Research progress on role of cholesterol in liposomes and replacement with sterols and saponins / 中草药

With the development of process study of liposomes, the design of multifunctional liposomes has been a research hotspot. Cholesterol is one of the main components in liposome preparations, and plays an important role in the liposome's structure and stability. Sterols, saponins with the similar structure and certain pharmacological activities can be used to replace cholesterol in liposomes, which can also form good liposomes. Also, the pharmacological activities of sterols and saponins endow the liposomes with better application value. With the relevant literatures at home and abroad in recent years, this paper reviews the research progress of the role of cholesterol and the replacement design of cholesterol in liposomes with sterols and saponins.

Lipase-catalyzed construction of glucose-modified brain targeting liposomes with paclitaxel and research on its optimized preparation process / 中草药

Objective: To synthesize brain targeting lipid material [(5-cholesten-3β-yl) (D-glucopyranose-6) sebacate, CHS-SE-GLU] by lipase as catalyst in nonaqueous phase and optimize the preparation technology and formulation of CHS-SE-GLU-modified liposomes. Methods: CHS-SE-GLU was synthesized from CHS-SE prepared in previous work and D-glucose using lipase Novozym 435 in acetone. The structure characterization of the products is obtained by MS and NMR. The CHS-SE-GLU-modified paclitaxel-loaded brain targeting liposomes (GLU-PTX-LP) were prepared by thin film dispersion method. Single factor evaluation was applied to optimizing its preparation technology and formulation. Results: CHS-SE-GLU was confirmed by MS and NMR as target products. The optimal formulation and technology of GLU-PTX-LP were as follows: HSPC as membrane material, the ratio of HSPC to PTX was 0.1, the ratio of CHS to HSPC was 0.5, the dosage of DSPG-Na was 2.5%, hydration time was 0.5 h, and hydration temperature was 50 ℃. Three batches of samples were prepared by optimum preparation process and the average encapsulation efficiency was (93.62±1.34)%, (93.75±1.77)%, (92.04±1.50)%; The average particle size was (89.56±1.35), (92.05±3.42), (104.91±3.71) nm; And the average Zeta potential was (-25.21±0.27), (-26.43±0.44), (-25.17±0.65) mV, respectively. Conclusion: Lipase-catalyzed method for the preparation of brain targeting lipid material is simple and environment friendly with high yield. The entrapment efficiency, particle size, and stability of brain targeting drug-loading liposomes modified by CHS-SE-GLU all meet the requirement, which shows good application prospect.