Polyethylenimine-mediated cochlear gene transfer in guinea pigs.
OBJECTIVE
To demonstrate and compare polycationic-mediated cochlear gene transfer with linear polyethylenimine (PEI) via cochleostomy and osmotic pump infusion method.


METHODS
A dissociated cochlear culture was used to select the optimum nitrogen to phosphate ratio of PEI/DNA complexes to be used in vivo. The PEI-enhanced green fluorescent protein reporter gene DNA complex was introduced with single inoculation (cochleostomy) or with sustained delivery (osmotic pump method) into guinea pig cochleas and examined for transgene expression.


METHODS
Male Albino Hartley guinea pigs (250-350 g).


RESULTS
The relatively low transfection efficiency of PEI limits its potential when compared with viral counterparts; however, sustained release of the vector solution was able to improve PEI's transfection efficiency. The PEI-infused cochleas maintained intact cellular and tissue architecture with absence of inflammation. Transfection confined to the perilymphatic space highlights the need to target the gene vector into the scala media if transfection is targeted at cells within the organ of Corti.


CONCLUSIONS
These findings indicate that PEI is able to transfect the cochlea in vivo with sustained delivery and present an alternative for nonviral cochlear gene therapy.
Tan
Brian Tiong Gee
BT
Delivery of Drugs, Proteins, and Genes Group, Institute of Bioengineering and Nanotechnology, Singapore, Singapore.
Foong
Kok Heng
KH
Lee
Myranda Mui Gek
MM
Ruan
Runsheng
R
D000818:Animals; D001489:Basilar Membrane / Q000378:metabolism / Q000473:pathology; D003051:Cochlea / Q000166:cytology* / Q000378:metabolism* / Q000473:pathology; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006168:Guinea Pigs; D008297:Male; D018613:Microscopy, Confocal; D011094:Polyethyleneimine; D014162:Transfection / Q000379:methods*
D049452:Green Fluorescent Proteins; D011094:Polyethyleneimine