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Published on: July 4, 2017
Facile preparation of multifunctional superparamagnetic PHBV microspheres containing SPIONs for biomedical
Wei Li1, Jan Zaloga2, Yaping Ding3
1Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen, Germany.
Abstract:
The promising potential of magnetic polymer microspheres in various biomedical applications has been frequently reported. However, the surface hydrophilicity of superparamagnetic iron oxide nanoparticles (SPIONs) usually leads to poor or even failed encapsulation of SPIONs in hydrophobic polymer microspheres using the emulsion method. In this study, the stability of SPIONs in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) solution was significantly increased after surface modification with lauric acid. As a result, magnetic PHBV microspheres with high encapsulation efficiencies (71.0-87.4%) were prepared using emulsion-solvent extraction/evaporation method. Magnetic resonance imaging (MRI) showed significant contrast for the magnetic PHBV microspheres. The toxicity of these magnetic PHBV microspheres towards human T-lymphoma suspension cells and adherent colon carcinoma HT-29 cells was investigated using flow cytometry, and they were shown to be non-toxic in a broad concentration range. A model drug, tetracycline hydrochloride, was used to demonstrate the drug delivery capability and to investigate the drug release behavior of the magnetic PHBV microspheres. The drug was successfully loaded into the microspheres using lauric acid-coated SPIONs as drug carrier, and was released from the microspheres in a diffusion controlled manner. The developed magnetic PHBV microspheres are promising candidates for biomedical applications such as targeted drug delivery and MRI.
Insights
Surface-modified superparamagnetic iron oxide nanoparticles (SPIONs) were encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microspheres. These magnetic PHBV microspheres show promise for drug delivery and MRI applications.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Polymer Chemistry
Background:
- Superparamagnetic iron oxide nanoparticles (SPIONs) have biomedical potential but face encapsulation challenges due to surface hydrophilicity.
- Hydrophilic SPIONs often exhibit poor encapsulation in hydrophobic polymers using standard emulsion methods.
Purpose of the Study:
- To develop a method for efficiently encapsulating SPIONs into poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microspheres.
- To evaluate the characteristics and biomedical applicability of the resulting magnetic PHBV microspheres.
Main Methods:
- Surface modification of SPIONs with lauric acid to enhance stability in polymer solutions.
- Preparation of magnetic PHBV microspheres using an emulsion-solvent extraction/evaporation technique.
- Assessment of encapsulation efficiency, MRI contrast, cell toxicity, and drug release kinetics.
Main Results:
- Lauric acid modification significantly improved SPION stability and enabled high encapsulation efficiencies (71.0-87.4%) in PHBV microspheres.
- Magnetic PHBV microspheres demonstrated significant contrast in Magnetic Resonance Imaging (MRI).
- Flow cytometry confirmed the non-toxicity of the microspheres across a broad concentration range against human T-lymphoma and HT-29 cells.
- Model drug (tetracycline hydrochloride) loading and diffusion-controlled release were successfully demonstrated.
Conclusions:
- Surface-modified SPIONs can be effectively encapsulated in PHBV microspheres, overcoming previous limitations.
- The developed magnetic PHBV microspheres are non-toxic and suitable for MRI contrast enhancement.
- These magnetic microspheres show significant potential for targeted drug delivery systems and advanced MRI applications.
