Dendrimers can target tumor taking advantage of enhanced permeation and retention effect(EPR).In this study
partially acetylated generation 5(G5) polyamidoamine(PAMAM) dendrimer was conjugated with the active targeting moiety(avidin).The nanoparticles which have passive and active tumor-targeting were radiolabel with 99mTc.The nano-particle conjugated with avidin(avidin-G5-1B4M-99mTc) exhibited much higher cellular uptake into Hela cells than those without avidin conjugate.Using this conjugate
excellent SPECT imaging results were obtained in tumor-bearing nude.This radiolabelling nano-particle has the potential of early stage cancer diagnosis