Stimuli-Responsive Thiomorpholine Oxide-Derived Polymers with Tailored Hydrophilicity and Hemocompatible Properties

Area of Science:

• Polymer Science
• Materials Science
• Nanomedicine

Background:

• Thermo-responsive polymers with tunable lower critical solution temperature (LCST) are crucial for nanomedicine.
• Dual LCST/pH-responsive polymers are highly desirable for biological applications due to disease-related pH changes.

Purpose of the Study:

• To synthesize and characterize a novel dual LCST/pH-responsive polymer based on ethylthiomorpholine oxide methacrylate (THOXMA).
• To evaluate the polymer's responsiveness, biocompatibility, and potential for biological applications.

Main Methods:

• Polymerization of THOXMA via the RAFT process to create well-defined polymers.
• Preparation of copolymers with hydroxyethyl methacrylate (HEMA) to tune LCST.
• Dynamic light scattering (DLS) to assess LCST behavior and pH responsiveness.
• Cytotoxicity, haemolysis, and red blood cell aggregation assays to evaluate biocompatibility.

Main Results:

• Successfully synthesized well-defined polymers and copolymers of THOXMA using RAFT polymerization.
• Demonstrated tunable LCST behavior in alkaline conditions (40-60 °C) and loss of LCST in acidic conditions due to protonation.
• Confirmed high biocompatibility, with no cytotoxicity, haemolysis, or red blood cell aggregation.

Conclusions:

• The novel THOXMA-based polymer exhibits promising dual LCST/pH responsiveness.
• Its high biocompatibility and tunable properties make it a strong candidate for smart materials in biological and nanomedicine applications.