Dış Kaynaklı Proje Süreçleri Yönetim Sistemi
Ünsaler üstün S., Bulut E. (Araştırmacı), Uzun C.
The purpose of the study is to increase the concentration of dexamethasone, a type of steroid, injected into the inner ear by intratympanic injection with the help of, a drug carrier, chitosan dextran gel. Steroid drugs are preferred in the treatment of sudden idiopathic hearing loss. In routine treatment, high-dose steroids are given to the patient systemically. As an alternative steroid (drug) is injected into the patient intratympanically via a fine needle through eardrum. Then dexamethasone diffuses into the cochlea through round membrane. However, in this method, the desired therapeutic drug level may not be reached because the drug can pass into the nasopharynx through the eustachian tube. Therefore, the application is repeated 3-5 times with 2 days intervals to reach the sufficient drug level. Thanks to Chitosan-dextran gel, which is known to have no ototoxicity in clinical animal studies, dexamethasone can obtain the opportunity to stay in tympanic cavity for a longer time (2 weeks). An animal experiment will be organized and the levels of dexamethasone in the inner ear will be analyzed quantitively by ELISA method and the samples taken from the cochlear tissues of animals will be assessed with immunofluorescence for qualitative analysis of distribution of DEX in the cochlea.
Method
Initially, dexamethasone-chitosan dextran gel will be prepared in appropriate proportions in the laboratory. Later, 48 Wistar rats will
be divided into 3 groups. The first two groups consist of 20 animals, while the last group will be the control group and consists of 8
animals. While those in group 1 will be injected with only dexamethasone, those in group 2 Dexamethasone-Chitosan dextran gel mixture will be injected into the middle ear of the animals by intratympanic way. In the third group, the only physiological serum will be applied. While the application is applied 3 times with two days intervals to the 1st group, it will be applied once to the 2nd group. 24 hours after injection, 10 animals in groups 1 and 2; 4 animals in groups 3 will be euthanized. After 1-week, the remaining animals will be euthanized. Half of the animals euthanized at both stages of the experiment will be used for qualitative analysis and the other half for quantitative analysis. The samples taken from the intra-cochlear tissues of animals will be examined by immunofluorescence tests qualitatively by using primary and secondary antibodies, and by the ELISA method quantitatively. The analysis, intracochlear dexamethasone can be compared between the groups. An adequate level of intra-cochleardexamethasone demonstrates the success of dexamethasone-chitosan dextran gel with intratympanic injection.