română RUXANDRA- ELENA GEANALIU-NICOLAE ADRIAN- IONUȚ NICOARĂ, ECATERINA ANDRONESCU, ROXANA TRUȘCĂ
Abstract
In order to obtain a drug delivery system used in tumoral treatment, this study presents the characterization of mesoporous silica /antitumor drug hybrid materials obtained in A NOVEL METHOD OF SYNTHESIS FOR NANOPOROUS SILICA MATERIALS [1]. There were synthesized eight hybrid materials, using two types of mesoporous silica as support material and irinotecan respectively thyme oil as active substances. Mesoporous silica was synthetized using two techniques, classical sol-gel and novel microwave-assisted hydrothermal method, resulting different structural characteristics for materials. Loading with irinotecan was realized in aqueous solution at neutral and acidic pH environment using impregnation method with drug solution. Other four materials were synthesized using thyme oil 3% and 5%.
In this study hybrid materials were characterized using different techniques such as X-ray diffraction, FT-IR, Thermal analysis, scanning electron microscopy which offered morpho-structural information. Others analysis performed were kinetics and in vitro cytotoxicity which established the potential use for biomedical applications showing the antitumoral activity.
Keywords
MCM, mesoporous silica, hexagonal mesostructure, drug delivery system, biomaterials, irinotecan, thyme oil, cancer treatment
DORINEL TĂLPEANU, MAGDALENA VALENTINA LUNGU, ANCA COJOCARU, DELIA PĂTROI, VIRGIL EMANUEL MARINESCU
Abstract
The study was focused on the development of some porous hydroxyapatite (HAp) based ceramic materials as bone substitutes for cranioplasty. The HAp samples were elaborated by a hot pressure casting technique at a casting temperature of 90°C and 5 atm pressure, having 77 wt.% HAp and 23 wt.% melted paraffin and bee wax binder. The samples were casted without and with the addition of 5 wt.% and 10 wt.% porogen agent. Then the cast samples were dried, dewaxed, and sintered at 1150°C, 1200°C, and 1250°C for 2 hours. The final sizes of the sintered samples were 10±0.05 mm in diameter and 40±0.3 mm in length. The structural properties were investigated by X-ray diffraction (XRD). The water absorption, apparent porosity and apparent density were determined by standard test methods for ceramics. The mechanical properties were investigated by flexural and compressive tests. The microstructure was analyzed by scanning electron microscopy (SEM). All the sintered samples revealed crystalline phases and homogeneous microstructure. The apparent density was 1.28-1.76 g/cm3, the apparent porosity was 43-57 %, the flexural strength was 4-8.6 MPa, and the compressive strength was 5.4-13.7 MPa. The obtained results meet the technical requirements imposed for porous ceramics used in cranioplasty. The properties were enhanced with the increase of the sintering temperature but the addition of the porogen agent contributed to an increase of the apparent porosity and a decrease in mechanical strength. The samples sintered at 1250°C revealed the best properties that recommend the developed HAp materials for biomedical applications.
Keywords
hydroxyapatite, biomaterials, hot pressure casting, porogen agent
OTLILIA CHIRCA, CORNELIA BICLEȘANU, ANAMARIA FLORESCU, LUDMILA MOTELICĂ, ALINA MARIA HOLBAN, ALEXANDRU BURCEA
Abstract
The purpose of this study is to analyze with the help of the scanning electron microscopy and FTIR microscopy, the way in which the adhesion to the dental structure and to different types of ceramics of some adhesive materials is made. For this study, 45 free teeth were used, which were divided into 3 equal groups: group I restored with IPS E.max CAD-On ceramic crowns, Ivoclar Vivadent cemented with Maxcem Elite, Kerr; group II restored with IPS E.max Press ceramic crowns, Ivoclar Vivadent cemented with RelyX Ultimate Clicker, 3M Espe and group III restored with Novodent GS Zirconia crowns cemented with Variolink Esthetic. The teeth were embedded into the resin, sectioned and subjected to the analyses.Both the tooth-cement interface and the cement-ceramic crown interface were evaluated with the help of SEM and FTIR. The materials used showed a good adhesion to the dental structure, and the presence of micro-cracks was observed at the ceramic interface. Moreover, the evaluated materials showed different microbial attachment ability, the most significant adherence inhibition of the Lactobacillus acidophilus being observed in the case of cemented Zirconia crowns.
Keywords
dental crown, ceramics, SEM, self adhesive cement, self-etch cement
ANDREI VIOREL PĂDURARU, OVIDIU OPREA, ADINA MAGDALENA MUȘUC, BOGDAN ȘTEFAN VASILE, ANTON FICAI, ECATERINA ANDRONESCU
Abstract
The paper describes a rapid and a simple method for preparing photoluminescent compounds of different concentration of europium (0-10%) by doping hydroxyapatite, synthetized by coprecipitatin method. The obtained nanomaterial were further characterized by Fourier transfrom infrared spectroscopy, X-ray diffraction analysis, UV-Visible spectroscopy, room-temperature photoluminescence spectroscopy, and scanning electron microscopy. The influence of dopant ion concentration on the structure of hydroxyapatite structure and morphology was followed Hence, the present study proves the integration of europium ions in hydroxyapatite lattice and an enhanced of the luminescent properties of obtained doped hydroxyapatite materials, even at lower concentrations, being able to extend their applications to bioimaging or drug delivery.
Keywords
europium, photoluminescence, hydroxyapatite, coprecipitation
HAYRI AKMAN, KORAY SÜRME , MEHMET AKIN
Abstract
This study evaluated the shear bond strength of self-adhesive flowable composite when used with acid etching or a self-etch adhesive system. Buccal enamel surfaces on 80 extracted human primary incisors were used and randomly assigned into four groups (n=20); group 1: Vertise™ Flow; group 2: Vertise Flow with acid etching; group 3: Vertise Flow with a self-etching bonding agent; group 4: Premise Flowable™ with a total-etch bonding agent as the control group. After 5000 rounds of thermocycling, the bond strength test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture analyzes of samples were evaluated using a light stereomicroscope. The results obtained were analyzed via analysis of variance (ANOVA) and Tukey’s tests. Statistically significant differences were observed among all groups (P<0.001). Group 1 generated a lower mean shear bond strength (2.63±1.08 MPa) than those of the other groups [group 2 (7.52±2.14 MPa), group 3 (5.12±2.93 MPa), and group 4 (14.18±2.93 MPa)]. Adhesive failure was the most common failure mode in Vertise Flow groups. Vertise Flow used with a self-etching agent or acid etching exhibited in lower shear bond strength than the control group.
Keywords
Dental materials, Primary teeth, Self-adhesive flowable composite, Shear bond strength, Vertise™ flow
I.GOMOIU , M. ENACHE, S. NEAGU , R. RUGINESCU, M. DUMBRĂVICIAN, R. RADVAN, L. GHERVASE, I. MOHANU, R. COJOC
Abstract
The development of effective and non-destructive conservation strategies is based on understanding the role of microorganisms as biodeteriogens and their metabolites in biocleaning and biological control. An efficient alternative to traditional strategy in restoration is biorestoration based on different green biotechnologies where microorganisms and their enzymes are main actors. They are used both in bioconsolidation due to their ability to produce calcium carbonate precipitation and biocleaning. Microorganisms are used as viable cells brushed on the art works or embedded in carriers. Biorestoration is characterized by low cost and invasiveness, high specificity, easy control, non-toxicity for restorers and friendly for environment. Due to the fact that biorestoration has advantages and disadvantages, a better information of conservators and restorers in the use of the biotechnologies applied to restoration and conservation together with new results on optimizing the biocleaning and bioconsolidation about microorganisms, enzymes and bioactive molecules is needed. They will contribute to technological transfer on a large scale.
Keywords
microorganisms, biotechnologies, biconsolidation, biocleaning, biological control, mural paintings, stone
IONELA ANDREEA NEACȘU , LILIA MATEI, ALEXANDRA CĂTĂLINA BÎRCĂ, ADRIAN IONUȚ NICOARĂ, VLADIMIR LUCIAN ENE, LAURA DENISA DRAGU, ANTON FICAI, CORALIA BLEOTU, ECATERINA ANDRONESCU
Abstract
The purpose of this study was to obtain and characterize curcumin-loaded hydroxyapatite materials for bone cancer treatment. The hydroxyapatite synthesis was performed under controlled conditions in order to obtain monodisperse, fine nanoparticles and to avoid later uncontrolled deposition of these nanoparticles, starting from Ca(OH)2 and (NH4)2HPO4. The obtained dried precipitate was thermal treated, then suspended in curcumin – dichloromethane solution (where curcumin was added in order to represent 5%, 10% wt. from the amount of hydroxyapatite) and homogenized until solvent evaporation. Morphological and structural characterization, as well as in vitro characterization were performed. All samples were biologically tested and antitumor studies were performed.
Keywords
bone cancer treatment, curcumin, hydroxyapatite