Time filter

Source Type

Montcada i Reixac, Spain

Kim E.J.,Cleveland Clinic Lerner Research Institute | Kim E.J.,Cleveland State University | Boehm C.A.,Cleveland Clinic Lerner Research Institute | Boehm C.A.,Cleveland Clinic | And 6 more authors.
Acta Biomaterialia

The influence of surface microtexture on osteogenesis was investigated in vitro by examining the proliferation and differentiation characteristics of a class of adult stem cells and their progeny, collectively known as connective tissue progenitor cells (CTPs). Human bone marrow-derived CTPs were cultured for up to 60 days on smooth polydimethylsiloxane (PDMS) surfaces and on PDMS with post microtextures that were 10 μm in diameter and 6 μm in height, with 10 μm separation. DNA quantification revealed that the numbers of CTPs initially attached to both substrates were similar. However, cells on microtextured PDMS transitioned from lag phase after 4 days of culture, in contrast to 6 days for cells on smooth surfaces. By day 9 cells on the smooth surfaces exhibited arbitrary flattened shapes and migrated without any preferred orientation. In contrast, cells on the microtextured PDMS grew along the array of posts in an orthogonal manner. By days 30 and 60 cells grew and covered all surfaces with extracellular matrix. Western blot analysis revealed that the expression of integrin α5 was greater on the microtextured PDMS compared with smooth surfaces. Real time reverse transcription-polymerase chain reaction revealed that gene expression of alkaline phosphatase had decreased by days 30 and 60, compared with that on day 9, for both substrates. Gene expression of collagen I and osteocalcin was consistently greater on post microtextures relative to smooth surfaces at all time points. © 2009 Acta Materialia Inc. Source

Mata A.,Nanotechnology Platform
International Journal of Biomedical Engineering and Technology

Regenerative therapies that can reproducibly stimulate cells and restore human tissues are a major medical priority. Within the fields of tissue engineering and regenerative medicine the scaffold material has become a central and essential component. This leading role has been primarily a result of the capacity to fabricate materials that communicate with biology at fundamental cellular and subcellular levels. Micro and nanotechnologies are emerging as essential participants in the bioengineering of modern scaffolds. This review summarises major approaches in which researchers are using microfabrication and/or molecular self-assembly to develop scaffolds for tissue engineering and regenerative medicine. © 2011 Inderscience Enterprises Ltd. Source

Van Zanten T.S.,CIBER ISCIII | Lopez-Bosque M.J.,Nanotechnology Platform | Garcia-Parajo M.F.,CIBER ISCIII | Garcia-Parajo M.F.,Catalan Institution for Research and Advanced Studies

Optical antennas that confine and enhance electromagnetic fields in a nanometric region hold great potential for nanobioimaging and biosensing. Probe-based monopole optical antennas are fabricated to enhance fields localized to <30nm near the antenna apex in aqueous conditions. These probes are used under appropriate excitation antenna conditions to image individual antibodies with an unprecedented resolution of 26±4nm and virtually no surrounding background. On intact cell membranes in physiological conditions, the obtained resolution is 30 ±6 nm. Importantly, the method allows individual proteins to be distinguished from nanodomains and the degree of clustering to be quantified by directly measuring physical size and intensity of individual fluorescent spots. Improved antenna geometries should lead to true live cell imaging below 10-nm resolution with position accuracy in the subnanometric range. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA. Source

Tejeda-Montes E.,Nanotechnology Platform | Smith K.H.,Nanotechnology Platform | Rebollo E.,Advanced Fluorescence Microscopy Unit | Gomez R.,Biomolecular Screening and Protein Technologies | And 5 more authors.
Acta Biomaterialia

This study focuses on the in vitro characterization of bioactive elastin-like recombinamer (ELR) membranes for bone regeneration applications. Four bioactive ELRs exhibiting epitopes designed to promote mesenchymal stem cell adhesion (RGDS), endothelial cell adhesion (REDV), mineralization (HAP), and both cell adhesion and mineralization (HAP-RGDS) were synthesized using standard recombinant protein techniques. The materials were then used to fabricate ELR membranes incorporating a variety of topographical micropatterns including channels, holes and posts. Primary rat mesenchymal stem cells (rMSCs) were cultured on the different membranes and the effects of biomolecular and physical signals on cell adhesion, morphology, proliferation, and differentiation were evaluated. All results were analyzed using a custom-made MATLAB program for high throughput image analysis. Effects on cell morphology were mostly dependent on surface topography, while cell proliferation and cell differentiation were largely dependent on the biomolecular signaling from the ELR membranes. In particular, osteogenic differentiation (evaluated by staining for the osteoblastic marker osterix) was significantly enhanced on cells cultured on HAP membranes. Remarkably, cells growing on membranes containing the HAP sequence in non-osteogenic differentiation media exhibited significant up-regulation of the osteogenic marker as early as day 5, while those growing on fibronectin-coated glass in osteogenic differentiation media did not. These results are part of our ongoing effort to develop an optimized molecularly designed periosteal graft. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Source

Sisquella X.,Nanotechnology Platform | De Pourcq K.,University of Barcelona | Alguacil J.,University of Barcelona | Robles J.,University of Barcelona | And 5 more authors.
FASEB Journal

An important goal of nanotechnology is the application of individual molecule handling techniques to the discovery of potential new therapeutic agents. Of particular interest is the search for new inhibitors of metabolic routes exclusive of human pathogens, such as the 2-C-methyl-D-erythritol-4- phosphate (MEP) pathway essential for the viability of most human pathogenic bacteria and of the malaria parasite. Using atomic force microscopy single-molecule force spectroscopy (SMFS), we have probed at the single-molecule level the interaction of 1-deoxy-D-xylulose 5-phosphate synthase (DXS), which catalyzes the first step of the MEP pathway, with its two substrates, pyruvate and glyceraldehyde-3-phosphate. The data obtained in this pioneering SMFS analysis of a bisubstrate enzymatic reaction illustrate the substrate sequentiality in DXS activity and allow for the calculation of catalytic parameters with single-molecule resolution. The DXS inhibitor fluoropyruvate has been detected in our SMFS competition experiments at a concentration of 10 μM, improving by 2 orders of magnitude the sensitivity of conventional enzyme activity assays. The binding of DXS to pyruvate is a 2-step process with dissociation constants of k off = 6.1 × 10 -4 ± 7.5 × 10 -3 and 1.3 × 10 -2 ± 1.0 × 10 -2 s -1, and reaction lengths of x β = 3.98 ± 0.33 and 0.52 ± 0.23 Å. These results constitute the first quantitative report on the use of nanotechnology for the biodiscovery of new antimalarial enzyme inhibitors and open the field for the identification of compounds represented only by a few dozens of molecules in the sensor chamber. © FASEB. Source

Discover hidden collaborations