title: The effect of cryoprotection on the use of PLGA encapsulated iron oxide nanoparticles for magnetic cell labeling.
abstract: Magnetic PLGA nanoparticles are a significant advancement in the quest to translate MRI-based cell tracking to the clinic. The benefits of these types of particles are that they encapsulate large amounts of iron oxide nanocrystals within an FDA-approved polymer matrix, combining the best aspects of inert micron-sized iron oxide particles, or MPIOs, and biodegradable small particles of iron oxide, or SPIOs. Practically, PLGA nanoparticle fabrication and storage requires some form of cryoprotectant to both protect the particle during freeze drying and to promote resuspension. While this is a commonly employed procedure in the fabrication of drug loaded PLGA nanoparticles, it has yet to be investigated for magnetic particles and what effect this might have on internalization of magnetic particles. As such, in this study, magnetic PLGA nanoparticles were fabricated with various concentrations of two common cryoprotectants, dextrose and sucrose, and analyzed for their ability to magnetically label cells. It was found that cryoprotection with either sugar significantly enhanced the ability to resuspend nanoparticles without aggregation. Magnetic cell labeling was impacted by sugar concentration, with higher sugar concentrations used during freeze drying more significantly reducing magnetic cell labeling than lower concentrations. These studies suggest that cryoprotection with 1% dextrose is an optimal compromise that preserves monodispersity following resuspension and high magnetic cell labeling.
authors: Department of Biomedical Engineering, Yale University, New Haven, CT 06511, USA.
authors: Kevin S
authors: KS
authors: Tang
authors: Department of Chemical & Environmental Engineering, Yale University, New Haven, CT 06511, USA.
authors: Sara M
authors: SM
authors: Hashmi
authors: Department of Biomedical Engineering, Yale University, New Haven, CT 06511, USA.|Molecular and Cellular MRI Laboratory, Magnetic Resonance Research Center, Department of Diagnostic Radiology, 300 Cedar Street, Yale University School of Medicine, New Haven, CT 06510, USA.
authors: Erik M
authors: EM
authors: Shapiro
mesh_terms: D000818:Animals; D058948:Cell Tracking / Q000379:methods*; D002478:Cells, Cultured; D003451:Cryoprotective Agents / Q000737:chemistry* / Q000494:pharmacology*; D005947:Glucose / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D051379:Mice; D053769:Nanocapsules / Q000737:chemistry*; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013395:Sucrose / Q000737:chemistry; D013818:Thermogravimetry
chemical_list: D003451:Cryoprotective Agents; D058185:Magnetite Nanoparticles; D053769:Nanocapsules; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D013395:Sucrose; D005947:Glucose