Zwitterionic polycarboxybetaines (PCBs) have gained attention as alternative stealth polymers whose

liposomal formulation and protein conjugates were reported not to elicit anti-polymer antibodies. Here, we

studied the blood retention and antigenicity of liposomes modified with PCBs focusing on their chemical

structures and doses. We compared PCBs with either 1 or 3 (PCB1 or PCB3) spacer carbons between the

carboxylate and ammonium groups. PCB3-modified liposomes had a short blood retention, whereas PCB1-

modified liposomes demonstrated extended blood retention that was somewhat superior to PEGylated liposome.

This confirmed the excellent non-fouling nature of PCB1 reported previously. Interestingly, PCB1-liposome as

well as PCB3-liposome elicited specific IgMs toward each PCB. The dose-dependent production of specific

IgMs to PCB-liposomes was similar to that of PEGylated liposome, i.e., high doses of PCB-liposomes reduced

the production of specific IgMs, termed immunological tolerance. These results indicate the importance of

investigating the effect of dose to clarify the existence of antigenicity of stealth polymers

Search

Refine Search