Biomanufacturing of a novel in vitro biomimetic blood-brain barrier model

Abstract

A glioma is a malignant tumor that severely threatens human health. However, it is difficult for most therapeutic agents to penetrate through the blood-brain barrier (BBB) and exhibit their antineoplastic activity in the brain. In this article, a biomimetic in vitro BBB model was created by a composite process, this model can provide a significant foundation for the research of drug transport, tumor treatment, tumor microenvironment and other fields. A series of tests and comparative experiments were performed to evaluate this model. The tests showed that the model enabled preliminary simulation of the structure and function of the BBB. Experimental results demonstrated: (1) the new technology enabled controlled release of growth factors and successfully induced endothelial progenitor cells into endothelial cells. Compared with the traditional gold standard, the Transwell model, the expression of four specific proteins that are related to the BBB characteristics was significantly increased (alkaline phosphatase(ALP) by 89.82%, γ-GT by 88.86%, zonula occludens-1 (ZO-1) by 57.40%, and Claudin-5 by 102.32%) in this model; (2) astrocytes had a promoting effect on the microvascular endothelial cells to form tight junction (ZO-1 increased by 249.35%, Claudin-5 increased by 184.99%), and there was a great difference between whether these two types of cells were contact cultured or not; (3) the gelatinous cell U118 had a destructive effect on the tight junction of BBB (ZO-1 decreased by 55.86%, Claudin-5 decreased by 37.84%).

Engineering of tissue constructs using coaxial bioprinting

“…Coaxial nozzles have an outer layer, which produces the sheath, and an inner layer, which produces the core. Nozzle sizes vary greatly depending on the application, and sheath nozzles with inner diameter up to 7 mm have been shown successful if proper curing and crosslinking procedures are implemented [ 21 ]. Core nozzle inner diameter can be as small as 210 μm [ 22 ].…”

“…A notable and widely used physical crosslinking method is the reaction of alginate with divalent anions such as Ca 2+ . This reaction is quicker than most physical methods and requires a bath [ 21 ], aerosol spray [ 29 ], or inline flow of calcium ions [ 30 ]. A vacuum under the stage may be used to remove the excess ion solution as deposition occurs [ 30 ].…”

“…3 B). Growth factor incorporation in coaxially extruded constructs can also achieve controlled release, whether the growth factor is incorporated in the core or the sheath fluid [ 21 , 60 , 64 ]. This can be extended for a variety of small molecules, such as angiogenic factors, sustained release of which can aid in endothelialization.…”

“…In vivo understanding of these processes is difficult; various 2D and 3D cell culture models have been developed to bridge this gap [ 69 , 70 ]. Recently, Liu et al presented a coaxially printed model where they co-cultured brain microvascular endothelial cells, endothelial progenitor cells, and astrocytes [ 21 ]. After printing a hydrogel construct, the group sequentially deposited cell and material layers, resulting in a complex final structure.…”

Culture models produced via biomanufacturing for neural tissue-like constructs based on primary neural and neural stem cells

“…These models, however, typically result in unreliable results due to the lack of a similar microenvironment in vitro . Several studies have revealed that differences exist between the 2D and 3D cultures and across species [47]. This is why many “efficient” drugs that perform well lose their effects in clinical trials.…”