A hybrid cellulose-based programmable nanoplatform for applications in precision radiation oncology is described. Here, sugar heads work as tumor targeting moieties and steer the precise delivery of radiosensitizers, i.e. gold nanoparticles (AuNPs) into triple negative breast cancer (TNBC) cells. This "Trojan horse" approach promotes a specific and massive accumulation of radiosensitizers in TNBC cells, thus avoiding the fast turnover of small-sized AuNPs and the need for high doses of AuNPs for treatment. Application of X-rays resulted in a significant increase of the therapeutic effect while delivering the same dose, showing the possibility to use roughly half dose of X-rays to obtain the same radiotoxicity effect. These data suggest that this hybrid nanoplatform acts as a promising tool for applications in enhancing cancer radiotherapy effects with lower doses of X-rays.