@article{haslauer_moghe_osborne_gupta_loboa_2011, title={Collagen-PCL Sheath-Core Bicomponent Electrospun Scaffolds Increase Osteogenic Differentiation and Calcium Accretion of Human Adipose-Derived Stem Cells}, volume={22}, ISSN={["1568-5624"]}, DOI={10.1163/092050610x521595}, abstractNote={Human adipose-derived stem cells (hASCs) are an abundant cell source capable of osteogenic differentiation, and have been investigated as an autologous stem cell source for bone tissue engineering applications. The objective of this study was to determine if the addition of a type-I collagen sheath to the surface of poly(ε-caprolactone) (PCL) nanofibers would enhance viability, proliferation and osteogenesis of hASCs. This is the first study to examine the differentiation behavior of hASCs on collagen–PCL sheath–core bicomponent nanofiber scaffolds developed using a co-axial electrospinning technique. The use of a sheath–core configuration ensured a uniform coating of collagen on the PCL nanofibers. PCL nanofiber scaffolds prepared using a conventional electrospinning technique served as controls. hASCs were seeded at a density of 20 000 cells/cm2 on 1 cm2 electrospun nanofiber (pure PCL or collagen–PCL sheath–core) sheets. Confocal microscopy and hASC proliferation data confirmed the presence of viable cells after 2 weeks in culture on all scaffolds. Greater cell spreading occurred on bicomponent collagen–PCL scaffolds at earlier time points. hASCs were osteogenically differentiated by addition of soluble osteogenic inductive factors. Calcium quantification indicated cell-mediated calcium accretion was approx. 5-times higher on bicomponent collagen–PCL sheath–core scaffolds compared to PCL controls, indicating collagen–PCL bicomponent scaffolds promoted greater hASC osteogenesis after two weeks of culture in osteogenic medium. This is the first study to examine the effects of collagen–PCL sheath–core composite nanofibers on hASC viability, proliferation and osteogenesis. The sheath–core composite fibers significantly increased calcium accretion of hASCs, indicating that collagen–PCL sheath–core bicomponent structures have potential for bone tissue engineering applications using hASCs.}, number={13}, journal={JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION}, author={Haslauer, Carla Maria and Moghe, Ajit K. and Osborne, Jason A. and Gupta, Bhupender S. and Loboa, Elizabeth G.}, year={2011}, pages={1695–1712} } @article{mccullen_haslauer_loboa_2010, title={Fiber-reinforced scaffolds for tissue engineering and regenerative medicine: use of traditional textile substrates to nanofibrous arrays}, volume={20}, ISSN={["1364-5501"]}, DOI={10.1039/c0jm01443e}, abstractNote={Regenerative medicine is a promising therapeutic strategy for the repair and replacement of diseased or injured tissues and organs. The main approach for this method is the fabrication and use of scaffold materials to act as a surrogate framework and promote cell-seeded populations to develop into a mature and functional tissue. Scaffold based strategies for regenerative medicine have focused on the use of three dimensional, biocompatible, biodegradable structures to provide an adequate template for ex vivo cell expansion and maturation, native tissue ingrowth, and restoration of the original tissue qualities with respect to the tissue's biochemical constituents, morphology, form, and function. To achieve this, the use of fiber and/or textile substrates have been used as either the underlying skeleton or reinforcing agents with or without three-dimensional matrices to provide scaffolds that exhibit suitable mechanical properties, high cellularity, and better mimicry of the natural tissue organization and its resulting composition. In this article we discuss (1) fiber reinforcement in natural tissues, (2) literature examples of fiber reinforcement in engineered tissues, and (3) strategies and next steps to expand this field. Fiber reinforcement continues to be an ideal strategy for tissue scaffolds that require mechanical reinforcement while providing high surface volume in a compliant form.}, number={40}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={McCullen, Seth D. and Haslauer, Carla M. and Loboa, Elizabeth G.}, year={2010}, pages={8776–8788} } @article{moody_haslauer_kirk_kannan_loboa_mccarty_2010, title={In Situ Monitoring of Adipogenesis with Human-Adipose-Derived Stem Cells Using Surface-Enhanced Raman Spectroscopy}, volume={64}, ISSN={["1943-3530"]}, DOI={10.1366/000370210793335106}, abstractNote={ Methods capable of nondestructively collecting high-quality, real-time chemical information from living human stem cells are of increasing importance given the escalating relevance of stem cells in therapeutic and regenerative medicines. Raman spectroscopy is one such technique that can nondestructively collect real-time chemical information. Living cells uptake gold nanoparticles and transport these particles through an endosomal pathway. Once inside the endosome, nanoparticles aggregate into clusters that give rise to large spectroscopic enhancements that can be used to elucidate local chemical environments through the use of surface-enhanced Raman spectroscopy. This report uses 40-nm colloidal gold nanoparticles to create volumes of surface-enhanced Raman scattering (SERS) within living human-adipose-derived adult stem cells enabling molecular information to be monitored. We exploit this method to spectroscopically observe chemical changes that occur during the adipogenic differentiation of human-adipose-derived stem cells over a period of 22 days. It is shown that intracellular SERS is able to detect the production of lipids as little as one day after the onset of adipogenesis and that a complex interplay between lipids, proteins, and chemical messengers can be observed shortly thereafter. After 22 days of differentiation, the cells show visible and spectroscopic indications of completed adipogenesis yet still share spectral features common to the progenitor stem cells. }, number={11}, journal={APPLIED SPECTROSCOPY}, author={Moody, Benjamin and Haslauer, Carla M. and Kirk, Elizabeth and Kannan, Arthi and Loboa, Elizabeth G. and McCarty, Gregory S.}, year={2010}, month={Nov}, pages={1227–1233} } @article{mccullen_haslauer_loboa_2010, title={Musculoskeletal mechanobiology: Interpretation by external force and engineered substratum}, volume={43}, ISSN={["1873-2380"]}, DOI={10.1016/j.jbiomech.2009.09.017}, abstractNote={Mechanobiology aims to discover how the mechanical environment affects the biological activity of cells and how cells' ability to sense these mechanical cues is converted into elicited cellular responses. Musculoskeletal mechanobiology is of particular interest given the high mechanical loads that musculoskeletal tissues experience on a daily basis. How do cells within these mechanically active tissues interpret external loads imposed on their extracellular environment, and, how are cell–substrate interactions converted into biochemical signals? This review outlines many of the main mechanotransduction mechanisms known to date, and describes recent literature examining effects of both external forces and cell–substrate interactions on musculoskeletal cells. Whether via application of external forces and/or cell–substrate interactions, our understanding and regulation of musculoskeletal mechanobiology can benefit by expanding upon traditional models, and shedding new light through novel investigative approaches. Current and future work in this field is focused on identifying specific forces, stresses, and strains at the cellular and tissue level through both experimental and computational approaches, and analyzing the role of specific proteins through fluorescence-based investigations and knockdown models.}, number={1}, journal={JOURNAL OF BIOMECHANICS}, author={McCullen, Seth D. and Haslauer, Carla M. and Loboa, Elizabeth G.}, year={2010}, month={Jan}, pages={119–127} } @article{rouse_haslauer_loboa_monteiro-riviere_2008, title={Cyclic tensile strain increases interactions between human epidermal keratinocytes and quantum dot nanoparticles}, volume={22}, ISSN={["0887-2333"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000254694500024&KeyUID=WOS:000254694500024}, DOI={10.1016/j.tiv.2007.10.010}, abstractNote={The effects of quantum dots (QD) on cell viability have gained increasing interest due to many recent developments utilizing QD for pharmaceutical and biomedical applications. The potential use of QD nanoparticles as diagnostic, imaging, and drug delivery agents has raised questions about their potential for cytotoxicity. The objective of this study was to investigate the effects of applied strain on QD uptake by human epidermal keratinocytes (HEK). It was hypothesized that introduction of a 10% average strain to cell cultures would increase QD uptake. HEK were seeded at a density of 150,000 cells/mL on collagen-coated Flexcell culture plates (Flexcell Intl.). QD were introduced at a concentration of 3 nM and a 10% average strain was applied to the cells. After 4 h of cyclic strain, the cells were examined for cell viability, QD uptake, and cytokine production. The results indicate that addition of strain results in an increase in cytokine production and QD uptake, resulting in irritation and a negative impact on cell viability. Application of physiological load conditions can increase cell membrane permeability, thereby increasing the concentration of QD nanoparticles in cells.}, number={2}, journal={TOXICOLOGY IN VITRO}, author={Rouse, Jillian G. and Haslauer, Carla M. and Loboa, Elizabeth G. and Monteiro-Riviere, Nancy A.}, year={2008}, month={Mar}, pages={491–497} }