Superparamagnetic iron oxide/chitosan core/shells for hyperthermia application: Improved colloidal stability and biocompatibility

2014 ◽  
Vol 355 ◽  
pp. 22-30 ◽  
Author(s):  
R.M. Patil ◽  
P.B. Shete ◽  
N.D. Thorat ◽  
S.V. Otari ◽  
K.C. Barick ◽  
...  
2003 ◽  
Vol 789 ◽  
Author(s):  
M. Chastellain ◽  
A. Petri ◽  
H. Hofmann

ABSTRACTNanoscaled particles showing a superparamagnetic behavior have been intensively studied these past years for biomedical applications and water-based ferrofluids turned out to be promising candidates for various in vivo as well as in vitro applications. Nevertheless, the lack of well-defined particles remains an important problem. One of the major challenges is still the large-scale synthesis of particles with a narrow size distribution. In this work iron oxide nanoparticles are obtained by classical co-precipitation in a water-based medium and are subsequently coated with polyvinyl alcohol. The thus obtained ferrofluids are studied and a focus is made on their colloidal stability.


2016 ◽  
Vol 6 (6) ◽  
pp. 20160068 ◽  
Author(s):  
Etelka Tombácz ◽  
Katalin Farkas ◽  
Imre Földesi ◽  
Márta Szekeres ◽  
Erzsébet Illés ◽  
...  

Nanoparticles do not exist in thermodynamical equilibrium because of high surface free energy, thus they have only kinetic stability. Spontaneous changes can be delayed by designed surface coating. In biomedical applications, superparamagnetic iron oxide nanoparticles (SPIONs) require an optimized coating in order to fulfil the expectation of medicine regulatory agencies and ultimately that of biocompatibility. In this work, we show the high surface reactivity of naked SPIONs due to ≡Fe–OH sites, which can react with H + /OH − to form pH- and ionic strength-dependent charges. We explain the post-coating of naked SPIONs with organic polyacids via multi-site complex bonds formed spontaneously. The excess polyacids can be removed from the medium. The free COOH groups in coating are prone to react with active biomolecules like proteins. Charging and pH- and salt-dependent behaviour of carboxylated SPIONs were characterized quantitatively. The interrelation between the coating quality and colloidal stability measured under biorelevant conditions is discussed. Our coagulation kinetics results allow us to predict colloidal stability both on storage and in use; however, a simpler method would be required to test SPION preparations. Haemocompatibility tests (smears) support our qualification for good and bad SPION manufacturing; the latter ‘promises’ fatal outcome in vivo .


2021 ◽  
Author(s):  
Mahdi Mohammadi Ghanbarlou ◽  
Shahriyar Abdoli ◽  
Hadi Bamehr ◽  
Leila Qazizadeh ◽  
Hamed Omid ◽  
...  

Abstract Background: The CRISPR-Cas9 system, a powerful tool, has revolutionized genome engineering in eukaryotic cells and living organisms. However, this approach poses unique concerns and limitations when used by conventional transfection methods, including limited packaging size and low delivery efficiency. Here, we aim at assessing the transfection efficiency of DNA encoding for the CRISPR-Cas9 system by PEI coated Magnetic NanoParticle (MNPs) to improve the delivery of CRISPR/Cas9 constructs into eukaryotic cells. Results: Superparamagnetic iron oxide nanoparticles (SPIONs) coated with polyethylenimine (PEI) and then complexed with pCXLE-dCas9VPH-T2A-GFP-shP53 plasmid DNA. We used HEK-293 (human embryonic kidney) and Human foreskin fibroblasts (HFF) cells to express GFP after transfection to evaluate delivery efficiency with MNPs and Lipofection methods. PEI-coated nanoparticles with magnetic iron oxide core were synthesized by co-precipitation technique resulting in an average size of ~ 20 nm in diameter. Characterization of Magnetic Nano Particle (MNPs) revealed that particles have narrow size distribution sufficient colloidal stability. The result showed that the magnetofection method with an efficiency around 85.7% for HEK-293 and 28.2% for HFF. Also, transfection efficiency by lipofection method was 83.2% and 7.89% for HEK-293 and HFF respectively. Conclusion: The magnetofection was revealed to be more efficient than classic Lipofectamine transfection as measured by GFP expression. We show that PEI-MNPs enable effective delivery and improved safety of plasmids encoding CRISPR/Cas9 into eukaryote cells.


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