Related Experiment Videos
Pharmaceutical evaluation of gas-filled microparticles as gene delivery system
Stefanie Seemann1, Peter Hauff, Marcus Schultze-Mosgau
1Schering AG, Research Laboratories, Berlin, Germany.
Purpose:
To produce and characterize a nonviral ultrasound-controlled release system of plasmid DNA (pDNA) encapsulated in gas-filled poly(D,L-lactide-co-glycolide) microparticles (PLGA-MPs).
Methods:
Different cationic polymers were used to form pDNA/polymer complexes to enhance the stability of pDNA during microparticle preparation. The physico-acoustical properties of the microparticles, particle size, pDNA integrity, encapsulation efficiency and pDNA release behavior were studied in vitro.
Results:
The microparticles had an average particle size of around 5 microm. More than 50% of all microparticles contained a gas core, and when exposed to pulsed ultrasound as used for color Doppler imaging create a signal that yields typical color patterns (stimulated acoustic emission) as a result of the ultrasound-induced destruction of the microparticles. Thirty percent of the pDNA used was successfully encapsulated and approximately 10% of the encapsulated pDNA was released by ultrasound within 10 min.
Conclusions:
Plasmid DNA can be encapsulated in biodegradable gas-filled PLGA-MPs without hints for a structural disintegration. A pDNA release by ultrasound-induced microparticle-destruction could be shown in vitro.