biostudies-literatureTamaki MJapan Society for the Promotion of Science28147-28151https://www.ebi.ac.uk/biostudies/studies/S-EPMC9084302biostudies-literatureUnknown8(49)Dendrimers are unique polymers with well-defined structures, and are useful as functional unimolecular nanoparticles. Previous reports have shown that polyamidoamine (PAMAM) dendrimers modified with hydrophobic molecules, such as amino-terminal phenylalanine (Phe), are thermosensitive at high pH. In the present study, we designed carboxyl-terminal Phe-modified PAMAM dendrimers that are thermosensitive under acidic conditions. We reacted an amino-terminal PAMAM dendrimer with various acid anhydrides, such as succinic anhydride, cyclohexanedicarboxylic anhydride, and phthalic anhydride, prior to the reaction with Phe. Interestingly, the amino-terminal Phe-modified PAMAM dendrimers exhibited LCST (lower critical solution temperature)-type thermosensitivity at approximately pH 7, but the carboRSC advancesDual pH-sensitive and UCST-type thermosensitive dendrimers: phenylalanine-modified polyamidoamine dendrimers with carboxyl termini.PMC9084302Scientific Research (C)/No. 17K06004Kojima CTamaki MFukushima DfalseDual pH-sensitive and UCST-type thermosensitive dendrimers: phenylalanine-modified polyamidoamine dendrimers with carboxyl termini.Dendrimers are unique polymers with well-defined structures, and are useful as functional unimolecular nanoparticles. Previous reports have shown that polyamidoamine (PAMAM) dendrimers modified with hydrophobic molecules, such as amino-terminal phenylalanine (Phe), are thermosensitive at high pH. In the present study, we designed carboxyl-terminal Phe-modified PAMAM dendrimers that are thermosensitive under acidic conditions. We reacted an amino-terminal PAMAM dendrimer with various acid anhydrides, such as succinic anhydride, cyclohexanedicarboxylic anhydride, and phthalic anhydride, prior to the reaction with Phe. Interestingly, the amino-terminal Phe-modified PAMAM dendrimers exhibited LCST (lower critical solution temperature)-type thermosensitivity at approximately pH 7, but the carbo2018-01-01T00:00:00Z2018 Aug2025-04-19T13:20:46.676Z2025-04-19T13:20:46.676ZS-EPMC90843023554275010.1039/c8ra05381b