Maria Victória Souto Cholera toxin is often utilized as a supplement in 3D skin maintenance medium to stimulate keratinocyte differentiation and skin structure maintenance. The B-subunit of cholera toxin (CTB) binds to cell surface gangliosides and may permeate the stratum corneum of the skin, enabling its topical application as an adjuvant in vaccines.

While cholera toxin is widely utilized in 3D skin models, it is not required, and other additives can be used instead. For example, in the absence of cholera toxin, several studies have employed retinoids or transforming growth factor-beta (TGF-beta) as a supplement to preserve skin differentiation.

The use of cholera toxin in 3D skin models might generate issues regarding toxicity and immune response. The use of CTB-conjugated cholera toxin can alleviate these concerns since CTB is low in toxicity and induces a tolerogenic immune response.

In conclusion, while cholera toxin is a frequent supplement used in 3D skin models, it is not required, and alternate supplements such as retinoids or TGF-beta can be used instead. CTB-conjugated cholera toxin may be a safer option than unmodified cholera toxin. The supplements used will be determined by the specific study questions and the desired qualities of the 3D skin model.