Preparation,thermal stability,and antibacterial activity of cationic liposomes encapsulating bacteriophage qdvp001

Abstract:

[Background] The bacteriophage qdvp001 has a great potentiality in preventing Vibrio parahaemolyticus contamination.However,the phage is highly sensitive to temperature and will be deactivated under high temperature.[Objective] We encapsulated qdvp001 in cationic liposomes to improve its thermal stability and explored the antibacterial activities of the cationic liposomes encapsulating qdvp001.[Methods] The cationic liposomes encapsulating qdvp001 were prepared and characterized,and their thermal stability and bactericidal activity were investigated.[Results] Compared with the neutral liposome without octadecylamine (ODA,a positively charged amine compound),the addition of ODA contributed to the positive charging of the liposome surface.The average particle size of liposomes decreased with the increase in the absolute value of surface charge.The polydispersity index (PDI) of different liposomes were all below 0.7,indicating the good uniformity of these liposomes.Besides,the cationic liposomes encapsulating qdvp001 showed good thermal stability at 50,60 and 70℃.The heat preventive effects of liposomes to bacteriophage gradually improved with the increase in the surface positive charges of the liposomes.In addition,the cationic liposomes encapsulating qdvp001 had stronger antibacterial activities than the neutral liposomes encapsulating the bacteriophage.[Conclusion] The cationic liposomes encapsulating qdvp001 can protect the phage at high temperature and have good antibacterial activity.It makes qdvp001 have a better application prospect.