This paper reports the potential of silica network to sensitize tumor cells and stimulate antitumor toxicity of fludarabine (FLU) and paclitaxel (PAC) against HCT8 cells. SiO₂, SiO₂/FLU and SiO₂/PAC nanostructured materials were characterized by X-Ray Diffraction, Scanning Electron Microscopy, InfraRed Microscopy and in vitro biological assays. When using SiO₂/PAC, it can be observed that the cytostatic effect of PAC is boosted only at high concentrations of this material. On the other hand, in the case of SiO₂/FLU, data showed an enhancement in the cytostatic activity of FLU by up to 25%, also when using this nanomaterial in low doses. These data represent preliminary study on the impact on silica nano-networks in targeted delivery and controlled release of antitumor drugs and they may be efficiently used for future biomedical applications in cancer therapy.