**3.4. Transmission electron microscopic studies**

The BKα gene cloned in pCDNA3.1 mammalian expression vector and transfected in mouse cochlear hair cell cultures by using Nucleofector device. After transfection, both control and BK transfected cells were harvested and the cells were fixed with glutaraldehyde. The fixed cells were transferred in to wire gauge. The morphological changes of hair cells with respective of apoptosis such as plasma membrane dissolution; mitochondrial bulging, ER, and nuclear fragmentation were observed under electron microscopy with different concentration of BK transfection in the absence and presence of curcumin loaded silica nanoparticles. The synthesis of silica nanoparticles and encapsulation of curcumin will be carried out using a published procedure. One of the Co-PI is familiar with the synthesis and characterization of silica nanoparticles. The silica nanoparticles will be coated with polymers (polyethylene glycol) (PEG) or polyethylenimine (PEI) to enhance the biocompatibility of the nanoparticles. Initially, the amount of BK with appropriate time intervals is evaluated to activate apoptotic pathways in mouse cochlear cells.
