Development of wrapped liposomes: Novel liposomes comprised of polyanion drug and cationic lipid complexes wrapped with neutral lipids

Abstract

Novel wrapped liposomes comprised of polyanion drug and cationic lipid complexes wrapped with neutral lipids were prepared using an efficient, innovative procedure. In this study, dextran fluorescein anionic (DFA) was used as an example of a polyanionic compound. During the process, neutral lipids accumulated around the complexes and eventually covered the complexes. The resulting liposomes were 120-140 nm in diameter and the encapsulation efficiency was up to 90%. In fetal bovine serum, DFA/cationic lipid complexes degraded rapidly but the wrapped liposomes were considerably more stable. Following intravenous administration to rats, DFA/cationic lipid complexes were rapidly eliminated whereas the wrapped liposomes exhibited a much longer blood half-life. These data suggest that DFA is located on the surface of the complexes, but DFA is present inside the wrapped liposomes. The drug-delivery properties of the wrapped liposomes established in the present study suggests that formulations based on this technology could offer important advantages for the administration of many types of drug including antisense oligonucleotides, plasmids and siRNAs which may therefore lead to improved therapeutic effectiveness of this range of drugs. The method of preparation of the wrapped liposomes is so simple that it should be straightforward to adapt to a manufacturing scale.

Polymersome delivery of siRNA and antisense oligonucleotides

“…This encapsulation efficiency is discussed in more depth later but appears similar to that of oligonucleotides in nano-complexes with the commercially available cationic lipid delivery vehicle Lipofectamine 2000 (LF2k) (Table S2) as well as that of other drugs in both polymersomes and liposomes [33,34]. …”

The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment

“…However, their systemic toxicity remains an issue in clinical applications. 39 No significant gene silencing effect was observed for naked siRNA. Negligible gene silencing was also observed for nanoparticles composed of R 9 G 10 -chitosan and for siGFP used as scrambled siRNA (scRNA) compared to that of R 9 G 10 -chitosan/siCypB nanoparticles.…”

Lipid-Based Nanoparticles for Delivery of Vaccine Adjuvants and Antigens: Toward Multicomponent Vaccines

“…Studies also linked the induction of cell-mediated immune responses with the antigen loading mode. For applications related to mucosal administration and tumor-targeting, where anionic or neutral liposomes are preferred, encapsulation may be the chosen method for antigen loading due to absence of strong electrostatic forces between negatively charged antigens and liposomes, which does not favor the strong surface binding. In contrast, cationic liposomes can be used for encapsulation and/or adsorption, which may be ideal for initial and prolonged exposure of antigen …”