Silk Fibroin Formed Bioadhesive Ophthalmic Gel for Dry Eye Syndrome Treatment.

PURPOSE: Dry eye syndrome (DES), arising from various etiologic factors, leads to tear film instability and ocular surface damage. Given its anti-inflammatory effects, cyclosporine A (CsA) has been widely used as a short-term treatment option for DES. However, poor bioavailability and solubility of CsA in aqueous phase make the development of a cyclosporine A-based eye drop for ocular topical application a huge challenge. METHODS: In this study, a novel strategy for preparing cyclosporine A-loaded silk fibroin nanoemulsion gel (CsA NBGs) was proposed to address these barriers. Additionally, the rheological properties, ocular irritation potential, tear elimination kinetics, and pharmacodynamics based on a rabbit dry eye model were investigated for the prepared CsA NBGs. Furthermore, the transcorneal mechanism across the ocular barrier was also investigated. RESULTS: The pharmacodynamics and pharmacokinetics of CsA NBGs exhibited superior performance compared to cyclosporine eye drops, leading to a significant enhancement in the bioavailability of CsA NBGs. Furthermore, our investigation into the transcorneal mechanism of CsA NBGs revealed their ability to be absorbed by corneal epithelial cells via the paracellular pathway. CONCLUSION: The CsA NBG formulation exhibits promising potential for intraocular drug delivery, enabling safe, effective, and controlled administration of hydrophobic drugs into the eye. Moreover, it enhances drug retention within the ocular tissues and improves systemic bioavailability, thereby demonstrating significant clinical translational prospects.

High-dose vitamin C suppresses the invasion and metastasis of breast cancer cells via inhibiting epithelial-mesenchymal transition.

PURPOSE: Vitamin C (VC) is a kind of essential nutrient in the body regarded as a canonical antioxidant during the past hundred years. However, the anti-cancer effect of VC is controversial. Our study is trying to clarify the relationship between VC dosage and breast cancer metastasis. METHODS: Human breast cancer cell lines Bcap37 and MDA-MB-453 were treated with VC at three different concentrations (low-dose, 0.01 mM; medium-dose, 0.1 mM; high-dose, 2 mM). Wound healing assays were conducted for migration assay; transwell tests were performed to detect the ability of cell invasion. The protein levels were evaluated by Western blot analysis or immunohistochemistry. Tumor xenografts in nude mice were built to test the effects of VC on breast cancer cell proliferation and metastasis. RESULTS: 0.01 and 0.1 mM VC promoted cell migration and invasion when compared with the control group, but 2 mM VC significantly suppressed cell migration and invasion of breast cancer cell lines. High-dose VC increased E-cadherin and reduced Vimentin, indicating that high-dose VC suppressed epithelial-mesenchymal transition (EMT) in breast cancer cells. Besides, high-dose VC inhibited cell invasion promoted by TGF-ß1 in breast cancer cells. Meanwhile, high-dose VC reversed the suppression of E-cadherin and enhancement of Vimentin induced by TGF-ß1 in breast cancer cells. Furthermore, high-dose VC significantly inhibited breast cancer metastasis in vivo. CONCLUSION: High-dose VC inhibits cell migration and invasion of breast cancer cell lines through suppressing EMT. Thus, it may be considered as an anticancer drug candidate for breast cancer patients.

[High dose vitamin C inhibits proliferation of breast cancer cells through reducing glycolysis and protein synthesis].

OBJECTIVE: To investigate the effects of high dose vitamin C (VC) on proliferation of breast cancer cells and to explore its mechanisms. METHODS: Human breast cancer cells Bcap37 and MDA-MB-453 were treated with VC at low dose (0.01 mmol/L), medium dose (0.10 mmol/L) and high dose (2.00 mmol/L). Cell proliferation was determined with CCK-8 assay, protein expression was evaluated by Western blot, and the secretion of lactic acid in tumor cells was detected by colorimetric method. Bcap37 cells were inoculated in nude mice, and tumor baring nude mice were intraperitoneally injected with high VC(4 g/kg, VC group, n=5)or normal saline (control group, n=5) for 24 d. Tumor weight and body weight were calculated. RESULTS: In vitro experiments demonstrated that high dose VC significantly inhibited cell proliferation in Bcap37 and MDA-MB-453 cells (all P<0.01); the expressions of Glut1 and mTOR signaling pathway-related proteins were decreased (all P<0.05); and the secretion of lactic acid was also markedly reduced (all P<0.05). In vivo experiment showed that the tumor weight was decreased in mice treated with high-dose VC as compared with control group (P<0.05), but no difference in body weights between two groups was observed. CONCLUSIONS: High dose VC may inhibit proliferation of breast cancer cells both in vitro and in vivo through reducing glycolysis and protein synthesis.

[Effects of Honokiol on cognitive function in mice with kainic acid-induced epilepsy].

OBJECTIVE: To investigate the effects of Honokiol on cognitive function in mice with epilepsy. METHODS: Kainic acid (38 mg/kg) was intraperitoneally injected in 5 weeks old male ICR mice to induce epilepsy. Honokiol at dose of 3, 10, 30 mg/kg was given to epilepic mice by intraperitoneal injection for 10 days. Fluoro-Jade B staining was used to assess neuronal death; Morris water maze and Y maze tests were used to measure cognitive function such as learning and memory; Western blot was performed to detect the expression of acetylated superoxide dismutase (SOD), microtubule associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ) and P62 in hippocampus tissue; thiobarbituric acid and WST-1 methods were used to detect malondialdehyde (MDA) and SOD. RESULTS: Compared with control group, the levels of acetylated-SOD, MDA, LC3-Ⅱ, P62 and neuronal death increased, cognitive function and SOD decreased in model group (P<0.05 or P<0.01). Honokiol at the dose of 10 mg/kg and 30 mg/kg decreased SOD acetylation, MDA content, expression of LC3-Ⅱ and P62, as well as neuronal death, and the cognitive function was improved (P<0.05 or P<0.01), especially in 30 mg/kg Honokiol group. CONCLUSIONS: Honokiol alleviates oxidative stress and autophagy degradation disorder, decreases neuronal death, and therefore improves cognitive function in epilepsy mice.