|
|
|
» Influence of sintering temperature on morphology of dense bioceramics based on hydroxyapatite derived from porcine bones
|
|
Anna Maria Janus  ROMAN MAJOR MAREK FARYNA
Hydroxyapatite (HAp - Ca10(PO4)6(OH)2) is the major constituent
of mineral phase of human bone. It characterizes itself with high
biocompatibility and has been used in medicine and stomatology
for more than 20 years [1].
Hydroxyapatite can be obtained either by synthesis or by extraction
from natural sources. Commercially available hydroxyapatite
materials are listed in Table 1. Hydroxyapatite derived from porcine
bones has not been commercialized yet, thus its development seems
to be an attractive field of research.
Biocompatibility of hydroxyapatite of porcine origin has been
proved under in vitro and in vivo conditions [2, 3].
Heat treatment significantly influences chemical composition of
the regarded hydroxyapatite derived from the animal bone. Such
observation is proved by the other investigators [4, 5]. The information,
found in literature and concerning influence of the sintering
conditions on the dense bioceramics biocompatibility, however, do
not cover all possible sintering conditions [5÷8].
The aim of the presented work was to examine the influence of
the temperature of sintering process on the hydroxyapatite morphology.
The properties of the investigated materials were afterwards
subject of in vitro biocompatibility investigation.
MATERIALS AND METHODS
Hydroxyapatite of porcine origin was obtained from long porcine
bones. Preparation procedure comprised bones boiling in distilled
water for 24 h, mechanical removal of tissue and spongy parts residues,
leaching out of organic matter with 4 M sodium hydroxide solution
during 48 h at 100°C, rinsing with distilled water in order to
remove NaOH, drying at 120°C to constant mass, milling, sieving
and calcination at 450°C in atmosphere of air for complete removal
of organic matter.
As reference material HA BIOCER synthetic hydroxyapatite
from Chema-Elektromet (Pola[...]
więcej»
w zeszycie
INŻYNIERIA MATERIAŁOWA 2010/3
|
|
|
|
|
|
|
|
|
|
|
|
» Microstructure of the surface layer of a Ti6Al4V alloy and X5CrNi18-10 steel after laser treatment
|
|
|
Magdalena Rozmus -Górnikowska Jan Kusiński Marek Blicharski Roman Major
One of the relatively new method of mechanical surface treatments
is Laser Shock Processing (LSP), which introduce strain hardening
and compressive residual stresses into the treated surface layer. LSP
uses laser pulses with pulse duration within the nanosecond range
to modify the surface layers by means of high pressure [1, 2]. Laser
parameters for LSP require power density ≥0.1 GW/cm2 and laser
pulse duration ≤10-6 s.
During the process, the laser beam is directed onto the surface
of the material. The area to be treated is usually covered with two
types of coatings: an absorbing coating, opaque to the laser beam,
for example black paint, placed directly on the surface of the investigated
material, and over this a transparent to the laser beam
coating for example water [3, 4]. Figure 1 shows the scheme of the
Laser Shock Processing.
When the laser beam with sufficient intensity is directed onto the
surface, it passes through the transparent layer and is absorbed by
the black coating. The absorbing coating is vaporized and the vapor
rapidly achieves very high temperatures at which electrons are ionized
and a plasma plume is formed. The rapidly expanding plasma
is confined on the surface of the metal by the layer of water, creating
high pressures. This pressure propagating into the treated material
as a shock wave, can induce microstructural changes and cause high
increase of dislocation density and produce a high residual surface
compressive stresses [5, 6].
The aim of this work was to investigate the effect of Laser Shock
Processing on the microstructure and roughness of the surface layer
of the Ti6Al4V titanium alloy and X5CrNi18-10 austenitic stainless
steel.
MATERIALS AND E[...]
więcej»
w zeszycie
INŻYNIERIA MATERIAŁOWA 2010/3
|
|
|
|
|
|
» Wpływ struktury powłok na bazie tytanu i węgla na właściwości biofizyczne biomateriałów do kontaktu z krwią
|
|
ROMAN MAJOR JUERGEN M. LACKNER PIOTR WILCZEK KATARZYNA MAKSYMOW BOGUSŁAW MAJOR
Adhezja i aktywacja komórek do powierzchni materiałów o przeznaczeniu
na implanty medyczne jest bardzo istotnym zagadnieniem
[1, 2]. Parametry strukturalne wytworzonej powłoki kontaktowej
istotnie wpływają na interakcję biomateriału z tkanką
łączną [3]. Celem prowadzonych prac przez zespół autorów jest
wytworzenie nowego, gradientowego materiału o odpowiednich
właściwościach strukturalnych i dobrej biozgodności [4].
Przedmiotem realizowanych badań były cienkie warstwy gradientowe
na bazie tytanu metalicznego oraz stechiometrycznego
TiN i Ti(C, N) nanoszone różnymi metodami, a mianowicie: ablacji
laserowej (PLD) [5], magnetronową oraz hybrydową łączącą
PLD z magnetronową, głównie na klinicznie stosowany poliuretan
[6÷9]. Tematykę poszerzono o powłoki na bazie węgla. W związku
szerokim zainteresowaniem podłożami polimerowymi, pokrywanie
podłoży metalicznych zostało zminimalizowane. Proces osadzania
realizowano w Centrum Laserowym w Austrii, kompleksową
diagnostykę strukturalną na podstawie badań XRD, SEM,
TEM, HRTEM wykonano w IMIM PAN w Krakowie i w Laboratorium
Biofizycznym na Politechnice w Grenoble oraz Fundacji
Rozwoju Kardiochirurgii w Zabrzu, gdzie prowadzono testy wyznaczenia
kinetyki przylegania komórek do materiałów o potencjalnym
zastosowaniu biomedycznym. Skonstruowano unikatową
aparaturę do badań adhezji komórek w warunkach przepływu medium,
na której zrealizowano badania.
Dane doświadczalne uzyskuje się na drodze analizy obrazów
fluorescencyjnych po przeprowadzonym teście w warunkach kinetycznych
i służą one do wyznaczania krzywych kinetycznych.
Kompleksowa diagnostyka strukturalna realizowana była metodą
rentgenografii strukturalnej oraz skaningowej i transmisyjnej
mikroskopii elektronowej oraz laserowej mikroskopii konfokalnej
i akustycznej mikroskopii skaningowej i miała na celu
opis morfologii powierzchni, analizę właściwości fizycznych oraz
mechanicznych. Uzyskane wyniki z przeprowadzonych badań
mikrostrukt[...]
więcej»
w zeszycie
INŻYNIERIA MATERIAŁOWA 2010/4
|
|
|
» Surface functionalization for tissue analog of blood contacting materials
|
|
ROMAN MAJOR JUERGEN M. LACKNER PIOTR WILCZEK MAREK SANAK MICHAŁ SOBOTA MAREK KOWALCZUK JAN MARCZAK KATARZYNA MAKSYMOW BOGUSŁAW MAJOR
Blood contacting materials could initiate several processes, which
can endanger the life, like the formation of thromboemboli. Properties
of new designed materials could minimize influence of the human
organism. For blood contact, the biocompatibility requirements
are of the highest level of all biomaterial applications, which is due
to the continuous blood flow and the high reactivity of blood molecules
and cells. Blood contacting materials could initiate several
life-endangering processes such as formation of thromboemboli,
even in the presence of anti-clotting agents. Thus, our research in
the frame of integrated national and international activity is focused
on fabrication and diagnostics of materials characterized by reduction
or erasing of thrombogenicity.
In the last years of material development, lower thrombogenicity
was primarily tried to reach by modifying existing material
surfaces. Despite the successes in reducing protein and cellular
deposits on some materials, this approach do not target to a truly
non-thrombogenic surface. Recently, attempts are starting to create
self-assembling layers. Such approach is realized in our research
activity by the multidisciplinary, international work.
Estimation of the cell-material interaction plays an important
role in the biomaterial design. Titanium and carbon basis biomaterials,
such as diamond-like carbon (DLC), titanium (Ti), and stoichiometric
titanium nitride (TiN) as well as titanium carbo-nitrade
(Ti(C, N)), seem to be good candidates for future blood-contact applications.
These materials were deposited as thin films by the hybrid
pulsed laser deposition (PLD) technique to examine the influence
of such surfaces on cell behavior. The cell-material reactions
were examined in static conditions and then subjected to a dynamical
test by application of a radial flow chamber specially design to
observe the cell detachment kinetics.
Concept of design
The concept of design is[...]
więcej»
w zeszycie
INŻYNIERIA MATERIAŁOWA 2011/4
|
|
|
|
Strona 1
|
Twój Profil
Twój koszyk
