTT-NPs. PPTT-NPs can increase the intestinal adhesion of drugs and exert high permeation by intestinal enterocytes which demonstrate significant and efficient potential for oral delivery of the BCS III drugs. Graphical Abstract:

Soman is an organophosphorus compound that induces neurotoxicity. In addition to its direct toxic effects resulting from acetylcholine accumulation, neurotoxicity may also be exacerbated by inducing endoplasmic reticulum (ER) stress. In light of the current scarcity of appropriate in vitro assessment models, in the present study, we used cerebral organoids derived from human pluripotent stem cells, a new tool for investigating the mechanisms of neurotoxicity, to investigate soman‐induced ER stress. The results demonstrated that soman significantly suppressed acetylcholinesterase activity and activated the GRP78‐ATF6‐CHOP (i.e. glucose‐regulated protein 78‐activating transcription factor 6‐C/EBP homologous protein) ER stress cascade, driving apoptosis in cerebral organoids. Pharmacological inhibition of ER stress by pre‐treating cerebral organoids with the ER stress inhibitor 4‐phenylbutyric acid prior to soman exposure attenuated apoptotic signaling and downregulated GRP78, ATF6 and CHOP expression. Parallel in vivo validation utilized a rat model with subcutaneous soman exposure, focusing on hippocampal and striatal ER stress markers. Consistent with the in vitro findings, soman‐exposed rats exhibited marked ER stress activation in brain regions critical for neurotoxicity. This study establishes ER stress as a key contributor to soman‐induced neurotoxicity and highlights cerebral organoids as a physiologically relevant model for organophosphorus compound research. We propose ER stress modulation as a potential therapeutic strategy to mitigate neurotoxic outcomes.

Infections secondary to Pasteurella multocida frequently occur in patients who have been exposed to domestic pets. Human infections caused by Pasteurella multocida vary in severity, and clinical features include localised cellulitis, osteomyelitis, systemic bacteraemia, meningitis and pneumonia. No vaccine has been developed against Pasteurella multocida; it is treated with antibacterial agents and, in most cases, surgical intervention. This article discusses the authors' experience in treating a woman with severe cellulitis and osteomyelitis on her hand caused by Pasteurella multocida. She refused surgical intervention and was successfully treated with honey-containing dressings and antibiotics after failure to heal following conservative treatment using conventional wound dressings combined with antibiotics.

The treatment of ocular diseases relies on efficient and precise drug delivery to intraocular target sites to achieve therapeutic concentrations (Akhter et al. 2022, Biswas et al. 2023). However, t...