title: Enteric-coated capsule containing β-galactosidase-loaded polylactic acid nanocapsules: enzyme stability and milk lactose hydrolysis under simulated gastrointestinal conditions.
abstract: In order to protect peroral β-galactosidase from being degraded and hydrolyse milk lactose efficiently in the environments of gastrointestinal tract, a double-capsule delivery system composed of enteric-coated capsule and polylactic acid (PLA) nanocapsules (NCs) was developed for encapsulation of β-galactosidase. β-galactosidase-loaded PLA NCs in the size range of 100-200 nm were prepared by a modified w1/o/w2 technique. During the encapsulation process, dichloromethane/ethyl acetate (1 : 1, v/v) as the solvent composition, high-pressure homogenisation (150 bar, 3 min) as the second emulsification method and polyvinyl alcohol or Poloxamer 188 as a stabiliser in the inner phase could efficiently improve the activity retention of β-galactosidase (>90%). Subsequently, the prepared NCs were freeze-dried and filled in a hydroxypropyl methylcellulose phthalate (HP55)-coated capsule. In vitro results revealed that the HP55-coated capsule remained intact in the simulated gastric fluid and efficiently protected the nested β-galactosidase from acidic denaturation. Under the simulated intestinal condition, the enteric coating dissolved rapidly and released the β-galactosidase-loaded PLA NCs, which exhibited greater stability against enzymatic degradation and higher hydrolysis ratio (∼100%) towards milk lactose than the free β-galactosidase. These results suggest that this double-capsule delivery system represents promising candidate for efficient lactose hydrolysis in the gastrointestinal tract.
authors.affiliation: College of Life Sciences,Yantai University,Yantai 264005,PR China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: He
authors.affiliation: College of Life Sciences,Yantai University,Yantai 264005,PR China.
authors.forename: Xueting
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering,Yantai University,Yantai 264005,PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sheng
mesh_terms: D000818:Animals; D004795:Enzyme Stability; D005744:Gastric Acid / Q000737:chemistry / Q000378:metabolism; D041981:Gastrointestinal Tract; D006868:Hydrolysis; D019344:Lactic Acid / Q000737:chemistry*; D007785:Lactose / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008892:Milk / Q000737:chemistry*; D053769:Nanocapsules; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D013997:Time Factors; D001616:beta-Galactosidase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D053769:Nanocapsules; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D001616:beta-Galactosidase; D007785:Lactose