The effect of vesicle size on the photopolymerization products of the
polymerizable diacetylene lipid tricosa-10,12-diynoyl)-sn-glycero-3-ph
osphocholine (DC8,9PC) has been examined using size exclusion chromato
graphy (SEC) and mass spectrometry. Lipid polymers from 50-, 100-, 300
-, and 600-nm vesicles have the same molecular weight range with a pro
minent polystyrene equivalent molecular weight peak between 1.6 x 10(6
) and 2.2 x 10(4). The observed intensity of this peak increased as ve
sicle size was increased from 50- through 300-nm diameter, but was dec
reased in 600-nm diameter vesicles. After acid catalyzed transesterifi
cation of the lipid polymers, the derived acyl chain polymers were exa
mined by SEC. These polymers have a common prominent peak correspondin
g to a polystyrene equivalent molecular weight between 2.5 X 10(4) and
2.2 x 10(3). Size exclusion chromatography (SEC) and chemical ionizat
ion mass spectrometry revealed the presence of the polymerized acyl-ch
ain dimer and trimer after methanolysis of the lipid polymer.