Trends in
Biomaterials & Artificial Organs
An International Journal Published by the 
Society for Biomaterials and Artificial Organs India
ISSN 0971-1198 (print)
Volume 22, Number 2, September-December 2008

Full text can be accessed by clicking on the pdf link.

The journal has now initiated online manuscript submission and peer-review management system in technical collaboration with www.criticalmath.com . Authors can now submit their manuscripts at http://tbao.criticalmath.com .

p 65-72

Biphasic Finite Element Modelling of Contact Mechanics of Hemi-arthroplasty

of Human Hip Joint. Part II: Polycarbonate Urethane on Cartilage Contact

A.C. Cilingir^a,*, V. Ucar^a, I.J. Udofia^b, Z.M. Jin^b

^aSchool of Mechanical Engineering, Esentepe Campus, Sakarya University, 54187, Sakarya, Turkey

^bSchool of Mechanical Engineering, University of Leeds, LS2 9JT, Leeds, UK

^*Corresponding author e-mail cilingir@sakarya.edu.tr

Received 31 October 2007; published online 1 August 2008

Poroelastic finite element study was performed to compare the contact mechanics of employing different 

biomaterials such as metal and polycarbonate urethane for hemiarthroplasty hip resurfacing. The effects of loading,

radial clearance and cartilage thickness on the predicted maximum contact pressure and pore pressure were

 investigated in this study. The femoral component, considered in part 1, was modified on the bearing surface by 

using a polycarbonate urethane layer with thickness of 2 mm to investigate the effect of soft bearing material against 

the articular cartilage. The stress distributions within the components of hemiarthroplasty of hip joint were also 

studied. The most significant effect on the predicted maximum contact pressure and pore pressure for metal on 

cartilage and polycarbonate urethane on cartilage models was found to be cartilage thickness in this study. 

Therefore it was concluded that because of cartilage degeneration by time, using soft femoral component 

decreased the predicted maximum contact pressure and pore pressure on cartilage in this study. Varying the 

radial clearance between femoral component and articular cartilage and applied load did not show a significant 

effect on the contact mechanics between metal on cartilage and polycarbonate urethane on cartilage models. 

Also a comparison of the predicted maximum von Mises stresses within the components of metal on 

cartilage and polycarbonate urethane on cartilage models had only small differences, ranged from 0 to 10%.

© Society for Biomaterials and Artificial Organs ( India ), 20071031-16.

p 73-78

L-arginine Protect from Pringle Manoeuvere of Ischemia-reperfusion and

Pringle described a new technique to reduced blood loss during liver surgery. Adult wister rat underwent to
1 h of partial liver ischemia and followed by 3 h reperfusion. Eighteen Wister rats were divided into shamoperated
control group (I) (n = 6), ischemia and reperfusion (I/R) group (II) (n = 6), L – arginine treated group
(10mg/kg body weight /daily by oral route for 7 days before induced ischemia reperfusion maneuver) (III) (n =

6). Pre- treatment with L- arginine significantly decreased plasma-ALT, AST and ischemic zone after 1 h

ischemia followed by 3 h of reperfusion. Nitric oxide production, in hepatocytes was increased 2 fold when

compared with I/ R group rats. Ischemic zone was reduced by L- arginine compared to I/R group. Histopathology,

flow cytometry and fluorescence microscopy studies showed markedly diminished hepatocellular injury

in L- arginine pretreated rats during hepatic I/R, which reached a level comparable to saline-treated rat of sham

operated group. On the basis of our findings it may be concluded that L- arginine afforded significant protection

from hepatobiliary function from I/R injury by up nitric oxide production in liver transplantation model.

p 79-86

Development and Validation of a Reversed-Phase HPLC Method for In-

Vitro Loading and Release Analysis of Paclitaxel Coated Stent

A simple, rapid and sensitive high-performance liquid chromatographic method is described for determination

of Paclitaxel (PCL) from coated stent surface using a reverse phase X-terra C18 (5 ìm) column at 227 nm and

using acetonitrile, methanol and water in the ratio of 60:5:35 (v/v) as a mobile phase following single-step

extraction from Phosphate buffer saline (PBS) pH 7.4 with dichloromethane. The assay was validated against

the classical criteria and was applied to detect paclitaxel content as well as release amount from the stent

surface. Sink condition of paclitaxel coated stent was maintained in PBS throughout the experiments by

different criteria. It was maintained by modifying the release medium such as methanolic PBS, PBS containing

DENA (N, N- Diethylnicotinamide), and 0.1% sodium azide in PBS. With the “sampling” technique, drug-loaded

stent was introduced into a vessel, and release was monitored over a period of time by analyzing aliquots of

release medium. In the use of agitation by means of orbital shaking incubator, the sampling seems to be easier

than the continuous flow method. In the “continuous flow” technique, media is continuously circulated through

a cell containing drug-loaded stent followed by analysis. The extraction method achieves a chemical separation

of drug from the release media by use of a separating funnel. With all these methods, the setup and sampling

techniques seem to influence in vitro release. © Society for Biomaterials and Artificial Organs (India),

20071205-20.

p 87-92

New Generation Sirolimus Eluting PTCA Angioplasty Balloon Catheter for

Drug eluting stents have shown promising antirestenotic effects in clinical practice. Non-stent based local

delivery of drug may offer additional flexibility and also reach vessel areas beyond the immediate stent

coverage [1]. The purpose of current research was to study the feasibility of Sirolimus coating on intracoronary

dilatation balloon catheter and evaluate its release pattern in-vitro. The balloon catheter was coated with

drug-biodegradable polymers blend in solution form as a single layer to render anti-proliferative and immunosuppressive

property. Also it was thought that drug eluting catheter can also prevent catheter related infections,

bacteremia and bacterial colonization and thrombus formation after injury in a blood vessel from balloon.

Dip coating technique was effectively developed to coat the balloon catheter with Sirolimus drug-polymeric

blend for programmed drug release. The drug content and in-vitro drug elution kinetics were analyzed using

High performance liquid chromatography (HPLC) method. Scanning electron microscopy (SEM) was used to

characterize the coating surface uniformity and smoothness. © Society for Biomaterials and Artificial Organs

(India), 20071205-21.

p 93-103

Small-diameter Polyethylene terephthalate (PET) textile prostheses display poor patency rates. Among the

many factors which may explain this, the absence of neoendothelium formation on the inner surface of the

graft is one cause of failure. This neoendothelialization may depend on the material’s structure, which clearly

influences endothelial cells development. Thus far, little is known regarding the effect of textile structure on

cell development. To determine the influence of a material’s chemistry and micro-structure on cell adhesion and

proliferation, this study compared the behaviour of bovine aortic endothelial cells (BAECs) on a flat PET film

and those on non-coated textile structures of knitted and woven commercial prostheses with and without

velour. One-hour cell adherence tests were performed followed by cell proliferation tests at 2, 3, 5, 9, and 15

days under static conditions. Results show a significant structural difference (p < .001) between the PET film

and the PET textile when BAEC adherence was promoted on the textile structures. No differences were

measured between the four types of textile. Proliferation tests showed differences between each sample,

with better proliferation on the velour knit samples. Immunofluorescence micrographs confirmed that the textile

structures enabled the isolation of individual BAECs because of their high specific surface. Although appearing

as promising adherence promoters, the textiles were incompatible with monolayer BAEC proliferation. In

light of this finding, prosthetic surface morphology resulting from textile structure must be modified to support

monolayer cell proliferation. © Society for Biomaterials and Artificial Organs (India), 20080214-21.

p 104-110

Physical Vapour Deposition and Bioactivity of Crystalline Titanium Dioxide

Lack of interfacial stability is one of the causes behind the need for revision surgery of metallic implants. Thin

films of titanium oxide have recently been proven to be bioactive (in vitro) and non-resorbable. The objective

of the paper is to investigate the relationship between deposition parameters of thin crystalline titanium oxide

films (using reactive sputtering), their microstructure and the in vitro bioactivity. The relative amounts of

anatase and rutile were hard to control via the deposition parameters tested. No direct coupling between the

hydroxylapatite layer and the crystalline films from different deposition runs could be derived from this

investigation. © Society for Biomaterials and Artificial Organs (India), 20080314-15.

body in its repair process. © Society for Biomaterials and Artificial Organs (India), 20080327-16.