From screening to the rational design of hydrogels. Statistical data of monomers Fmoc-amino acids (A), amines (B), aldehydes or ketones (C), and isocyanides (D) that formed gels. (E) Method for the preparation of hydrogels. (F) Design of machine learning methods. (G) Screening results of hydrogels (red, gel formed; gray, solution state). (H–K) Correlation between hydrogel percentages with nHBAcc (H), nHBDon (I), nBase (J), and ALogP (K).