Cytotoxicity and apoptotic gene expression in an in vitro model of the blood–brain barrier following exposure to poly(butylcyanoacrylate) nanoparticles

Abstract

Background Poly(butylcyanoacrylate) (PBCA) nanoparticles (NPs) loaded with doxorubicin (DOX) and coated with polysorbate 80 (PS80) have shown efficacy in the treatment of rat glioblastoma. However, cytotoxicity of this treatment remains unclear.

Purpose The purpose of this study was to investigate cytotoxicity and apoptotic gene expression using a proven in vitro co-culture model of the blood–brain barrier.

Methods The co-cultures were exposed to uncoated PBCA NPs, PBCA-PS80 NPs or PBCA-PS80-DOX NPs at varying concentrations and evaluated using a resazurin-based cytotoxicity assay and an 84-gene apoptosis RT-PCR array.

Results The cytotoxicity assays showed PBCA-PS80-DOX NPs exhibited a decrease in metabolic function at lower concentrations than uncoated PBCA NPs and PBCA-PS80 NPs. The apoptosis arrays showed differential expression of 18 genes in PBCA-PS80-DOX treated cells compared to the untreated control.

Discussion As expected, the cytotoxicity assays demonstrated enhanced dose-dependent toxicity in the DOX loaded NPs. The differentially expressed apoptotic genes participate in both the tumor necrosis factor receptor-1 and mitochondria-associated apoptotic pathways implicated in current DOX chemotherapeutic toxicity.

Conclusion The following data suggest that the cytotoxic effect may be attributed to DOX and not the NPs themselves, further supporting the use of PBCA-PS80 NPs as an effective drug delivery vehicle for treating central nervous system conditions.

Keywords:

• Apoptosis
• blood–brain barrier
• doxorubicin
• poly(butylcyanoacrylate) nanoparticles
• polysorbate 80

Acknowledgements

The authors would like to thank Dr. Stephen Linn (Department of Biological Sciences, NKU) and Dr. Celeste Morris (Department of Chemistry, NKU) for their contributions to this work. In addition, the authors would like to acknowledge the late Dr. Heather Bullen for her conceptualization and contributions to this work.

Disclosure statement

This research was supported by the National Institutes of Health (NINDS) 1R15NS067548–01A1, Kentucky NSF EPSCoR, Merck/AAAS Undergraduate Science Research Program, National Center for Research Resources Grant P20 RR16481 (Fellowship), NKU Research Foundation and NKU CINSAM (to K. L. H).