Limits...
In situ precipitation: a novel approach for preparation of iron-oxide magnetoliposomes.

Xia S, Li P, Chen Q, Armah M, Ying X, Wu J, Lai J - Int J Nanomedicine (2014)

Bottom Line: 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.The iron-oxide cores were confirmed as Fe3O4 by X-ray diffraction and demonstrated a superparamagnetic response.In situ precipitation could be a simple and efficient approach for the preparation of iron-oxide magnetoliposomes.

View Article: PubMed Central - PubMed

Affiliation: Yiwu Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.

ABSTRACT

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 Fe(3+) + 50 mM Fe(2+).

Conclusion: In situ precipitation could be a simple and efficient approach for the preparation of iron-oxide magnetoliposomes.

Show MeSH

Related in: MedlinePlus

The effect of alkalization duration.Abbreviations: Fe(t), the amount of total iron in the liposomes after alkalization; Fe(f), the amount of free iron ions in the liposomes after alkalization.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4043714&req=5

f7-ijn-9-2607: The effect of alkalization duration.Abbreviations: Fe(t), the amount of total iron in the liposomes after alkalization; Fe(f), the amount of free iron ions in the liposomes after alkalization.

Mentions: The EE and drug loading were increased as alkalization duration lengthened and reached a maximum at 60 minutes. The Fe(t) decreased slightly with longer alkalization duration, while the Fe(f) markedly decreased at 30 minutes, then remained at almost the same level after that (as shown in Table 3 and Figure 7).


In situ precipitation: a novel approach for preparation of iron-oxide magnetoliposomes.

Xia S, Li P, Chen Q, Armah M, Ying X, Wu J, Lai J - Int J Nanomedicine (2014)

The effect of alkalization duration.Abbreviations: Fe(t), the amount of total iron in the liposomes after alkalization; Fe(f), the amount of free iron ions in the liposomes after alkalization.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043714&req=5

f7-ijn-9-2607: The effect of alkalization duration.Abbreviations: Fe(t), the amount of total iron in the liposomes after alkalization; Fe(f), the amount of free iron ions in the liposomes after alkalization.
Mentions: The EE and drug loading were increased as alkalization duration lengthened and reached a maximum at 60 minutes. The Fe(t) decreased slightly with longer alkalization duration, while the Fe(f) markedly decreased at 30 minutes, then remained at almost the same level after that (as shown in Table 3 and Figure 7).

Bottom Line: 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.The iron-oxide cores were confirmed as Fe3O4 by X-ray diffraction and demonstrated a superparamagnetic response.In situ precipitation could be a simple and efficient approach for the preparation of iron-oxide magnetoliposomes.

View Article: PubMed Central - PubMed

Affiliation: Yiwu Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China.

ABSTRACT

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 Fe(3+) + 50 mM Fe(2+).

Conclusion: In situ precipitation could be a simple and efficient approach for the preparation of iron-oxide magnetoliposomes.

Show MeSH
Related in: MedlinePlus