Photoinitiated Radical Thiol–Ene/Methacrylate versus Thia-Michael Addition in Polyurethane-Grafted Networks: A Comparative Study of Polymeric Drug Delivery Platforms

Results show that the base-initiated click reaction yielded a greater thiol conversion (47.5%) and a more homogeneous network compared to the photoinitiated approach (22.8%). While both graft copolymers exhibited significant shear thinning and thermoplastic behavior, the highly cross-linked photo-based polymer (Graft-P) showed a greater steady shear viscosity. Ultimately, the thia-Michael polyurethane-grafted network (Graft-C) with tailored hydrophilic–hydrophobic balance provided better sustained paclitaxel release, resulting in about 70% cancer cell mortality over 72 h as opposed to 55% for the photo-based grafted polymer network.

Through this integrative approach, we demonstrate how tuning backbone chemistry and postsynthetic grafting drives functional performance and shape the next generation of engineered biomaterials: more resilient, tunable, and better predictive in their biological interactions, well-suited for advanced healthcare applications, especially cancer treatment.