Carboxymethyl cellulose films containing nanoliposomes loaded with an angiotensin-converting enzyme inhibitory collagen hydrolysate

Abstract

A collagen hydrolysate (HC) obtained from giant squid (Dosidicus gigas) tunics was encapsulated in soy phosphatidylcholine liposomes in the presence and absence of glycerol. The z-average and ζ-potential of empty and loaded liposomes ranged from 92.4 to 96.0 nm and from −30.4 to −34.5 mV, respectively. The HC was encapsulated with an entrapment efficiency of 80–83%, and the resulting liposomal dispersions showed ≈50% of angiotensin-converting enzyme (ACE) inhibitory capacity. An in vitro process of gastrointestinal digestion of the liposomes increased the antihypertensive potential, regardless of the presence or absence of glycerol. The liposomal dispersions were incorporated into carboxymethyl cellulose films, in which two ways of adding glycerol were compared: adding it directly to the film-forming dispersion or incorporating it previously into the liposomes. The presence of intact liposomes in the films, which was corroborated by transmission electronic microscopy at cryogenic temperature, decreased the water solubility and increased adhesiveness. The results demonstrated that glycerol-containing liposomes were less affected by the film drying step and also the subsequent simulated gastrointestinal digestion, with greater preservation of vesicle size and morphology, than if glycerol was added directly to the film-forming solution.