Désirée Martini

Publications of Désirée Martini

• Early Healing Events around Titanium Implant Devices with Different Surface Microtopography: A Pilot Study in an In Vivo Rabbit Model.

  Authors: Ester Orsini, Stefano Salgarello, Désirée Martini, Beatrice Bacchelli, Marilisa Quaranta, Luciano Pisoni, Emma Bellei, Monika Joechler, Vittoria Ottani

  TheScientificWorldJournal. 01/2012; 2012:349842.

  In the present pilot study, the authors morphologically investigated sandblasted, acid-etched surfaces (SLA) at very early experimental times. The tested devices were titanium plate-like implantsIn the present pilot study, the authors morphologically investigated sandblasted, acid-etched surfaces (SLA) at very early experimental times. The tested devices were titanium plate-like implants with flattened wide lateral sides and jagged narrow sides. Because of these implant shape and placement site, the device gained a firm mechanical stability but the largest portion of the implant surface lacked direct contact with host bone and faced a wide peri-implant space rich in marrow tissue, intentionally created in order to study the interfacial interaction between metal surface and biological microenvironment. The insertion of titanium devices into the proximal tibia elicited a sequence of healing events. Newly formed bone proceeded through an early distance osteogenesis, common to both surfaces, and a delayed contact osteogenesis which seemed to follow different patterns at the two surfaces. In fact, SLA devices showed a more osteoconductive behavior retaining a less dense blood clot, which might be earlier and more easily replaced, and leading to a surface-conditioning layer which promotes osteogenic cell differentiation and appositional new bone deposition at the titanium surface. This model system is expected to provide a starting point for further investigations which clarify the early cellular and biomolecular events occurring at the metal surface.

• Evidence of a discrete axial structure in unimodal collagen fibrils.

  Authors: Mario Raspanti, Marcella Reguzzoni, Marina Protasoni, Désirée Martini

  Biomacromolecules. 11/2011; 12(12):4344-7.

  The collagen fibrils of cornea, blood vessel walls, skin, gut, interstitial tissues, the sheath of tendons and nerves, and other connective tissues are known to be made of helically wound subfibrilsThe collagen fibrils of cornea, blood vessel walls, skin, gut, interstitial tissues, the sheath of tendons and nerves, and other connective tissues are known to be made of helically wound subfibrils winding at a constant angle to the fibril axis. A critical aspect of this model is that it requires the axial microfibrils to warp in an implausible way. This architecture lends itself quite naturally to an epitaxial layout where collagen microfibrils envelop a central core of a different nature. Here we demonstrate an axial domain in collagen fibrils from rabbit nerve sheath and tendon sheath by means of transmission electron microscopy after a histochemical reaction designed to evidence all polysaccharides and by tapping-mode atomic force microscopy. This axial domain was consistently found in fibrils with helical microfibrils but was not observed in tendon, whose microfibrils run longitudinal and parallel.

• Contribution of glycosaminoglycans to the microstructural integrity of fibrillar and fiber crimps in tendons and ligaments.

  Authors: Marco Franchi, Viviana De Pasquale, Désirée Martini, Marilisa Quaranta, Maria Macciocca, Alessio Dionisi, Vittoria Ottani

  TheScientificWorldJournal. 01/2010; 10:1932-40.

  The biomechanical roles of both tendons and ligaments are fulfilled by the extracellular matrix of these tissues. In particular, tension is mainly transmitted and resisted by protein (collagen,The biomechanical roles of both tendons and ligaments are fulfilled by the extracellular matrix of these tissues. In particular, tension is mainly transmitted and resisted by protein (collagen, elastin) fibers, whereas compression is opposed by water-soluble glycosaminoglycans (GAGs). GAGs spanning the interfibrillar spaces and interacting with fibrils through the interfibrillar proteoglycans also seem to play a part in transmitting and resisting tensile stresses. Both tendons and ligaments showing similar composition, but different functional roles and collagen array, exhibit periodic undulations of collagen fibers or crimps. Each crimp is composed of many knots of each single fibril or fibrillar crimps. Fibrillar and fiber crimps play a mechanical role in absorbing the initial loading during elongation of both tendons and ligaments, and in recoiling fibrils and fibers when tissues have to return to their original length. This study investigated whether GAGs covalently attached to proteoglycan core proteins directly affect the 3D microstructural integrity of fibrillar crimp regions and fiber crimps in both tendons and ligaments. Achilles tendons and medial collateral ligaments of the knee from eight female Sprague-Dawley rats (90 days old) incubated in a chondroitinase ABC solution to remove GAGs were observed under a scanning electron microscope (SEM). In addition, isolated fibrils of these tissues obtained by mechanical disruption were analyzed by a transmission electron microscope (TEM). Both Achilles tendons and medial collateral ligaments of the rats after chemical or mechanical removal of GAGs still showed crimps and fibrillar crimps comparable to tissues with a normal GAG content. All fibrils in the fibrillar crimp region always twisted leftwards, thus changing their running plane, and then sharply bent, changing their course on a new plane. These data suggest that GAGs do not affect structural integrity or fibrillar crimp functions that seem mainly related to the local fibril leftward twisting and the alternating handedness of collagen from a molecular to a supramolecular level.

• Correlative microscopy of bone in implant osteointegration studies.

  Authors: Alessandra Trirè, Désirée Martini, Ester Orsini, Marco Franchi, Viviana De Pasquale, Beatrice Bacchelli, Mario Raspanti, Alessandro Ruggeri, Vittoria Ottani

  TheScientificWorldJournal. 01/2010; 10:2238-47.

  Routine morphological analyses usually include investigations by light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Each of these techniquesRoutine morphological analyses usually include investigations by light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Each of these techniques provides specific information on tissue morphology and all the obtained results are then combined to give an in-depth morphological overview of the examined sample. The limitations of this traditional comparative microscopy lie in the fact that each technique requires a different experimental sample, so that many specimens are necessary and the combined results come from different samples. The present study describes a technical procedure of correlative microscopy, which allows us to examine the same bone section first by LM and then, after appropriate processing, by SEM or TEM. Thanks to the possibility of analyzing the same undecalcified bone sections both by LM and SEM, the approach described in the present study allows us to make very accurate evaluations of old/new bone morphology at the bone-implant interface.

• Influence of a zirconia sandblasting treated surface on peri-implant bone healing: An experimental study in sheep.

  Authors: Beatrice Bacchelli, Gianluca Giavaresi, Marco Franchi, Désirée Martini, Viviana De Pasquale, Alessandra Trirè, Milena Fini, Roberto Giardino, Alessandro Ruggeri

  Acta biomaterialia. 02/2009;

  A sandblasting process with round zirconia (ZrO(2)) particles might be an alternative surface treatment to enhance the osseointegration of titanium dental implants. Our previous study on sheepA sandblasting process with round zirconia (ZrO(2)) particles might be an alternative surface treatment to enhance the osseointegration of titanium dental implants. Our previous study on sheep compared smooth surface titanium implants (control) with implant surfaces sandblasted with two different granulations of ZrO(2). As the sandblasted surfaces proved superior, the present study further compared the ZrO(2) surface implant with other surface treatments currently employed: machined titanium (control), titanium oxide plasma sprayed (TPS) and alumina sandblasted (Al-SL) at different times after insertion (2, 4 and 12weeks). Twelve sheep were divided into three groups of four animals each and underwent implant insertion in tibia cortical bone under general anaesthesia. The implants with surrounding tissues were subjected to histology, histomorphometry, scanning electron microscopy and microhardness tests. The experimentation indicated that at 2weeks Zr-SL implants had the highest significant bone ingrowth (p<0.05) compared to the other implant surfaces, and a microhardness of newly formed bone inside the threads significantly higher than that of Ti. The present work shows that the ZrO(2) treatment produces better results in peri-implant newly formed bone than Ti and TPS processing, whereas its performance is similar to the Al-SL surface treatment.

• Decorin transfection induces proteomic and phenotypic modulation in breast cancer cells 8701-BC.

  Authors: Ida Pucci-Minafra, Patrizia Cancemi, Gianluca Di Cara, Luigi Minafra, Salvatore Feo, Antonella Forlino, M Enrica Tira, Ruggero Tenni, Désirée Martini, Alessandro Ruggeri, Salvatore Minafra

  Connective tissue research. 02/2008; 49(1):30-41.

  Decorin is a prototype member of the small leucine-rich proteoglycan family widely distributed in the extracellular matrices of many connective tissues, where it has been shown to play multipleDecorin is a prototype member of the small leucine-rich proteoglycan family widely distributed in the extracellular matrices of many connective tissues, where it has been shown to play multiple important roles in the matrix assembly process, as well as in some cellular activities. A major interest for decorin function concerns its role in tumorigenesis, as growth-inhibitor of different neoplastic cells, and potential antimetastatic agent. The aim of our research was to investigate wide-ranged effects of transgenic decorin on breast cancer cells. To this purpose we utilized the well-characterized 8701-BC cell line, isolated from a ductal infiltrating carcinoma of the breast, and two derived decorin-transfected clones, respectively, synthesizing full decorin proteoglycan or its protein core. The responses to the ectopic decorin production were examined by studying morphological changes, cell proliferation rates, and proteome modulation. The results revealed new important antioncogenic potentialities, likely exerted by decorin through a variety of distinct biochemical pathways. Major effects included the downregulation of several potential breast cancer biomarkers, the reduction of membrane ruffling, and the increase of cell-cell adhesiveness. These results disclose original aspects related to the reversion of malignant traits of a prototype of breast cancer cells induced by decorin. They also raise additional interest for the postulated clinical application of decorin.

• Displayed correlation between gene expression profiles and submicroscopic alterations in response to cetuximab, gefitinib and EGF in human colon cancer cell lines.

  Authors: Rossella Solmi, Mattia Lauriola, Mirko Francesconi, Désirée Martini, Manuela Voltattorni, Claudio Ceccarelli, Giampaolo Ugolini, Giancarlo Rosati, Simone Zanotti, Isacco Montroni, Gabriella Mattei, Mario Taffurelli, Donatella Santini, Furio Pezzetti, Alessandro Ruggeri, Gastone Castellani, Lia Guidotti, Domenico Coppola, Pierluigi Strippoli

  BMC cancer. 02/2008; 8:227.

  BACKGROUND: EGFR is frequently overexpressed in colon cancer. We characterized HT-29 and Caco-2, human colon cancer cell lines, untreated and treated with cetuximab or gefitinib alone and inBACKGROUND: EGFR is frequently overexpressed in colon cancer. We characterized HT-29 and Caco-2, human colon cancer cell lines, untreated and treated with cetuximab or gefitinib alone and in combination with EGF. METHODS: Cell growth was determined using a variation on the MTT assay. Cell-cycle analysis was conducted by flow cytometry. Immunohistochemistry was performed to evaluate EGFR expression and scanning electron microscopy (SEM) evidenced the ultrastructural morphology. Gene expression profiling was performed using hybridization of the microarray Ocimum Pan Human 40 K array A. RESULTS: Caco-2 and HT-29 were respectively 66.25 and 59.24 % in G0/G1. They maintained this level of cell cycle distribution after treatment, suggesting a predominantly differentiated state. Treatment of Caco-2 with EGF or the two EGFR inhibitors produced a significant reduction in their viability. SEM clearly showed morphological cellular transformations in the direction of cellular death in both cell lines treated with EGFR inhibitors. HT-29 and Caco-2 displayed an important reduction of the microvilli (which also lose their erect position in Caco-2), possibly invalidating microvilli absorption function. HT-29 treated with cetuximab lost their boundary contacts and showed filipodi; when treated with gefitinib, they showed some vesicles: generally membrane reshaping is evident. Both cell lines showed a similar behavior in terms of on/off switched genes upon treatment with cetuximab. The gefitinib global gene expression pattern was different for the 2 cell lines; gefitinib treatment induced more changes, but directly correlated with EGF treatment.In cetuximab or gefitinib plus EGF treatments there was possible summation of the morphological effects: cells seemed more weakly affected by the transformation towards apoptosis. The genes appeared to be less stimulated than for single drug cases. CONCLUSION: This is the first study to have systematically investigated the effect of cetuximab or gefitinib, alone and in combination with EGF, on human colon cancer cell lines. The EGFR inhibitors have a weaker effect in the presence of EGF that binds EGFR. Cetuximab treatment showed an expression pattern that inversely correlates with EGF treatment. We found interesting cyto-morphological features closely relating to gene expression profile. Both drugs have an effect on differentiation towards cellular death.

• Influence of different implant surfaces on peri-implant osteogenesis: histomorphometric analysis in sheep.

  Authors: Marco Franchi, Beatrice Bacchelli, Gianluca Giavaresi, Viviana De Pasquale, Désirée Martini, Milena Fini, Roberto Giardino, Alessandro Ruggeri

  Journal of periodontology. 06/2007; 78(5):879-88.

  BACKGROUND: The present study investigated peri-implant osteogenesis and implant biologic fixation in different zirconia sandblasted endosseous titanium surfaces (SLA-60 and SLA-120) and a turnedBACKGROUND: The present study investigated peri-implant osteogenesis and implant biologic fixation in different zirconia sandblasted endosseous titanium surfaces (SLA-60 and SLA-120) and a turned titanium surface (T) 2 and 4 weeks after surgery. METHODS: Seventy-two implant screws were implanted in tibia of six sheep. Histologic sections of implants (2 and 4 weeks after surgery) were analyzed with light microscopy for histomorphometric analysis of bone-to-implant contact (BIC), bone ingrowth (BI), and bone surface (BS/BV). Histologic blocks were used to perform bone microhardness studies next to the implants. Some implants were also observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). RESULTS: In general, the highest values of BIC, BI, BS/BV, and Vickers hardness number (HV) were measured in SLA-60 samples, followed by SLA-120 and T implants. Two weeks after surgery, all the implants appeared biologically fixed by a newly formed woven bone arranged in thin bone trabeculae and filling the gap between implant and host bone. Four weeks after implantation, the thickness of the woven bone trabeculae had increased, especially around the SLA-60 and SLA-120 implants by a gradual deposition of parallel-fiber bone. CONCLUSIONS: Our results suggest that, in the early period of peri-implant healing, the implant surface morphology that seemed to influence the increase of peri-implant osteogenesis, bone turnover, and peri-implant bone maturation was SLA-60. We suggest that this surface, characterized by moderately deep titanium cavities very similar to the osteocyte lacunae, could act as a microscopic scaffold for mesenchymal and/or osteoblast-like cells adhesion.