Human Immortalized Cell-Based Blood–Brain Barrier Spheroid Models Offer an Evaluation Tool for the Brain Penetration Properties of Macromolecules

• Published in: Molecular pharmaceutics Vol. 19; no. 8; pp. 2754 - 2764
• Main Authors: Kitamura, Keita, Okamoto, Ayaka, Morio, Hanae, Isogai, Ryuto, Ito, Ryo, Yamaura, Yoshiyuki, Izumi, Saki, Komori, Takafumi, Ito, Shingo, Ohtsuki, Sumio, Akita, Hidetaka, Furihata, Tomomi
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.08.2022
• Subjects: blood−brain barrier; in vitro model; new modality; drug delivery carriers; receptor-mediated transcytosis; spheroid
• ISSN: 1543-8384; 1543-8392; 1543-8392
• DOI: 10.1021/acs.molpharmaceut.2c00120

Blood–brain barrier (BBB)-permeable middle- or macromolecules (middle/macromolecules) have recently attracted significant attention as new drug delivery carriers into the human brain via receptor-mediated transcytosis (RMT). During the development process of such carriers, it is necessary to thoroughly evaluate their human BBB permeability levels. In such evaluations, our recently established human immortalized cell-based multicellular spheroidal BBB models (hiMCS-BBB models) have shown high potential. However, the specifics of those capabilities have yet to be elucidated. Therefore, in this study, we characterize the ability of the hiMCS-BBB models to evaluate RMT-mediated BBB penetration properties of middle/macromolecules. More specifically, we began by validating transferrin receptor (TfR)-mediated RMT functionalities using transferrin in the hiMCS-BBB models and then examined the BBB permeability levels of MEM189 antibodies (known BBB-permeable anti-TfR antibodies). The obtained results showed that, as with the case of transferrin, temperature-dependent uptake of MEM189 antibodies was observed in the hiMCS-BBB models, and the extent of that uptake increased in a time-dependent manner until reaching a plateau after around 2 h. To further expand the evaluation applicability of the models, we also examined the BBB permeability levels of the recently developed SLS cyclic peptide and observed that peptide uptake was also temperature-dependent. To summarize, our results show that the hiMCS-BBB models possess the ability to evaluate the RMT-mediated BBB-permeable properties of antibodies and peptides and thus have the potential to provide valuable tools for use in the exploration and identification of middle/macromolecules showing excellent BBB permeability levels, thereby contributing powerfully to the development of new drug delivery carriers for transporting drugs into the human brain.