Protective and rescue effects of cationic liposome - mediated bFGF/GFP on Gentamicin - induced ototoxicity in guinea pig

doi:10.3969/j.issn.1672-2922.2003.04.003

Abstract：Objectiye To observe the expression of cationic liposome (Stearylamine SA) mediated bFGF/GFP gene, and evaluate the efficacy of bFGF against the damage of Gentamicin in guinea pig cochlea. Methods 36 guinea pigs were divided into 3 groups. The guinea pigs in the preventive group were inoculated SA- bFGF/GFP complexes into cochleae via round window of the right ear, and were subsequently injected with Gentamicin 150mg. Kg-1 .d-1 for 8 days. The animals in the remedial group were previously administrated Gentamicin for 8 days and then received infusion of SA- bFGF/GFP complexes from nextday. The animals in the control group were only injected with Gentamicin for 8 days. Auditory brainstem response (ABR) was measured preceding test, after test and before the animals were sacrificed, respectively. ~ expression of GFP in cochlea was observed by a fluorescent microscope. The surface preparation of cochlea was made and stained with NBT for counting the absent outer and inner hair cells, which was also examined by scanning electronic microscope (SEM). Results There was expression of GFP gene in guinea pig cochleae both in preventive and remedial groups. ABR threshold in two experimental groups was lower than that of the control group before animals were killed, and the difference was statistical signifieance(P ＜ 0.01,P ＜ 0.05). Similar to the ABR results, the number of missing outer and inner hair cells was fewer in two experimental groups(P ＜ 0. 01, P ＜ 0.05). The damage in cochleae of the experimental groups was less severe than that of the control group under the SEM. Conciusion SA - liposome mediated bFGF/GFP gene, which was perfused in one ear, can be expressed in both cochleae of the guinea pig. It may also protect and rescue cochlea from Gentamicin ototoxicity. The results demonstrate the feasibility of gene therapy for cochlear application.