Synthesis of Fe3O4-Chlorophyllin Nanoparticles for Preventing Amyloid Formation by Human Calcitonin

The accumulation of amyloid fibrils is crucial in thedevelopmentof amyloidosis. In addition, some hormone peptides, such as humancalcitonin (hCT), have limited therapeutic potential owing to a hightendency of amyloid formation. Nowadays, nanotechnology offers manyadvantages in various scientific fields and can overcome some of thelimitations in the development of traditional therapeutics. In thepresent study, we applied iron and copper chlorophyllin in the synthesisof iron-oxide nanoparticles to obtain porphyrin derivative-coatednanoparticles, namely, Fe3O4-Chl/Fe and Fe3O4-Chl/Cu, respectively. We observed that the twonanoparticles, especially Fe3O4-Chl/Fe, stabilizedhCT and influenced hCT aggregation. To further confirm the applicabilityof Fe3O4-Chl/Fe, we utilized another benzothiazole-basedfluorescent probe to monitor hCT amyloid formation. Several biophysicaltechniques, including transmission electron microscopy, dynamic lightscattering, and isothermal titration calorimetry, were also implementedin our examinations. The fibrillar content of hCT after co-incubationwas further determined using Bis-ANS and Nile red assays. The remainingsoluble monomeric or oligomeric content of hCT was assessed by gelelectrophoresis and biological assays. We believed that our findingswould assist in the development of hCT drug formulation. Applicationof Fe3O4-Chl/Fe can increase the stability andbioactivity of hCT.

Automated summary

In this study, iron-oxide nanoparticles coated with porphyrin derivatives, Fe3O4-Chl/Fe and Fe3O4-Chl/Cu, were synthesized and used to stabilize and influence the aggregation of human calcitonin (hCT). The formation of hCT amyloid fibrils was monitored using a fluorescent probe. These findings can contribute to the development of hCT drug formulation.