Supramolecular complexes are formed by polyanionic polymers and spermidine having a ratio of anionic equivalents raging from 101:1 to 107:1 eq/eq, more preferably from 102:1 to 104:1 eq/eq, whose components are linked by non-covalent, ionic interactions. The supramolecular complexes are exhibit high potency in eliciting fibroblast proliferation. Disclosed are medicinal/cosmetic compositions containing the supramolecular complexes for the trophism, maintenance, regeneration, and repair of connective tissues and mucosae in damaged or senescent conditions.