Polydopamine Nanoparticle-Reinforced Near-Infrared Light-Triggered Shape Memory Polycaprolactone-Polydopamine Polyurethane for Biomedical Implant Applications

Near-infrared (NIR) light-triggered shape memory polymers are expected to have a more promising prospect in biomedical applications compared with traditional heat-triggered shape memory polymers. In this work, a new kind of polyurethane with NIR light-triggered shape memory property was prepared by using polycaprolactone (PCL), polydopamine nanoparticles (PDANPs), hexamethylene diisocyanate (HDI), and 1,4-butanediol (BDO). The synthesized PCL-PDA polyurethanes, especially when the weight content of PDANPs was 0.17%, showed excellent mechanical properties because the PDANPs were well-dispersed in polyurethanes by the chain extension reaction. Moreover, it also showed an NIR light-triggered rapid shape recovery because of the photothermal effect of polydopamine. The in vitro and in vivo tests showed that the PCL-PDA polyurethane would not inhibit cell proliferation nor induce a strong host inflammatory response, revealing the non-cytotoxicity and good biocompatibility of the material. In addition, the PCL-PDA polyurethane exhibited excellent in vivo NIR light-triggered shape memory performance under an 808 nm laser with low intensity (0.33 W cm(-2)), which was harmless to the human skin. These results demonstrated the potential of the PCL PDA polyurethane in biomedical implant applications.

Automated summary

This study developed a new type of near-infrared light-triggered shape memory polyurethane using polydopamine nanoparticles. The polyurethane showed excellent mechanical properties and rapid shape recovery under near-infrared light due to the dispersion of polydopamine nanoparticles and the photothermal effect. In vitro and in vivo tests demonstrated the biocompatibility and shape memory performance of the polyurethane under low-intensity near-infrared light. This material has potential for biomedical implant applications.