Immobilization of lipase onto functional cyclomatrix polyphosphazene microspheres

• Functional polyphosphazene microspheres with high tunability were synthesized by thiol-ene modification.
• Glycosylated polyphosphazene microspheres could achieve relative high lipase loading capacity, enhanced thermal stability and pH adaptability.
• Those microspheres have large size dispersity with a mean diameter of 680 nm and their surfaces are nagetively charged.
• These polyphosphazene microspheres will provide potential biomedical applications in medicine and tissue engineering.

Functional polyphosphazene cyclomatrix microspheres (PMS) containing glucose and dodecyl moieties were utilized for physical adsorption of lipase. In this regard, Candia Rugosa lipase was immobilized onto the above microspheres through physical adsorption, which exhibited catalytic hydrolysis of glycerol triacetate as the model reaction. As observed under transmission electron microscope (TEM) and scanning electron microscope (SEM), the size of all the microspheres ranged from 400 nm to 1 μm with a mean diameter of 680 nm. Zeta potential analysis demonstrated that the microspheres were negatively charged. The influences of buffer pH, substrate concentration and temperature were also studied along with reusability. The obtained results demonstrated that the immobilized lipase on deprotected glycosylated PMS (D-GPMS) showed the best performance and possessed the highest enzymatic loading activity around 1.0884 mmol L−1 min−1 g−1, and retained nearly 50% of its initial activity even after 10 cycles of application. Moreover, the lipase-microsphere complex displayed high pH adaptability from 7 to 9 and temperature stability above 40 °C. From the viewpoint of biocompatible PMS support, the GPMS-lipase conjugate have potential applications in field such as food, medicine and environment.

Functional polyphosphazene microspheres (PMSs) were used as a novel lipase loading material via physical adsorption. Relative activity in function of substrate concentration, pH, temperature and repeated uses were studied and it was found that PMS decorated by glucose moieties had better performance owing to the formation of biocompatible surface. PMS-lipase conjugate will provide potential biomedical applications in tissue engineering.Figure optionsDownload as PowerPoint slide