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pH‐Sensitive Hydrogels as Gastrointestinal Tract Absorption Enhancers: Transport Mechanisms of Salmon Calcitonin and Other Model Molecules Using the Caco‐2 Cell Model
Author(s) -
TorresLugo Madeline,
García Marcos,
Record Rae,
Peppas Nicholas A.
Publication year - 2002
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp0101379
Subject(s) - paracellular transport , chemistry , fluorescein , water transport , biophysics , fluorescein isothiocyanate , biochemistry , membrane , water flow , biology , physics , quantum mechanics , environmental engineering , engineering , permeability (electromagnetism) , fluorescence
The main interest of this work was the investigation of the transport mechanisms of salmon calcitonin through the epithelial cell monolayer in the presence and absence of pH‐sensititive hydrogel nanospheres composed of poly(methacrylic acid‐grafted‐poly(ethylene glycol)) (PMAA‐g‐EG). For this purpose, a gastrointestinal cell culture model, the Caco‐2 cell line, was employed. The transport of other macromolecules such as fluorescein sodium, fluorescein isothiocyanate dextran, and 14 C‐mannitol were also investigated and compared. Transport experiments were conducted in the apical‐to‐basolateral direction at 37 and 5 °C and from the basolateral‐to‐apical direction at 37 °C. Results revealed that the presence of P(MAA‐g‐EG) nanospheres increased the transport of paracellularly transported molecules such as 14 C‐mannitol and fluorescein isothiocyanate dextran when compared to controls. Fluorescein sodium salt solutions were investigated as an actively transported molecule. The transport of fluorescein was affected by the concentration of PEG chains in the structure. Salmon calcitonin transport was enhanced in the presence of the nanospheres. The comparison of the transport behavior of dextran and calcitonin revealed that the main transport mechanism for salmon calcitonin through epithelial cell monolayers is predominantly paracellular.