Grapefruit Oil and Cobalt Nitrate-Loaded Polyurethane Hybrid Nanofibrous Scaffold for Biomedical Applications

The goal of this work is to fabricate a new composite based on polyurethane (PU), grapefruit (GP) oil, and cobalt nitrate [Co(NO3)2] using an electrospinning technique. Morphology results revealed the reduction in the fiber diameter of the composites compared to pristine PU control. The interaction of PU with GP and Co(NO3)2 was confirmed by hydrogen bond formation evident in infrared analysis. The fabricated PU/GP composites depicted a more hydrophobic behavior, while PU/GP/Co(NO3)2 showed a hydrophilic behavior than the pristine PU. Atomic force micrographs (AFM) revealed that the developed composites showed a decrease in the surface roughness (Ra) compared to PU. The addition of GP and Co(NO3)2 improved the mechanical strength of the pristine PU. The blood compatibility assays concluded not only the increase in blood clotting levels but also the less toxic nature of the fabricated composites compared to the pristine PU. Hence, the newly designed composites possessing outstanding physicochemical and biological properties may be used as a potential candidate for scaffolding in tissue engineering applications

Biomass Mediated Synthesis of ZnO and ZnO/GO for the Decolorization of Methylene Blue under Visible Light Source

: In this study, zinc oxide (ZnO) as well as ZnO/GO (zinc oxide/graphene oxide) were successfully synthesized. The Carica papaya leaf extract was used to synthesize ZnO and oil palm empty fruit bunch biomass to obtain graphene, which was further used to obtain graphene oxide. The samples were characterized through a variety of analytical methods such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy and UV–Visible spectroscopy in order to understand their morphology, size, structural phase purity, functional groups and optical properties. Various peaks such as O-H, Zn-OH and Zn-O were found in the case of ZnO. Some additional peaks, such as C-C and C=C, were also been detected while analyzing the sample by Fourier-transform infrared spectroscopy. The results of the XRD and SEM studies demonstrated that the synthesized material shows the crystalline nature of the substance in the case of ZnO, and the crystallinity decreases for ZnO/GO. The average crystallite size was found to 80.0 nm for ZnO and 74.0 nm for ZnO/GO. Further, a red shift was shown in the case of ZnO/GO, which was indicated by the UV–Vis absorption spectrum. In the TEM analysis, the particles were shown to be nanosized. For instance, the highest number of particles was found in the range of 100 to 120 nm in the case of ZnO, while 80–100 nm sized particles were found for ZnO/GO. Using synthesized ZnO and ZnO/GO, the decolorization of methylene blue was found to be 64% and 91%, respectively

Advanced nanofibrous textile-based dressing material for treating chronic wounds

In the present work, an electrospun nanofibrous textile composed of polyurethane (PU), sodium bicarbonate (NaHCO 3) and pantothenic acid (PA) is developed for treating chronic wounds. Wounds are a common health problem and in particular, the chronic wounds such as vascular ulcers, diabetic ulcers and pressure ulcers cause a large number of morbidity and mortality. The main problems of the chronic wounds are prolonged inflammation phase and presence of acidic environment. These events deactivate the operation of growth factors and also the progression of natural healing mechanism. Hence, various types of advanced textile-based dressings are developed to address the clinical complications associated with chronic wound management. The prepared electrospun scaffolds were characterized to study their physicochemical and haemocompatible properties. The scanning electron microscopy micrographs depicted continuous, smooth-interconnected nanofibrous morphology of PU–NaHCO3–PA scaffolds. The Fourier transform infrared spectroscopy spectra indicated the addition of NaHCO3 and PA-based hydrophilic chemical groups, which significantly enhanced the wettability of the composites. Further, the PU–NaHCO3–PA composite membrane inferred to have a highly porous structure with the mean porosity of 79.4 ± 4.8%, which may provide a conducive environment for adherence and proliferation of skin cells. The composite scaffold also offers a highly haemocompatible surface by delaying coagulation of blood through contact activation pathways and by limiting red blood cells damage. Therefore, the excellent physicochemical properties, blood compatibility and the delivery of PA are anticipated to speed up the impaired healing process of chronic wounds

Novel synthesis and characterization studies of spinel NixCo1-xAl2O4 (x=0.0 to 1.0) nano-catalysts for the catalytic oxidation of benzyl alcohol

Ni-doped cobalt aluminate NixCo1−xAl2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) spinel nanoparticles were successfully synthesized by a simple microwave combustion method using urea as the fuel and as well as reducing agent. X-ray powder diffraction (XRD) was confirmed the formation of single phase, cubic spinel cobalt-nickel aluminate structure without any other impurities. Average crystallite sizes of the samples were found to be in the range of 18.93 nm to 21.47 nm by Scherrer’s formula. Fourier transform infrared (FT-IR) spectral analysis was confirmed the corresponding functional groups of the M–O, Al–O and M–Al–O (M = Co and Ni) bonds of spinel NixCo1−xAl2O4 structure. Scanning electron microscope (SEM) and transmission electron microscope (TEM) images was confirmed the particle like nanostructured morphology. Energy band gap (Eg) value was calculated using UV-Visible diffuse reflectance spectra (DRS) and the Eg values increased with increasing Ni2+ dopant from x =0.2 (3.58 eV) to x =1.0 (4.15 eV). Vibrating sample magnetometer (VSM) measurements exposed that undoped and Ni-doped CoAl2O4 samples have superparamagnetic behavior and the magnetization (Ms) values were increased with increasing Ni2+ ions. Spinel NixCo1−xAl2O4 samples has been used for the catalytic oxidation of benzyl alcohol into benzaldehyde and was found that the sample Ni0.6Co0.4Al2O4 showed higher conversion 94.37% with 100% selectivity than other samples, which may be due to the smaller particle size and higher surface area

Morphological, thermal, and blood-compatible properties of electrospun nanocomposites for tissue engineering application

In this work, the morphological, thermal, and blood compatibility properties of prepared polyurethane (PU) and gandharvahasthadi eranda thailam (GHT) nanocomposites were investigated. Morphological and thermal characterization revealed reduced diameter, improved surface roughness, and higher thermal degradation compared to control. The activated partial thromboplastin time (APTT) and prothrombin time (PT) assay revealed that the fabricated nanocomposites displayed delayed blood clotting time owing to improved surface morphology. The hemolytic assay suggested that nanocomposites would be nonhemolytic material due to low hemolytic index of about 1.15% compared to pure PU (2.733%) portraying its safety with the red blood cells. Thus, the newly developed PU/GHT composite scaffold possessing better physicochemical and blood compatibility may be considered as a potential substitute scaffold for replacing damaged tissue. POLYM. COMPOS., 39:E132–E139, 2018

Single stage electrospun multicomponent scaffold for bone tissue engineering application

Incorporation of oils in to the polymer matrix results in the improvement of physicochemical and biocompatible properties. A novel polyurethane based composite bone scaffold was fabricated by electrospinning using sunflower and neem oil for the first time. Scanning electron microscopy (SEM) revealed the mean fiber diameter of the electrospun nanocomposite was decreased with the addition of sunflower oil (816 ± 129.54 nm) and sunflower/neem oil (739 ± 130.922 nm) into the PU matrix (890 ± 116.9115 nm). The strong interactions between PU, sunflower oil and neem oil were observed through Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Contact angle analysis depicted the hydrophobic (PU/sunflower oil - 112° ± 1) nature and with the incorporation of neem oil it shifted to hydrophilic (PU/sunflower oil/neem oil - 61.67° ± 2.517) behavior. Further, the tensile strength analysis showed the improvement in the mechanical strength with the addition of sunflower oil (10.62 MPa) and sunflower/neem oil (11.67 MPa) in to the PU matrix (7.12 MPa). In addition, the developed composites exhibited reduced hemolytic index percentage and enhanced blood clotting time through coagulation studies. Moreover, the cytocompatibility investigation revealed the non-toxic nature of the fabricated nanocomposites with human dermal fibroblast (HDF) cells than the pristine PU. Hence, the developed PU based composites rendering better physio-chemical and cytocompatible properties can serve as an alternate substitute for bone tissue engineering applications

The potential of biomimetic nanofibrous electrospun scaffold comprising dual component for bone tissue engineering

Oils play a putative choice for alleviating various symptoms associated with bone-related disorders. In this present study, polyurethane (PU) scaffold encompassing with Mahua oil (MO) and propolis (PP) were developed using the electrospinning technique. Morphological analysis showed the reduction in the diameter of the electrospun scaffold with blending of MO and MO/PP into the PU matrix. The strong interactions between PU, MO, and PP were evident through the infrared spectrum and thermal analysis. The wettability results showed the hydrophobic nature in electrospun PU/MO scaffold and hydrophilic behavior in electrospun PU/MO/PP scaffold. Mechanical testing indicated the enhancement in the strength of the PU due to the addition of MO and PP. Moreover, the fabricated scaffolds exhibited nontoxicity, low hemoglobin release and improved blood clotting time as evident in the coagulation studies. The cell proliferation studies showed the enhanced fibroblast cell adhesion in the developed nanocomposites than the pristine PU. Hence, the fabricated PU scaffolds blended with MO and PP having desirable properties can serve as a valuable candidate for bone tissue repair