5687
Surprisingly , delivering Foscan by transferrin - conjugated PEG - liposomes to oesophageal cancer cells did not improve the photocytotoxicity or the intracellular accumulation of Foscan when compared to unmodified liposomes or indeed free photosensitiser .
 Foscan, PEG, Foscan
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Foscan, PEG, Foscan