负载噬菌体qdvp001的阳离子脂质体的制备及热稳定性和抗菌活性

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

摘要:

【背景】副溶血弧菌噬菌体qdvp001在防治副溶血弧菌污染方面具有巨大的应用潜力，但其对温度的敏感性较高，在较高的温度环境下会失活。【目的】利用阳离子脂质体包埋保护噬菌体qdvp001以提高其热稳定性，同时探究其脂质体包被液的抗菌活性。【方法】制备和表征负载副溶血弧菌噬菌体qdvp001的阳离子脂质体，测定阳离子脂质体包埋下的噬菌体经高温处理后的效价，并对脂质体包被液的杀菌活力进行测定。【结果】相对于未添加十八胺(octadecylamine，ODA，带正电的胺类化合物)的中性脂质体，ODA的添加使脂质体的表面带正电荷。脂质体平均粒径随着表面电荷绝对值的增加呈现减小的趋势，不同脂质体的多分散系数(polydispersity index，PDI)均在0.7以下，表明其具有较好的均匀性。负载副溶血弧菌噬菌体qdvp001的阳离子脂质体在50、60和70 ℃条件下表现出较好的热稳定性，随着脂质膜表面电荷的不断增大，其对噬菌体的热保护性也逐渐提升。此外，负载噬菌体qdvp001的阳离子脂质体也表现出比中性脂质体更好的抗菌活性。【结论】负载噬菌体qdvp001的阳离子脂质体在高温下对噬菌体有很好的保护性，同时具备更优良的抗菌活性，使噬菌体qdvp001有更好的应用前景。

关键词:阳离子脂质体;噬菌体;热稳定性;抗菌活性

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.

Key words:cationic liposomes;bacteriophage;thermal stability;antibacterial activity