Evaluation of paracrine interactions between macrophages and endothelial cells in a microfluidic device

• Grant number: 24/23662-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2025
• End date: May 31, 2026
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Katiúcia Batista da Silva Paiva
• Grantee: Ricardo D'Alevedo dos Reis
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Bone tissue resident macrophages (osteomacs) are the first cell types recruited to the region of a bone lesion. Through the secretion of pro-inflammatory cytokines (TNF-¿, IL-1 and IL-6), they are able to recruit other cells to act in the regeneration processes of that tissue. The main cells recruited are lymphocytes, monocytes and macrophages. Monocytes can differentiate into M¿ macrophages that polarize into M1 or M2 depending on the stage of regeneration. M1 macrophages activate an acute inflammatory process in the injured region through the release of pro-inflammatory cytokines and vascular endothelial growth factor (VEGF). M2 macrophages secrete anti-inflammatory factors that promote tissue regeneration and angiogenesis such as VEGF. The cells responsible for angiogenesis are the endothelial cells that line the walls of blood vessels which, when induced by VEGF, enter a process of proliferation and migration, in which new blood vessels are formed and irrigate the site of the injury. Thus, cellular communication between macrophages and endothelial cells is notable in bone repair. In this sense, microfluidics plays a fundamental role for in vitro tests, as it allows to mimic the biodynamic and microphysiological conditions of the human body that conventional in vitro tests could not predict. Hence, the microfluidic chip approach becomes a powerful tool for evaluating cellular interactions in the human body. Therefore, this project aims to evaluate the paracrine interaction between macrophages and endothelial cells that play a fundamental role in bone tissue repair using a microfluidic device.