Scienze mediche

Settori scientifico disciplinari compresi nell'area 6:

  • MED/01 STATISTICA MEDICA
  • MED/02 STORIA DELLA MEDICINA
  • MED/03 GENETICA MEDICA
  • MED/04 PATOLOGIA GENERALE
  • MED/05 PATOLOGIA CLINICA
  • MED/06 ONCOLOGIA MEDICA
  • MED/07 MICROBIOLOGIA E MICROBIOLOGIA CLINICA
  • MED/08 ANATOMIA PATOLOGICA
  • MED/09 MEDICINA INTERNA
  • MED/10 MALATTIE DELL'APPARATO RESPIRATORIO
  • MED/11 MALATTIE DELL'APPARATO CARDIOVASCOLARE
  • MED/12 GASTROENTEROLOGIA
  • MED/13 ENDOCRINOLOGIA
  • MED/14 NEFROLOGIA
  • MED/15 MALATTIE DEL SANGUE
  • MED/16 REUMATOLOGIA
  • MED/17 MALATTIE INFETTIVE
  • MED/18 CHIRURGIA GENERALE
  • MED/19 CHIRURGIA PLASTICA
  • MED/20 CHIRURGIA PEDIATRICA E INFANTILE
  • MED/21 CHIRURGIA TORACICA
  • MED/22 CHIRURGIA VASCOLARE
  • MED/23 CHIRURGIA CARDIACA
  • MED/24 UROLOGIA
  • MED/25 PSCHIATRIA
  • MED/26 NEUROLOGIA
  • MED/27 NEUROCHIRURGIA
  • MED/28 MALATTIE ODONTOSTOMATOLOGICHE
  • MED/29 CHIRURGIA MAXILLOFACCIALE
  • MED/30 MALATTIE APPARATO VISIVO
  • MED/31 OTORINOLARINGOIATRIA
  • MED/32 AUDIOLOGIA
  • MED/33 MALATTIE APPARATO LOCOMOTORE
  • MED/34 MEDICINA FISICA E RIABILITATIVA
  • MED/35 MALATTIE CUTANEE E VENEREE
  • MED/36 DIAGNOSTICA PER IMMAGINI E RADIOTERAPIA
  • MED/37 NEURORADIOLOGIA
  • MED/38 PEDIATRIA GENERALE E SPECIALISTICA
  • MED/39 NEUROPSICHIATRIA INFANTILE
  • MED/40 GINECOLOGIA E OSTETRICIA
  • MED/41 ANESTESIOLOGIA
  • MED/42 IGIENE GENERALE E APPLICATA
  • MED/43 MEDICINA LEGALE
  • MED/44 MEDICINA DEL LAVORO
  • MED/45 SCIENZE INFERMIERISTICHE GENERALI, CLINICHE E PEDIATRICHE
  • MED/46 SCIENZE TECNICHE DI MEDICINA DI LABORATORIO
  • MED/47 SCIENZE INFERMIERISTICHE OSTETRICO-GINECOLOGICHE
  • MED/48 SCIENZE INFERMIERISTICHE E TECNICHE NEURO-PSICHIATRICHE E RIABILITATIVE
  • MED/49 SCIENZE TECNICHE DIETETICHE APPLICATE
  • MED/50 SCIENZE TECNICHE MEDICHE APPLICATE

Browse

Recent Submissions

Now showing 1 - 5 of 115
  • Publication
    Rola of collagen cross-linkers on the stability of bonded interface
    (Università degli studi di Trieste, 2015-03-26)
    Angeloni, Valeria
    ;
    Breschi, Lorenzo
    Restorative adhesive dentistry is based on the infiltration of dental adhesive resin within the dentin collagen network creating the hybrid layer. The stability and integrity of collagen fibrils within the hybrid layer are crucial for the maintenance of bond effectiveness over time. The matrix metallo-proteinases enzymes (MMPs), which are endogenous enzymes present in dentin tissue, are claimed to play a key role in affecting the integrity of the hybrid layer causing the hydrolysis and degradation of dentin collagen. The aim of this research project was to evaluate the efficacy of different cross-linking agent in preserving the adhesive/dentin layer. Two water soluble collagen cross-linking agents riboflavin, and the carbodiimide hydrochloride, 1-ethyl-3-[3-dimethylaminopropyl] (EDC) were initially tested, then additional cross-linking agents were included in the study: acrolein, (water soluble), and the N,N'-dicyclohexylcarbodiimide (DCC) (soluble in acetone and ethanol). The concentration of each solution was chosen according to the previous studies: 0.1% riboflavin/wt, 0.3M EDC/wt, 0,01% acrolein/wt, 0.5M DCC/ethanol, 0.5M/acetone. Cross-linkers were associated to different adhesive systems available on the market and different tests were performed to evaluate the ability of cross-linkers in preserving the hybrid layer: mechanical test (microtensile bond strength), qualitative test (nanoleakage analysis), and biochemical assays (zymographic analysis and in situ zymographic analysis). For the microtensile bond strength recently extracted third molars (N=5 for each group) were selected and restorative treatments were performed: in the experimental groups teeth were pretreated with the tested cross-linkers before the application of the adhesive systems (XP Bond, Scotch Bond 1XT, Optibond FL, Clearfil SE), while in the control groups the adhesives were applied according to the manufacturers’ instructions. The experimental groups were divided as follow: 1) 0.1% riboflavin/XP Bond; 0.3M EDC/Scotch Bond 1XT; 2) 0.3M EDC+XP Bond 3) 0.3M EDC+Scotch Bond 1XT; 4) 0.3M EDC+Optibond FL; 5) 0.01% acrolein+Scotch Bond 1XT; 6) 0.3M EDC+Clearfil SE. The bonded specimens were serially sectioned to obtain approximately 1-mm-thick beams in accordance with the microtensile non-trimming technique. Beams were stored at 37°C in artificial saliva to reproduce the oral cavity environment and then were stressed to failure after 24hours (T0), 6 months (T6) or 1 year (T12) using a simplified universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed using Two-Way (variables: cross-linker pretreatment and storage time) analysis of variance (ANOVA) and post hoc Tukey test (p values < 0.05 were considered as statistically significant). The results of microtensile bond strength showed that the use of the tested cross-linkers tested does not affect the immediate bond strength, while at T12 bond strength values of the experimental groups are significantly higher compared to the control groups. For the qualitative interfacial nanoleakage analysis, additional molars (4 per group) were selected to evaluate the integrity of the tooth/resin interfaces. The experimental groups were divided as follow: 1) 0.1% riboflavin-XP Bond; 2) 0.3M EDC-Scotch Bond 1XT; 3) 0.3M EDC-Optibond FL. The specimens were prepared and stored as described for the microtensile test; after storage the beams were immersed for 24h in AgNO3, then rinsed in distilled water and immersed in photo-developing solution to reduce silver ions into metallic silver grain. Nanoleakage analysis was performed under light microscopy and the interfacial nanoleakage degree was scored on a scale of 0–4 based on the percentage of the adhesive surface showing silver nitrate deposition: 0: no nanoleakage; 1: <25% nanoleakage; 2: 25 to ≤50% nanoleakage; 3: 50 to ≤75% nanoleakage; and 4: >75% nanoleakage. Statistical differences among nanoleakage group scores were analyzed using the χ2 test. The results did not reveal differences in the interfacial nanoleakage expression between the experimental groups 2 (0.3M EDC-Scotch Bond 1XT) and 3 (0.3M EDC-Optibond FL) and their respective control group. After 12-month storage the treatment with the riboflavin significantly reduce the infiltration of AgNO3 within the hybrid layer created with XP Bond. For the biochemical assay of the enzymatic activity, zymographic analysis and in situ zymography were performed. The following groups were added to the previously described treatments and submitted to these tests: 0.5M DCC/ethanol, 0.5M DCC/acetone, 0.5M DCC/ethanol- Scotchbond 1XT, 0.5M DCC/acetone Scotchbond 1XT. For the zymographic analysis dentin powder was obtained from thirty human sound molars; the powder was treated with the cross-linking agents in association or not with the different adhesive systems. The extract proteins were submitted to electrophoresis on SDS-polyacrylamide gels copolymerized with gelatin as MMPs substrate. Zymograms showed that the use of cross-linkers before the adhesive application was able to reduce or totally inhibit the activity of MMPs (especially MMP-2 and MMP-9). The specimens submitted to in situ zymography were prepared as previous described for the microtensile test. Bonded specimens were cut in order to expose the adhesive/dentin interfaces and in situ zymography was performed applying a self-quenched fluorescein-conjugated gelatin on adhesive/dentin interface. The specimens were light-protected and incubated in humidified chambers at 37°C for 24 h, then the hydrolysis of quenched fluorescein-conjugated gelatin substrate (related to endogenous gelatinolytic enzyme activity) was assessed by examination with a confocal laser scanning microscope. Images revealed reduced green fluorescence in the hybrid layer of experimental groups (pretreated with the cross-linking agents) compared to the control group fluorescence. The results of all these studies suggest that the use of cross-linking agents before the bonding procedures improves the stability of the resin/dentin interface. We can speculated that cross-linkers are able to reinforced the dentin collagen network increasing the mechanical properties of the hybrid layer, as confirmed by the microtensile test. Furthermore the results showed that these agents are able to inhibit the MMP gelatinolytic activity, preserving the dentin collagen fibrils from the hydrolysis and avoiding the failure of the hybrid layer.
      1084  2049
  • Publication
    Characterization of cancer behaviour after laser biostimulation at cellular and molecular level
    (Università degli studi di Trieste, 2015-03-26)
    Ottaviani, Giulia
    ;
    Biasotto, Matteo
    ;
    Zacchigna, Serena
    The main aim of this project is to provide an answer to the following issues: - on the one hand the definition of the cellular and molecular mechanisms of action of the laser therapy and its interaction with tissues - on the other hand the safety of laser therapy and is potential consequences on cancer behaviour We created a mouse model of oral carcinogenesis to assess potential differences in tumour angiogenesis in tissues treated with laser therapy compared to the control ones, by using both histological analysis and injection of Nano FluoSpheres®. A chemical carcinogen (4-NQO) dissolved in their drinking water was administered to C57BL/6 female mice (n = 50), 8-week old, since this compound is able to induce the formation of multiple oral tumours. Among these, 25 mice underwent to 4 session of laser therapy on consecutive days employing the HPLT-1 protocol, while the remaining mice were used as controls. During the 21st week, 15 animals per group were sacrificed to perform an accurate histological analysis of their tongue, while 10 were subjected to a quantitative assessment of angiogenesis through a 3D reconstruction of the tumour vascular network after the in vivo perfusion with Nano FluoSpheres®. Any increase concerning neither the number/extension of dysplastic and neoplastic areas nor tumour angiogenesis was registered in the treated group. Moreover, treated animals showed a tendency to border and to isolate tumour areas. The laser seemed to normalize tumour vessels, promoting their covering by smooth muscle cells, thus reducing ectasia and vascular permeability, as assessed by reduced Nano FluoSpheres® leakiness. The histological analysis performed on the oral carcinogenesis mice model was compared to the images of the same tumours acquired by Narrow Band Imaging. Three raters experienced in the use of this technology analyzed the images, classifying all visible lesions according to different pathological grades; the obtained results were than compared with the histological analysis, used as reference standard. The statistical analysis revealed both high sensitivity (96%) and specificity (99%) for this technology. Supported by other studies, the Narrow Band Imaging is expected to hold great potential for the clinical evaluation of tumour angiogenesis, as well as for the early detection of potentially malignant lesions of the oral cavity. The important clinical outcome in term of wound healing and our interest in the analysis of cell behaviour after laser therapy were the starting point for the evaluation of the effect of laser therapy on different cell lines: Human Skin Fibroblasts, Human Umbilical Vein Endothelial Cells, Human Coronary Artery Smooth Muscle Cells, Neonatal Rat Ventricular Myocytes, Human Bone Osteosarcoma Epithelial Cells and Mouse B16F10 Melanoma Cells. We set different powers, energies and wavelengths, and we performed the evaluations at different experimental times (6, 24, 48 and 96 hours after the irradiation). In general, laser irradiation resulted in an increase of both cell metabolism (ATPlite) and proliferation (cell count, AlamarBlu, BrdU incorporation), albeit with different timing and intensity in the various cell lines. Consistent with published results, we observed a clear increase in cancer cell metabolism upon laser irradiation; to evaluate the cancer behaviour in vivo, the same melanoma cells were implanted in C57BL/6 female mice (n = 16), 6-week old, at the dorsal subcutaneous level. As soon as the masses were visible to the naked eye (approximately on day 10), mice were homogeneously divided into 4 groups according to tumour size: 3 groups were subjected to different laser protocols (LPLT-6; MPLT-13 and HPLT-7) for 4 consecutive days (days 11 to 14), while the fourth group was used as control. On day 15, all animals were euthanized to measure the tumour volume and weight. A deep histological analysis on tumour invasion and cancer immune response (CD1a, CD4, CD8, CD25, CD68 kp1 and Melan-A) was performed, as well as the analysis of the expression levels of cytokines involved in the immune system activation (TNFα, IFNα and IFNγ). Laser therapy did not foster tumour growth or invasiveness (CD68 kp1 and Melan-A), but rather seemed to contain its extension. Moreover, in the laser groups, tumour infiltration by immune cells was much more higher compared to the control ones (CD4+, CD8+, CD25+ cells), consistent with the increased expression of IFNγ. Of notice, CD1a positive dendritic cells were particularly abundant in the dermis in the control group, while they migrated to "wrap" the tumour in laser groups. Based on these results, we applied the same laser protocols on primary mouse bone marrow dendritic cells, with and without lipopolysaccharide stimulation. These cells did not enhance cell metabolism upon laser treatment, but reduced TNFα and increased IFNγ expression. Finally, CD-1 female mice (n = 30), age 6-7 weeks old, were used to assess the expression of different cytokines (Collagen I, Collagen III, Collagen IV, FSP1, IL-2, IL-6, IL-10, IFNα, IFNβ, IFNγ, MMP-9, PDGFβ, TGFβ, TNFα) after the laser therapy at the dorsal level with and without the presence of a skin wound. The analysis confirmed an increase in the IFNγ expression; a similar trend was registered concerning IL-2, IL-6, IFNα, IFNβ, Collagen I, Collagen III, MMP-9, PDGFβ expression in the laser treated mice compared to controls. From both in vitro and in vivo analysis we can state that the laser therapy is effective in stimulating cell metabolism and proliferation, and in boosting a potent immune response in vivo. We can therefore foresee that the treatment of cutaneous and mucosal lesions in oncological patients can be safely performed even in potentially dysplastic or neoplastic areas.
      856  650
  • Publication
    Development of a new nano-engineered biopolymer-based dental adhesive system
    (Università degli studi di Trieste, 2015-03-26)
    Diolosà, Marina
    ;
    Cadenaro, Milena
    Lo scopo di questa tesi di dottorato è stato studiare l'effetto sulla durabilità dell’interfaccia adesiva del chitosano, modificato con gruppi metacrilici, con l’obiettivo di migliorare l'affidabilità clinica dei restauri dentali. Attualmente, la ricerca in questo settore mira ad aumentare la durata nel tempo del legame resina-dentina. Questa ricerca propone un nuovo concetto di sistema adesivo bi-funzionale basato su un biopolimero naturale in grado di creare doppia reticolazione covalente. Il chitosano è un polimero biocompatibile e non tossico. In questo studio è stato ipotizzato che il chitosano modificato con gruppi metacrilici sia in grado di legarsi covalentemente alla resina dei restauri dentale e, grazie alla presenza di cariche positive residue sul polisaccaride, di interagire elettrostaticamente con la dentina demineralizzata. Il Chitosano metacrilato è stato introdotto nel primer di un sistema adesivo sperimentale etch&rinse a tre passaggi per valutarne la forza di legame alla dentina. Le prove d’invecchiamento sono state condotte utilizzando due metodiche: invecchiamento statico e dinamico. Il secondo metodo simula la presenza del sistema adesivo nell’ambiente orale, sottoposto sia a carico masticatorio, che a stress termici. Le metodiche d’invecchiamento sono necessarie per valutare la stabilità nel tempo dei restauri dentali. L'introduzione del chitosano modificato con gruppi metacrilici nel primer di un sistema adesivo etch&rinse ha determinato: buoni valori di adesione dopo 24 ore (T0 μTBS); (2) buona stabilità dello strato ibrido quando sottoposto a simulazione meccanica della masticazione e stress termici (TCS μTBS). In sintesi, la prima parte di questa tesi di dottorato ha avuto lo scopo di esaminare lo stato dell'arte dei materiali dentali attualmente utilizzati in odontoiatria e il problema più importante in odontoiatria restaurativa: la degradazione dell'interfaccia adesiva. La seconda fase di questa ricerca è stata dedicata al trovare la formulazione ottimale di un sistema adesivo contenente chitosano modificato con gruppi metacrilici. Diverse formulazioni sono state testate e il sistema sperimentale identificato come A3* è stato considerato la migliore formulazione utilizzabile come sistema adesivo. Questa formulazione è stata poi nominata Chit-MA70. Sono stati eseguiti diversi test per valutare le caratteristiche dell’adesivo sperimentale, compresi test meccanici (test di microtensile). L'espressione del nanoleakage è stata valutata utilizzando la microscopia ottica e la microscopia elettronica a scansione (SEM). Per valutare la sostantività del chitosano sullo strato adesivo, il polimero è stato marcato con fluoresceina e i campioni sono stati osservati al microscopio confocale a scansione laser (CLSM). Nella fase finale di questo studio sono stati condotti test di citotossicità per valutare l'effetto del sistema adesivo Chit-MA70 sulla vitalità cellulare. Le prove eseguite su fibroblasti gengivali hanno rivelato una tossicità ridotta, se non praticamente assente, del sistema adesivo contenente chitosano metacrilato. Considerando i buoni risultati di questo studio, il chitosano modificato con gruppi metacrilici è stato proposto come componente di un sistema adesivo sperimentale. I risultati ottenuti utilizzando questo nuovo sistema adesivo sono stati rivendicati in un brevetto (febbraio 2014) e pubblicati in Biomacromolecules nel mese di ottobre (2014).
      804  600
  • Publication
    The influence of resin-based dental materials on oral biofilms developement
    (Università degli studi di Trieste, 2015-03-26)
    Ionescu, Andrei Cristian
    ;
    Breschi, Lorenzo
    ;
    Cadenaro, Milena
    Resin-based composites (RBCs) are the most widespread restorative dental materials used nowadays. Nanotechnologies allowed the development and improvement of a new generation of RBCs which nevertheless still present many unsolved issues. The most important is secondary caries, which is the recurrence of dental caries in tissues close to the restoration. Dental caries disease is driven by a dysbiotic biofilm colonizing both natural and artificial surfaces. Many approaches have been developed in order to address this issue, mainly the development of bioactive surfaces with contact-active properties, the optimization of surfaces to obtain anti-adhesive properties and the synthesis of biomimetic materials. The aim of this PhD thesis was to explore the use of nanotechnologies in order to synthesize, evaluate and optimize the formulation of RBCs aimed at successfully controlling oral biofilms development. The experimental part explored all three previously mentioned approaches. Regarding the first approach, a lactose-modified Chitosan carrier for silver nanoparticles (nAg) was developed and used as a coating for RBCs in order to study the antibacterial behavior of a novel material possessing contact-killing properties. The results indicated an antibacterial activity of the coating related to nAg concentration, however rinsing procedures interfered with the coating and deprived nAg of their effect. The surface activation of RBC surfaces prior to coating application showed itself good antibacterial properties that are currently under examination. Considering the second approach, experimental resin-based dental materials differing in their compositions were extensively studied, hypothesizing that biofilm formation on the experimental materials may show a dependency on their surface characteristics and nanotexture. In this sense, the anti-adhesive properties of these materials were evaluated as a possible effective way to control biofilm formation without the need for biocidal agents. The results showed that both hydrophobicity of the resin matrix of RBCs and filler content can influence oral biofilm formation. The lowest values of cariogenic biofilm were reached by less hydrophobic resin and by nanofillers. The third approach evaluated the possibility that biomimetic materials (designed to positively interact with dental hard tissues) may have to control oral biofilms, without the need for specifically biocidal agents. Resin-functionalized nanoparticles of dicalcium phosphate dihydrate (nDCPD) were incorporated into an experimental RBC. Results showed that the RBC filled with functionalized nDCPD showed reduced biofilm formation when compared to a RBC filled with non-functionalized nDCPD. In conclusion, all these three approaches proved to significantly impact oral biofilm formation on RBCs surfaces, however the most interesting result suggests the possibility of influencing biofilm formation without necessarily adding biocidal compounds. In fact, recent studies regarding the human microbiome show that many diseases, including dental caries, are caused by an imbalance between host and biofilms. These diseases may be restored by modifying biofilms composition, without attempting to eradicate biofilms.
      1225  1104
  • Publication
    Use of immune-nanoparticles containig chemiotherapeutic agents for the treatment of B-cell malignancies
    (Università degli studi di Trieste, 2015-03-26)
    Capolla, Sara
    ;
    Macor, Paolo
    B-cell malignancies are a heterogeneous group of clinical conditions including indolent diseases such as Chronic Lymphocytic Leukemia (CLL) and highly aggressive lymphoproliferative disorders such as Burkitt’s lymphoma. B-cell malignancies treatments take advantage of dose-intensive chemotherapeutic regimens and immunotherapy via monoclonal antibodies. Unfortunately, they may lead to insufficient tumor distribution of therapeutic agents and cause several adverse effects. Thus, we propose a novel therapeutic approach for the treatment of CLL and Burkitt’s lymphoma in which high-doses of the association of hydroxychloroquine and chlorambucil (HCQ/CLB) or fludarabine were loaded inside biodegradable nanoparticles (BNPs) coated with an anti-CD20 antibody. First of all, a Burkitt’s lymphoma cell line (BJAB), two CLL cell lines (MEC1 and EHEB) and cells purified from patients’ blood samples were used to confirm CD20 expression and to assess BNPs binding and internalization. These studies demonstrated BNPs ability to bind malignant B cells and to enter inside cells in a process different from endocytosis. Then, BNPs therapeutic effect was evaluated by MTT test, AnnV/PI assay and western blot to put in evidence apoptosis induction and autophagy inhibition. These experiments demonstrated drugs-loaded BNPs ability to kill malignant B cells with comparable effects than those obtained with free drugs whereas empty BNPs were practically ineffective. In vivo BNPs characterization included the evaluation of their toxicity, biodistribution and therapeutic effect. C57/BL mice were used to evaluate BNPs toxicity which was studied considering survival, loss of body weight and several tissue markers in the blood. Mice receiving 8 injections of free HCQ+CLB died in this experiment whereas animals challenged with the same amount of drugs encapsulated inside BNPs did not show toxic effects suggesting BNPs safety. The importance of antiCD20 antibody in the homing of BNPs was confirmed by in vivo Time-Domain Optical Imaging performed in localized B-cell malignancy-bearing mice. This analysis suggested the ability of antiCD20-conjugated BNPs to specifically target tumor B-cells, with a pick after 24-48 hours. On the contrary, untargeted BNPs localization inside tumor was significantly decreased. In this analysis it was also evident that the liver is the main site of BNPs’ elimination while in the other organs the presence of fluorescent BNPs was very low. Finally, BNPs ability to treat a new xenograft human/SCID leukemia and Burkitt’s lymphoma mouse model was studied. Drugs-loaded BNPs were able to improve HCQ/CLB efficacy in vivo allowing the cure of treated all Burkitt’s lymphoma-bearing mice and 3 out of 7 leukemia-bearing animals. All these data together put the basis for the potential use of BNPs in the treatment of B-cell malignancies.
      823  797