Tumor Gene Targeting Using Microspheres: Cell Culture and in vivo Studies.
C R Dass1, E E Decruz1, T L Walker1
1a School of Biomedical Sciences, Charles Start University-Riverina, Wagga, Wagga, Australia.
Drug Delivery
|November 20, 2015
Summary
Ion-exchange microspheres effectively deliver plasmid DNA for gene therapy, showing improved transfection in cell cultures and in vivo. While hydroxyapatite microspheres were cytotoxic, polystyrene divinylbenzene microspheres demonstrated safe and effective plasmid delivery, enhancing gene expression in tumors.
Area of Science:
- Biotechnology
- Gene Delivery Systems
- Nanomedicine
Background:
- Previous studies demonstrated ion-exchange microspheres binding and releasing plasmids but did not assess plasmid functionality.
- Evaluating the functional capacity of plasmids after binding to microspheres is crucial for gene delivery applications.
Purpose of the Study:
- To investigate the functionality of pCMV-CAT plasmid DNA bound to hydroxyapatite (HA) and polystyrene divinylbenzene (PDB) ion-exchange microspheres.
- To compare the transfection efficiency and safety of microsphere-mediated plasmid delivery versus free plasmid delivery in vitro and in vivo.
Main Methods:
- pCMV-CAT plasmid was bound to HA and PDB microspheres.
- In vitro transfection studies using rat tumor cells.
- In vivo transfection studies in animal models, assessing gene expression in kidneys and tumors.
Main Results:
- HA microspheres showed significantly higher transfection rates in vitro but were cytotoxic.
- PDB microspheres exhibited no cytotoxicity and facilitated plasmid delivery with improved gene expression in vivo, particularly in tumors.
- While microsphere delivery showed trends for better in vivo transfection, results were not always statistically significant (p >.05).
Conclusions:
- Ion-exchange microspheres do not negatively impact plasmid DNA expression.
- Microsphere-mediated delivery offers protection against enzymatic degradation and enhances plasmid transfection in vivo, especially within the tumor vascular bed.
- PDB microspheres represent a promising, non-cytotoxic platform for enhanced gene delivery applications.
