Development of a New Formulation Based on In Situ Photopolymerized Polymer for the Treatment of Spinal Cord Injury.

Spinal Cord Injury (SCI) promotes a cascade of inflammatory events that are responsible for neuronal death and glial scar formation at the site of the injury, hindering tissue neuroregeneration. Among the main approaches for the treatment of SCI, the use of biomaterials, especially gelatin methacryloyl (GelMA), has been proposed because it is biocompatible, has excellent mechanical properties, favoring cell adhesion and proliferation. In addition, it can act as a carrier of anti-inflammatory drugs, preventing the formation of glial scars. The present work presents the development and in situ application of a light-curing formulation based on GelMA containing a natural extract rich in anti-inflammatory, antioxidant and neuroprotective substances (hydroalcoholic extract of red propolis-HERP) in an experimental model of SCI in rats. The formulations were prepared and characterized by time of UV exposition, FTIR, swelling and degradation. The hydrogels containing 1 mg/mL of HERP were obtained by the exposure to UV radiation of 2 µL of the formulation for 60 s. The locomotor evaluation of the animals was performed by the scale (BBB) and demonstrated that after 3 and 7 days of the injury, the GelMA-HERP group (BBB = 5 and 7) presented greater recovery compared to the GelMA group (BBB = 4 and 5). Regarding the inflammatory process, using histomorphological techniques, there was an inflammation reduction in the groups treated with GelMA and GelMA-HERP, with decreases of cavitation in the injury site. Therefore, it is possible to conclude that the use of GelMA and GelMA-HERP hydrogel formulations is a promising strategy for the treatment of SCI when applied in situ, as soon as possible after the injury, improving the clinical and inflammatory conditions of the treated animals.

Green LED light has anti-inflammatory effects on burns in rats.

PURPOSE: The aim of this study was to evaluate the effects of green LED light on inflammatory cells in skin burns: a histological study in rats. METHODS: In this study, 40 rats were randomly divided into 2 groups: G1 - Control (CTR) and G2 - Green Led (LED). Immediately after injury, green light (60J/cm(2), 10s, λ520 at 550nm) was applied in a timely manner in the four coinciding points of the wound angles and at each point, the amount of 60J/cm (2) with a time of 10s was delivered, totaling 240J/cm(2) per session with 24h intervals until the day before animal sacrifice at 3, 7, 14 and 21 days with a lethal dose of intraperitoneal anesthetic. RESULTS: In the histological analysis, animals treated with green LED, from 7 days, showed a significant decrease (p<0.05) in inflammatory cells when compared to control group. CONCLUSIONS: Green LED light provides an anti-inflammatory effect on skin burns of rats.