已发表论文

原位沉淀:一种新的方法用于制备氧化铁磁性脂质体

 

Authors Xia S, Li P, Chen Q, Armah M, Ying X, Wu J, Lai J

Published Date May 2014 Volume 2014:9(1) Pages 2607—2617

DOI http://dx.doi.org/10.2147/IJN.S59859

Received 29 December 2013, Accepted 17 February 2014, Published 23 May 2014

 
Background: Conventional methods of preparing magnetoliposomes are complicated and inefficient. A novel approach for magnetoliposomes preparation was investigated in the study reported here.
Methods: FeCl3/FeCl2 solutions were hydrated with lipid films to obtain liposome-encapsulated iron ions by ultrasonic dispersion. Non-encapsulated iron ions were removed by dialysis. NH3 · H2O was added to the system to adjust the pH to a critical value. Four different systems were prepared. Each was incubated at a different temperature for a different length of time to facilitate the permeation of NH3 · H2O into the inner phase of the liposomes and the in situ formation of magnetic iron-oxide cores in the liposomes. Single-factor analysis and orthogonal-design experiments were applied to determinate the effects of alkalization pH, temperature, duration, and initial Fe concentration on encapsulation efficiency and drug loading.
Results: The magnetoliposomes prepared by in situ precipitation had an average particle size of 168±14 nm, zeta potential of -26.2±1.9 mV and polydispersity index of 0.23±0.06. The iron-oxide cores were confirmed as Fe3O4 by X-ray diffraction and demonstrated a superparamagnetic response. Encapsulation efficiency ranged from 3% to 22%, while drug loading ranged from 0.2 to 1.58 mol Fe/mol lipid. The optimal conditions for in situ precipitation were found to be an alkalization pH of 12, temperature of 60°C, time of 60 minutes, and initial Fe concentration of 100 mM Fe3+ + 50 mM Fe2+.
Conclusion: In situ precipitation could be a simple and efficient approach for the preparation of iron-oxide magnetoliposomes.
Keywords: magnetoliposomes, in situ precipitation, iron oxide, alkalization, permeability