Photobiomodulation with consecutive and simultaneous irradiation using 660nm and 808nm and the angiogenesis response in a chorioallantoic membrane assay

• Grant number: 25/15163-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Maria Cristina Zindel Deboni
• Grantee: Ana Celine Bruneli Cavalcanti Santo Andre
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Tissue repair is a complex mechanism that involves the ability of the living organism to recompose the structures injured or lost after an aggression. This aggression can be caused by physical agents (e.g. trauma, surgery, burns), chemical (e.g. action of chemical substances), biological (microorganisms) and immunological (e.g. autoimmune reactions), leading to the appearance of a wound. Angiogenesis plays a fundamental role in tissue repair because they are responsible for the distribution of oxygen and nutrients to the tissue in formation. The use of photobiomodulation as a therapeutic form seems to be relevant and with lower risks of side effects than other therapies. FBM has shown that it is able to improve the repair process and the regeneration of wounds, scars and blood perfusion, as well as promote analgesia. Several protocols have been used for photobiomodulation of tissues aiming at repair without there being a consensus on the real effects of FBM applications, different wavelengths with isolated, consecutive and/or simultaneous applications could show different and perhaps more efficient results. In addition, the market has launched pre-configured equipment with the objective of facilitating the "dual" use of the therapy and handling by most professionals without the need for major adjustments in the parameters of the devices. In this context, our proposal is to investigate whether the effect of photobiomodulation at two wavelengths (660 nm and 808 nm) and the irradiation in either a consecutive or simultaneous manner using both types of lasers can influence the formation of blood vessels. To test this hypothesis, we will utilize the chorioallantoic membrane assay (CAM) model using fertilized chicken eggs. The chorioallantoic membrane assay is one of the most widely used methods to determine the angiogenic responses to various interventions. This type of assay allows for a rapid, simple, and cost-effective evaluation. The fertilized eggs will be irradiated with the same energy (1 J) and a minimum power of 100 mW using a Therapy DC diode laser (Brand model) in a single application on the seventh embryonic day, with red laser (660 nm) and infrared laser (808 nm) applied separately, consecutively (one after the other in the same session), or simultaneously (both wavelengths together in the same session). Control groups will consist of eggs that do not undergo irradiation but will be exposed to the same duration in a simulated intervention (SHAM).After a maximum incubation period of 14 days, which minimizes the suffering of the embryo, the irradiated and SHAM eggs will be evaluated. To assess the angiogenic response, macroscopic analyses will be performed through standardized stereoscopic digital imaging, and qualitative and quantitative microscopic analyses will be conducted through histological examination of vascular formation in the chorioallantoic membranes (CAMs) of the eggs across the different groups. The obtained data will be subjected to normality tests to verify adherence to a normal or non-normal distribution, and appropriate statistical tests will be applied using the JAMOVI 5.0 software, with a significance level of 5%. (AU)