Anti-angiogenic activity of polymeric nanoparticles loaded with ursolic acid.

Ursolic acid (UA) is an abundant natural product and has shown great promise for treating diseases related to the appearance of new blood vessels. However, its clinical use is limited due to its low solubility in aqueous media, resulting in reduced bioavailability. The present study aimed to synthetize poly(lactic-co-glycolic acid) nanoparticles loaded with UA by nanoprecipitation method and to evaluate the toxicity and anti-angiogenic activity using the in vivo chorioallantoic model. The nanoparticles were obtained in the size range that varied from 103.0 to 169.3 nm, they presented a uniform distribution (polydispersity index <0.2), and a negatively charged surface, with an encapsulation efficiency close to 50%. The release profile of the developed nanoformulation showed an initial burst in the first 2 h and demonstrated no acute toxicity (irritation index <0.9). Moreover, the chorioallantoic assay showed a significant reduction in both geometrical and topological parameters compared to saline control (p < .05). In conclusion, the study revealed a quick and simple way to obtain poly(lactic-co-glycolic) acid nanoparticles, a drug delivery system to UA, which showed potential antiangiogenic action and can be used to treat diseases involving neovascularisation.

The proteolytic fraction from Vasconcellea cundinamarcensis accelerates wound healing after corneal chemical burn in rabbits.

INTRODUCTION: Chemical ocular burns are among the most frequently eye-related injuries, which require immediate and intensive evaluation and care since they may lead to potential complications such as superinfection, corneal perforation, and blindness.Vasconcellea cundinamarcensis, a species from Caricaceae family, contains highly active proteolytic enzymes in its latex that show healing activity in animal models bearing lesions of different etiologies. METHODS: We evaluate the ocular toxicity of the proteolytic fraction from V. cundinamarcensis (P1G10) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Hen's Egg Test-Chorioallantoic Membrane test. The corneal healing property of P1G10 was studied by the ethanol-chemical burn in the rabbit's eyes. RESULTS: P1G10 is safe for ocular administration, except when administrated at 10µg/mL. P1G10 at 1µg/mL accelerates the corneal re-epithelization achieving complete wound closure after 72h of chemical burn. Also, P1G10 modulated the inflammatory response and controlled the arrangement of collagen fibers in the stroma, demonstrating its potential corneal healing properties. CONCLUSIONS: Our work was the first one to evaluate the ophthalmic application of P1G10. Here we demonstrated that P1G10 is suitable for ocular administration and it has a promising corneal healing activity which may emerge as a new pharmacological tool to the development of a new drug for ocular surface chemical injuries in the future.

Gelatin-based membrane containing usnic acid-loaded liposomes: A new treatment strategy for corneal healing.

PURPOSE: To evaluate the safety and potential healing efficacy of the topical ocular administration of a gelatin membrane containing usnic acid/liposomes (UALs) for corneal cicatrization. UALs have shown healing activity in animal models of dermal burn lesions. We evaluated the safety of topical ocular administration of UAL and its potential healing efficacy as an ophthalmic treatment on chemical lesions in rabbit eyes. METHOD: The Draize test was used to check for ocular toxicity and the score was zero at each observation, indicating the ocular safety of a gelatin membrane containing usnic acid/liposome. Its potential healing efficacy as an ophthalmic treatment on chemical lesions in rabbit eyes was also assessed. RESULTS: After epithelial removal and treatment with UAL, there was a 49.4 % reduction in injury under in vivo conditions compared with a 36.6 % reduction in the control, a gelatin membrane containing liposome without usnic acid. Histological analysis of ocular surface chemical injury-tissue sections after treatment with UAL supported these observations. The corneal expression of VEGF and TGF-ß1increased by 70 % and 50 % respectively following treatment with UAL gelatin membrane. CONCLUSION: These results indicate the potential therapeutic application of UAL gelatin membranes as an ophthalmic treatment that may be used for corneal cicatrization.