title: Polyurethane thermoplastic elastomers with inherent radiopacity for biomedical applications.
abstract: Synthesis and characterization of three different radiopaque thermoplastic polyurethane elastomers are reported. Radiopacity was introduced to the polyurethanes by incorporating an iodinated chain extender, namely, 4,4'-isopropylidinedi-(2,6-diiodophenol) (IBPA), into the polymer chain during polyurethane synthesis. Radiopaque polyurethanes (RPUs) were synthesized by reacting 4,4'-methylenebis(phenyl isocyanate) (MDI), IBPA, and three different diols. The polyols used for the synthesis were polypropylene glycol, polycaprolactone diol, and poly(hexamethylene carbonate) diol. RPUs were characterized by infrared spectroscopy, contact angle measurements, thermogravimetry, dynamic mechanical analysis, energy dispersive X-ray analysis, gel permeation chromatography, X-ray fluorescence spectroscopy, and X-radiography. X-ray images showed that all RPUs prepared using IBPA as the chain extender are highly radiopaque compared with an Aluminum wedge of equivalent thickness. Elemental analysis revealed that the polyurethanes contained 18-19% iodine in the polymer matrix. The RPUs developed have radiopacity equivalent to that of a polymer filled with 20 wt % barium sulfate. Results revealed that RPUs of wide range of properties may be produced by incorporating different diols as the soft chain segment. Cell culture cytotoxicity studies conducted using L929 cells by direct contact test and MTT assay proved that these RPUs are noncytotoxic in nature.
authors: Polymer Processing Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Satelmond Palace Campus, Trivandrum 695 012, Kerala, India.
authors: S
authors: S
authors: Kiran
authors: Nirmala R
authors: NR
authors: James
authors: A
authors: A
authors: Jayakrishnan
authors: Roy
authors: R
authors: Joseph
mesh_terms: D000818:Animals; D020811:Biomedical Technology / Q000379:methods*; D002460:Cell Line; D002850:Chromatography, Gel; D003287:Contrast Media / Q000494:pharmacology*; D055119:Elastic Modulus / Q000187:drug effects; D020724:Elastomers / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008970:Molecular Weight; D011140:Polyurethanes / Q000494:pharmacology*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D044366:Transition Temperature; D014961:X-Ray Diffraction
chemical_list: D003287:Contrast Media; D020724:Elastomers; D011140:Polyurethanes