Quantification of β-CDs Showing Guest Inclusion Ability. When considering the applications of β-CD/PP NWFs for drug delivery systems, the amount of β-CD with guest inclusion ability (functional β-CD) is an important parameter. To determine the amount of functional β-CD on PP NWF, we quantified the MOs that formed a 1:1 inclusion complex withβ-CD. MO staining was performed on the non-treated, Ox, and Plasma samples (Figure ). The β-CD-supported samples were immersed in a MO aqueous solution and rinsed with distilled water. The incorporated MOs were desorbed using 70% ethanol. The number of MO inclusions per unit mass of β-CD/PP NWFs (μmol/g) was calculated from the absorbance of the ethanol solution at 428 nm (Table ). The MO inclusions in Ox-60-CD and Ox-80-CD were higher than those in the other samples. This result implied that more β-CDs were immobilized on Ox-60 and Ox-80 than on Ox-30, which is consistent with the results of the TBO assay. Here, the weight ratio of functional β-CD to Ox-80-CD was approximately 0.5%. This suggests that the amount of supported β-CD was very small, which is compatible with the result that β-CD supported on PP NWF could not be quantified via TGA (Figure ).