54 research outputs found
Mislabeling and nomenclatorial confusion of Typhlotanais sandersi Kudinova-Pasternak, 1985 (Crustacea: Tanaidacea) and establishment of a new genus
Re-examination of historical collections allowed us to resolve the taxonomic status of Typhlotanais sandersi Kudinova-Pasternak, 1985, originally described based on a single specimen from Great-Meteor Seamount. The holotype of this species was considered lost and the species redescribed based on a second specimen from the type locality by Błażewicz-Paszkowycz (2007a), who placed Ty. sandersi on a newly established genus Typhlamia. Thorough morphological analysis of Typhlamia and Typhlotanais species and recently obtained genetic data of typhlotanaids from N Atlantic and NW Pacific waters allow us to conclude that the redescription of Ty. sandersi by Błażewicz-Paszkowycz (2007a) was based on a wrongly labelled specimen that, rather than a type of Ty. sandersi, represents in fact a new species of Typhlamia. The morphological comparison of the type species of Typhlotanais (Ty. aequiremis) with all 'long-bodied' typhlotanaid taxa with rounded pereonites margins (i.e., Typhlamia, Pulcherella, Torquella), and the use of genetic evidence, support the establishment of a new genus to accommodate: Ty. sandersi, Ty. angusticheles Kudinova-Pasternak, 1989, and a third species from N Atlantic waters, that is described here for the first time. Current knowledge on 'long-bodied' typhlotanaids with rounded pereonites is summarised and a taxonomical key for their identification provided
An "in Vitro" study of polymer-based composites
Structures of most tissues in the human body can be simulated with fibrous composite materials. A major problem associated with designing biocompatible composites for reconstruction of damaged or missing tissues is the ability to mimic such structures. The physical, chemical and mechanical properties of composite materials should be similar to those of the native tissue. Another very important factor of polymer-based fibrous composite materials, which can relatively easily be modified, is their surface microstructure. This surface microstructure depends on the way of preparation, type of polymer matrix and kind of reinforcement. This work was aimed to determine the biological properties of composites obtained from carbon fibres and a polymer matrix, which can be used as biomaterial in the reconstruction of cartilage tissue. Two types of samples made from short carbon fibres and two kinds of polymers were tested. The samples were prepared by casting technique. MTT tests were carried out in the presence of hFOB-1.19-line human osteoblasts and HS-5-line human fibroblasts. The results show differences in viability of living cells. Results of the work show significant differences in biocompatibility of pure polymers and composites with short carbon fibres
Elaboration and characterization of biodegradable scaffolds from poly (L-Lactide-co-glycolide) synthesized with low-toxic zirconium acetylacetonate
Objectives: The aim of the study was to answer the questions whether poly (L-lactide-co-glycolide) synthesized with the use of zirconium acetylacetonate: (i) is less toxic in vitro than that synthesized with tin compound; (ii) is it possible to produce scaffolds from such copolymer, and (iii) how these scaffolds degrade in vitro. Methods: A human osteoblast line (Saos2) was used to verify the biocompatibility of the copolymer. Porous scaffolds were obtained via the solvent casting / particulate leaching technique. The scaffolds were characterized in terms of surface chemistry (FTIR-ATR, contact angle), microstructure (porosity, water uptake, SEM) and degradation in PBS (GPC, SEM, FTIR-ATR, mass loss). Results: The copolymer synthesized with the zirconium compound performs better in contact with osteoblasts in vitro than that synthesized with tin. Porous scaffolds from a such copolymer can be easily prepared by the solvent casting/salt leaching technique. These scaffolds, having a high open porosity (88% ± 2%) and water uptake of (630% ± 50%) maintain their dimensions and porous microstructure for 8 weeks in PBS. The scaffolds degrade in vitro, but the rate of degradation is quite low. Conclusion: The results of biological, textural, and physico-chemical properties of obtained porous material, regarding its behaviour in conditions simulating biological environment, show that it could be used as a scaffold for bone tissue engineering
Fabrication of multi-walled carbon nanotube layers with selected properties via electrophoretic deposition : physicochemical and biological characterization
On the influence of various physicochemical properties of the CNTs based implantable devices on the fibroblasts' reaction in vitro
Coating the material with a layer of carbon
nanotubes (CNTs) has been a subject of particular interest for
the development of new biomaterials. Such coatings, made
of properly selected CNTs, may constitute an
implantable electronic device that facilitates tissue regeneration
both by specific surface properties and an ability to
electrically stimulate the cells. The goal of the presented
study was to produce, evaluate physicochemical properties
and test the applicability of highly conductible material
designed as an implantable electronic device. Two types of
CNTs with varying level of oxidation were chosen. The
process of coating involved suspension of the material of
choice in the diluent followed by the electrophoretic deposition
to fabricate layers on the surface of a highly biocompatible
metal-titanium. Presented study includes an
assessment of the physicochemical properties of the material’s
surface along with an electrochemical evaluation and
in vitro biocompatibility, cytotoxicity and apoptosis studies
in contact with the murine fibroblasts (L929) in attempt to
answer the question how the chemical composition and
CNTs distribution in the layer alters the electrical properties
of the sample and whether any of these properties have
influenced the overall biocompatibility and stimulated
adhesion of fibroblasts. The results indicate that higher level
of oxidation of CNTs yielded materials more conductive than the metal they are deposited on. In vitro study revealed
that both materials were biocompatible and that the cells
were not affected by the amount of the functional group and
the morphology of the surface they adhered to
Polymer-carbon composite for guided tissue regeneration
Leczenie chorób przyzębia techniką kontrolowanej regeneracji tkanek wymaga od implantu, aby pełnił rolę membrany odizolowującej komórki tkanki łącznej i nabłonka dziąsła od miejsca gojenia i umożliwiał komórkom ozębnej repopulację i utworzenie cementu korzeniowego z wbudowanymi włóknami kolagenowymi. W stomatologii obserwuje się coraz większe zainteresowanie implantami membranowymi do leczenia
chorób przyzębia. Znanych jest wiele materiałów organicznych resorbowalnych i nieresorbowalnych, z których wytwarza się implanty dla sterowanej rekonstrukcji
tkanek. W pracy przedstawiono próbę otrzymania trójfazowego implantu będącego połączeniem dwóch biozgodnych składników a mianowicie: włókniny węglowej i poli-L-laktydu. Zewnętrzną część implantu stanowi błona polimerowa będąca barierą dla
niepożądanych komórek nabłonka zaś wewnętrzna część zbudowana jest z włókien węglowych stymulujących proces regeneracji tkanki kostnej. Implant polimerowo-
węglowy został poddany badaniom przy zastosowaniu metod: FTIR, SEM i DSC co pozwoliło na charakterystykę jego budowy chemicznej i morfologii, natomiast inkubacja próbek w sztucznym płynie ustrojowym dostarczyła danych o trwałości implantu w warunkach in vitro.In the treatment of parodontopathy by guided tissue regeneration, it is required that the implant should play a role of a membrane that separates the connective tissue and gingival epithelium from the healing site. It should also permit repopulation of the periodontium cells along with formation of tooth root cement with the collagen fibres. In stomatology the interest in membrane implants for the treatment of parodontopathy continually increases. There are many resorbable and non-resorbable organic materials used as implants in guided tissue reconstruction. This work is an attempt to develop a three-phase implant being a combination of two biocompatible components, i.e.
carbon felt and poly-L-lactide. The outer part of the implant is built of a polymeric membrane, a barrier for undesirable gingival epithelium cells, while the inner part consists of carbon fibres that stimulate the process of bone tissue regeneration. The polymer-carbon implant was examined using FTIR, SEM, and DSC, to characterise its chemistry and morphology, while incubation of samples in simulated body fluid provided
the data on their stability in the in vitro conditions
Soft tissue response to degradation products of carbon biomaterials : a histochemical study
The regeneration processes of soft tissues in the presence of carbon biomaterials implants of three types were investigated using histochemical methods. Biomaterials in the form of powder, implanted into the rat muscle did not cause a disadvantage of
celIs functions expressed by the activity of main enzymes of metabolic pathway and by the tissue regeneration processes
Degradation of fibrous carbon nanocomposites (SFC+NHAP) in resorbable polymer PL(L/LD)A matrix : preliminary studies
2D-Raman correlation spectroscopy as a method to recognize of the interaction at the interface of carbon layer and albumin
In modern nanomaterial production, including those
for medical purposes, carbon based materials are important, due to their inert nature and interesting properties. The essential attribute for biomaterials is their
biocompatibility, which indicates way of interactions
with host cells and body fluids. The aim of our work
was to analyze two types of model carbon layers differing primarily in topography, and developing their
interactions with blood plasma proteins. The first layer
was formed of pyrolytic carbon C (CVD) and the second
was constructed of multi-walled carbon nanotubes obtained by electrophoretic deposition (EPD), both set on
a Ti support. The performed complex studies of carbon
layers demonstrate significant dissimilarities regarding
their interaction with chosen blood proteins, and points
to the differences related to the origin of a protein:
whether it is animal or human. However the basic examinations, such as: wettability test and nano sctatch
tests were not sufficient to explain the material properties. In contrast, Raman microspectroscopy thoroughly
decodes the phenomena occurring at the carbon structures in contact with the selected blood proteins. The
2D correlation method selects the most intense interaction and points out the different mechanism of interactions of proteins with the nanocarbon surfaces and
differentiation due to the nature of the protein and its
source: animal or human. The 2D correlation of the
Raman spectra of the MWCNT layer+HSA interphase
proves an increase in albumin β-conformation. The presented results explain the unique properties of the Clayers (CVD) in contact with human albumin
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