title: Novel multi-layer APPPA microcapsules for oral delivery: preparation condition, stability and permeability.
abstract: Oral therapy utilizing cell microencapsulation has shown promise in the treatment of many diseases. Current obtainable microcapsule membranes, however, show inadequate stability in the gastrointestinal (GI) environment, thus restricting the general application of live cells for oral therapy. To overcome this limitation, we have previously developed a novel multilayer alginate/poly-L-lysine/pectin/poly-L-lysine/alginate microcapsule (APPPA) with demonstrated improvement on membrane stability over the frequently reported alginate/poly-L-lysine/alginate (APA) microcapsules. In this study, we further examined the effects of preparation conditions on microcapsule formation, and assessed the membrane strength and GI stability. Results showed that increased membrane strength of the APPPA microcapsules was attained by using pectin with low degree of esterification as the mid-layer material, saline as the solvent for the preparation solutions and washing medium, and 0.1 M CaCl2 as the gelling solution for alginate cores. Resistance of this membrane to the simulated GI fluids was also investigated. Permeability of and release profiles from the APPPA microcapsules were found comparable to the APA microcapsules. These findings suggested that the multi-layer APPPA microcapsule formulation may have potential in oral delivery of proteins, live bacterial cells and other biomedical applications.
authors.affiliation: Department of Biomedical Engineering and Physiology, Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, 3775 University Street, Montreal, QC H3A 2B4 Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Ouyang
authors.forename: Hongmei
authors.initials: H
authors.lastname: Chen
authors.forename: Mitchell L
authors.initials: ML
authors.lastname: Jones
authors.forename: Tasima
authors.initials: T
authors.lastname: Haque
authors.forename: Christopher
authors.initials: C
authors.lastname: Martoni
authors.forename: Fateme
authors.initials: F
authors.lastname: Afkhami
authors.forename: Satya
authors.initials: S
authors.lastname: Prakash
mesh_terms: D000284:Administration, Oral; D000464:Alginates / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D002122:Calcium Chloride / Q000737:chemistry; D002214:Capsules; D002417:Cattle; D002463:Cell Membrane Permeability; D004339:Drug Compounding / Q000379:methods*; D004355:Drug Stability; D041981:Gastrointestinal Tract / Q000378:metabolism; D010368:Pectins / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: C552480:APPPA compound; D000464:Alginates; D002214:Capsules; D012965:Sodium Chloride; D010368:Pectins; D012964:Sodium; D002122:Calcium Chloride