Bio-Medical Materials and Engineering - Volume 12, issue 1

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 1-2, 2002

Authors: Lerouge, S. | Tabrizian, M. | Wertheimer, M.R. | Marchand, R. | Yahia, L'H.

Article Type: Research Article

Abstract: Plasma‐based sterilization is a promising alternative to the use of pure ethylene oxide (EO), for low‐temperature clinical sterilization of medical instruments and devices. However, few studies have been published that evaluate its safety in terms of possible damage to materials, particularly polymers. The objective of this work was to evaluate polymer surface modifications induced by commercial plasma‐based sterilizers, in comparison with pure EO: Samples from 5 polymer‐based devices were subjected to 1, 5, and 10 sterilization cycles by Sterrad‐100® , Plazlyte™, and pure EO. Surface analysis was carried out by X‐ray photoelectron spectroscopy (XPS), dynamic contact angle measurements (DCA), and …scanning electron microscopy (SEM). Surface oxidation and wettability changes were observed on all samples sterilized by plasma‐based techniques, the degree of modifications depending on the sterilizer (Sterrad® , Plazlyte™) and the type of polymer. Drastic changes of surface appearance were also observed by SEM on PVC samples sterilized by Plazlyte™ and by pure EO. Possible repercussions on safety are discussed. Show more

Keywords: Plasma‐based sterilization, safety, polymer‐based medical device, surface modification, oxidation

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 3-13, 2002

Authors: Demers, Caroline | Hamdy, C. Reggie | Corsi, Karin | Chellat, Fatiha | Tabrizian, Maryam | Yahia, L'Hocine

Article Type: Research Article

Abstract: Natural coral graft substitutes are derived from the exoskeleton of marine madreporic corals. Researchers first started evaluating corals as potential bone graft substitutes in the early 1970s in animals and in 1979 in humans. The structure of the commonly used coral, Porites, is similar to that of cancellous bone and its initial mechanical properties resemble those of bone. The exoskeleton of these high content calcium carbonate scaffolds has since been shown to be biocompatible, osteoconductive, and biodegradable at variable rates depending on the exoskeleton porosity, the implantation site and the species. Although not osteoinductive or osteogenic, coral grafts act as …an adequate carrier for growth factors and allow cell attachment, growth, spreading and differentiation. When applied appropriately and when selected to match the resorption rate with the bone formation rate of the implantation site, natural coral exoskeletons have been found to be impressive bone graft substitutes. The purpose of this article is to review and summarize all the pertinent work that has been published on natural coral as a bone graft including in vitro, animal and clinical human studies. Preliminary report of our own experiments as well as our recommendations on the use of coral are also included. Show more

Keywords: Coral, biomaterial, bone graft substitute, bioresorbable, osteoconductive

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 15-35, 2002

Authors: Hernández, R. | Polizu, S. | Turenne, S. | Yahia, L'H.

Article Type: Research Article

Abstract: We investigate the behavior of NiTi porous alloys, possessing the property of shape memory, by using different characterization methods XPS, Auger, DSC and SEM. The study mainly focuses on the determination of porosity, surface characteristics and the phase transformation. In the case of porous material the biomechanical compatibility is closely related to the internal structure and porosity distribution. To describe appropriately the influence of the properties of NiTi on the memory shape, two types of materials provided by different sources has been analyzed. Despite the fact that both materials present different pores size, they exhibit an open and interconnected porosity. …Our measurements show that the temperature of the inception of the martensite‐austenite phase transition occurs at 60°C, which is by 20°C greater than the body temperature. Moreover, we show that the surface characteristics can be greatly influenced by heat treatment. Furthermore, we observe that the R‐phase occurs only for one of the used materials after its heat treatment. The correlation between the composition and the other characteristics measured has been found. Show more

Keywords: NiTi alloys, SEM, DSC, XPS, Auger

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 37-45, 2002

Authors: Hagemeister, Nicola | Long, Raymond | Yahia, L'Hocine | Duval, Nicolas | Krudwig, Wilfried | Witzel, Ulrich | de Guise, Jacques A.

Article Type: Research Article

Abstract: In this project, we compared knee laxity and 3‐D knee kinematics after ACL reconstruction on cadaver knees using (1) bone–patellar tendon–bone two‐tunnel; (2) synthetic ligament two‐tunnel; and (3) synthetic ligament “over‐the‐top” technique. We used a computer assisted system, based on the acquisition of the knee's movement with magnetic sensors (Polhemus, Vermont, USA). The use of personalised three‐dimensional (3D) models of the bones enabled us to ensure a reproducible measurement of three‐dimensional kinematic and laxity parameters. Our results showed that even when knee laxity was restored to normal, 3D kinematic measurements revealed that the reconstructions tended to under or over‐constrain the …knee's movement. This study shows that 3D kinematics is a complementary measurement that can be useful to get a better comprehension of the knee's function after ligament reconstruction. Show more

Keywords: Ligament, reconstruction, 3D kinematics, in vitro, evaluation

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 47-57, 2002

Authors: Krudwig, Wilfried K.

Article Type: Research Article

Abstract: Between April 1989 and July 1996, 217 anterior cruciate ligament reconstructions using a synthetic ligament of polyethylene terephthalate (PET Trevira® – hochfest) were performed. 160 (74%) cases have been followed‐up with a mean time of 4.8 years (1.0–8.3) and evaluated by the IKDC standard knee ligament evaluation form. Altogether 88% excellent and good results were found. The best outcomes involved isolated ACL tears and reconstruction within a few month. The amount and intensity of lasting symptoms depended mostly on osteoarthrotic changes (chondral and meniscal lesions) and correlated with the interval between injury and reconstruction. All findings are presented …in detail and critically discussed. Show more

Keywords: Anterior cruciate ligament, reconstruction, synthetic graft

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 59-67, 2002

Authors: Shabalovskaya, Svetlana A.

Article Type: Research Article

Abstract: The present review surveys studies on physical‐chemical properties and biological response of living tissues to NiTi (Nitinol) carried out recently, aiming at an understanding of the place of this material among the implant alloys in use. Advantages of shape memory and superelasticity are analyzed in respect to functionality of implants in the body. Various approaches to surface treatment, sterilization procedures, and resulting surface conditions are analyzed. A review of corrosion studies conducted both on wrought and as‐cast alloys using potentiodynamic and potentiostatic techniques in various corrosive media and in actual body fluids is also given. The parameters of localized and …galvanic corrosion are presented. The corrosion behavior is analyzed with respect to alloy composition, phase state, surface treatment, and strain and compared to that of conventional implant alloys. Biocompatibility of porous Nitinol, Ni release and its effect on living cells are analyzed based on understanding of the surface conditions and corrosion behavior. Additionally, the paper offers a brief overview of the comparative toxicity of metals, components of commonly used medical alloys, indicating that the biocompatibility profile of Nitinol is conducive to present in vivo applications. Show more

Keywords: Nitinol, as‐cast, wire, porous, sintering, ignition, austenite, martensite, nickel, titanium, molibdenum, implant, shape memory, superelesticity, surface chemistry, XPS, AFM, wettability, surface treatment, oxidation, passivation, boiling, hydrogen peroxide, sterilization, autoclaving, ethylene oxide, amorphous, precipitates, corrosion, ASTM, potetiodynamic, potentiostatic, scratch tests, breakdown, pitting potential, strain, stress, tension, compression, cold drawn, Ni release, Ni toxicity, biocompatibility, in vitro, in vivo, bone ingrowth, lymphocytes, smooth muscle cells, platelet, albumin, fibrinogen, tissue engineering, orthopaedic, maxillofacial, vascular stent restenosis

Citation: Bio-Medical Materials and Engineering, vol. 12, no. 1, pp. 69-109, 2002