309 research outputs found

    J Community Health

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    Alzheimer's disease (AD) is the fourth leading cause of death in Puerto Rico. Using multi-media resources and in-person education may be an effective approach to improve knowledge and awareness of AD. The Un Caf\uc3\ua9 por el Alzheimer program in Puerto Rico incorporates an education component at coffee shops and a social media campaign using Facebook. The current study evaluates this initiative through an analysis of pre/post education survey results and social media content and use. Surveys contained close-ended and open-ended questions to understand participants' perceptions and knowledge about AD. Post-education surveys also included questions related to program satisfaction. Social media analysis of the Facebook community page examined posts from March 1 to September 30, 2015. Descriptive statistics were used to analyze survey and Facebook data. Four education sessions were conducted with a total of 212 participants. Fifty-one of the participants completed both pre- and post-surveys. Following the education program participants reported improved knowledge of risk and protective factors. All participants reported learning new information from the program. There were a total of 250 posts on the Un Caf\uc3\ua9 por el Alzheimer community Facebook page; 168 posts related to AD. The Facebook page reached 294,109 people, with 9963 page likes, 610 comments, 17,780 post clicks, and 3632 shares. There was an average increase of 64.8\uc2\ua0% in number of people reached by the Facebook page following the education sessions. The approach of combining social media resources and in-person education is beneficial to increase public awareness of AD and disseminate health information.U48 DP005000/DP/NCCDPHP CDC HHS/United States2016-10-01T00:00:00Z26983930PMC501143

    Living biointerfaces based on non-pathogenic bacteria to direct cell differentiation

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    Genetically modified Lactococcus lactis, non-pathogenic bacteria expressing the FNIII7-10 fibronectin fragment as a protein membrane have been used to create a living biointerface between synthetic materials and mammalian cells. This FNIII7-10 fragment comprises the RGD and PHSRN sequences of fibronectin to bind α5β1 integrins and triggers signalling for cell adhesion, spreading and differentiation. We used L. lactis strain to colonize material surfaces and produce stable biofilms presenting the FNIII7-10 fragment readily available to cells. Biofilm density is easily tunable and remains stable for several days. Murine C2C12 myoblasts seeded over mature biofilms undergo bipolar alignment and form differentiated myotubes, a process triggered by the FNIII7-10 fragment. This biointerface based on living bacteria can be further modified to express any desired biochemical signal, establishing a new paradigm in biomaterial surface functionalisation for biomedical applications

    Selective laser melting–enabled electrospinning: Introducing complexity within electrospun membranes

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    Additive manufacturing technologies enable the creation of very precise and well-defined structures that can mimic hierarchical features of natural tissues. In this article, we describe the development of a manufacturing technology platform to produce innovative biodegradable membranes that are enhanced with controlled microenvironments produced via a combination of selective laser melting techniques and conventional electrospinning. This work underpins the manufacture of a new generation of biomaterial devices that have significant potential for use as both basic research tools and components of therapeutic implants. The membranes were successfully manufactured and a total of three microenvironment designs (niches) were chosen for thorough characterisation. Scanning electron microscopy analysis demonstrated differences in fibre diameters within different areas of the niche structures as well as differences in fibre density. We also showed the potential of using the microfabricated membranes for supporting mesenchymal stromal cell culture and proliferation. We demonstrated that mesenchymal stromal cells grow and populate the membranes penetrating within the niche-like structures. These findings demonstrate the creation of a very versatile tool that can be used in a variety of tissue regeneration applications including bone healing

    The heparin binding domain of von Willebrand factor binds to growth factors and promotes angiogenesis in wound healing

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    During wound healing, the distribution, availability, and signaling of growth factors (GFs) are orchestrated by their binding to extracellular matrix components in the wound microenvironment. Extracellular matrix proteins have been shown to modulate angiogenesis and promote wound healing through GF binding. The hemostatic protein von Willebrand factor (VWF) released by endothelial cells (ECs) in plasma and in the subendothelial matrix has been shown to regulate angiogenesis; this function is relevant to patients in whom VWF deficiency or dysfunction is associated with vascular malformations. Here, we show that VWF deficiency in mice causes delayed wound healing accompanied by decreased angiogenesis and decreased amounts of angiogenic GFs in the wound. We show that in vitro VWF binds to several GFs, including vascular endothelial growth factor-A (VEGF-A) isoforms and platelet-derived growth factor-BB (PDGF-BB), mainly through the heparin-binding domain (HBD) within the VWF A1 domain. VWF also binds to VEGF-A and fibroblast growth factor-2 (FGF-2) in human plasma and colocalizes with VEGF-A in ECs. Incorporation of the VWF A1 HBD into fibrin matrices enables sequestration and slow release of incorporated GFs. In vivo, VWF A1 HBD-functionalized fibrin matrices increased angiogenesis and GF retention in VWF-deficient mice. Treatment of chronic skin wounds in diabetic mice with VEGF-A165 and PDGF-BB incorporated within VWF A1 HBD-functionalized fibrin matrices accelerated wound healing, with increased angiogenesis and smooth muscle cell proliferation. Therefore, the VWF A1 HBD can function as a GF reservoir, leading to effective angiogenesis and tissue regeneration

    Extracellular Matrix Aggregates from Differentiating Embryoid Bodies as a Scaffold to Support ESC Proliferation and Differentiation

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    Embryonic stem cells (ESCs) have emerged as potential cell sources for tissue engineering and regeneration owing to its virtually unlimited replicative capacity and the potential to differentiate into a variety of cell types. Current differentiation strategies primarily involve various growth factor/inducer/repressor concoctions with less emphasis on the substrate. Developing biomaterials to promote stem cell proliferation and differentiation could aid in the realization of this goal. Extracellular matrix (ECM) components are important physiological regulators, and can provide cues to direct ESC expansion and differentiation. ECM undergoes constant remodeling with surrounding cells to accommodate specific developmental event. In this study, using ESC derived aggregates called embryoid bodies (EB) as a model, we characterized the biological nature of ECM in EB after exposure to different treatments: spontaneously differentiated and retinoic acid treated (denoted as SPT and RA, respectively). Next, we extracted this treatment-specific ECM by detergent decellularization methods (Triton X-100, DOC and SDS are compared). The resulting EB ECM scaffolds were seeded with undifferentiated ESCs using a novel cell seeding strategy, and the behavior of ESCs was studied. Our results showed that the optimized protocol efficiently removes cells while retaining crucial ECM and biochemical components. Decellularized ECM from SPT EB gave rise to a more favorable microenvironment for promoting ESC attachment, proliferation, and early differentiation, compared to native EB and decellularized ECM from RA EB. These findings suggest that various treatment conditions allow the formulation of unique ESC-ECM derived scaffolds to enhance ESC bioactivities, including proliferation and differentiation for tissue regeneration applications. © 2013 Goh et al

    LEGO® bricks as building blocks for centimeter-scale biological environments

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    LEGO bricks are commercially available interlocking pieces of plastic that are conventionally used as toys. We describe their use to build engineered environments for cm-scale biological systems, in particular plant roots. Specifically, we take advantage of the unique modularity of these building blocks to create inexpensive, transparent, reconfigurable, and highly scalable environments for plant growth in which structural obstacles and chemical gradients can be precisely engineered to mimic soil

    Compressed collagen and decellularized tissue: novel components in a pipeline approach for the study of cancer metastasis

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    Metastasis is a complex process which is difficult to study and model. Experimental ingenuity is therefore essential when seeking to elucidate the biological mechanisms involved. Typically, in vitro models of metastasis have been overly simplistic, lacking the characteristic elements of the tumour microenvironment, whereas in vivo models are expensive, requiring specialist resources. Here we propose a pipeline approach for the study of cell migration and colonization, two critical steps in the metastatic cascade.We used a range of extracellular matrix derived contexts to facilitate a progressive approach to the observation and quantification of cell behaviour in 2D, 3D and at border zones between dimensions. At the simplest level, cells were set onto collagen-coated plastic or encapsulated within a collagen matrix. To enhance this, a collagen compression technique provided a stiffened, denser substrate which could be used as a 2D surface or to encapsulate cells. Decellularized tissue from the chorioallantoic membrane of the developing chicken embryo was used to provide a more structured, biologically relevant extracellular matrix-based context in which cell behaviour could then be compared with its in vivo counterpart.Cell behaviour could be observed and quantified within each context using standard laboratory techniques of microscopy and immunostaining, affording the opportunity for comparison and contrast of behaviour across the whole range of contexts. In particular, the temporal constraints of the in vivo CAM were removed when cells were cultured on the decellularized CAM, allowing for much longer-term cell colonization and cell-cell interaction.Together the assays within this pipeline provide the opportunity for the study of cell behaviour in a replicable way across multiple environments. The assays can be set up and analysed using easily available resources and standard laboratory equipment. We believe this offers the potential for the detailed study of cell migration and colonization of tissue, essential steps in the metastatic cascade. Also, we propose that the pipeline could be used in the wider arena of cell culture in general with the increasingly more complex contexts allowing cell behaviours and interactions to be explored in a stepwise fashion in an integrated way

    Hybrid Titanium/Biodegradable Polymer Implants with an Hierarchical Pore Structure as a Means to Control Selective Cell Movement

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    UNLABELLED: In order to improve implant success rate, it is important to enhance their responsiveness to the prevailing conditions following implantation. Uncontrolled movement of inflammatory cells and fibroblasts is one of these in vivo problems and the porosity properties of the implant have a strong effect on these. Here, we describe a hybrid system composed of a macroporous titanium structure filled with a microporous biodegradable polymer. This polymer matrix has a distinct porosity gradient to accommodate different cell types (fibroblasts and epithelial cells). The main clinical application of this system will be the prevention of restenosis due to excessive fibroblast migration and proliferation in the case of tracheal implants. METHODOLOGY/PRINCIPAL FINDINGS: A microbead-based titanium template was filled with a porous Poly (L-lactic acid) (PLLA) body by freeze-extraction method. A distinct porosity difference was obtained between the inner and outer surfaces of the implant as characterized by image analysis and Mercury porosimetry (9.8±2.2 µm vs. 36.7±11.4 µm, p≤0.05). On top, a thin PLLA film was added to optimize the growth of epithelial cells, which was confirmed by using human respiratory epithelial cells. To check the control of fibroblast movement, PKH26 labeled fibroblasts were seeded onto Titanium and Titanium/PLLA implants. The cell movement was quantified by confocal microscopy: in one week cells moved deeper in Ti samples compared to Ti/PLLA. CONCLUSIONS: In vitro experiments showed that this new implant is effective for guiding different kind of cells it will contact upon implantation. Overall, this system would enable spatial and temporal control over cell migration by a gradient ranging from macroporosity to nanoporosity within a tracheal implant. Moreover, mechanical properties will be dependent mainly on the titanium frame. This will make it possible to create a polymeric environment which is suitable for cells without the need to meet mechanical requirements with the polymeric structure

    The inhibitory effect of an RGD-human chitin-binding domain fusion protein on the adhesion of fibroblasts to reacetylated chitosan films

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    Biomaterials used for tissue engineering applications must provide a structural support for the tissue development and also actively interact with cells, promoting adhesion, proliferation, and differentiation. To achieve this goal, adhesion molecules may be used, such as the tripeptide Arg-Gly-Asp (RGD). A method based on the use of a carbohydrate-binding module, with affinity for chitin, was tested as an alternative approach to the chemical grafting of bioactive peptides. This approach would simultaneously allow the production of recombinant peptides (alternatively to peptide synthesis) and provide a simple way for the specific and strong adsorption of the peptides to the biomaterial. A fusion recombinant protein, containing the RGD sequence fused to a human chitin-binding module (ChBM), was expressed in E. coli. The adhesion of fibroblasts to reacetylated chitosan (RC) films was the model system selected to analyze the properties of the obtained proteins. Thus, the evaluation of cell attachment and proliferation on polystyrene surfaces and reacetylated chitosan films, coated with the recombinant proteins, was performed using mouse embryo fibroblasts 3T3. The results show that the recombinant proteins affect negatively fibroblasts anchorage to the materials surface, inhibiting its adhesion and proliferation. We also conclude that this negative effect is fundamentally due to the human chitin-binding domain.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/27359/2006, POCTI/BIO/45356/200
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