Engineering Commons^™

Invertebrate Retinal Progenitors As Regenerative Models In A Microfluidic System, Caroline D. Pena, Stephanie Zhang, Robert Majeska, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

Regenerative retinal therapies have introduced progenitor cells to replace dysfunctional or injured neurons and regain visual function. While contemporary cell replacement therapies have delivered retinal progenitor cells (RPCs) within customized biomaterials to promote viability and enable transplantation, outcomes have been severely limited by the misdirected and/or insuffcient migration of transplanted cells. RPCs must achieve appropriate spatial and functional positioning in host retina, collectively, to restore vision, whereas movement of clustered cells differs substantially from the single cell migration studied in classical chemotaxis models. Defining how RPCs interact with each other, neighboring cell types and surrounding extracellular matrixes are critical to …

Electro-Chemotactic Fields Induce Cooperative Movement Of Cns Cells, Shawn Mishra, Stephen Redenti, Maribel Vazquez

Publications and Research

Vision loss in adults with Age Related Macular Degeneration (AMD) is attributed to damage of retinal photoreceptor cells that initiate vision by absorbing light. Mouse models have suggested that transplantation of precursor cells may be a novel approach to restore vision. This project uses a combination of electrotactic and chemotactic stimuli to promote and guide CNS cell migration within a microdevice model.

Controlled Microfluidics To Examine Growth-Factor Induced Migration Of Neural Progenitors In The Drosophila Visual System, Cade Beck, Tanya Singh, Angela Farooqi, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

BACKGROUND:

The developing visual system in Drosophila melanogaster provides an excellent model with which to examine the effects of changing microenvironments on neural cell migration via microfluidics, because the combined experimental system enables direct genetic manipulation, in vivo observation, and in vitro imaging of cells, post-embryo. Exogenous signaling from ligands such as fibroblast growth factor (FGF) is well-known to control glia differentiation, cell migration, and axonal wrapping central to vision.

NEW METHOD:

The current study employs a microfluidic device to examine how controlled concentration gradient fields of FGF are able to regulate the migration of vision-critical glia cells with and …

Biomechanical Performances Of Networked Polyethylene Glycol Diacrylate: Effect Of Photoinitiator Concentration, Temperature, And Incubation Time, Morshed Khandaker, Albert Orock, Stefano Tarantini, Jeremiah White, Ozlem Yasar

Publications and Research

Nutrient conduit networks can be introduced within the Polyethylene Glycol Diacrylate (PEGDA) tissue construct to enable cells to survive in the scaffold. Nutrient conduit networks can be created on PEGDA by macrochannel to nanochannel fabrication techniques. Such networks can influence the mechanical and cell activities of PEGDA scaffold. There is no study conducted to evaluate the effect of nutrient conduit networks on the maximum tensile stress and cell activities of the tissue scaffold.The study aimed to explore the influence of the network architecture on the maximum tensile stress of PEGDA scaffold and compared with the nonnetworked PEGDA scaffold. Our study …

Role Of Epidermal Growth Factor-Triggered Pi3k/Akt Signaling In The Migration Of Medulloblastoma-Derived Cells, Veronica Dudu, Richard A. Able, Jr., Veronica Rotari, Qingjun Kong, Maribel Vazquez

Publications and Research

Medulloblastoma (MB) is the most common brain cancer diagnosed among children. The cellular pathways that regulate MB invasion in response to environmental cues remain incompletely understood. Herein, we examine the migratory response of human MB-derived Daoy cells to different concentration profiles of Epidermal Growth Factor (EGF) using a microfluidic system. Our findings provide the first quantitative evidence that EGF concentration gradients modulate the chemotaxis of MB-derived cells in a dose-dependent manner via the EGF receptor (EGF-R). Data illustrates that higher concentration gradients caused increased number of cells to migrate. In addition, our results show that EGF-induced receptor phosphorylation triggered the …

Sendai Virus-Based Liposomes Enable Targeted Cytosolic Delivery Of Nanoparticles In Brain Tumor-Derived Cells, Veronica Dudu, Veronica Rotari, Maribel Vazquez

Publications and Research

BACKGROUND: Nanotechnology-based bioassays that detect the presence and/or absence of a combination of cell markers are increasingly used to identify stem or progenitor cells, assess cell heterogeneity, and evaluate tumor malignancy and/or chemoresistance. Delivery methods that enable nanoparticles to rapidly detect emerging, intracellular markers within cell clusters of biopsies will greatly aid in tumor characterization, analysis of functional state and development of treatment regimens.

RESULTS: Experiments utilized the Sendai virus to achieve in vitro, cytosolic delivery of Quantum dots in cells cultured from Human brain tumors. Using fluorescence microscopy and Transmission Electron Microscopy, in vitro experiments illustrated that these virus-based …

Migration And Invasion Of Brain Tumors, Richard A. Able, Jr., Veronica Dudu, Maribel Vazquez

Publications and Research

Recent advances in molecular biology have led to new insights in the development, growth and infiltrative behaviors of primary brain tumors (Demuth and Berens, 2004; Huse and Holland, 2010; Johnson et al., 2009; Kanu et al., 2009). These tumors are derived from various brain cell lineages and have been historically classified on the basis of morphological and, more recently, immunohistochemical features with less emphasis on their underlying molecular pathogenesis (Huse and Holland, 2010). The detailed molecular characterization of brain tumors has laid the groundwork for augmentation of standard treatment with patient-specific designed targeted therapies (Johnson et al., 2009; Kanu et …

Identification Of An Archaeal Presenilin-Like Intramembrane Protease, Celia Torres-Arancivia, Carolyn M. Ross, Jose Chavez, Zahra Assur, Georgia Dolios, Filippo Mancia, Iban Ubarretxena-Belandia

Publications and Research

Background: The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the c-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of b-amyloid peptides (Ab) implicated in Alzheimer’s disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs). The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea.

Methodology and Principal Findings: We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, …

Aaas Lecture Series On Women In Science And Engineering, Maribel Vazquez

Publications and Research

The winning essay for a Travel Award from the American Association for the Advancement in Science Women Lecture Series.

http://ehrweb.aaas.org/womeninscience/essays/vazquez.htm

Low Concentration Microenvironments Enhance The Migration Of Neonatal Cells Of Glial Lineage, Richard A. Able, Jr., Celestin Ngnabeuye, Cade Beck, Eric C. Holland, Maribel Vazquez

Publications and Research

Glial tumors have demonstrated abilities to sustain growth via recruitment of glial progenitor cells (GPCs), which is believed to be driven by chemotactic cues. Previous studies have illustrated that mouse GPCs of different genetic backgrounds are able to replicate the dispersion pattern seen in the human disease. How GPCs with genetic backgrounds transformed by tumor paracrine signaling respond to extracellular cues via migration is largely unexplored, and remains a limiting factor in utilizing GPCs as therapeutic targets. In this study, we utilized a microfluidic device to examine the chemotaxis of three genetically-altered mouse GPC populations towards tumor conditioned media, as …