Liposphere Based Lipoprotein-Mimetic Delivery System for 6-Mercaptopurine

Abstract

Long-circulating lipospheres containing 6-mercaptopurine (6-MP) were prepared by solidification of warm microemulsion at low temperature. Palmitoyl PEG was incorporated in the system to confer stealth-type nature. The size of lipospheres was in the range of 60-70 nm and was inversely proportional to sonication time. The size range was attained after 8 h. of sonication. The entrapped 6-MP contained 0.12 mmol/mole of lipid. The coating efficiency of 63-71% was attained. The zeta potential substantially decreased after PEG coating, however, the lipospheres were stable due to steric repulsion and exhibited no aggregation. The release of 6-MP was found to be 18-25% of administered dose in 24 h. and followed a mixed profile for stealth lipospheres. The percent dose remaining in plasma was found to be high even after 24 h as compared to control, indicating an increase in circulation time of lipospheres. Tissue accumulation of drug correlated with the pharmacokinetic behavior of lipospheres. The system seems to be an ideal carrier for anticancer drug delivery.

Protein‐Based Nanomedicine Platforms for Drug Delivery

“…Liposomes were first reported for drug delivery in 1965 72. Liposome‐based templates include lipospheres and lipobeads 73–78. Liposome probes comprise an outer phospholipid layer forming a spherical vesicle that has an aqueous core, while lipobeads possess an inner polymeric core (see Figure 3 for examples of liposomes, lipobeads, and other non‐protein‐based DDS that have previously been developed).…”

Levitation and movement of tripalmitin‐based cationic lipospheres on a dielectrophoresis‐based lab‐on‐a‐chip device

“…1,5 In addition to liposomes and microspheres, lipospheres (LSs) can be very useful in experiments aimed at the delivery of drugs to target cells and tissues. [19][20][21][22][23][24] LSs represent a particular type of nonviral vectors constituted of a mixture of neutral lipids (generally triglycerides) and, when required, positively charged lipids that can interact with negatively charged nucleic acid molecules [cationic lipospheres (CLSs)]. CLSs are solid microparticles with a mean diameter usually between 0.2 and 500 lm, 25 CLSs present several advantages, including a high drug loading capacity, good physical stability, low cost of ingredients, and ease of preparation.…”

“…In addition to liposomes and microspheres, lipospheres (LSs) can be very useful in experiments aimed at the delivery of drugs to target cells and tissues 19–24. LSs represent a particular type of nonviral vectors constituted of a mixture of neutral lipids (generally triglycerides) and, when required, positively charged lipids that can interact with negatively charged nucleic acid molecules [cationic lipospheres (CLSs)].…”