title: Permeation enhancement via thiolation: in vitro and ex vivo evaluation of hyaluronic acid-cysteine ethyl ester.
abstract: It was the aim of this study to evaluate the permeation-enhancing effect of synthesized thiolated hyaluronic acid (HA). HA, a naturally found polysaccharide, was chemically modified with l-cysteine ethyl ether (C) via amide bond formation. In vitro permeation enhancement was tested on Caco-2 cells with two compounds, sulforhodamine (SR) and fluorescein isothiocyanate-dextran (FD4). Cytotoxicity assays as lactate dehydrogenase and thiazolyl blue tetrazolium bromide (MTT) were performed on colon carcinoma cell line. Transepithelial electrical resistance (TEER) measurements were conducted. Ex vivo evaluation was accomplished on rat intestinal mucosa in order to predict the permeation enhancing effect with SR, sodium fluorescein (SF), and FD4, respectively. The MTT as well as lactate dehydrogenase revealed no toxicity over time periods of 3 and 12 h, respectively. The bioconjugate is biocompatible and safe to use. Furthermore, TEER measurements showed the integrity of tight junctions. The in vitro permeation studies on cell studies exhibit 1.28-fold enhancement for SR and 1.47-fold enhancement for FD4 with hyaluronic acid-cysteine ethyl ester (HAC) in comparison to unmodified one. The ex vivo transport studies exhibit 1.9-fold enhancement for SF, 1.31-fold enhancement for Rhodamine123, and 1.3-fold enhancement for FD4 with HAC in comparison to unmodified one, respectively. Thus, the promising results encourage further investigations and exploitation of this versatile polysaccharide.
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.
authors.forename: Flavia
authors.initials: F
authors.lastname: Laffleur
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Psenner
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.
authors.forename: Wongsakorn
authors.initials: W
authors.lastname: Suchaoin
mesh_terms: D000818:Animals; D018938:Caco-2 Cells; D002277:Carcinoma; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism; D003545:Cysteine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D003911:Dextrans / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D007408:Intestinal Absorption / Q000502:physiology; D007413:Intestinal Mucosa / Q000378:metabolism; D010539:Permeability; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012235:Rhodamines / Q000737:chemistry / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry* / Q000378:metabolism*; D019108:Tight Junctions / Q000378:metabolism
chemical_list: D003911:Dextrans; D004337:Drug Carriers; C509315:HA-DTPH-PEGDA; D012235:Rhodamines; D013438:Sulfhydryl Compounds; C015219:fluorescein isothiocyanate dextran; C086359:hyaluronic acid ethyl ester; C031752:ethyl cysteine; D011092:Polyethylene Glycols; D006820:Hyaluronic Acid; D016650:Fluorescein-5-isothiocyanate; D003545:Cysteine
keywords: Caco-2 cells; biomaterial; mucosal drug delivery; oral drug delivery; permeation enhancers