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College of Pharmacy, Chongqing Medical University, Chongqing, P. R. China AbstractThis study reports on the performance of sodium alginate (SA)/poly(vinyl alcohol) (PVA)/ moxifloxacin hydrochloride (MH) nanofibrous membranes (NFM) capable of providing antibacterial agent delivery for wound-dressing applications. The aim of this work was to prepare antibacterial NFM with good permeability properties by employing PVA and SA as carriers. A group of 12% PVA/2% SA solutions blended in various ratios (8:2, 7:3, 6:4, 5:5 and 4:6, v/v) and containing 0.5, 1, 2 or 4 wt% MH were studied for electrospinning into nanoscale fibermats. The optimum ratio found to form smooth fibers with uniform fibrous features was 6:4. The drug release behavior of the electrospun, the antibacterial effects on Pseudomonas aeruginosa and Staphylococcus aureus and the animal wound dressing capabilities were also investigated. As much as 80% of the MH was released from the electrospun after 10 h of incubation at 37 C. In addition, the NFM with 0.5 MH exhibited less activity, whereas those with higher concentrations of MH exhibited greater antibacterial effect. Furthermore, the MH-loaded electrospun accelerated the rate of wound dressing compared to other groups. The results of the in vitro and in vivo experiments suggest that MH/PVA/SA nanofibers might be an interesting bioactive wound dressing for clinical applications.

Diabetic retinopathy is one of the most common and severe complications of diabetes mellitus. Arctiin, a bioactive compound isolated from the dry seeds of Arctium lappa L., has been reported to have antidiabetic activity. In this study, we investigated the effect of arctiin on the serum glucose and HBA1c levels, the blood viscosity, and VEGF expression in the retinal tissues of rats with diabetic retinopathy. We first extracted arctiin from Fructus Arctii and then investigated its chemopreventive effect on streptozotocin-induced diabetic retinopathy in male Sprague-Dawley rats. After the induction of diabetes using streptozotocin (30 mg/kg, i. p.), the rats were randomly divided into five groups (n = 20 per group) and treated with intragastric doses of 30, 90, or 270 mg/kg/d wt of arctiin, 100 mg/kg/d wt of calcium dobesilate, or 0.5 % CMC-Na. Twenty nondiabetic sham-treated rats were treated with 0.5 % CMC-Na. The occurrence of diabetic retinopathy did not differ dramatically among the groups. However, at week 16, the glycosylated haemoglobin (HBA1c) level was significantly decreased in all of the arctiin-treated groups when compared with the control group, and the serum glucose level was also decreased in the rats treated with the highest dose of arctiin. In addition, treatment with arctiin ameliorated retinal oedema, detachment of the retina, and VEGF expression in the retina, as detected using histological and immunochemical examinations. Finally, arctiin increased the viability of retinal microvascular endothelial cells in vitro. Together, these findings demonstrate that arctiin decreases the severity of diabetic complications, demonstrating the importance of this compound as an inhibitor of diabetic retinopathy.

The conventional photosensitizers used in photodynamic therapy (PDT), such as haematoporphyrin (HP), have not yet reached satisfactory therapeutic effects on port-wine stains (PWSs), due largely to the long-term dark toxicity. Previously we have showed that hypericin exhibited potent photocytotoxic effects on Roman chicken cockscomb model of PWSs. However, the molecular mechanism of hypericin-mediated photocytotoxicity remains unclear. In this study, we employed human umbilical vein endothelial cells (HUVECs) to investigate the hypericin-photolytic mechanism. Our study showed that hypericin-PDT induced reactive oxygen species (ROS), resulting in cell killings and an activation of the inflammatory response. Importantly, we have also discovered that photoactivated hypericin induced apoptosis by activating the mitochondrial caspase pathway and inhibiting the activation of the vascular endothelial growth factor-A (VEGF-A)-mediated PI3K/Akt pathway. Notably, we found that hypericin exhibited a more potent photocytotoxic effect than HP, and largely addressed the inconvenience issue associated with the use of HP. Thereby, hypericin may be a better alternative to HP in treating PWSs.

Hypericin (HY) is a promising photosensitizer (PS) for use in photodynamic therapy (PDT). Port-wine stains (PWSs) are congenital superficial dermal capillary malformations. In this study, we evaluated the photocytotoxic effects of HY for PDT in human vascular endothelial cells and a chicken cockscomb model. HY significantly inhibited the growth of human umbilical vein endothelial cells (HUVECs), as determined by colorimetric assays and morphological observation, and flow cytometry assays indicated induction of apoptosis and collapse of the mitochondrial membrane potential. In addition, HY more effectively inhibited growth of and induced apoptosis in HUVECs compared with hematoporphyrin (HP). Further experiments performed in a Roman chicken cockscomb model also showed a clear photocytotoxic effect on the cockscomb dermal capillary upon intravenous injection of HY. This effect may be due to the role of HY in the induction of apoptosis. Transmission electron microscopical analysis showed mitochondrial morphological changes such as incomplete ridges and swelling, and immunohistochemical assays showed an increase in the release of cytochrome c. In conclusion, HY exhibited a greater photocytotoxic activity than did HP toward the growth of endothelial cells and may thus represent a potent PS for PWS PDT.