Electrospun porous materials laden with tea tree oil and zinc nitrate exhibiting tailored physicochemical and in vitro apatite formation

Abstract

Scaffold designs must accommodate the complex regeneration processes of damaged bone tissues. We attempt to achieve this goal by developing a composite electrospun scaffold mimicking the structural and functional requirements of extra cellular matrix This study investigates the use of a novel bone tissue regeneration formulation of tea tree oil (TT) and zinc nitrate Zinc2 incorporated into a polyurethane (PU) nanofibres scaffold fabricated via the well-known electrospinning technique.The diameter of these nanocomposites fibres was smaller (PU/TT-495 ± 184 nm and PU/TT/(ZnNO3)2–409 ± 155 nm) than polyurethane (1099 ± 118 nm) on its own. Fourier transform infrared spectroscopy analysis revealed that the PU and the additives interact through hydrogen-bond formation. Measuring the wettability of the PU/TT indicated a hydrophobic nature (115 ± 2) which was reversed by the addition of (ZnNO3)2 to PU/TT (69° ± 2). TT and the addition of (ZnNO3)2 increased the tensile strength. Atomic force microscopy showed that the fibres of PU/TT (633 ± 297 nm) and PU/TT/(ZnNO3)2 (345 ± 147 nm)were smoother than the PU (854 ± 32 nm). The developed nanocomposites showed delayed blood clot activation and reduced toxicity as determined by anticoagulant studies. Further, bone-forming abilities quantified by in vitro calcium deposition studies indicated enhanced calcium deposition (PU/TT-5.6% and PU/TT/(ZnNO3)2–10.8%) in comparison to PU (2.4%). We have demonstrated that the attributes of these nanocomposites maybe successfully exploited for bone reconstruction.