7-1. SUNBRIGHT® BD Series

NOF has developed novel acetal linkage releasable PEGs that have self-immolative acetal linkers. The linkers can be
cleaved at physiological conditions and release native bioactive substance gradually. Therefor, the low bioactivity of PEGylated bioactive substances can be improved. The release rate of bioactive substances can be adjusted appropriately with different substitutions in the aromatic structure next to acetal moiety.

We conducted release test with PEGylated Insulin by SUNBRIGHT® BD series at physiological condition and monitored releasing substances over time by HPLC. The results demonstrated that PEGylated insulin by SUNBRIGHT® BD series released native insulin.

We conducted cell proliferation assay with Multi-PEGylated IL2 by SUNBRIGHT® BD series or non-releasable PEG and calculated EC50 value respectively. The results demonstrated that Multi-PEGylated IL2 by SUNBRIGHT® BD series had lower EC50 value and higher efficacy than Multi-PEGylated IL2 by releasing native IL2 during assay.