Stability of polymeric cationic niosomes and their plasmid DNA-based complexes as gene delivery carriers

Abstract

This study aims to explore the stability of lipo-polymeric niosomes/niosome-based pCMS-EGFP complexes under different storage temperatures (25 °C, 4 °C, and −20 °C). To date, the question of nucleic acid-complex stability is one of the most vital issues in gene delivery applications. The need for stable vaccines during the COVID-19 pandemic has merely highlighted it. In the case of niosomes as gene carriers, the scientific literature still lacks comprehensive stability studies. In this study, the physicochemical features of niosomes/nioplexes in terms of size, surface charge, and polydispersity index (PDI), along with transfection efficiency, and cytotoxicity in NT2 cells were evaluated for 8 weeks. Compared to day 0, the physicochemical features of the niosomes stored at 25 °C and −20 °C changed dramatically in terms of size, zeta potential, and PDI, while remaining in reasonable values when stored at 4 °C. However, niosomes and nioplexes stored at 4 °C and −20 °C showed nearly stable transfection efficiency values, yet an obvious decrease at 25 °C. This article provides a proof of concept into the stability of polymeric cationic niosomes and their nioplexes as promising gene delivery vehicles. Moreover, it highlights the practical possibility of storing nioplexes at 4 °C for up to 2 months, as an alternative to niosomes, for gene delivery purposes.

Graphical Abstract

Keywords:

• Stability
• non-viral vectors
• gene delivery
• cationic niosome
• nioplexes

Acknowledgements

Authors wish to thank the intellectual and technical assistance from the ICTS ‘NANBIOSIS,’ more specifically by the Drug Formulation Unit (U10) of the CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) at the University of Basque Country (UPV/EHU). Technical and human sup- port provided by SGIKER (UPV/EHU) is also gratefully acknowledged. Finally, authors would like to acknowledge the Margarita Salas grants MARSA21/97 and MARSA21/98 at the University of Basque Country UPV/EHU.

Author contributions statement

Mohamed Mashal, Noha Attia, Santiago Grijalvo, Ramón Eritja Gustavo Puras and José Luis Pedraz were involved in the conception and design of the work. Mohamed Mashal and Noha Attia were involved in were involved in the analysis and interpretation of the data, and drafting of the paper. Santiago Grijalvo, Ramón Eritja, Gustavo Puras and José Luis Pedraz revised it critically and provided constructive discussion; and Gustavo Puras and José Luis Pedraz made the final approval of the version to be published. All authors agree to be accountable for all aspects of the work.

Data availability statement

The data that support the findings of this study are available from the corresponding author, [José Luis Pedraz], upon reasonable request.

Disclosure statement

The authors report there are no competing interests to declare.

Ethical approval statement

NA.

Additional information

Funding

This work was supported by the Basque Country Government (Department of Education, University and Research, Consolidated Groups IT907-16). Additional funding was provided by the CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), an initiative of the Carlos III Health Institute (ISCIII).