''RGD-BASED CELL LIGANDS FOR CELL-TARGETED DRUG DELIVERY ACT AS POTENT TROPHIC FACTORS.'' DOMINGO-ESPÍN J, PETEGNIEF V, DE VERA N, CONCHILLO-SOLÉ O, SACCARDO P, UNZUETA U, VAZQUEZ E, CEDANO J, NEGRO L, DAURA X, PELUFFO H, PLANAS AM, VILLAVERDE A, FERRER,