Browsing by Author "Zieger, Michael A."

Now showing 1 - 4 of 4
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    Distinct Effects of Adipose-derived Stem Cells and Adipocytes on Normal and Cancer Cell Hierarchy
    (AACR, 2016-07) Anjanappa, Manjushree; Burnett, Riesa; Zieger, Michael A.; Merfeld-Clauss, Stephanie; Wooden, William; March, Kieth; Tholpady, Sunil; Nakshatri, Harikrishna; Department of Surgery, IU School of Medicine
    Adipose-derived stem cells (ASC) have received considerable attention in oncology because of the known direct link between obesity and cancer as well as the use of ASCs in reconstructive surgery after tumor ablation. Previous studies have documented how cancer cells commandeer ASCs to support their survival by altering extracellular matrix composition and stiffness, migration, and metastasis. This study focused on delineating the effects of ASCs and adipocytes on the self-renewal of stem/progenitor cells and hierarchy of breast epithelial cells. The immortalized breast epithelial cell line MCF10A, ductal carcinoma in situ (DCIS) cell lines MCF10DCIS.com and SUM225, and MCF10A-overexpressing SRC oncogene were examined using a mammosphere assay and flow cytometry for the effects of ASCs on their self-renewal and stem-luminal progenitor-differentiated cell surface marker profiles. Interestingly, ASCs promoted the self-renewal of all cell types except SUM225. ASC coculture or treatment with ASC conditioned media altered the number of CD49fhigh/EpCAMlow basal/stem-like and CD49fmedium/EpCAMmedium luminal progenitor cells. Among multiple factors secreted by ASCs, IFNγ and hepatocyte growth factor (HGF) displayed unique actions on epithelial cell hierarchy. IFNγ increased stem/progenitor-like cells while simultaneously reducing the size of mammospheres, whereas HGF increased the size of mammospheres with an accompanying increase in luminal progenitor cells. ASCs expressed higher levels of HGF, whereas adipocytes expressed higher levels of IFNγ. As luminal progenitor cells are believed to be prone for transformation, IFNγ and HGF expression status of ASCs may influence susceptibility for developing breast cancer as well as on outcomes of autologous fat transplantation on residual/dormant tumor cells. Implications: This study suggests that the ratio of ASCs to adipocytes influences cancer cell hierarchy, which may impact incidence and progression.
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    Improving Post-Operative Outcomes in Aged and Diabetic Obese Mice
    (AALAS, 2018) Szilágyi, Keely L.; Zieger, Michael A.; Li, Jiliang; Kacena, Melissa A.; Laboratory Animal Resource Center (LARC)
    Due to their small size, high metabolic rate, and large surface to volume ratio, mice are a challenge to work with surgically and peri-operatively. Working with mice that are more susceptible to anesthetic agents, aged, or obese (e.g., diabetic mice), provides even more challenges. In two separate studies, we found simple that supportive care measures during and after surgery improved post-operative outcomes.
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    Integrated sensing and delivery of oxygen for next-generation smart wound dressings
    (Springer Nature, 2020-05-18) Ochoa, Manuel; Rahimi, Rahim; Zhou, Jiawei; Jiang, Hongjie; Yoon, Chang Keun; Maddipatla, Dinesh; Narakathu, Binu Baby; Jain, Vaibhav; Oscai, Mark Michael; Morken, Thaddeus Joseph; Oliveira, Rebeca Hannah; Campana, Gonzalo L.; Cummings, Oscar W.; Zieger, Michael A.; Sood, Rajiv; Atashbar, Massood Z.; Ziaie, Babak; Pathology and Laboratory Medicine, School of Medicine
    Chronic wounds affect over 6.5 million Americans and are notoriously difficult to treat. Suboptimal oxygenation of the wound bed is one of the most critical and treatable wound management factors, but existing oxygenation systems do not enable concurrent measurement and delivery of oxygen in a convenient wearable platform. Thus, we developed a low-cost alternative for continuous O2 delivery and sensing comprising of an inexpensive, paper-based, biocompatible, flexible platform for locally generating and measuring oxygen in a wound region. The platform takes advantage of recent developments in the fabrication of flexible microsystems including the incorporation of paper as a substrate and the use of a scalable manufacturing technology, inkjet printing. Here, we demonstrate the functionality of the oxygenation patch, capable of increasing oxygen concentration in a gel substrate by 13% (5 ppm) in 1 h. The platform is able to sense oxygen in a range of 5–26 ppm. In vivo studies demonstrate the biocompatibility of the patch and its ability to double or triple the oxygen level in the wound bed to clinically relevant levels.
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    Rapid prototyping of a novel and flexible paper based oxygen sensing patch via additive inkjet printing process
    (RSC, 2019) Maddipatla, Dinesh; Narakathu, Binu B.; Ochoa, Manuel; Rahimi, Rahim; Zhou, Jiawei; Yoon, Chang K.; Jiang, Hongjie; Al-Zubaidi, Hazim; Obare, Sherine O.; Zieger, Michael A.; Ziaie, Babak; Atashbar, Massood Z.; Surgery, School of Medicine
    A novel and flexible oxygen sensing patch was successfully developed for wearable, industrial, food packaging, pharmaceutical and biomedical applications using a cost-efficient and rapid prototypable additive inkjet print manufacturing process. An oxygen sensitive ink was formulated by dissolving ruthenium dye and ethyl cellulose polymer in ethanol in a 1 : 1 : 98 (w/w/w) ratio. The patch was fabricated by depositing the oxygen sensitive ink on a flexible parchment paper substrate using an inkjet printing process. A maximum absorbance from 430 nm to 480 nm and a fluorescence of 600 nm was observed for the oxygen sensitive ink. The capability of the oxygen sensitive patch was investigated by measuring the fluorescence quenching lifetime of the printed dye for varying oxygen concentration levels. A fluorescence lifetime decay (τ) from ≈4 μs to ≈1.9 μs was calculated for the printed oxygen sensor patch, for oxygen concentrations varying from ≈5 mg L−1 to ≈25 mg L−1. A sensitivity of 0.11 μs mg L−1 and a correlation coefficient of 0.9315 was measured for the printed patches. The results demonstrated the feasibility of employing an inkjet printing process for the rapid prototyping of flexible and moisture resistant oxygen sensitive patches which facilitates a non-invasive method for monitoring oxygen and its concentration levels.