D. Arcos | Universidad Complutense de Madrid (original) (raw)

Papers by D. Arcos

Macromolecular Bioscience, 2012

Therapeutic strategies for bone regeneration involve the selection of suitable biomaterials, grow... more Therapeutic strategies for bone regeneration involve the selection of suitable biomaterials, growth factors, and cell types to mimic the cellular microenvironment where molecular and mechanical signals control the reconstruction of bone tissue. The immobilization of basic fibroblast growth factor (FGF-2) on powdered silicon-substituted hydroxyapatite (Si-HA) allows to prepare a biofunctional biomaterial able to interact with bone cells in a very specific way. The biological activity of FGF-2/Si-HA, evaluated in Saos-2 osteoblasts and MC3T3-E1 preosteoblasts through the PLCγ and MAPK/ERK signal transduction pathways, shows that FGF-2 immobilized on Si-HA provides the right signals to cells stimulating crucial intracellular mechanisms of osteoblast proliferation and differentiation.

Acta Biomaterialia, 2010

Ordered mesoporous 85SiO 2 -10CaO-5P 2 O 5 bioactive glass (MBG85) is an excellent candidate as a... more Ordered mesoporous 85SiO 2 -10CaO-5P 2 O 5 bioactive glass (MBG85) is an excellent candidate as a graft for bone tissue regeneration, owing to its excellent textured properties, structural characteristics and crystalline apatite rate formation. To assess MBG85 biocompatibility, different parameters have been evaluated (cell morphology, size/complexity, proliferation, viability, cell cycle, reactive oxygen species content, lactate dehydrogenase release) using human Saos-2 osteoblasts after treatment with either MBG85 extracts or 1% MBG85 directly added to cells. The osteoblast response to MBG85 was compared with L929 fibroblast behaviour after the same treatment. The high cell viability observed and the absence of signs of cell damage in both cell types demonstrates MBG85 biocompatibility. Only a cytostatic effect was observed through the reduction of cell proliferation, related with the initial Ca elution, whereas Si leaching did not result into any negative effect. In vitro lymphocytic proliferation analysis was also carried out with SR.D10 clone after treatment with either MBG85 extracts or culture supernatants of L929 fibroblasts previously treated with 1% MBG85 (cell-conditioned extracts). The absence of modification of in vitro T-cell response underlines the biocompatibility of MBG85 and its potential application in the field of bone and dental grafting.

Journal of biomedical materials research, Jan 5, 2002

Biomaterial pieces, with suitable osteogenic properties for use in the treatment of bone defects ... more Biomaterial pieces, with suitable osteogenic properties for use in the treatment of bone defects and the capability to avoid bone infections, have been synthesized. These materials are composed exclusively of gentamicin sulfate and bioactive SiO(2)-CaO-P(2)O(5) sol-gel glass (previously synthesized). Implant processing was achieved by uniaxial and isostatic pressure of the components mixture. After implanting the pieces into rabbit femur, we studied (i) the antibiotic release, determining the concentration in proximal and distal bone, liver, kidney, and lung as a function of time; and (ii) the bone growth resulting from the glass reactivity in the biologic environment. The results indicate that the implants are good carriers for local gentamicin release in the osseous tissue, exhibiting excellent biocompatibility and bone integration. Moreover, these implants are able to promote bone growth during their resorption process.

Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2012

We review the benefits of using 29 Si and 1 H magic angle spinning (MAS) nuclear magnetic resonan... more We review the benefits of using 29 Si and 1 H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy for probing the local structures of both bulk and surface portions of mesoporous bioactive glasses (MBGs) of the CaO-SiO 2 −(P 2 O 5 ) system. These mesoporous materials exhibit an ordered pore arrangement, and are promising candidates for improved bone and tooth implants. We discuss experimental MAS NMR results from three MBGs displaying different Ca, Si and P contents: the 29 Si NMR spectra were recorded either directly by employing radio-frequency pulses to 29 Si, or by magnetization transfers from neighbouring protons using cross polarization, thereby providing quantitative information about the silicate speciation present in the pore wall and at the MBG surface, respectively. The surface modifications were monitored for the three MBGs during their immersion in a simulated body fluid (SBF) for intervals between 30 min and one week. The results were formulated as a reaction sequence describing the interconversions between the distinct silicate species. We generally observed a depletion of Ca 2+ ions at the MBG surface, and a minor condensation of the silicate-surface network over one week of SBF soaking.

Drug Development and Industrial Pharmacy, 1994

Chemistry of Materials, 2009

Current needs in catalysis and controlled release of therapeutic agents have triggered an intensi... more Current needs in catalysis and controlled release of therapeutic agents have triggered an intensive quest in the design of porous materials with mesoscale structure. Monoliths, fibers, nanotubes, or thin films showing mesoporosity have been synthesized in the past few years. Spheres are one of the most investigated morphologies due to their suitability for a great number of applications. 1 There are several methods for obtaining mesoporous materials as microspheres, among them, the so-called modified Stöber method, 2 based on the condensation of silica under a basic medium in the presence of a cationic structure directing agent, is a well-known synthetic process yielding monodisperse microspheres with diverse mesoporous arrangements. On the other hand, aerosol-assisted method permits using not only cationic but also anionic and nonionic surfactants for achieving mesoporous microspheres, 3 thus facilitating the many different pore sizes and organizations. Many research groups have considered using core-shell structures based on mesoporous microspheres. Recently, materials with different hydrophilic profiles between core and shell components but with a uniform pore size were synthesized by Yano et al. Furthermore, mesoporous shells have been added to hollow and solid silica core microspheres or to magnetic nanoparticles covered by amorphous silica. 4 To the best of our knowledge, this work describes for the first time the synthesis of core-shell silica based microspheres showing different ordered mesoporous arrangements in core and shell. The combination of two versatile synthetic routes gives rise to materials with a hierarchically organized porous structure, in which a wide variety of core-shell networks could be developed. Additionally, this system is compatible with readily available functionalization pathways, opening the possibility of producing a range of fine-tuned devices.

Chemistry of Materials, 2006

Star gels hybrid materials, suitable for use in bone repair, have been synthesized by the sol-gel... more Star gels hybrid materials, suitable for use in bone repair, have been synthesized by the sol-gel method, incorporating a calcium alkoxide to the synthesis process. To determine the network connectivity and the Ca 2+ cation location into the hybrid network, the physical and chemical properties of star gels with different compositions have been studied. In vitro bioactivity tests evidence that the star gels develop an apatite-like phase on their surface in contact with simulated body fluid, although this property depends on the Si/Ca ratio. Finally, the study of mechanical properties demonstrated that star gels are less rigid than conventional bioactive glasses, show similar fracture toughness values than cortical bone, and point to excellent long-term fatigue behavior.

Biomaterials, 2001

Gentamicin sulfate has been incorporated in composites prepared from a SiO }CaO}P O bioactive gla... more Gentamicin sulfate has been incorporated in composites prepared from a SiO }CaO}P O bioactive glass and polymethylmethacrylate. Data showed that these materials could be used as drug delivery system, keeping the bioactive behavior of the glass. The composites supply high doses of the antibiotic during the "rst hours when they are soaked in simulated body #uid (SBF). Thereafter, a slower drug release is produced, supplying &maintenance' doses until the end of the experiment. The gentamicin release rate is related with the ionic Ca> and H O> exchange between composite and SBF. The porous structure of the composites allows the growth of hydroxycarbonate apatite on the surface and into the pores.

Journal of Materials Science: Materials in Medicine, 2011

Fibroblast growth factors (FGFs) are polypeptides that control the proliferation and differentiat... more Fibroblast growth factors (FGFs) are polypeptides that control the proliferation and differentiation of various cell types including osteoblasts. FGFs are also strong inducers of angiogenesis, necessary to obtain oxygen and nutrients during tissue repair. With the aim to incorporate these desirable FGF biological properties into bioceramics for bone repair, silicon substituted hydroxyapatites (Si-HA) were used as materials to immobilize bioactive FGF-1 and FGF-2. Thus, the binding of these growth factors to powdered Si-HA and Si-HA scaffolds was carried out efficiently in the present study and both FGFs maintained its biological activity on osteoblasts after its immobilization. The improvement of cell adhesion and proliferation onto Si-HA scaffolds suggests the potential utility of these FGF/scaffolds for bone tissue engineering.