Preparation of Temozolomide-Loaded Nanoparticles for Glioblastoma Multiforme Targeting—Ideal Versus Reality

Abstract

Temozolomide (TMZ) is one of the most effective chemotherapeutic agents for glioblastoma multiforme, but the required high administration dose is accompanied by side effects. To overcome this problem and to further improve TMZ’s efficacy, targeted delivery of TMZ by using polymeric nanoparticles has been explored. We synthesised the PLGA-PEG-FOL copolymer and attempted encapsulation of TMZ into PLGA-PEG-FOL nanoparticles using the emulsion solvent evaporation method and the nanoprecipitation method. Conjugation of PEG and FOL to PLGA has been reported to be able to increase the delivery of TMZ to the brain as well as targeting the glioma cells. However, despite making numerous modifications to these methods, the loading of TMZ in the nanoparticles only ranged between 0.2% and 2%, and the nanoparticles were between 400 nm and 600 nm in size after freeze-drying. We proceed with determining the release profile of TMZ in phosphate buffered saline (PBS). Our initial data indicated that TMZ was slowly released from the nanoparticles. The metabolite of TMZ rather than the parent compound was detected in PBS. Our study suggests that while PLGA-PEG-FOL can be used as a polymeric or encapsulation material for central delivery of TMZ, a practical and cost effective formulation method is still far from reach.

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Effects of solvent used for fabrication on drug loading and release kinetics of electrosprayed temozolomide‐loaded PLGA microparticles for the treatment of glioblastoma

“…To overcome this, Zhang et al saturated the aqueous emulsion phase with 0.5 wt/vol % of drug (i.e., 400 mg of drug per synthesis of a standard batch of particles), resulting in the use of a lot of drugs which can be very costly . Lee et al who tried altering different parameters of fabrication of nanoparticles using the emulsion solvent extraction/evaporation method were not successful at obtaining high entrapment efficiency and drug loading and thus, concluded that the emulsion solvent evaporation method of fabrication of TMZ‐loaded microparticles is not efficient and other method should be utilized to fabricate these particles . Ananta et al investigated different emulsion solvent extraction/evaporation techniques (i.e., single and double emulsion) for the fabrication of TMZ/PLGA nanoparticles.…”

“…18 Lee et al who tried altering different parameters of fabrication of nanoparticles using the emulsion solvent extraction/evaporation method were not successful at obtaining high entrapment efficiency and drug loading and thus, concluded that the emulsion solvent evaporation method of fabrication of TMZ-loaded microparticles is not efficient and other method should be utilized to fabricate these particles. 28 Ananta et al investigated different emulsion solvent extraction/evaporation techniques (i.e., single and double emulsion) for the fabrication of TMZ/PLGA nanoparticles. They found that by using a single emulsion technique with TMZ saturation in the aqueous phase, they were able to increase loading efficiency by 90-700% and the encapsulation efficiency by 2-to 15-fold.…”