Poly(ε-Caprolactone) Resorbable Auxetic Designed Knitted Scaffolds for Craniofacial Skeletal Muscle Regeneration.

Craniofacial microsomia is a congenital deformity caused by asymmetric development of the skull (cranium) and face before birth. Current treatments include corrective surgery and replacement of the deformed structure using autograft tissue, which results in donor site morbidity. An alternative therapy can be achieved by developing a resorbable scaffold for skeletal muscle regeneration which will help restore the symmetry and function of the facial muscles and reduce donor site morbidity.

Primary Cilia Exhibit Mechanosensitivity to Cyclic Tensile Strain and Lineage-Dependent Expression in Adipose-Derived Stem Cells.

Non-motile primary cilia are dynamic cellular sensory structures and are expressed in adipose-derived stem cells (ASCs). We have previously shown that primary cilia are involved in chemically-induced osteogenic differentiation of human ASC (hASCs) in vitro. Further, we have reported that 10% cyclic tensile strain (1 Hz, 4 hours/day) enhances hASC osteogenesis.

Engineering small-caliber vascular grafts from collagen filaments and nanofibers with comparable mechanical properties to native vessels.

At the present time, there is no successful synthetic, off-the-shelf small-caliber vascular graft (<6 mm) for the repair or bypass of the coronary or carotid arteries. This stimulates on-going investigations to fabricate an artificial vascular graft that has both sufficient mechanical properties as well as superior biological performance. Collagen has long been considered as a viable material to encourage cell recruitment, tissue regeneration, and revascularization, but its use has been limited by its inferior mechanical properties.

Primary cilia are sensors of electrical field stimulation to induce osteogenesis of human adipose-derived stem cells.

In this study, we report for the first time that the primary cilium acts as a crucial sensor for electrical field stimulation (EFS)-enhanced osteogenic response in osteoprogenitor cells. In addition, primary cilia seem to functionally modulate effects of EFS-induced cellular calcium oscillations. Primary cilia are organelles that have recently been implicated to play a crucial sensor role for many mechanical and chemical stimuli on stem cells.

Novel genipin-collagen immobilization of polylactic acid (PLA) fibers for use as tissue engineering scaffolds.

The material surface plays an important role in the case of biomaterials used as tissue engineering scaffolds. On exposure to a biological environment, extra cellular matrix (ECM) proteins are adsorbed non-specifically onto the surface and cells interact indirectly with the surface through the adsorbed proteins. Most synthetic polymeric biomaterials lack the desirable surface properties for cells as well as have poor cellular adhesion due to their hydrophobic nature.

In vitro dermal and epidermal cellular response to titanium alloy implants fabricated with electron beam melting.

Transdermal osseointegrated prostheses (TOPs) are emerging as an alternative to socket prostheses. Electron beam melting (EBM) is a promising additive manufacturing technology for manufacture of custom, freeform titanium alloy (Ti6Al4V) implants. Skin ongrowth for infection resistance and mechanical stability are critically important to the success of TOP, which can be influenced by material composition and surface characteristics.

Age-related effects on the potency of human adipose-derived stem cells: creation and evaluation of superlots and implications for musculoskeletal tissue engineering applications.

Human adipose-derived stem cells (hASC) are now a prevalent source of adult stem cells for studies in tissue engineering and regenerative medicine. However, researchers utilizing hASC in their investigations often encounter high levels of donor-to-donor variability in hASC differentiation potential. Because of this, conducting studies with this primary cell type can require extensive resources to generate statistically significant data.

Primary cilia: the chemical antenna regulating human adipose-derived stem cell osteogenesis.

Adipose-derived stem cells (ASC) are multipotent stem cells that show great potential as a cell source for osteogenic tissue replacements and it is critical to understand the underlying mechanisms of lineage specification. Here we explore the role of primary cilia in human ASC (hASC) differentiation. This study focuses on the chemosensitivity of the primary cilium and the action of its associated proteins: polycystin-1 (PC1), polycystin-2 (PC2) and intraflagellar transport protein-88 (IFT88), in hASC osteogenesis.

The effects of cyclic hydrostatic pressure on chondrogenesis and viability of human adipose- and bone marrow-derived mesenchymal stem cells in three-dimensional agarose constructs.

This study investigates the effects of cyclic hydrostatic pressure (CHP) on chondrogenic differentiation of human adipose-derived stem cells (hASCs) in three-dimensional (3-D) agarose constructs maintained in a complete growth medium without soluble chondrogenic inducing factors. hASCs were seeded in 2% agarose hydrogels and exposed to 7.5 MPa CHP for 4 h per day at a frequency of 1 Hz for up to 21 days.

Mammalian cell viability in electrospun composite nanofiber structures.

Incorporation of mammalian cells into nanofibers (cell electrospinning) and multilayered cell-nanofiber structures (cell layering) via electrospinning are promising techniques for tissue engineering applications. We investigate the viability of 3T3-L1 mouse fibroblasts after incorporation into poly(vinyl alcohol) nanofibers and multilayering with poly(caprolactone) nanofibers and analyze the possible factors that affect cell viability. We observe that cells do not survive cell electrospinning but survive cell layering.

The development and validation of a LIPUS system with preliminary observations of ultrasonic effects on human adult stem cells.

To study the potential effects of low-intensity pulsed ultrasound (LIPUS) on cell response in vitro, the ability to alter LIPUS parameters is required. However, commercial LIPUS systems have very little control over parameter selection. In this study, a custom LIPUS system was designed and validated by exploring the effects of using different pulse repetition frequency (PRF) parameters on human adipose derived adult stem cells (hASCs) and bone marrow derived mesenchymal stem cells (hMSCs), two common stem cell sources for creating bone constructs in vitro.

Effect of varied ionic calcium on human adipose-derived stem cell mineralization.

Human adipose-derived stem cells (hASCs) are a relatively abundant and accessible stem cell source with multilineage differentiation capability and have great potential for bone tissue engineering applications. The success of bone tissue engineering is intimately linked with the production of a mineralized matrix that mimics the natural mineral present within native bone. In this study, we examined the effects of ionic calcium levels of 1.

Osteogenic effects of rest inserted and continuous cyclic tensile strain on hASC lines with disparate osteodifferentiation capabilities.

We investigated the effects of two types of cyclic tensile strain, continuous and rest inserted, on osteogenic differentiation of human adipose-derived adult stem cells (hASCs). The influence of these mechanical strains was tested on two hASC lines having different mineral deposition potential, with one cell line depositing approximately nine times as much calcium as the other hASC line after 14 days of culture in osteogenic medium on tissue culture plastic. Results showed that both continuous (10% strain, 1 Hz) and rest inserted cyclic tensile strain (10% strain, 1 Hz, 10 s rest after each cycle) regimens increased the amount and rate of calcium deposition for both high and low calcium depositing hASC lines as compared to unstrained controls.

Cellular incorporation into electrospun nanofibers: retained viability, proliferation, and function in fibroblasts.

Nanofibers are an emerging scaffold for tissue engineering. To date no one has reported cell incorporation into nanofibers. Human foreskin fibroblasts and human adipose-derived adult stem cells (hADAS) were grown to confluence, resuspended in phosphate-buffered saline, and then solubilized in polyvinyl alcohol (PVA).

Characterization of electrospun nanocomposite scaffolds and biocompatibility with adipose-derived human mesenchymal stem cells.

Electrospun nanocomposite scaffolds were fabricated by encapsulating multi-walled carbon nanotubes (MWNT) in poly (lactic acid) (PLA) nanofibers. Scanning electron microscopy (SEM) confirmed the fabrication of nanofibers, and transmission electron microscopy identified the alignment and dispersion of MWNT along the axis of the fibers. Tensile testing showed an increase in the tensile modulus for a MWNT loading of 0.

Differential effects on messenger ribonucleic acid expression by bone marrow-derived human mesenchymal stem cells seeded in agarose constructs due to ramped and steady applications of cyclic hydrostatic pressure.

This study investigated the differential effects of ramped and steady applications of cyclic hydrostatic pressure (CHP) on chondrogenic differentiation of bone marrow-derived human mesenchymal stem cells (hMSCs) in 3-dimensional culture in the absence of transforming growth factor-beta (TGF-beta). A custom hydrostatic pressure system was designed and manufactured. hMSCs were seeded in agarose and exposed to steady (7.

Effects of serial passaging on the adipogenic and osteogenic differentiation potential of adipose-derived human mesenchymal stem cells.

Adipose-derived human mesenchymal stem cells (hMSCs) will be more valuable for tissue engineering applications if they can be extensively subcultured without loss of phenotype and multilineage differentiation ability. This study examined the effects of serial passaging on growth rate, gene expression, and differentiation potential of adipose-derived hMSCs. Differentiation was assessed by analyzing changes in messenger RNA (mRNA) expression of osteogenic and adipogenic marker genes and by determining production of calcium deposits and lipid vacuoles.

Osteogenic differentiation of human mesenchymal stem cells in collagen matrices: effect of uniaxial cyclic tensile strain on bone morphogenetic protein (BMP-2) mRNA expression.

Human mesenchymal stem cells (hMSCs) differentiate down an osteogenic pathway with appropriate mechanical and/or chemical stimuli. This study describes the successful culture of hMSCs in 3D collagen matrices under mechanical strain. Bone marrow-derived hMSCs were seeded in linear 3D type I collagen matrices and subjected to 0%, 10%, or 12% uniaxial cyclic tensile strain at 1 Hz for 4 h/day for 7 or 14 days.

Developing a sustainable process to provide quality control materials for genetic testing.

Purpose: To provide a summary of the outcomes of two working conferences organized by the Centers for Disease Control and Prevention (CDC), to develop recommendations for practical, sustainable mechanisms to make quality control (QC) materials available to the genetic testing community.

Methods: Participants were selected to include experts in genetic testing and molecular diagnostics from professional organizations, government agencies, industry, laboratories, academic institutions, cell repositories, and proficiency testing (PT)/external Quality Assessment (EQA) programs. Current efforts to develop QC materials for genetic tests were reviewed; key issues and areas of need were identified; and workgroups were formed to address each area of need and to formulate recommendations and next steps.

Genetically characterized positive control cell lines derived from residual clinical blood samples.

Background: Positive control materials for clinical diagnostic molecular genetic testing are in critically short supply. High-quality DNA that closely resembles DNA isolated from patient specimens can be obtained from Epstein-Barr virus (EBV)-transformed peripheral blood lymphocyte cell lines. Here we report the development of a process to (a) recover residual blood samples with clinically important mutations detected during routine medical care, (b) select samples likely to provide viable lymphocytes for EBV transformation, (c) establish stable cell lines and confirm the reported mutation(s), and (d) validate the cell lines for use as positive controls in clinical molecular genetic testing applications.

Bioelectronic sensor technology for detection of cystic fibrosis and hereditary hemochromatosis mutations.

Context: Bioelectronic sensors, which combine microchip and biological components, are an emerging technology in clinical diagnostic testing. An electronic detection platform using DNA biochip technology (eSensor) is under development for molecular diagnostic applications. Owing to the novelty of these devices, demonstrations of their successful use in practical diagnostic applications are limited.