Incorporation of OTPh or P3HT into NaDC aggregates in aerated solutions led to the protection of these molecules from photodegradation which was readily observed in aerated chloroform solutions (Figure DLS experiments showed that the interaction of OTPh or P3HT with NaDC does not significantly change the size of the NaDC aggregates in solution but changes the distribution between the different types of aggregates and their polydispersity. Bile salts form small primary aggregates that further aggregate into secondary aggregates as the concentration of bile salt is raised. The hydrodynamic radius (Rh) of the primary aggregates increased from 1.2 nm to 1.5 nm, while the Rh of the secondary aggregates increased from 170 nm to 300 nm when the NaDC concentration was raised from 50 to 200 mM (Table , Figure ). Addition of OTPh to NaDC solutions led to an increase of the fraction of the larger aggregates without significantly changing the Rh values. The OTPh addition also led to an increase in the polydispersity of the particle sizes, which was larger at the lower NaDC concentration of 50 mM. Control experiments showed that the fluorescence intensity did not change after the solutions were filtered through 0.45 µm filters for samples with 100 mM NaDC, while samples containing 50 mM NaDC showed a 14% decrease in the emission intensity (Figure ). This result suggests that samples with 50 mM NaDC contained larger particles which are not represented in the DLS experiments and which were absent when the NaDC concentration was 100 mM. The addition of P3HT to NaDC solutions had the same effect as observed for OTPh (Table ) and P3HT was completely solubilized in the presence of 200 mM NaDC as the fluorescence intensity remained the same after filtration (Figure ).