Assessing Factors of Environmental Stewardship Success: Organizational Perceptions from the Niagara Region of Ontario, Canada.

Environmental stewardship is increasingly important as human actions threaten the natural world. Now, more than ever, it is necessary to understand what makes stewardship initiatives successful. This study investigates stewardship success in the Niagara Region of Ontario, Canada.

Chorion-derived extracellular matrix hydrogel and fibronectin surface coatings show similar beneficial effects on endothelialization of expanded polytetrafluorethylene vascular grafts.

The endothelium plays an important regulatory role for cardiovascular homeostasis. Rapid endothelialization of small diameter vascular grafts (SDVGs) is crucial to ensure long-term patency. Here, we assessed a human placental chorionic extracellular matrix hydrogel (hpcECM-gel) as coating material and compared it to human fibronectin in-vitro.

Riboflavin-mediated photooxidation to improve the characteristics of decellularized human arterial small diameter vascular grafts.

Vascular grafts with a diameter of less than 6 mm are made from a variety of materials and techniques to provide alternatives to autologous vascular grafts. Decellularized materials have been proposed as a possible approach to create extracellular matrix (ECM) vascular prostheses as they are naturally derived and inherently support various cell functions. However, these desirable graft characteristics may be limited by alterations of the ECM during the decellularization process leading to decreased biomechanical properties and hemocompatibility.

Tenascin-C promotes chronic pressure overload-induced cardiac dysfunction, hypertrophy and myocardial fibrosis.

Aims: Left ventricular (LV) hypertrophy is characterized by cardiomyocyte hypertrophy and interstitial fibrosis ultimately leading to increased myocardial stiffness and reduced contractility. There is substantial evidence that the altered expression of matrix metalloproteinases (MMP) and Tenascin-C (TN-C) are associated with the progression of adverse LV remodeling. However, the role of TN-C in the development of LV hypertrophy because of chronic pressure overload as well as the regulatory role of TN-C on MMPs remains unknown.

In vitro effects of particulate bone substitute materials on the resorption activity of human osteoclasts.

Much research has been done on bone cells, but only a few studies deal with biomaterial-induced effects on human osteoclasts, which may take on an important role in the successful regeneration of bone. In order to highlight such effects, human peripheral blood mononuclear cells (PBMCs) were extracted from venous blood, differentiated to osteoclasts and then cultured in, the presence of five particulate hydroxyapatite (HA)/β-tricalcium phosphate (TCP) biomaterials, on bovine bone slices and glass cover slips. The biomaterials, AlgOSS 50/50 (50 % HA/50 % TCP), AlgOSS 20/80 (20 % HA/80 % TCP), Algipore (98 % HA), Cerasorb (100 % TCP) and Bio-Oss (100 % HA) were chosen to assess their influence on cell morphology and numbers.

Bioelectrical signals improve cardiac function and modify gene expression of extracellular matrix components.

Aims: Beyond the influence of stimulating devices on cardiac excitation, their use in treating patients with heart failure has positive effects on the myocardium at the molecular level. Electrical signals can induce a wide spectrum of effects in living tissue. Therefore, we sought to determine whether applying electrical microcurrent directly to failing hearts leads to functional improvement.

Microcurrent stimulation promotes reverse remodelling in cardiomyocytes.

Aims: It has been shown that electrical stimulation can improve tissue repair in patients. Imbalances in the extracellular matrix composition induce manifestation of heart failure. Here we investigated the application of microcurrent (MC) to modulate the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in cardiomyocytes and to reverse remodelling in the heart in spontaneous hypertensive rats (SHR).

Hypoxia-inducible factor-1β (HIF-1β) is upregulated in a HIF-1α-dependent manner in 518A2 human melanoma cells under hypoxic conditions.

Solid tumors include hypoxic areas due to excessive cell proliferation. Adaptation to low oxygen levels is mediated by the hypoxia-inducible factor (HIF) pathway promoting invasion, metastasis, metabolic alterations, chemo-resistance and angiogenesis. The transcription factor HIF-1, the major player within this pathway consists of HIF-1α and HIF-1β.

Efficient curing of vinyl carbonates by thiol-ene polymerization.

Vinyl carbonates have recently been identified as a suitable alternative to (meth)acrylates, especially due to the low irritancy and cytotoxicity of these monomers. The drawback of some vinyl carbonates containing abstractable hydrogens arises through their moderate reactivity compared with acrylates. Within this paper, we use the thiol-ene concept to enhance the photoreactivity of vinyl carbonates to a large extent to reach the level of those of similar acrylates.

Polyethylene terephthalate (PET) enhances chondrogenic differentiation of ovine meniscocytes in a hyaluronic acid/polycaprolactone scaffold in vitro.

Purpose: The purpose of this study was to assess the effect of polyethylene terephthalate (PET) on proliferation, differentiation, and attachment of ovine meniscocytes seeded in a hyaluronic acid/polycaprolactone biomaterial (BF-1)

Methods: BF-1 (30 % hyaluronic acid and 70 % polycaprolactone) cylinders with PET (CO-PET) or without PET, were seeded with 2 x 10(6) ovine meniscus cells. The specimens were harvested in triplets at 12 hours, seven, 14, 21 and 28 days. DNA content was measured to test proliferation, histological analysis for cell morphology, and biochemical assessment of glycosaminoglycan content and RT-PCR for type I and II collagen were used to assess differentiation, with immunohistochemistry as post-translational control.

Different behavior of meniscal cells in collagen II/I,III and Hyaff-11 scaffolds in vitro.

The purpose of this study was to evaluate the behavior of ovine meniscal cells seeded on biomaterials made from collagen and hyaluronan, respectively. Ovine meniscal cells were isolated from the medial menisci of stifle joints, expanded in monolayer culture, and seeded on scaffolds made of collagen type II and I/III and a hyaluronan derivative (Hyaff-11). The samples were cultured for 12 h and 7, 14, 21, and 28 days.

Behavior of cardiomyocytes and skeletal muscle cells on different extracellular matrix components--relevance for cardiac tissue engineering.

Myocardial cell transplantation in patients with heart failure is emerging as a potential therapeutic option to augment the function of remaining myocytes. Nevertheless, further investigations on basic issues such as ideal cell type continue to be evaluated. Therefore, the aim of our studies was to compare the performance of skeletal muscle cells and cardiomyocytes with respect to their proliferation rate and viability on different extracellular matrix components (EMCs).

The mandatory CAM testing of cells and scaffolds for tissue engineering: benefits for the three Rs of cooperation with the vaccine industry.

In cooperation with BAXTER Vaccine AG, which supplies incubated special pathogen-free chicken eggs (including a full veterinary record), a permanent hen's egg chorio-allantoic membrane test (HET-CAM) unit has been established, where angiogenesis testing, cell culture, and digital and histological analyses are performed. At the Core Unit for Biomedical Research, the location of the animal testing facility of the Medical University Vienna, cell-scaffold constructs must be evaluated in vitro and in ovo prior to eventual in vivo tissue engineering experiments. The animal testing advisory committee requires that new test proposals are first evaluated by using cell culture and HET-CAM models.

MR imaging of the her2/neu and 9.2.27 tumor antigens using immunospecific contrast agents.

Molecular imaging of tumor antigens using immunospecific magnetic resonance (MR) contrast agents is a rapidly evolving field, which can potentially aid in early disease detection, monitoring of treatment efficacy, and drug development. In this study, we designed, synthetized, and tested in vitro two novel monocrystalline iron oxide nanoparticles (MION) conjugated to antibodies against the her2/neu tyrosine kinase receptor and the 9.2.

Proliferation of myocytes on different ECM-components of animal/human origin in vitro.

For the purpose of tissue regeneration gels of reconstituted basement membrane have been suggested as a vehicle to transfer autologous cells. Results do look promising, but it should be considered that extracellular matrix (ECM) gel (Matrigel) is a soluble extract of Engelbreth-Holm-Swarm (EHS) mouse tumor. Therefore objections arising concerning possible risks complicate clinical use in human subjects.

[Good cell culture practice--implementation of a relational cell culture database].

The claim for cell culture to provide validable in vitro models for biomedical research postulates evasion of possible fatal record keeping errors. A prototype of a relational computer database for IBM-compatible personal computers using Microsoft(r) Windows 95/98/2000 and NT for administration of cell culture data has been developed using Microsoft(r) Access 98 (Microsoft Corporation, Redmond, USA), -Access Basic, -Visual Basic and Structured Query Language (SQL) (IBM Corporation, Armonk, USA), and was tested successfully. The modular software application manages the many aspects of cell culture laboratory record keeping like detailed information on tissue donor, primary cell isolation/cell line origin, immunohistochemical/molecular biological characterisation, cell countings at passaging/subcultivation/cell aliquotation and cryopreservation.

[Concerning cell cultures for biocompatibility-testing: monitoring by DNA-fingerprinting].

Cell cultures are innovative tools for e.g. biocompatibility testing of biomaterials in vitro.