Purpose: To evaluate the potential application of different types of modified cyclodextrins, in this work we have prepared and characterized nano-aggregates. We have also investigated and compared the insertion effects of these modified cyclodextrins in DPPC-MLV, as biomembrane models, at different molar ratio. Methods: Nano-aggregates were prepared by nanoprecipitation method with two medusa like (CydC4 and CydC8) and one bouquet like (CydC6-oligo-PEG) cyclodextrins. The nano-aggregates were characterized by PCS and stability studies were carried out at 25 °C until 75 days. Interaction studies with biomembrane models were carried out with DSC. Results: Nanoprecipitation method allowed to obtain nano-aggregates with all used cyclodextrins. Stability studies showed that CydC8 and CydC6-oligo-PEG maintained unchanged mean size, instead of CydC4 resulted unstable at the tested conditions. As a consequence of cyds insertion, the bilayer undergoes lipid rearrangements according to the chemical structure of cyds. Tm little shifted to lower values, unlike ΔH values exhibited different trend related to cyd type. A linear decrease of enthalpy was observed increasing “medusa like” cyds molar ratio. “Bouquet like” cyd showed the ΔH decrease increasing molar ratio, but at the molar ratio of 0.003 and 0.03, enthalpy values were near to “blank” enthalpy value. Conclusion: The three cyds showed different insertion effects, the hypothesis were that: CydC4 presented a “defect” insertion, CydC8 a “rod-like” and CydC6-oligo-PEG a “ channel like”. Besides CydC8 and CydC6-oligo-PEG will be selected to obtain stable nanoaggregates.
Cyclodextrins “medusa like” and “bouquet like”: interaction studies and preparation of nanoaggregates
VENTURA, Cinzia Anna;
2013-01-01
Abstract
Purpose: To evaluate the potential application of different types of modified cyclodextrins, in this work we have prepared and characterized nano-aggregates. We have also investigated and compared the insertion effects of these modified cyclodextrins in DPPC-MLV, as biomembrane models, at different molar ratio. Methods: Nano-aggregates were prepared by nanoprecipitation method with two medusa like (CydC4 and CydC8) and one bouquet like (CydC6-oligo-PEG) cyclodextrins. The nano-aggregates were characterized by PCS and stability studies were carried out at 25 °C until 75 days. Interaction studies with biomembrane models were carried out with DSC. Results: Nanoprecipitation method allowed to obtain nano-aggregates with all used cyclodextrins. Stability studies showed that CydC8 and CydC6-oligo-PEG maintained unchanged mean size, instead of CydC4 resulted unstable at the tested conditions. As a consequence of cyds insertion, the bilayer undergoes lipid rearrangements according to the chemical structure of cyds. Tm little shifted to lower values, unlike ΔH values exhibited different trend related to cyd type. A linear decrease of enthalpy was observed increasing “medusa like” cyds molar ratio. “Bouquet like” cyd showed the ΔH decrease increasing molar ratio, but at the molar ratio of 0.003 and 0.03, enthalpy values were near to “blank” enthalpy value. Conclusion: The three cyds showed different insertion effects, the hypothesis were that: CydC4 presented a “defect” insertion, CydC8 a “rod-like” and CydC6-oligo-PEG a “ channel like”. Besides CydC8 and CydC6-oligo-PEG will be selected to obtain stable nanoaggregates.Pubblicazioni consigliate
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