title: Use of β-galactosidase liposome model as a novel method to screen freeze-drying cryoprotectants.
abstract: This study developed a novel method of screening cryoprotectants used to improve the survivability of lyophilized Lactobacillus helveticus. To develop a liposome encapsulated β-galactosidase (β-gal) as a cell membrane model, the β-gal liposome was characterized in terms of mean size, poly dispersity index, zeta potential, along with transmission electron microscopy. 800 W of ultrasonic power and 10 min of sonication time were the optimal experimental conditions to obtain the desirable β-gal liposome. Subsequently, different cryoprotectants were mixed with the β-gal liposome during freeze-drying. After freeze-drying, liposomes were hydrolized, and the protective effect of cryoprotectants was assessed as the release rate of encapsulated β-gal. The lowest release rate of β-gal was obtained using 10 mg/100 ml trehalose and 0.2 mg/100 ml hyaluronic acid.
authors.affiliation: College of Biological Science and Biotechnology, Beijing Forestry University, Box 162, Qinghua E Rd 35, Beijing, People's Republic of China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Sun
authors.forename: Lili
authors.initials: L
authors.lastname: Gao
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Youqun
authors.initials: Y
authors.lastname: Liu
authors.forename: Bolin
authors.initials: B
authors.lastname: Zhang
mesh_terms: D002462:Cell Membrane / Q000528:radiation effects; D003451:Cryoprotective Agents / Q000302:isolation & purification* / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005612:Freeze Drying; D052198:Lactobacillus helveticus / Q000502:physiology / Q000528:radiation effects; D008081:Liposomes / Q000528:radiation effects*; D001616:beta-Galactosidase / Q000032:analysis*
chemical_list: D003451:Cryoprotective Agents; D008081:Liposomes; D001616:beta-Galactosidase