• Fourier Transform Infrared Spectroscopy
• Halloysite Nanotubes
• Kaolinite
• Protein
• Thermogravimetric analysis

Halloysite nanotubes (HNTs) are considered an ideal materials for biotechnological and medical applications. The study of interaction between nanopaticles/nanotubes and proteins is important because the modifications that biological molecules undergo upon their interaction with nanostructured materials may alter their function. Protein aggregation into amyloid fibrils is implicated in severe neurodegenerative diseases and nanoparticles are known to interfere with protein amyloid formation but no studies are reported on the conformational changes induced by nanoparticle or nanotubes on the aggregated proteins.
In this thesis, I studied the interactions between halloysite nanotubes (HNTs) and proteins using Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric analysis. This study can be diveded in two part:
1) Study of the conformational changes induced by surface interaction between halloysite nanotubes (HNTs) and aggregated bovine serum albumin (BSA) and non-aggregated BSA using Fourier transform infrared spectroscopy (FTIR). We also investigated, as comparison, the interaction between BSA and Kaolite (Kao), that have the same composition of HNTs but different structure. We show cleary that the conformational changes of BSA depend by protein concentration, by clay morphology and by amount of clay used. In the case of aggregate protein, the interaction with flat surface of Kao promotes formation of desordered structures for low Kao/BSA ratio and there is no interaction for high Kao/BSA ratio. While, in the all investigated range of HNTs/BSA ratio, the interaction with curved nanoscale surface of HNTs promotes the convertion of aggregated BSA to more ordered structure. The interaction of non-aggregated proteins with clays promotes the convertion of BSA to partial aggregated structure for low Clay/BSA ratio and BSA interacts poorly or not for high Clay/BSA ratio.
2) Loading of HNTs with proteins: spectroscopic and thermogravimetric study. The protein investigated are Bovine serum albumin, Alpha lacalbumin and Beta lactoglobulin. I used the thermogravimetric analysis to determination of HNTs loading and FTIR to study the conformational changes of protein induced by this interaction with HNTs. The results showed that proteins interact with HNTs and ordered secondary structures increased.
These results have demonstrated that HNTs interfere with the alpha-beta transition of proteins which is responsible of many several severe diseases (protein misfolding) but further studies are needed to generalize the effects observed in this work to specific proteins associated with severe diseases such as Alzheimer's, Parkinson's, diabetes type 2, etc.