Stable unilamellar dipalmitoylphosphatidylcholine vesicles were produced by using oligo(malic acid) and cholesterol. Detailed physico-chemical characterization prove that by using oligo(malic acid) the substitution of PEGylated lipids for sterically stabilization comes possible. The polymer molecules cover the outer surface of spherical-shaped vesicles, and an asymmetrical composition occurs in the two leaflets of the phospholipid bilayer. The oligo(malic-acid) and cholesterol are enriched in the outer side assuring the stabilization of vesicles. Cholesterol plays an important role in the self-assembly of components as it makes the entering of oligomers possible deep into the polar head-region of lipids. The presence of oligo(malic acid) molecules does not induce degradation by hydrolysis of lipid molecules but the vesicle system turns into a sensitive form giving a possibility for pH sensitive targeting. Preliminary investigation on the investigated oligo(malic acid)-stabilized vesicles do not show any toxic effect promising their applicability in the field of liposomal drug delivery.
Bibliographical noteFunding Information:
The work was supported by the János Bolyai Research Scholarships of the Hungarian Academy of Sciences (J.M. and Z.V.) and the Hungarian Scientific Research Found (OTKA, Hungary) and the National Innovation Office (NIH, Hungary) under grant agreements CNK-81056 and PD-124451 (A.W.). Teréz Kiss is gratefully acknowledged for performing the FF-TEM pictures. We are grateful to the European Synchrotron Radiation Facility for provision of beam time at ID02 (proposal no. SC-3269, Z.V.).
- Freeze fracture
- Oligo(malic acid)
- Small-angle X-ray scattering (SAXS)
- Sterically stabilized vesicle