Transfection of DNA into Cochlear Cells by Functionalized Calcium Phosphate Nanoparticles

Introduction:

Calcium phosphate nanoparticles (CaP-NP) can be combined with a variety of drugs, proteins and/or nucleic acids and penetrate a cell membrane with these conjugates without any additional aids. As a carrier for DNA, they are thus extremely potent transfection reagents, comparable to Lipofectamine (R). So far, there are no studies on the transfection efficiency of CaP-NP with respect to inner ear cells. In this way, for example, a long-term secretion of neurotrophic or anti-inflammatory factors in the area of the spiral ganglion cells after cochlear implantation would be possible.

Materials and Methods:

Multi-layer CaP-DNA CaP-DNA-CaP-PEI (polyethylenimine) with an average size of 274nm and 403nm were generated. The conjugated DNA used was the green fluorescent protein eGFP or mOrange. The particles were then co-cultured with spiral ganglia explants from neonatal rats as well as with HeLa cells and, after immunohistochemical staining, were microscoped and evaluated.

Results:

There was a very effective uptake of the nanoparticle conjugates into all cells of the spiral ganglia explant. A smaller but significant proportion of these cells showed stable expression of dye-encoding DNA after about 5 days.

Conclusion:

Schwann cells in particular, but also fibroblasts and even spiral ganglion cells can take up DNA with the help of CaP-NP and secrete a functional protein after transfection. Thus, it would be possible to coat a CI electrode with functionalized CaP-NP and to stimulate inner ear cells nearby the electrode for the secretion of neurotrophic or anti-inflammatory factors.

Publication History

Publication Date:
23 April 2019 (online)