title: Polyhedral oligomeric silsesquioxane (POSS) suppresses enzymatic degradation of PCL-based polyurethanes.
abstract: In this Article, we studied the enzymatic hydrolytic biodegradation behavior of a novel multiblock thermoplastic polyurethane (TPU) system, which incorporates polyhedral oligomeric silsesquioxane (POSS) into linear biodegradable thermoplastic polyurethanes containing poly(ε-caproactone) (PCL) and polyethylene glycol (PEG) blocks. The biodegradation behavior of POSS-PCL-PEG TPUs was characterized by proton nuclear magnetic resonance spectroscopy ((1)H NMR), differential scanning calorimetry (DSC), tensile tests, scanning electron microscopy (SEM), and wavelength dispersive X-ray spectrometry (WDS) after enduring 22-day accelerated enzymatic hydrolytic degradation tests. POSS incorporation significantly suppressed in vitro enzymatic hydrolytic degradation of PCL-PEG-based multiblock TPUs by a surface passivation mechanism. WDS observations revealed that the covalently bonded POSS moieties developed a near-continuous and robust POSS-layer after initial degradation, which prevented ester bonds of PCL from enzymatic attack, thereby inhibiting further degradation. These striking results provide a new strategy to fabricate the polyester-based biostable thermoplastic polyurethanes (TPUs) of potential use in long-term surgical implants.
authors.affiliation: Syracuse Biomaterials Institute, Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States.
authors.forename: Xinzhu
authors.initials: X
authors.lastname: Gu
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Mather
mesh_terms: D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D017646:Organosilicon Compounds / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*
chemical_list: D017646:Organosilicon Compounds; D011140:Polyurethanes