In this work an in vitro degradable poly(ester-urethane)urea (PEUU) was synthesized using polycaprolactone diol, hexamethylene diisocyanate, and calcium salt of p-aminobenzoic acid. The synthesized polymer was characterized by (1) H-NMR and FTIR spectroscopy and viscosity studies. Scaffolds having random micro fibrous structures were fabricated from PEUU by electrospinning process. The thermal properties of the scaffold were evaluated by thermogravimetric analysis and dynamic mechanical analysis. The mechanical property evaluation showed that the scaffold possess sufficiently high tensile strength of 16 MPa. The in vitro degradation studies of the electrospun scaffold were carried out in phosphate buffer saline for 6 months. The average mass loss of the scaffold after 6 months of hydrolytic degradation was 25%. FTIR spectroscopy study confirmed the degradation of the PEUU from decrease in intensity of 1400 cm(-1) peak corresponding to ionic carboxylate group. Presence of amine group and calcium ions in the degradation medium further confirmed the degradation of the hard segment in the hydrolytic medium. The mechanical property evaluation of the scaffold indicated a gradual decrease in tensile strength and modulus whereas percentage elongation of the scaffold increases with time of in vitro degradation. The morphological evaluation of the scaffold after degradation by SEM shows evidence of broken fibers and pores in the scaffold. Preliminary in vitro cytotoxicity test demonstrated that both the material and the degradation products were noncytotoxic in nature and the material showed good proliferation to L-929 cells.

In this study, a calcium-containing monomer, namely calcium lactate, was used for the synthesis of calcium-containing polyurethane for use in biomedical applications. Ether-based polyurethane was prepared using poly(oxytetramethylene)glycol, hexamethylene diisocyanate and calcium lactate. The prepared polymer was characterized by FTIR spectroscopy, which confirmed the presence of ionic linkages in the main chain. The thermal behavior, mechanical properties and viscosity of the polymer were studied, and the properties were compared with those of a control polyurethane sample without any metal. Because of ionic clustering in calcium lactate-incorporated ionic polyurethane, the mechanical properties and storage modulus were enhanced compared with those of nonionic polyurethane. The prepared calcium-containing polyurethane was evaluated for its blood compatibility. An evaluation of blood-material interactions revealed that the material is blood compatible and that the polymer does not induce any hemolysis.

Gold nanoparticles generated and stabilized by a β-cyclodextrin–cyano phenyl boronic acid complex enable the colorimetric detection of glucose.

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The synthesis and characterization of calcium-containing poly(urethane-ether)s, having ionic links in the main chain, is reported. Calcium salt of p-hydroxybenzoic acid (HBA-Ca) was prepared from p-hydroxybenzoic acid (HBA) and used as the chain extender in the preparation of calcium-containing poly(urethane-ether)s. Poly(urethane-ether)s, having two different compositions, were prepared by varying the mole ratios of poly(tetramethylene glycol), hexamethylene diisocyanate, and HBA-Ca. The synthesized poly(urethane-ether)s were characterized by infrared spectroscopy, thermogravimetric analysis, and dynamic mechanical analysis. The presence of calcium in the polymer chain was confirmed by energy-dispersive X-ray analysis. The inherent viscosity of metal-containing polymers decreased with the increase in the metal content of the polymer. The introduction of metal into the polymer lowers the thermal stability of the polymers as indicated by the decreased initial decomposition temperature. The glass transition temperature (T g ) and the storage modulus of the metal-containing polymers increase with the increase in metal content presumably due to the formation of physical crosslink's in the polymer. From the mechanical studies of the polymer, it was observed that the metal-containing polymers exhibit high tensile strength and modulus.