HTRA1 and neoplasm: Improving tumor targeting and precise payload delivery through rational bacterial engineering is essential for increasing efficacy and safety.<h4>Methods</h4>An attenuated <i>Salmonella</i> Δ<i>htrA</i>::<i>luxI</i>-VNP20009 strain expressing OmpA-SpyTag (AISI-ST) was constructed for the modular surface conjugation of SpyCatcherΔ (SC)-fused quadruple arginine-glycine-aspartic acid (RGD) peptides (named AISI-ST/SC-RGD×4) and for building biointerfaces for enhanced tumor adhesion via RGD-mediated integrin αvβ3 interactions.