Regenerative medicine relies on growth factors — EGF, PDGF, TGF-β and similar signaling molecules — to stimulate a population of cells on a scaffold to proliferate and rebuild tissue. This simulator models the full delivery-to-response chain: choose a bolus injection or a sustained-release scaffold, set the dose and the clearance half-life, and watch the free growth-factor concentration evolve while a Hill-equation dose-response curve converts it into a logistic proliferation rate. Stay inside the therapeutic window and cells fill the scaffold in a controlled regenerative pattern; push the concentration past the tumor-risk threshold for too long and the same signaling pathway drives uncontrolled hyperproliferation, visualized as a red overgrowth nodule and a rising tumor-risk index — the exact trade-off real growth-factor dosing protocols are designed to avoid.