Galactose functionalized injectable thermoresponsive microgels for sustained protein release

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Thermoresponsive polymers offer tunable hydrogel properties for biomedical applications.
• Injectable hydrogels are desirable for minimally invasive drug delivery.
• Galactose functionalization can enhance biocompatibility and targeting.

Purpose of the Study:

• To synthesize and characterize novel galactose-functionalized thermoresponsive injectable microgels.
• To investigate the temperature-responsive behavior and gelation properties.
• To evaluate the potential of these microgels for sustained protein release.

Main Methods:

• Enzymatic transesterification and emulsion copolymerization were used for microgel synthesis.
• Field emission scanning electron microscopy (FESEM) analyzed microgel structure.
• Dynamic light scattering (DLS) assessed particle size changes with temperature.
• In vitro studies evaluated protein (BSA) release kinetics.

Main Results:

• Synthesized poly(N-isopropylacrylamide-co-vinyladipoyl-D-galactose) (P(NIPAAm-co-VAGA)) microgels showed reversible temperature-responsive behavior.
• Lower critical solution temperatures (LCSTs) were tunable and near body temperature (37 °C), enabling rapid thermal gelation.
• Porous microgel structures were observed via FESEM.
• Dramatic particle size reduction occurred upon heating through the LCST.
• In vitro studies demonstrated temperature- and composition-dependent BSA release.

Conclusions:

• Galactose-functionalized thermoresponsive microgels (P(NIPAAm-co-VAGA)) were successfully fabricated.
• These microgels exhibit tunable thermoresponsive properties suitable for injectable applications.
• The materials show promise as candidates for site-specific, sustained drug delivery systems.