در بيوفارماسي سلولي INVITRO به منظور تهيه مدل سلولي سد خوني مغزي براي تحقيقات C6 با سلول هاي آستروسايت ECV403 بررسي كشت توام سلول هاي

Characterization of immortalized ECV304 cells cocultured with astrocytes as a cell-based blood brain barrier model for in vitro cellular biopharmaceutics studies

Drug targeting to the brain is one of the most challenging areas of biopharmaceutical investigations due to the presence of the blood-brain barrier (BBB). Up until now, no cell culture models were shown to represent a well-characterized in vitro BBB model to be utilized for drug delivery and targeting to the brain. Cell lines derived from brain endothelium lack the ability to generate a restrictive barrier function despite possessing some characteristics of BBB such as carrier-mediated transporters. Among cell lines used as in vitro cell-based BBB models, we aimed to evaluate the most studied cell line (ECV304 cell line) for its bioelectrical properties and permeability characteristics upon treatments with astrocytic factors (using rat glioma C6 cells) in the absence or presence of various modulators including extra-cellular matrix and some other tight junction modulators (i.e, cAMP elevators, retinoic acid, dexamethasone, and y-linolenic acid). Significant (p<0.05) increase in trans-endothelial electrical resistance (TEER) values was only observed for ECV304 cells cocultured with astrocytes and treated with cAMP elevators (110 ?c.m2), however such TEER is not comparable to that of in vivo (1500-2000 ?.cm2).ECV304 cells cocultured with astrocytes and treated with cAMP elevators displayed the highest discrimination for permeability coefficients of trans-cellular marker propranolol (25*10ʹ6 cm/sec) and para-cellular marker sucrose (11.3*10^-6 cm/sec). The permeability coefficient ratio of propranolol over sucrose was 2 which is much lower than that of primarily isolated porcine brain microvascular endothelial cells. ECV304 cells failed to generate restrictive para-cellular barrier, thus it is not suggested to be used as an in vitro BBB model for drug screening although its usefulness has been shown for carrier-mediated transport studies.