Article

Reinforcement of electrospun membranes using nanoscale Al2O3 whiskers for improved tissue scaffolds

Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, USA.
Journal of Biomedical Materials Research Part A (Impact Factor: 2.83). 04/2012; 100(4):903-10. DOI: 10.1002/jbm.a.34027
Source: PubMed

ABSTRACT Poly(ε-caprolactone) (PCL) is a promising material for tissue engineering applications; however, it can be difficult to create scaffolds with the morphology, hydrophilicity, and mechanical properties necessary to support tissue growth. Typically, pure PCL scaffolds have good cellular adhesion, but somewhat low mechanical properties (elastic modulus and tensile strength). This study addresses these issues by incorporating Al(2)O(3) whiskers as reinforcements within PCL membranes generated by electrospinning. Membranes were prepared with Al(2)O(3) content ranging from 1 to 20 wt % and characterized using XRD, TEM, and SEM to determine composition and morphology. The Al(2)O(3) whiskers were well dispersed within the PCL fibers, and the membranes had a highly porous morphology. The elastic modulus was significantly improved by the well aligned whisker reinforcements as verified by tensile testing. The cell morphology and proliferation studies demonstrate Al(2)O(3) whisker reinforced PCL scaffolds maintained the good biocompatibility. These improvements demonstrate that Al(2)O(3) whisker reinforced PCL scaffolds can be considered as a biocompatible material for tissue engineering and dental applications.

1 Follower
 · 
162 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: To improve both the strength and toughness of poly(L-lactide) (PLLA), fibrous-like MgO whiskers with diameters of 0.15–1 μm and lengths of 15–110 μm were prepared, and subsequently surface modified with L-lactide to obtain grafted MgO whiskers (g-MgO whiskers). The structures and properties of MgO whiskers and g-MgO whiskers were studied. Then, a series of MgO whiskers/PLLA and g-MgO whiskers/PLLA composites were prepared by solution casting method, for comparison, MgO particles/PLLA composite was prepared too. The resulting composites were evaluated in terms of hydrophilicity, crystallinity, dispersion of whiskers, interfacial adhesion and mechanical performance by means of polarized optical microscopy (POM), contact angle measurement, field emission scanning electron microscope (FSEM), transmission electron microscopy (TEM) and tensile testing. The results revealed that the crystallization rate and hydrophilicity of PLLA were improved by the introduction of MgO whiskers and g-MgO whiskers. The g-MgO whiskers can disperse more uniformly in and show stronger interfacial adhesion with the matrix than MgO whiskers as a result of the surface modification. Due to the bridge effect of the whiskers and the excellent interfacial adhesion between g-MgO whiskers and PLLA, g-MgO whiskers/PLLA composites exhibited remarkably higher strength, modulus and toughness compared to the pristine PLLA, MgO particles/PLLA and MgO whiskers/PLLA composites.
    Applied Surface Science 03/2015; 332. DOI:10.1016/j.apsusc.2015.01.167 · 2.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery.
    09/2014; 3(5):4. DOI:10.1167/tvst.3.5.4
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nanofibrous Extracellular Matrix(NF-ECM) is usually produced by single syringe electrospinning with only one needle-jet at low production rates of 0.005-0.008g.min-1. We aimed to utilize a novel needle-free multi-jet electrospinning device with potential for fast mass production of NF-ECM exhibiting a controlled three-dimensional(3D) morphology for large scale applications such as skin defects. 3D NF-ECMs of the following synthetic and natural biopolymers were mass produced: collagen, gelatin, poly(caprolactone)(PCL) and poly(L-lactide-co-glycolide) (PLGA). Different concentrations of Gelatin polymer solutions were electrospun under varying processing conditions namely speed of spinning electrode rotation (u) and electric field intensity (E) by altering applied voltage(v) or the distance between electrodes (h) to achieve homogeneous desirable 3D morphology. Nanofiber diameters were assessed by scanning electron microscopy(SEM). Biocompatibility was tested by WST-1 proliferation assay of seeded human mesenchymal stem cells(HMSCs). Biological performance of HMSCs on 3D PLGA NF-ECM was compared to two-dimensional (2D) PLGA film controls via SEM and confocal. Western-blotting addressed the expression of surface adhesion proteins; focal adhesion kinase (FAK), phosphorylated FAK(pY397), α-tubulin, paxillin, vinculin and integrin subunits; α5, αv and β1 proteins. Large scale NF-ECM membranes with homogenous nanofiber morphology and 3D architecture could be fast mass produced (production rate of 0.394 ± 0.013 g.min-1.m-1). The nanofibers possessed diameters of around 180 ± 40 nm with 28 % deviation. HSMCs proliferation was significantly improved on 3D NF-ECMs derived from collagen, gelatin and PLGA when compared to PCL or flat cover-glass controls (p<0.01). PLGA NF-ECM in 3D nanofibrous architecture possessed significantly superior biocompatibility when compared to flat 2D PLGA film (p<0.05). On 3D PLGA NF-ECMs HSMCs expressed a higher amount of α-tubulin and paxillin compared to the HMSCs cultured on a 2D PLGA film(p<0.05). HMSCs exhibited a complex multi-faceted morphology on all NF-ECMs where cells appeared to be integrated into the 3D NF-ECMs niches with complex cell filopodia extending into to all directions. In contrast HMSCs on flat 2D films of the same materials or on cover-glass displayed a simple flattened, mono-layered structure. Needle-free multi-jet electrospinning can be used to mass produce artificial extracellular matrices with intrinsic biocompatibility and desirable integration of stem cells for large scale applications.
    Tissue Engineering Part C Methods 10/2012; 19(6). DOI:10.1089/ten.TEC.2012.0417 · 4.64 Impact Factor