What Are Organoids, and How Far Have They Come? [Reading Science]

From "Mini-Organs" to New Drug Development Tools

Organoids are biological models created by culturing cells obtained from humans in three dimensions to reproduce, for research and testing purposes, part of the structure and function of real organs. They are often called "mini-organs," but rather than being simply scaled-down models of organs, they are closer to experimental tools for observing in advance how the human body might respond.

Whereas conventional cell experiments have been conducted on a flat, two-dimensional surface, organoids allow cells to grow in three dimensions and partially reproduce organ-specific structures and functions. For this reason, they have drawn attention as a technology that can make drug responses, toxicity, and disease progression patterns appear more similar to what is seen in the human body.

Beyond the lab: organoids already in use

Organoids are no longer a technology confined to the laboratory. Global pharmaceutical companies are using organoids in the preclinical stage to screen drug candidates. By checking human cell-based responses once more before animal testing, they aim to reduce the likelihood of clinical trial failure.

In some cancer fields, research and services are underway that test individual patients' drug responses using organoids derived from their own tissue. The idea is to see in advance which anticancer drugs are likely to work better. Although this approach is not yet standard in all hospitals or treatment settings, experts say that its practical potential is being validated in the field of precision medicine.

In Korea as well, services for new drug evaluation using organoids, nonclinical testing, and precision-medicine-linked research are gradually increasing. However, the scope and manner of use differ by company and institution, and the overall stage is still closer to a transitional phase.

How far have we come, and why are they not yet the "standard"?

Even though organoids are spreading rapidly, this has not yet led to their full-scale adoption. This is because the required criteria differ depending on the intended use. The performance and quality levels that organoids must meet vary according to whether the goal is drug toxicity assessment, efficacy testing, disease modeling, or regenerative therapy.

Son Miyoung, Director of the National Agenda Research Division at the Korea Research Institute of Bioscience and Biotechnology (KRIBB), explains that standardizing organoids is "not a technological problem but a problem of defining their intended use." Only after it is clearly determined what purpose they will serve can appropriate quality standards and evaluation methods be established.

Yoo Jongman, CEO of Organoid Science, likewise said that one must "distinguish between using organoids as test tools and expanding them into therapeutics." Research-use organoids often employ substances that cannot be administered to humans, so if they are to be applied to actual patient treatment, the standards must be completely different from the starting point.

The same concern is being shared overseas. Janet Woodcock, former Commissioner of the U.S. Food and Drug Administration (FDA), stated in an official setting in 2024 that "we need experimental models that can predict human responses more accurately than animals." Her remark did not call for eliminating animal testing altogether, but rather for actively introducing tools that better reflect human responses into the preclinical stage.

Ultimately, the current position of organoids is clear. Their potential has already been demonstrated, and in some areas they are being used in practice. However, the extent to which they can be trusted and the extent of responsibility that can be delegated to them are still under active verification.

In effect, the field is in the process of gradually expanding the scope of organoid use in new drug development and clinical practice. Depending on how this process unfolds, organoids may remain auxiliary tools or may establish themselves as a new standard.