Journal of Applied Biomaterials & Biomechanics : JABB

In the last two decades the performance of total hip replacements (THR) has constantly improved, thanks largely to advances in the field of material science and technology. Although contemporary devices are clinically very reliable, some problems still need to be addressed: the wear of ultra high molecular weight polyethylene components, the release of metal ions from metal-on-metal joints, the toughness of the ceramic cups and the possibility of squeaking for ceramic-on-ceramic couplings. All these drawbacks become particularly relevant in case of THR for young and active patients, when the life expectancy of the orthopedic device is very high and the possibility of mechanical shocks is not negligible...

PURPOSE: Polymer blending is an attractive route to obtain new materials with superior properties. Control of their characteristics may be initially achieved by manipulating the phase morphology with different aspects (i.e, lamellar, dispersed or fibrillar) to form tailored architectures for different application fields. In particular, co-continuous microstructures due to the interpenetration of two different polymer phases in three dimensions are particularly interesting because they are able to offer a fully interconnected network with improvement of mechanical properties and fluid permeability for tissue engineering applications...

PURPOSE: To evaluate the biomechanical properties and biocompatibility of natural hydroxyapatite/chitosan (HA/CS) composites. METHODS: The natural HA/CS composites with a different proportion of HA and CS were prepared by the cross-linking method, and then the compressive strength, microstructure and pH values of extracts from these composites were measured by SEM and pH meter, respectively. Subsequently, the biocompatibility of the composites was evaluated by means of a series of biological tests, including MTT, acute systemic toxicity, heat source, and hemolysis tests in vitro...

PURPOSE: New methodology for long-term (270 h) biomechanical testing with living cartilage was developed. Polyurethane (PU) implant material was compared with stainless steel and reference samples in static unconfined compressive loading conditions on cartilage to provide a basis for dynamic testing of novel PU implant materials under conditions that simulate an articulating human knee joint. METHODS: Custom-made tools and techniques were developed to prepare cylindrical samples from bovine patella with cartilage including subchondral bone...

PURPOSE: A skeletal segment consisting exclusively of bone is the target outcome of bone regeneration. Granular hydroxyapatites form a hydroxyapatite-bone composite, unsuitable for effectively supporting implants, which may persist for many years. This work aimed to investigate the reasons for the bone replacement of Ostim®, a recently commercialized aqueous nanocrystalline hydroxyapatite. METHODS: Histology, SEM and X-ray microanalysis were employed to analyze 6- to 9-month biopsies of post-extractive sites or sinus floor lifts of the maxilla in 15 subjects...

PURPOSE: To delineate the association between extent of degeneration of the disc at C5-C6, simulated in a model of the full cervical spine, and biomechanical responses of the model. METHODS: A validated three-dimensional model of an intact, healthy, adult full cervical spine (C1-C7) was constructed. This model was then modified to create three models simulating mild, moderate, and severe grades of degeneration of the disc at C5-C6. For each of these four models, we used the finite element analysis method to obtain three biomechanical parameters at various tissues in the model, under seven different physiologically relevant loadings...

PURPOSE: Biomaterials have been widely used in the field of regenerative medicine. Bovine pericardium tissue has been successfully used as a bioprosthetic material in manufacturing heart valves, but studies concerning the tissue are ongoing in order to improve its storage, preservation and transportation. This article provides an overview of the characteristics of bovine pericardium tissue chemically treated after the freeze-drying process. These characteristics are essential to evaluate the changes or damage to the tissue during the process...

INTRODUCTION: To examine and compare biocompatibility, osteocompatibility, rate of resorption, and remodelling dynamics of 2 calcium phosphate cements in comparison with a well-established hydroxyapatite ceramic. MATERIALS AND METHODS: In a randomised fashion, Bone Source™, Cementek™, and Endobon™ were implanted bilaterally into the proximal metaphyseal tibiae of 35 Göttinger minipigs in a direct right vs. left intra-individual comparison. Fluorescent labelling was used...

PURPOSE: The purpose of this study is the evaluation of the differences and, eventually, of the advantages or disadvantages of manual formulations with respect to industrial ones. METHODS: Medical-grade bone cements (Palacos R® and Palacos LV®), based on poly-methyl methacrylate (PMMA) and used clinically in several cemented prosthetic devices were manually enriched with gentamicin sulphate during preparation and then compared with a commercially-available, antibiotic-loaded cement (Palacos R+G®) by means of an in vitro antibacterial test (inhibition zone evaluation)...

PURPOSE: The knowledge of the mechanical response of bones and their substitutes is pertinent to numerous medical problems. Understanding the effects of mechanical influence on the body is the first step toward developing innovative treatment and rehabilitation concepts for orthopedic disorders. METHODS: This was a comparative study of 5 synthetic scaffolds based on porous calcium phosphates and natural bones, with regard to their microstructural, chemical, and mechanical characterizations...

PURPOSE: Biphasic calcium phosphate (BCP) ceramics are suitable for synthetic bone applications. The strontium substituted calcium phosphate ceramics have potential for use in orthopedic surgeries. Aim of the present work is to introduce strontium into BCP (composed of hydroxyapatite and tricalcium phosphate) ceramics and to study their bioactivity and mechanical properties. METHODS: BCP ceramics have been synthesized at room temperature under the physiological pH of 7...

PURPOSE: The importance of polymer-based composite materials to make multifunctional substrates for tissue engineering and the strategies to improve their performances have been stressed in the literature. Bioactive features of sol-gel synthesized poly(ε-caprolactone)/TiO₂ or poly(ε-caprolactone)/ZrO₂ organic-inorganic hybrid materials are widely documented. Accordingly, the aim of this preliminary research was to develop advanced composite substrates consisting of a poly(ε-caprolactone) matrix reinforced with sol-gel synthesized PCL/TiO₂ or PCL/ZrO₂ hybrid fillers...

Atomistic computer simulations of protein adsorption on the heterogeneous surface of biomaterials and nanomaterials are reviewed. First, we present a very brief introduction to some relevant issues concerning force fields and the computational methodologies currently used, in particular molecular dynamics simulations for studying non-covalent interactions in general. The main results are then discussed, considering the adsorption of different protein subdomains and of whole proteins on different surfaces of an unlike nature...

AIM: The aim of this study was to evaluate the biomechanical effects of the Maverick(R) disc prosthesis at the implanted and adjacent level by the finite element (FE) method. MATERIALS AND METHODS: A 3D FE model of the L3-L5 segment was built. To simulate the different physiological movements (flexion, extension, lateral bending, axial rotation) pure moments of 10 Nm were applied. To evaluate the effect of the prosthesis, a 3D model of the device was built and inserted in the L3-L5 model...

PURPOSE: Hydroxyapatite (HA) lattices were made by extrusion freeforming, a rapid prototyping process, and sintered to produce hard tissue scaffolds for bone regeneration. These highly reticulated lattice structures can be built directly from a computer design file which decides and controls their macroscopic shape, pore structure and size distribution. They are therefore defect-specific and show potential in tissue engineering for non-load bearing sites. METHODS: Using a commercial human osteoblast-like cell line (HOS TE 85), biocompatibility was evaluated in an in vitro study...

PURPOSE: An important issue related to the use of highly crosslinked ultra-high molecular weight polyethylene (HXLPE) in arthroplasty concerns the long-term oxidation of the polymer and related degradation of its end-user properties. Although in very recent years several procedures have been introduced into the manufacturing of prosthetic components to overcome this problem, the risk of long-term oxidation has not been completely eliminated. The aim of this study is to compare the effects on the physical and mechanical properties of HXLPE from two different thermal treatments used to promote oxidative stabilization...

INTRODUCTION: Stresses resulting from cast clasp arms during insertion and the removal of removable partial dentures are the main causes of deformations or fractures. Therefore, achieving clasp designs producing less stress is very important. OBJECTIVE: Retentive clasp arms used for premolars were investigated through the reverse engineering approach. The aim was to determine stress distribution in oval and half-oval clasps cross-sections in order to analyse biomechanical behavior...

PURPOSE: Since stretching plays a key role in skeletal muscle tissue development in vivo, by making use of an innovative bioreactor and a biodegradable microfibrous scaffold (DegraPol(R)) previously developed by our group, we aimed to investigate the effect of mechanical conditioning on the development of skeletal muscle engineered constructs, obtained by seeding and culturing murine skeletal muscle cells on electrospun membranes. METHODS: Following 5 days of static culture, skeletal muscle constructs were transferred into the bioreactor and further cultured for 13 days, while experiencing a stretching pattern adapted from the literature to resemble mouse development and growth...

Tissue engineering may be defined as the application of biological, chemical and engineering principles toward the repair, restoration or regeneration of living tissue using biomaterials, cells and biologically active molecules alone or in combinations. The rapid restoration of tissue biomechanical function represents a great challenge, highlighting the need to mimic tissue structure and mechanical behavior through scaffold designs. For this reason, several biodegradable and bioresorbable materials, as well as technologies and scaffold designs, have been widely investigated from an experimental and/or clinical point of view...

PURPOSE: The aim of this study was to evaluate microbial contamination and inhibitory effect against Streptococcus mutans (SM) of Prime & Bond (PB), Single Bond (SB) and Excite (EX) bonding systems before use, and after 10 and 20 applications. METHODS: The bonding material was collected by applying a drop of the material directly on broth brain-heart infusion. The samples were homogenized, diluted and seeded on blood agar plates. To evaluate the inhibitory effect on SM, a drop of each bonding material was dispensed on filter discs and placed on blood agar plates...