română ELISABETA VASILESCU , VLAD GABRIEL VASILESCU, ION PĂTRAŞCU, CORNEL FRĂŢILĂ
Abstract
The quality of the biomaterial in implantology is assessed by its ability to allow rapid osseointegration. Tissues react differently to implant depending on the type of biomaterial while the nature of reactions at implant - tissue interface makes a clear distinction between bioinert, biotolerated, bioactive materials. Achieving tissue biointegration requires the presence of a biocompatible material, and also an optimally designed biosurface of the implant. Increasing the biosurface area , possible through various processing methods (mechanical, chemical, electrochemical, etc.), favors the implant osseointegration by the size of the implant - bone contact zone that influence the process of adherence, proliferation and cell growth. This study analyzes the results of the research on the conditions for modifying the surface microtopography of a new material, Ti10Zr bio alloy, by machining, anodic oxidation and acid corrosion and the cell response to surface modification.
X-ray diffraction indicated the presence of oxides TiO2 ( anatase ) and scanning electron microscopy analysis of experimental surfaces processed revealed a special configuration of the surface oxidized , particularly from those obtained by anodizing.
Keywords
bioalloy, citotoxicitaty, biocompatibility, anodic oxidation, biosurface, cell proliferation, cell adhesion
ALIN GIONEA , ECATERINA ANDRONESCU, CORALIA BLEOTU, GEORGETA VOICU
Abstract
The aim of this study is to investigate the influence of different thermal histories and yttrium oxide molar ratio on zirconia dental ceramics properties. Zirconia powders used in this study were stabilized with 2 mol%, 2.5 mol% and 3 mol% yttrium oxide. Final dense ceramics were obtained through hot isostatic pressing at temperature of 1300°C, plateau of 1 and 2 hours, under 150 MPa, in argon atmosphere. Phase composition and microstructure were determined through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Density of specimens was investigated through gas displacement method on a helium pycnometer. Compressive strength and Young’s modulus tests were also performed in order to evaluate the effect of HIP treatment. Finally, the ceramics were tested for biocompatibility, showing good results.
Keywords
ceramics, density, compressive strength, biocompatibility, dental
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Year
2016
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Issue
46 (1)
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Pages
17-24
RUXANDRA- ELENA GEANALIU - NICOLAE, ADRIAN - ALEXANDRU PÎRVAN, ECATERINA ANDRONESCU, ROXANA TRUȘCĂ
Abstract
In order to obtain a drug delivery system used in tumoral treatment, this study presents the synthesis of mineral clay /antitumor drug hybrid materials. There were used three types of mineral phases with different structural characteristics as matrix and epirubicin, fludarabine, gemcitabine as active substances. The obtaining process was performed by mixing an aqueous solution of the drugs with the swelled clay. For the active substances incorporation, drug-solutions were heated and added slowly in clays suspensions (at 60°C, using magnetic stirring - 350 rpm). The dried hybrid materials were obtained after the separation was performed by centrifugation of cooled suspension.
The synthesized hybrid materials were characterized using different experimental techniques as X-ray diffraction, thermal analysis, scanning electron microscopy etc.. The characterization gave information about the proper interlayer intercalation of cytostatic, the good adsorption of drug into the matrix and the microstructure.
Keywords
epirubicin, fludarabine, gemcitabine, kaolinite, halloysite, montmorillonite, hybrid materials, drug delivery systems
MĂDĂLINA-ANCA LAZĂR, MIUŢA FILIP, MIHAELA CECILIA VLASSA, LIDIA ADRIANA SORCOI, RADU SEPTIMIU CÂMPIAN, CRISTINA PREJMEREAN
Abstract
The aim of the present study was the elaboration and the characterization of new fiber-reinforced composites (FRCs) that will serve cranial bone reconstruction, particularly in the cases of large bicortical calvarial defects. A series of resins containing dimethacrylate and urethane-dimethacrylate monomers were prepared and characterized. The most promising resin was selected in order to be reinforced with continuous unidirectional and woven E-glass fibers, respectively. The elaborated FRCs were investigated in vitro by scanning electron microscopy (SEM) and by determining the flexural properties and in vivo by intramuscular implantation test. The results of this study pointed out that the FRCs based on urethane dimethacrylic resin reinforced with woven E-glass fibers could be good candidates for the reconstruction of large cranial bone defects.
Keywords
biomaterials, bone reconstruction, fiber-reinforced composite, residual monomer, flexural strength, biocompatibility
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Year
2016
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Issue
46 (2)
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Pages
142-151
MAHAMASUHAIMI MASAE, LEK SIKONG, KALAYANEE KOOPTARNOND, PARNUMART CHOOPOOL, ANURAK BONBANG
Abstract
The extract from mangosteen pericarp (MP) was applied to a silk fabric. Its dye ability of silk fabric has been studied together with its colorfastness, antibacterial activity and UV protection properties. The mordant are aluminum potassium sulfate, ferrous chloride and sodium hydroxide were used to dye fabric. The color fastness to washing, water, perspiration, light and crocking of the dyed samples was determined according to AATCC test methods. In this study the UV protection properties were investigated on silk fabrics. The chemical functional groups of the dyes that were characterized by using fourier transform infrared spectroscopy (FTIR). Our results revealed that MP dyed silk fabric exhibited fair to good and good to very good fastness to washing and crocking, fair to very good light fastness, except for fabric mordanted with sodium hydroxide, whose rating were very poor to poor light fastness. The water and perspiration fastness ratings were good to very good, except for fabric mordanted with aluminum potassium sulfate. Silk fabrics mordanted with ferrous chloride and dyed with MP usually showed good UV protection levels even if undyed. Antibacterial activity of this dyed silk was confirmed by exposing the fabric to Staphylococcus aureus. The fabric dyed with MP extract reduced the number of viable organisms by 98% mordanted with ferrous chloride. These extracts gave polyphenols, gallic acid and carboxylic acid contents. Therefore, it was suggested that MP has the potential in producing functional dyes that could be imparted into the silk dyeing natural colorant system and incorporated in several kinds of cloths.
Keywords
antibacterial, natural dyes, color fastness, UV protection
CHRISTU ŢÂRDEI, CLAUDIA MARIA SIMONESCU, CRISTIAN ONOSE, BOGDAN ALEXANRU SAVA, LUCICA BOROICA, BEATRICE-GABRIELA SBÂRCEA
Abstract
This study aimed to investigate the effect of preparation conditions on different hydroxyapatite nanopowders (n-HAP), obtained on the laboratory scale, by the solution–precipitation and sol-gel methods, and to correlate the main characteristics like crystallinity and specific surface area with the ion Pb2+ immobilization capacity. It is tested the increasing performance of nano-HAP so obtained, to remove heavy metals from aqueous solutions through dispersant addition (0.1…1.5%) and isomorphic substitution (Six-HAP, x=0.5; 1). Batch experiments were carried out using different synthetic nano-hydroxyapatites; powders were comparatively tested for lead removal process from aqueous solutions, under different conditions, i.e. initial metal ion concentration, and pH of the solutions. Results showed that all HAP powders obtained by precipitation contain hydroxyapatite as the only crystalline phase instead, the sol-gel HAP powders contains minor quantities of β-TCP. Experimental results shown that, the amount of metal ions (Pb2+) removed correlates to the nature of the adsorbents (morphology and specific surface area), and to the concentration of the synthetic solution in metallic ions.
Keywords
nano crystalline hydroxyapatite, heavy metals, lead removal, adsorption
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Year
2016
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Issue
46 (3)
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Pages
289-297
RUXANDRA – ELENA GEANALIU - NICOLAE, ADRIAN-ALEXANDRU PÎRVAN, ECATERINA ANDRONESCU, ROXANA TRUȘCĂ
Abstract
In this study, the bioevaluation results of drug- clay hybrid materials obtained in Synthesis and characterization of drug - mineral clay hybrid materials for biomedical applications as drug delivery systems – part I [1] are presented, in order to obtaine drug delivery systems used in cancer treatment. The bioevaluated materials were the nine types of hybrid materials, synthesised using three types of mineral phases with different structural characteristics as matrix and epirubicin, fludarabine, gemcitabine as active substances.
For morpho- structural characterization were used the following experimental techniques: X-ray diffraction, thermal analysis, scanning electron microscopy, which offered information about the proper interlayer intercalation of cytostatic, the good adsorption of drug into the matrix, the microstructure. In this study, the characterization was continued with bioevaluation, presenting informations about the kinetics and drug release. Thus, analysis performed was the in vitro cytotoxicity which established the potential use for biomedical applications showing the antitumoral activity.
Keywords
epirubicin, fludarabine, gemcitabine, kaolinite, halloysite, montmorillonite, hybrid materials, drug delivery systems