Synthesis of block copolymers containing a carbon chain and a polypeptide block

Abstract

The bifunctional initiators, bis(2-glycylaminophenyl) disulfide (1) and 2,2 '-az0-2,2 '-dimethyldipropionohydrazide (2), were used to obtain polymeric initiators of two types: carbon chain initiators with amino end groups initiating the polymerization of amino acid N-carboxyanhydrides (NCAs) and symmetric polypeptide initiators containing -S-S-or -N=Ngroups, which decompose on exposure to UV light or elevated temperature forming free radicals. These polymeric initiators were used to synthesize block copolymers (BC) containing carbon chain and polypeptide blocks of ABA and AB structures. It is shown that AB block copolymers are capable of aggregation to a much higher extent than those of ABA type. These BC can form liquid-crystalline polymer structures and undergo controlled biodegradation by enzymes.

Azo Polymers

“…Prepolymers, where M 1 = acrylamide, contain both hydrophobic and hydrophilic moieties (20) and can therefore be used in emulsion polymerizations as both the initiator and the surfactant (12,13). In the second route, monomers containing an azo group, in addition to a poly-merizable functionality, are copolymerized with other monomers:…”

“…(10) + An interesting variation of the simple anionic polymerization technique is shown below; an N-carboxy anhydride is polymerized in the presence of 2,2azodimethyl propiohydrazide to yield a polypeptide containing an azo group, which is detected by UV spectroscopy (20).…”

Synthesis of Polyoxazoline−(Glyco)peptide Block Copolymers by Ring-Opening Polymerization of (Sugar-Substituted) α-Amino Acid N-Carboxyanhydrides with Polyoxazoline Macroinitiators

“…15 Many of the block copolymers have been obtained by polymerization of vinyl monomers with polypeptide macroinitiators or by ring-opening polymerization of NCAs with macroinitiators. [17][18][19] The reaction between living poly(2-ethyl-2-oxazoline) and sequential peptide prepared by a stepwise condensation has already been reported. 20 Recently, we have synthesized glycopeptide-polyoxazoline block copolymers by mutual termination of living polymerizations of glucose derivativesubstituted serine NCA and 2-methyl-2-oxazoline.…”

“…Since the first synthesis of block copolymers containing polypeptide as one component was reported in 1969, numerous investigations have been undertaken to prepare block copolymers by the NCA method − The reaction between living poly(2-ethyl-2-oxazoline) and sequential peptide prepared by a stepwise condensation has already been reported . Recently, we have synthesized glycopeptide−polyoxazoline block copolymers by mutual termination of living polymerizations of glucose derivative-substituted serine NCA and 2-methyl-2-oxazoline …”