Explant (ex vivo) cultures allow for cost-effective, high-throughput screening of drugs for the ears.

The most relevant approach to evaluating treatments for the ears is to test these drugs and devices using intact auditory systems. However, such in vivo studies can be complicated, time-consuming, and relatively expensive – especially when a sponsor only needs early proof-of-concept or pilot testing. In these instances, explant cultures provide an excellent method to rapidly and effectively screen a large number of test article formulations and concentrations.

 

An otic explant study often begins by harvesting cochlear tissue from early post-natal mice, and placing each cochlea in culture conditions that include a combination of test article(s), negative control compounds, and/or positive control compounds. After several days, samples are fixed, immunostained, and analyzed with confocal microscopy to quantify hair cells, analyze cellular health and nuclear condensation, or perform other analyses.

The objective of each protocol is to create a culture environment that closely models actual in vivo conditions. Unlike using cell line cultures, explant samples maintain much of the natural tissue architecture, and allow cells to produce their normal cytokines and growth factors as much as possible. Explant studies can be challenging, though, as highly controlled environmental variables (temperature, media properties, sterility) are essential. The benefits of explant studies are significant – a sponsor can rapidly obtain information about a test article’s IC50/EC50, toxicity potential, and ability to protect fragile cochlear cells in a cost-effective manner.

 

Turner Scientific has significant experience in executing cochlear explant studies, and all necessary equipment in-house to conduct this work at any time. Please contact us to discover if this efficient analytical method is right for your otic drug development program.