Publications by authors named "William M Harris"

10 Publications

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Endothelial Differentiated Adipose-Derived Stem Cells Improvement of Survival and Neovascularization in Fat Transplantation.

Aesthet Surg J 2019 01;39(2):220-232

Department of Surgery, Cooper University Hospital, Camden, New Jersey.

Background: Adipose-derived stem cells (ASCs) assisted lipotransfer have been considered to facilitate the survival of fat grafts. However, emerging evidence of insufficient vascularization is another obstacle for fat graft survival in cell-assisted lipotransfer.

Objectives: This study evaluated if endothelial phenotype ASCs with fat lipoaspirate improves survival and neovascularization in fat transplantation.

Methods: ASCs were isolated from human periumbilical fat tissue and cultured in endothelial growth medium for 2 weeks. Fat lipoaspirate was mixed with fresh adipose stroma vascular fraction (SVF), endothelial differentiated ASCs (EC/ASCs), and fat lipoaspirate alone. Three fat mixtures were subcutaneously injected into the adult male Sprague-Dawley rat's dorsum at 3 locations. At 8 weeks after transplantation, the grafted fat lipoaspirates were harvested, and the extracted fat was evaluated using photographic, survival weights measurements and histological examination. Neo-vascularization was quantified by immunofluorescence and real-time RT-PCR.

Results: Grafts from the EC/ASC assisted group had a higher survival rate, morphologic integrity, and most uniform lipid droplets. They also revealed less inflammation and fibrosis with increased number of vessels by histological and immunofluorescence analysis. Quantitative RT-PCR analysis indicated that the expression levels of EC-specific markers of CD31 and vWF were higher in the EC/ASC group compared with in the control and fat with SVF transplants.

Conclusions: These results indicated that co-implantation of fat lipoaspirate with ASCs differentiated toward an endothelial phenotype improves both survival and neovascularization of the transplanted fat lipoaspirate, which might provide benefits and represents a promising strategy for clinical application in autologous fat transplantation.
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http://dx.doi.org/10.1093/asj/sjy130DOI Listing
January 2019

Human adipose-derived stem cell treatment modulates cellular protection in both in vitro and in vivo traumatic brain injury models.

J Trauma Acute Care Surg 2018 05;84(5):745-751

From the Department of Surgery (N.S.K., S.C., W.M.H., M.P., T.O., P.Z., J.P.C., S.A.B.), Cooper University Hospital, Camden, NJ; and Division of Trauma (J.P.H.), Cooper University Hospital, Camden, NJ.

Background: Traumatic brain injury (TBI) is a common cause of morbidity and mortality in the civilian population. The purpose of this study was to examine the effect(s) of adipose-derived stem cell (ASC) treatment on cellular and functional recovery in TBI via both in vitro and in vivo methods.

Methods: Cultured neuroblastoma cells, SH-SY5Y, were scratched to mimic TBI in an in vitro model. The effect of ASC-conditioned medium (CM) on cell death, mitochondrial function, and expression of inflammatory cytokines (tumor necrosis factor α [TNF-α], interleukin 1β [IL-1β], and IL-6), as well as apoptosis marker FAS, was measured. In our in vivo model, Sprague-Dawley rats underwent TBI via a frontal, closed-head injury model. Animals randomly received either intravenous human-derived ASCs or intravenous saline within 3 hours of injury and were compared with a sham group. Functional recovery was evaluated via accelerating Rotarod method. On post-TBI Day 3, brain tissue was harvested and assessed for cellular damage via enzyme-linked immunosorbent assay for TNF-α, as well as immunohistochemical staining for β-amyloid precursor protein (β-APP).

Results: Our in vitro data show that ASC treatment imparted reduced cell death (ratio to control: 1.21 ± 0.066 vs. 1.01 ± 0.056, p = 0.017), increased cell viability (ratio to control: 0.86 ± 0.009 vs. 1.09 ± 0.01, p = 0.0001), increased mitochondrial function (percentage of control: 78 ± 6% vs. 68 ± 3%), and significantly decreased levels of inflammatory cytokine IL-1β. In our in vivo study, compared with TBI alone, ASC-treated animals showed no difference in functional recovery, lower levels of expressed TNF-α (ratio to total protein, 0.47 ± 0.01 vs. 0.67 ± 0.04; p < 0.01), and lower levels of β-amyloid precursor protein (fluorescence ratio, 0.43 ± 0.05 vs. 0.69 ± 0.03; p < 0.01).

Conclusions: Adipose-derived stem cell treatment results in improved cell survival, decreased inflammatory marker release, and decreased evidence of neural injury. No difference in functional recovery was seen. These data suggest the potential for ASC treatment to aid in cellular protection and recovery in neural cells following TBI.
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http://dx.doi.org/10.1097/TA.0000000000001770DOI Listing
May 2018

Evaluation of function and recovery of adipose-derived stem cells after exposure to paclitaxel.

Cytotherapy 2017 02 22;19(2):211-221. Epub 2016 Nov 22.

Department of Surgery, Cooper University Hospital, Camden, New Jersey, USA.

Background Aims: Adipose-derived stem cells (ASCs) are considered to play a positive role in wound healing as evidenced by their increasing use in breast reconstructive procedures. After chemotherapy for breast cancer, poor soft tissue wound healing is a major problem. In the present study, the functional capabilities and recovery of ASCs after exposure to chemotherapeutic agent paclitaxel (PTX) using in vitro and ex vivo models were demonstrated.

Methods: Human ASCs were isolated from periumbilical fat tissue and treated with PTX at various concentrations. Adult Sprague-Dawley rats were given intravenous injections with PTX. Two and four weeks after the initial PTX treatment, ASCs were isolated from rat adipose tissue. Proliferation, cell viability, apoptosis and cell migration rates were measured by growth curves, MTT assays, flow cytometry and scratch assays. ASCs were cultured in derivative-specific differentiation media with or without PTX for 3 weeks. Adipogenic, osteogenic and endothelial differentiation levels were measured by quantitative reverse transcriptase polymerase chain reaction and histological staining.

Results: PTX induced apoptosis, decreased the proliferation and cell migration rates of ASCs and inhibited ASCs multipotent differentiation in both in vitro human ASC populations and ex vivo rat ASC populations with PTX treatment. Furthermore, after cessation of PTX, ASCs exhibited recovery potential of differentiation capacity in both in vitro and animal studies.

Conclusions: Our results provide insight into poor soft tissue wound healing and promote further understanding of the potential capability of ASCs to serve as a cell source for fat grafting and reconstruction in cancer patients undergoing chemotherapy treatment.
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http://dx.doi.org/10.1016/j.jcyt.2016.10.010DOI Listing
February 2017

In situ heater design for nanoscale synchrotron-based full-field transmission X-ray microscopy.

Microsc Microanal 2015 Apr 5;21(2):290-7. Epub 2015 Mar 5.

1Department of Mechanical Engineering,University of Connecticut,Storrs,CT 06269-3139,USA.

The oxidation of nickel powder under a controlled gas and temperature environment was studied using synchrotron-based full-field transmission X-ray microscopy. The use of this technique allowed for the reaction to be imaged in situ at 55 nm resolution. The setup was designed to fit in the limited working distance of the microscope and to provide the gas and temperature environments analogous to solid oxide fuel cell operating conditions. Chemical conversion from nickel to nickel oxide was confirmed using X-ray absorption near-edge structure. Using an unreacted core model, the reaction rate as a function of temperature and activation energy were calculated. This method can be applied to study many other chemical reactions requiring similar environmental conditions.
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http://dx.doi.org/10.1017/S1431927615000021DOI Listing
April 2015

Three-dimensional microstructural imaging of sulfur poisoning-induced degradation in a Ni-YSZ anode of solid oxide fuel cells.

Sci Rep 2014 Jun 10;4:5246. Epub 2014 Jun 10.

1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] Department of Mechanical Engineering, University of Connecticut.

Following exposure to ppm-level hydrogen sulfide at elevated temperatures, a section of a solid oxide fuel cell (SOFC) Ni-YSZ anode was examined using a combination of synchrotron-based x-ray nanotomography and x-ray fluorescence techniques. While fluorescence measurements provided elemental identification and coarse spatial mapping, x-ray nanotomography was used to map the detailed 3-D spatial distribution of Ni, YSZ, and a nickel-sulfur poisoning phase. The nickel-sulfur layer was found to form a scale covering most of the exposed nickel surface, blocking most fuel reformation and hydrogen oxidation reaction sites. Although the exposure conditions precluded the ability to develop a detailed kinetic description of the nickel-sulfur phase formation, the results provide strong evidence of the detrimental effects of 100 ppm hydrogen sulfide on typical Ni-YSZ anode materials.
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http://dx.doi.org/10.1038/srep05246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4050380PMC
June 2014

Characterization of 3D interconnected microstructural network in mixed ionic and electronic conducting ceramic composites.

Nanoscale 2014 May;6(9):4480-5

HeteroFoaM Center, a DOE Energy Frontier Research Center, USA.

The microstructure and connectivity of the ionic and electronic conductive phases in composite ceramic membranes are directly related to device performance. Transmission electron microscopy (TEM) including chemical mapping combined with X-ray nanotomography (XNT) have been used to characterize the composition and 3-D microstructure of a MIEC composite model system consisting of a Ce0.8Gd0.2O2 (GDC) oxygen ion conductive phase and a CoFe2O4 (CFO) electronic conductive phase. The microstructural data is discussed, including the composition and distribution of an emergent phase which takes the form of isolated and distinct regions. Performance implications are considered with regards to the design of new material systems which evolve under non-equilibrium operating conditions.
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http://dx.doi.org/10.1039/c3nr06684cDOI Listing
May 2014

Three-dimensional microstructural imaging methods for energy materials.

Phys Chem Chem Phys 2013 Oct 5;15(39):16377-407. Epub 2013 Aug 5.

Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269-3139, USA.

Advances in the design of materials for energy storage and conversion (i.e., "energy materials") increasingly rely on understanding the dependence of a material's performance and longevity on three-dimensional characteristics of its microstructure. Three-dimensional imaging techniques permit the direct measurement of microstructural properties that significantly influence material function and durability, such as interface area, tortuosity, triple phase boundary length and local curvature. Furthermore, digital representations of imaged microstructures offer realistic domains for modeling. This article reviews state-of-the-art methods, across a spectrum of length scales ranging from atomic to micron, for three-dimensional microstructural imaging of energy materials. The review concludes with an assessment of the continuing role of three-dimensional imaging in the development of novel materials for energy applications.
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http://dx.doi.org/10.1039/c3cp52356jDOI Listing
October 2013

Focused ion beam preparation of samples for X-ray nanotomography.

J Synchrotron Radiat 2012 Sep 12;19(Pt 5):789-96. Epub 2012 Jul 12.

Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Storrs, CT 06269-3139, USA.

The preparation of hard material samples with the necessary size and shape is critical to successful material analysis. X-ray nanotomography requires that samples are sufficiently thin for X-rays to pass through the sample during rotation for tomography. One method for producing samples that fit the criteria for X-ray nanotomography is focused ion beam/scanning electron microscopy (FIB/SEM) which uses a focused beam of ions to selectively mill around a region of interest and then utilizes a micromanipulator to remove the milled-out sample from the bulk material and mount it on a sample holder. In this article the process for preparing X-ray nanotomography samples in multiple shapes and sizes is discussed. Additionally, solid-oxide fuel cell anode samples prepared through the FIB/SEM technique underwent volume-independence studies for multiple properties such as volume fraction, average particle size, tortuosity and contiguity to observe the characteristics of FIB/SEM samples in X-ray nanotomography.
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http://dx.doi.org/10.1107/S0909049512027252DOI Listing
September 2012

Zone-doubled Fresnel zone plates for high-resolution hard X-ray full-field transmission microscopy.

J Synchrotron Radiat 2012 Sep 28;19(Pt 5):705-9. Epub 2012 Jul 28.

Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.

Full-field transmission X-ray microscopy is a unique non-destructive technique for three-dimensional imaging of specimens at the nanometer scale. Here, the use of zone-doubled Fresnel zone plates to achieve a spatial resolution better than 20 nm in the hard X-ray regime (8-10 keV) is reported. By obtaining a tomographic reconstruction of a Ni/YSZ solid-oxide fuel cell, the feasibility of performing three-dimensional imaging of scientifically relevant samples using such high-spatial-resolution Fresnel zone plates is demonstrated.
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http://dx.doi.org/10.1107/S0909049512029640DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3579491PMC
September 2012

Nondestructive volumetric 3-D chemical mapping of nickel-sulfur compounds at the nanoscale.

Nanoscale 2012 Mar 1;4(5):1557-60. Epub 2012 Feb 1.

Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Unit 3139, Storrs, CT 06269, USA.

Nano-structures of nickel (Ni) and nickel subsulfide (Ni(3)S(2)) materials were studied and mapped in 3D with high-resolution x-ray nanotomography combined with full field XANES spectroscopy. This method for characterizing these phases in complex microstructures is an important new analytical imaging technique, applicable to a wide range of nanoscale and mesoscale electrochemical systems.
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http://dx.doi.org/10.1039/c2nr11690aDOI Listing
March 2012