Thermoresponsive polymers with the
appropriate structure form physical
networks upon changes in temperature, and they find utility in formulation
science, tissue engineering, and drug delivery. Here, we report a
cost-effective biocompatible alternative, namely OEGMA300
15
-
b
-BuMA
26
-
b
-DEGMA
13
, which forms gels at low concentrations (as low as 2% w/w);
OEGMA300, BuMA, and DEGMA stand for oligo(ethylene glycol) methyl
ether methacrylate (MM = 300 g mol
–1
),
n
-butyl methacrylate, and di(ethylene glycol) methyl ether methacrylate,
respectively. This polymer is investigated in depth and is compared
to its commercially available counterpart, Poloxamer P407 (Pluronic
F127). To elucidate the differences in their macroscale gelling behavior,
we investigate their nanoscale self-assembly by means of small-angle
neutron scattering and simultaneously recording their rheological
properties. Two different gelation mechanisms are revealed. The triblock
copolymer inherently forms elongated micelles, whose length increases
by temperature to form worm-like micelles, thus promoting gelation.
In contrast, Pluronic F127’s micellization is temperature-driven,
and its gelation is attributed to the close packing of the micelles.
The gel structure is analyzed through cryogenic scanning and transmission
electron microscopy. Ex vivo gelation study upon intracameral injections
demonstrates excellent potential for its application to improve drug
residence in the eye.