# BODIPY-Based Nanomaterials--Sensing and Biomedical Applications
## 2 Metallic Nanoparticles@BODIPY
### Cancer Diagnosis and Therapy
#### 2.2.3. Zirconium and Metal-Organic Framework Nanoparticles  
[PERSON] and co-workers built a PDT usable nanoagent based on zirconium hydroxide nanoparticles bearing carboxyphenylporphyrin-PCN-222 and a BODIPY dye (Figure 20) [75]. Zirconium forms a MOF thanks to the attached BODIPY and improves singlet oxygen production in comparison to pure PCN-222. BODIPY was conjugated via the \"SALI\" (solvent-assisted ligand incorporation) process. The obtained nanoagent excited with white LED light revealed an IC\({}_{50}\) value of ca. 5 nM against human breast adenocarcinoma cells (MCF-7) and 9 nM against mouse melanoma (B16F10). The improvement of the activity in the light phase in contrast to the dark one was 2000 times for MCF-7 and 10,000 times for B16F10. Moreover, the authors observed that nanoparticles enter the cancer cells and spread in the cytosol [75]. MOF-BODIPY nanoparticles (UiO-PDT) based on zirconium were obtained by [PERSON] and co-workers via solvent-assisted ligands exchange [76]. The MOFs were based on zirconium (inorganic part) and benzenedcarboxylate (organic part). Their structure is presented in Figure 21. However, the BODIPY molecule was modified with iodine substituents to provide high efficacy of singlet oxygen formation. TEM (transmission electron microscopy) and SEM (scanning electron microscopy) analyses indicated that the MOF reveals an octahedral shape. The incorporation of BODIPY in the MOF resulted in a slight shift of the absorption band and a significant red shift of the emission (from 549 to 563 nm). The fluorescence ability was evaluated after incubation of UiO-PDT with mouse melanoma cells (B16F10). The authors noticed red emission of the UiO-PDT and free BODIPY placed in the cytoplasm, indicating that particles entered the cells. They also examined biocompatibility as an important factor of every potential drug. MOFs modified with BODIPY expressed low cytotoxicity against several cell lines (B16F10, C26, CT26) at a concentration of 1 mg/mL. In addition, the photocytotoxicity of obtained MOFs towards the above-mentioned cell lines was also evaluated. Simultaneously, the authors performed control experiments with a bare MOF and bare BODIPY. High photoactivity of bare BODIPY was observed (IC\({}_{50}\) < 0.8 ug/mL), while in dark conditions, the studied PS remained inactive. The control study with a bare MOF indicated no significant activity both under irradiation and in the dark. MOFs modified with BODIPY revealed high photoactivity against the above-mentioned cell lines with the IC\({}_{50}\) values within the range of 0.51-1.15 ug/mL [76]. [PERSON] and co-workers continued studies with UiO-PDT nanoparticles and used them as computed tomography (CT) imaging agents. In CT imaging, it is crucial to obtain the desired contrast deriving from molecules/atoms with high X-ray attenuation, i.e., iodine, barium, and bismuth. The authors proved the lack of cytotoxicity in an in vitro experiment with HepG2 cells. Next, they performed detailed in vivo experiments with a rat model. The hematoxylin and eosin staining of vital organs (heart, liver, spleen, lung, and kidney) was performed. Function markers of liver, kidney, gallbladder indicator and some blood parameters (hemolysis, prothrombin time, and activated partial thrombolin time) were measured. Based on the performed experiments, the authors concluded that UiO-PDT nanoparticles reveal high biocompatibility up to a dose of 100 mg/kg b.w. The contrasting ability of nanoparticles was evaluated via visualization of tumor in rats bearing hepatomas. Figure 19. The chemical structure of SPIONs conjugates with cytochrome c [74]. The highest signal was observed 24 h after intravenous agent injection. The hepatic tumor was indicated with a brighter signal when compared to the surrounding tissues, although not as bright as bones [77]. Figure 20: A fragment of the chemical structure of zirconium hydroxide-5,10,15,20-tetra(carboxyphenyl) porphyrin metal-organic framework-PCN-222, decorated with BODIPY dyes [75].