[Construction of a membrane-anchored bifunctional growth factor mimetic and its application in organoid culture]

Currently, organoids emerges as novel ex vivo models for biomedical research and biopharmaceutical development. However, the recombinant growth factors used for organoid culture faces challenges such as high costs, low batch consistency, and poor stability, which limit the standardization and scaling of organoid applications. This study aims to develop a membrane-anchored bifunctional growth factor mimetic based on functional nucleic acids to replace recombinant growth factors in organoid culture. Using nucleic acid aptamers as functional mimic units and cholesterol (Chol) as the membrane anchoring module, we constructed two bifunctional growth factor mimetics through base-complement pairing principles. The first was a dual-specificity aptamer (ApE+F-22-Chol) targeting the dimerization activation of both epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor 1 (FGFR1), simulating the synergistic function of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). The second was a dual-specificity aptamer (ApF+M-Chol) designed to target and induce the dimerization activation of mesenchymal-epithelial transition factor (Met) and FGFR1, mimicking the function of hepatocyte growth factor (HGF) and bFGF. The results demonstrated that ApE+F-22-Chol successfully anchored to cell membranes while efficiently activating both EGFR and FGFR1 signaling pathways, synergistically promoting cell proliferation and migration. In a patient-derived prostate cancer organoid culture system, ApE+F-22-Chol can fully replace EGF and bFGF in the culture medium, effectively supporting organoid formation and growth. Further experiments confirmed that the ApF+M-Chol constructed with the same strategy also exhibited significant growth-promoting activity in organoid culture, validating the broad applicability of this membrane-anchored bifunctional growth factor mimetic strategy. This study provides a novel tool with well-defined components, high stability, and high efficiency for organoid culture systems, showing promising applications in disease modeling, drug screening, and regenerative medicine.