Medicine and Health Sciences Commons^™

Antimicrobial Peptide Coating Of Dental Implants: Biocompatibility Assessment Of Recombinant Human Beta Defensin-2 For Human Cells, Patrick Warnke, Eske Voss, Paul Russo, Sebastien Stephens, Michael Kleine, Hendrik Terheyden, Qin Liu

Qin Liu

Purpose: Artificial materials such as dental implants are at risk of bacterial contamination in the oral cavity. Human beta defensins (HBDs), small cationic antimicrobial peptides that exert a broad-spectrum antibacterial function at epithelial surfaces and within some mesenchymal tissues, could probably help to reduce such contamination. HBDs also have protective immunomodulatory effects and have been reported to promote bone remodeling. The aim of this study, therefore, was to investigate the influence of recombinant HBD-2 on the proliferation and survival of cells in culture.

Materials and Methods: Human mesenchymal stem cells (hMSCs), human osteoblasts, human keratinocytes (control), and the HeLa cancer …

Comparison Of In Vitro Biocompatibility Of Nanobone(®) And Biooss(®) For Human Osteoblasts, Qin Liu, Timothy Douglas, Christiane Zamponi, Stephan Becker, Eugene Sherry, Sureshan Sivananthan, Frauke Warnke, Jörg Wiltfang, Patrick Warnke

Qin Liu

Introduction:Scaffolds for bone tissue engineering seeded with the patient's own cells might be used as a preferable method to repair bone defects in the future. With the emerging new technologies of nanostructure design, new synthetic biomaterials are appearing on the market. Such scaffolds must be tested in vitro for their biocompatibility before clinical application. However, the choice between a natural or a synthetic biomaterial might be challenging for the doctor and the patient. In this study, we compared the biocompatibility of a synthetic bone substitute, NanoBone®, to the widely used natural bovine bone replacement material BioOss®.Material and methods: The in …

Nanospiderwebs: Artificial 3d Extracellular Matrix From Nanofibers By Novel Clinical Grade Electrospinning For Stem Cell Delivery, Mohammad Alamein, Qin Liu, Sebastien Stephens, Stuart Skabo, Frauke Warnke, Robert Bourke, Peter Heiner, Patrick Warnke

Qin Liu

Novel clinical grade electrospinning methods could provide three-dimensional (3D) nanostructured biomaterials comprising of synthetic or natural biopolymer nanofibers. Such advanced materials could potentially mimic the natural extracellular matrix (ECM) accurately and may provide superior niche-like spaces on the subcellular scale for optimal stem-cell attachment and individual cell homing in regenerative therapies. The goal of this study was to design several novel “nanofibrous extracellular matrices” (NF-ECMs) with a natural mesh-like 3D architecture through a unique needle-free multi-jet electrospinning method in highly controlled manner to comply with good manufacturing practices (GMP) for the production of advanced healthcare materials for regenerative medicine, and …

Ceramic Scaffolds Produced By Computer-Assisted 3d Printing And Sintering: Characterization And Biocompatibility Investigations, Patrick Warnke, Hermann Seitz, Stephan Becker, Sureshan Sivananthan, Eugene Sherry, Qin Liu, Jorge Wiltfang, Timothy Douglas

Qin Liu

Hydroxyapatite (HAP) and tricalcium phosphate (TCP) are two very common ceramic materials for bone replacement. However, in general HAP and TCP scaffolds are not tailored to the exact dimensions of the defect site and are mainly used as granules or beads. Some scaffolds are available as ordinary blocks, but cannot be customized for individual perfect fit. Using computer-assisted 3D printing, an emerging rapid prototyping technique, individual three-dimensional ceramic scaffolds can be built up from TCP or HAP powder layer by layer with subsequent sintering. These scaffolds have precise dimensions and highly defined and regular internal characteristics such as pore size. …

A Clinically-Feasible Protocol For Using Human Platelet Lysate And Mesenchymal Stem Cells In Regenerative Therapies, Patrick Warnke, Andreas Humpe, Dirk Strunk, Sebastien Stephens, Frauke Warnke, Jorge Wiltfang, Katharina Schallmoser, Mohammad Alamein, Robert Bourke, Peter Heiner, Qin Liu

Qin Liu

The transplantation of human stem cells seeded on biomaterials holds promise for many clinical applications in cranio-maxillo-facial tissue engineering and regenerative medicine. However, stem cell propagation necessary to produce sufficient cell numbers currently utilizes fetal calf serum (FCS) as a growth supplement which may subsequently transmit animal pathogens. Human platelet lysate (HPL) could potentially be utilized to produce clinical-grade stem cell-loaded biomaterials as an appropriate FCS substitute that is in line with clinically-applicable practice. The goal of this study was to investigate whether HPL can be successfully used to propagate human mesenchymal stem cells (HMSCs) seeded on clinically-approved collagen materials …

Mass Production Of Nanofibrous Extracellular Matrix With Controlled 3d Morphology For Large-Scale Soft-Tissue Regeneration, Mohammad Alamein, Sebastien Stephens, Qin Liu, Stuart Skabo, Patrick Warnke

Qin Liu

Aim: Biomaterials that mimic the nanofibrous architecture of the natural extracellular matrix (ECM) are in the focus for stem cell hosting or delivery in tissue engineering of multilayered soft tissues such as skin, mucosa, or retina. Synthetic nanofibers for such ECM are usually produced by single-syringe electrospinning with only one needle-jet at very low production rates of 0.005–0.008 g·min−1. The aim of this study was to utilize a novel industrial needle-free multijet electrospinning device with the potential for mass production of nanofibrous ECM (NF-ECM) exhibiting a controlled three-dimensional (3D) morphology for large-scale applications such as large area skin regeneration in …

The Primordium Of A Biological Joint Replacement: Coupling Of Two Stem Cell Pathways In Biphasic Ultrasound Compressed Gel Niches, Mariea Brady, Sureshan Sivananthan, Vivek Mudera, Qin Liu, Joerg Wiltfang, Patrick Warnke

Qin Liu

The impaired temporomandibular joint might be the first to benefit from applied tissue engineering techniques because it is small and tissue growth in larger amounts is challenging. Bone and cartilage require different competing environmental conditions to be cultivated in vitro. But coupling both the osteogenic and cartilaginous pathways of mesenchymal stem cell differentiation in homeostasis will be a key essential to grow osteochondral constructs or even the first biological joint replacement in the future.

The aim of this study was to test a single source biomaterial and a single source cell type to engineer a biphasic osteochondral construct in vitro …

A Prospective Study Of The Transient Decrease In Ovarian Cancer Risk Following Childbirth, Qin Liu, Mats Lambe, Inkyung Baik, Sven Cnattingius, Tomas Riman, Anders R. Ekbom, Hans-Olov Adami, Chung-Cheng Hsieh

Qin Liu

Epidemiologic evidence shows that the risk of ovarian cancer is decreased following childbirth. We examined the time points when the decreased risk of postpartum maternal ovarian cancer reaches the lowest point and whether the protective effect diminishes over time. A case-control study nested within the Swedish Fertility Register included 10,086 cases of epithelial ovarian cancer recorded in the Swedish Cancer Register from 1961 to 2001. From the Fertility Register, 49,249 eligible subjects matched to the cases by age were selected as controls. The analysis contrasted risk between adjacent parities through logistic regression models that included indicator variables representing each year …

Profiles Of Human Serum Antibody Responses Elicited By Three Leading Hiv Vaccines Focusing On The Induction Of Env-Specific Antibodies, Michael Vaine, Shixia Wang, Qin Liu, James Arthos, David C. Montefiori, Paul Goepfert, M. Juliana Mcelrath, Shan Lu

Qin Liu

In the current report, we compared the specificities of antibody responses in sera from volunteers enrolled in three US NIH-supported HIV vaccine trials using different immunization regimens. HIV-1 Env-specific binding antibody, neutralizing antibody, antibody-dependent cell-mediated cytotoxicity (ADCC), and profiles of antibody specificity were analyzed for human immune sera collected from vaccinees enrolled in the NIH HIV Vaccine Trial Network (HVTN) Study #041 (recombinant protein alone), HVTN Study #203 (poxviral vector prime-protein boost), and the DP6-001 study (DNA prime-protein boost). Vaccinees from HVTN Study #041 had the highest neutralizing antibody activities against the sensitive virus along with the highest binding antibody …

Novel Ceramic Bone Replacement Material Ceraball® Seeded With Human Mesenchymal Stem Cells, Timothy Douglas, Qin Liu, Andreas Humpe, Jörg Wiltfang, Sureshan Sivananthan, Patrick Warnke

Qin Liu

Objectives: Hydroxyapatite (HA) and tricalcium phosphate (TCP) are two very common ceramic materials for bone replacement. A recently developed material for bone replacement is CeraBall®, which is a mixed HA-TCP scaffold available as porous spherical scaffolds of diameter 4 and 6 mm. Before their use as bone replacement materials in vivo, in vitro testing of these scaffolds is necessary. The goal of this study was to characterise 4 and 6 mm CeraBall® scaffolds in vitro with a view to their future use as bone replacement materials. Materials and methods: The proliferation of human mesenchymal stromal cells (hMSCs) seeded on CeraBall® …

Primordium Of An Artificial Bruch's Membrane Made Of Nanofibers For Engineering Of Retinal Pigment Epithelium Cell Monolayers, Patrick Warnke, Mohammad Alamein, Stuart Skabo, Sebastien Stephens, Robert Bourke, Peter Heiner, Qin Liu

Qin Liu

Transplanted Retinal Pigment Epithelium(RPE) cells hold promise for treatment of Age-related Macular Degeneration(AMD) and Stargardt Disease(SD), but it is conceivable that the degenerated host Bruch's membrane(BM) as a natural substrate for RPE might not optimally support transplanted cell survival with correct cellular organization. We fabricated novel ultrathin 3-dimensional(3D) nanofibrous membranes from Collagen type I and poly(lactic-co-glycolic acid) (PLGA) by an advanced clinical-grade needle-free-electrospinning process. The nanofibrillar 3D networks highly mimicked the fibrillar architecture of the native inner collagenous layer of human BM. Human RPE cells grown on our nanofibrous membranes bore striking resemblance to native human RPE. They exhibited a …

The Impact Of Worksite Weight-Related Social Norms On Associated Behaviors, Stephenie C. Lemon, Qin Liu, Robert P. Magner, Kristin L. Schneider, Lori Pbert

Qin Liu

Objective: To assess the association between descriptive social norms for weight and weight-related behaviors and associated behaviors at the worksite. Design and Sample: Baseline data from site-randomized trial of a worksite ecological intervention for weight control; 12 public high schools in central Massachusetts; Sample of 844 employees enrolled (~ 2/3 of all employees). Conclusions: Associations of weight loss and eating social norms with behavior; Unique from social support; No association of physical activity social norms with physical activity; May be little opportunity for and therefore little exposure to physical activity during the workday; Results support the development of weight loss …

Proliferation Assessment Of Primary Human Mesenchymal Stem Cells On Collagen Membranes For Guided Bone Regeneration, Qin Liu, A. Humpe, D. Kletsas, F. Warnke, S. Becker, T. Douglas, S. Sivananthan, P. Warnke

Qin Liu

Purpose: Human mesenchymal stem cells (hMSCs) hold the potential for bone regeneration because of their self-renewing and multipotent character. The goal of this study was to evaluate the influence of collagen membranes on the proliferation of hMSCs derived from bone marrow. A special focus was set on short-term eluates derived from collagen membranes, as volatile toxic materials washed out from these membranes may influence cell behavior during the short time course of oral surgery.

Materials and Methods: The proliferation of hMSCs seeded directly on a collagen membrane (BioGide) was evaluated quantitatively using the cell proliferation reagent WST-1 (4-3-[4-iodophenyl]-2-[4-nitrophenyl]-2H-[5-tetrazolio]-1, …

Correlation Of Umbilical Cord Blood Hormones And Growth Factors With Stem Cell Potential: Implications For The Prenatal Origin Of Breast Cancer Hypothesis, Todd M. Savarese, William C. Strohsnitter, Hoi Pang Low, Qin Liu, Inkyung Baik, William C. Okulicz, David P. Chelmow, Pagona Lagiou, Peter J. Quesenberry, Kenneth L. Noller, Chung-Cheng Hsieh

Qin Liu

INTRODUCTION: Prenatal levels of mitogens may influence the lifetime breast cancer risk by driving stem cell proliferation and increasing the number of target cells, and thereby increasing the chance of mutation events that initiate oncogenesis. We examined in umbilical cord blood the correlation of potential breast epithelial mitogens, including hormones and growth factors, with hematopoietic stem cell concentrations serving as surrogates of overall stem cell potential. METHODS: We analyzed cord blood samples from 289 deliveries. Levels of hormones and growth factors were correlated with concentrations of stem cell and progenitor populations (CD34+ cells, CD34+CD38- cells, CD34+c-kit+ cells, and granulocyte-macrophage colony-forming …

A Functional Notch-Survivin Gene Signature In Basal Breast Cancer, Connie Wing-Ching Lee, Karl Simin, Qin Liu, Janet Plescia, Minakshi Guha, Ashraf Khan, Chung-Cheng Hsieh, Dario C. Altieri

Qin Liu

INTRODUCTION: Basal-type, or triple-negative, breast cancer (lacking estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 expression) is a high-risk disease for which no molecular therapies are currently available. We studied genetic signatures of basal breast cancer potentially suitable for therapeutic intervention. METHODS: We analyzed protein expression of the Notch-1 intracellular domain and survivin by immunohistochemistry in a series of basal breast cancer patients. A hierarchical clustering and overall survival analysis was carried out on a microarray mRNA database of 232 breast cancer patients. Fifteen published mRNA datasets containing estrogen receptor-negative or estrogen receptor-positive samples were subjected to meta-analysis …