Abstract
Amphiphilic star-shaped block copolymers with biodegradable and biocompatible sequences are attracting increasing attention in biomaterials. Herein, we report the synthesis, characterization, solution properties, and biocompatibility of amphiphilic three-armed star-shaped poly(sarcosine)-
block
-poly(ε-caprolactone) (
s
-PSar-
b
-PCL) diblock copolymers. Tris-(2-aminoethyl)amine initiated ring-opening polymerization (ROP) of sarcosine
N
-carboxyanhydrides in a controlled manner, yielding star-shaped poly(sarcosine)s (
s
-PSars) with predictable molecular weights (from 3.3 to 9.8 kg mol
−1
) and narrow dispersities (
Đ
M
< 1.1). Well-defined amphiphilic
s
-PSar-
b
-PCL diblock copolymers were synthesized by ROP of ε-caprolactone using
s
-PSars as the macroinitiators in one pot. The obtained
s
-PSars and
s
-PSar-
b
-PCL diblock copolymers were characterized using
1
H NMR,
13
C NMR, MALDI-ToF MS, and size-exclusion chromatography (SEC). Intrinsic viscosities ([
η
]) of the
s
-PSar and
s
-PSar-
b
-PCL were estimated using SEC-MALS-VISC-DRI. Dynamic light scattering and transmission electron microscopy analysis showed that the
s
-PSar-
b
-PCL diblock copolymers self-assembled into spherical aggregates with average hydrodynamic diameters of 56–169 nm in aqueous solution. MTT assays (cell viability test) certified the biosafety (relative cell viability >80%) of the copolymers and their self-assembled nanostructures. Taken together, we (i) synthesized the novel
s
-PSar-
b
-PCL diblock copolymers, (ii) investigated the solution properties of the
s
-PSar-
b
-PCLs and
s
-PSars, and (iii) demonstrated the biocompatibility of
s
-PSar-
b
-PCLs.