Authors: S. Teixeira, S.M. Oliveira, M.P. Ferraz, F.J. Monteiro
Abstract: Calcium phosphate ceramics are widely used as bone substitutes since they are
biocompatible and bioactive. Having a chemical composition close to natural bone, calcium
phosphate ceramics are promising bone substitute materials in orthopaedics, maxillofacial surgery
and dentistry. Hydroxyapatite (HA) and tricalcium phosphate (TCP) are the most commonly used
calcium phosphates, because their calcium/phosphorus (Ca/P) ratios are close to that of natural bone
and they are relatively stable in physiological environment. HA is a major constituent of bone
materials and is resorbed after a long time of residence in the body.
In this work, highly porous hydroxyapatite scaffolds were produced by polymer replication method
and their properties evaluated by Scanning Electron Microscopy (SEM) and micro computerized
tomography ()-CT).
947
Authors: S. Teixeira, H.M. Fernandes, J. de Boer, M.P. Ferraz, F.J. Monteiro
Abstract: Calcium phosphate ceramics are widely used as bone substitutes since they are
biocompatible and bioactive. Given that their chemical composition is close to natural bone,
calcium phosphate ceramics are promising bone substitute materials in orthopaedics, maxillofacial
surgery and dentistry. Hydroxyapatite (HA) and tricalcium phosphate (TCP) are the most
commonly used calcium phosphates, because their calcium/phosphorus (Ca/P) ratios are close to
that of natural bone and they are relatively stable in physiological environment. Furthermore, other
critical parameters must be accomplished when designing a biomaterial for bone regeneration,
namely: pore size, shape and interconnectivity [1]. Porosity is one of the most important factors
since it influences the adhesion, migration nutrient supply and ultimately, proliferation of
mesenchymal stem cells. In this study, HA scaffolds with controlled porosity were obtained and
their capacity to support human and rat mesenchymal stem cells attachment and proliferation was
evaluated.
1129
Authors: A. Yovana Pataquiva Mateus, M.P. Ferraz, F.J. Monteiro
Abstract: This study concerns the preparation and characterisation of microspheres associating
alginate and two different types of hydroxyapatite (HA), which are intended to be used as drug
delivery systems and bone regeneration matrices. Hydroxyapatite nanoparticles (HA-1 and HA-2)
were prepared using a chemical precipitation synthesis based on H3PO4, Ca(OH)2 and a surfactant,
SDS (sodium dodecylsulphate), as starting reagents. These two powders of nanoHA and alginate
were used to prepare two different types of microspheres. Both powders and microspheres were
characterised using FTIR, TEM, SEM, mercury porosimetry analysis and X-ray diffraction Results
show that pure hydroxyapatite (HA) and mixtures of HA/β-TCP in the nanometre range were
obtained from both HA syntheses. Microspheres with different characteristics were obtained from
these two types of hydroxyapatite.
243
Authors: S. Teixeira, A.C. Queiroz, F.J. Monteiro, M.P. Ferraz, Rui Vilar, S. Eugénio
Abstract: Biocompatibility has long been associated with surface microtopography, microtexture and microchemistry. The surface topography ultimately affects the nature and the strength of the interactions that occur at biomaterial-biological environment (cell adhesion, mobility, spreading and proliferation). Thus, it is necessary to produce and work with controlled microtopographical surfaces that present reproducible microdomains of a dimension similar to that of the biological elements of interest (for instance, cells). [1] There are a number of substrates that already have been studied (such as silicone, polystyrene, poly-L-lactic acid and titanium coated polystyrene) in terms of surface topography. [2] However, few studies are related to hydroxyapatite substrates. As it is well established, hydroxyapatite is a well known ceramic that is extremely used in medical applications, namely implants and coatings. In this work, the surface topography of dense hydroxyapatite substrates was altered by using KFr excimer laser. Excimer lasers produce high-intensity, pulsed ultraviolet radiation and are especially well suited for materials processing due to their large beam cross-section area, which permits using mask projection technologies to process relatively large areas in a single step.[3]
105
Authors: C.M. Manuel, M. Foster, F.J. Monteiro, M.P. Ferraz, Robert H. Doremus, R. Bizios
903
Authors: M.P. Ferraz, F.J. Monteiro, D. Gião, Betty León, Pio González, Sara Liste, Julia Serra, J.L. Arias, Mariano Pérez Amor
347
Authors: C.M. Manuel, M.P. Ferraz, F.J. Monteiro
555
Authors: M.P. Ferraz, José D. Santos, A. Afonso, A.R. Vasconcelos, F.J. Monteiro
449