Recapitulation of 3D cylindrical human blood-brain barrier in vitro using brain and blood vessel tissue specific bioinks and 3D bioprinting technology

Abstract

Neuroinflammation-associated diseases, such as Alzheimer’s disease and Parkinson’s disease, have affected the health and quality of life of people globally. The major regulator of neuroinflammation is the blood-brain barrier (BBB), which controls the molecular transport from brain vasculature to the central nervous system. Since the BBB is a 3D complex structure consisting of various cell types, 2D cell culture models or animal models are difficult to use for in-depth mechanistic studies of neuroinflammation. Therefore, it is necessary to recapitulate the 3D cylindrical structure and tissue-specific intrinsic function of the human BBB in vitro. Previous researches demonstrated that decellularized extracellular matrix (dECM), derived from the target tissue, has advantage in providing tissue specific micro-environmental cues. In addition, previous studies successfully developed tissue engineered cylindrical Bio-Blood-Vessels using coaxial-based 3D cell printing strategy. Here, we conducted characterization and functional validation of brain-derived dECM (BdECM) and blood vessel-derived dECM (VdECM), and coaxial-based cell-laden fiber printing process optimization for recapitulating human BBB in vitro. Proteomic analysis revealed that BdECM and VdECM have target tissue specific ECM protein, collagen and laminin in BdECM and vimentin and tubulin in VdECM. Furthermore, cell encapsulation test showed that the mixture of BdECM and VdECM provides more stable environmental cues for protein expression of human brain microvascular endothelial cells and human brain vascular pericytes constructing BBB. Finally, we fabricated cylindrical BBB tissue using coaxial-based cell-laden fiber printing process and validated its potential barrier function. Later, this study will be the basis for developing BBB-on-a-Chip to investigate the mechanism of neuroinflammation.