SYNTHESIS, MECHANICAL AND STRUCTURAL PROPERTIES AND BIOLOGICAL ACTIVITY OF SOME NANOSTRUCTURED BONE SCAFFOLDS

Three new biodegradable and bioactive scaffolds based on hydroxyapatite (HAP), β tricalcium phosphate (β-TCP) and a composite HAP+β-TCP are studied in this paper. Their mechanical, structural properties and long term behaviour in simulated body fluid (SBF) were analysed. Also, these scaffolds were subjected to in vitro evaluation of cell behaviour. The open porosity from 16.41% to 34.26% it resulted. The compression resistance (2-3 MPa) is very close to the cancellous bone. It resulted that simultaneously with the dissolution, on the surface of materials were deposited calcium and phosphorous ions, namely, these materials are favourable to the bone formation. The scaffold morphology showed a dense polycrystalline structure with cavities (porosity), junctions and interconnections that can facilitate the cell proliferation. SEM micrographs revealed that, after 2100 immersion hours in SBF, the scaffolds coated with a layer of micro-sized grains. The in vitro results proved that hFOB 1.19 cells are able to attach, migrate in the interior of scaffolds, proliferate, synthesize and extracellularly assemble ECM molecules

Biochemical Investigation of Some Proteins from Human Primary Teeth to Evaluate Heavy Metal Pollution

This investigation is based on the premise that heavy metals are sequestered by the mineral phase of teeth [1,2], hydroxyapatite, during their formation and there is a relation between heavy metal pollution and progressive destruction of human primary tooth. Our study was carried out on temporary molars – sound and carious - extracted from children up to 6 year old, residing in an area of Romania known to be highly polluted with heavy metals (Pb and Cd). In carious dentin extracts we found increased levels of collagen type 1 and alkaline phosphatase activity that can be correlated with the remineralization processus during teeth decay. Gelatin zymography shown increased MMP-1 (type-I collagenase) and MMP-2 (gelatinase-A) activities only in dentin extract from carious teeth isolated from children residing in a highly polluted area, suggesting their role in pathological extracellular matrix (ECM) remodeling and degradation processes in the progression of carious decay.</jats:p

Osteoblast cell behavior on the new beta-type Ti25Ta25Nb alloy

International audienc

One Small Step for Rhinos, One Giant Leap for Wildlife Management- Imaging Diagnosis of Bone Pathology in Distal Limb

Chronic foot disease poses a threat to the general health, represents a tremendous clinical challenge, and often is a reason for euthanasia in captive megaherbivores, among them the elephant and rhinoceros. Nevertheless, apart from the elephant, foot pathology is handled as being confined only to soft tissues whereas bone pathology is often overlooked. As a case in point, the authors selected the second largest mammal on land, the rhinoceros. We performed a computed tomographic (CT) study using the highest resolution available in veterinary world, followed by digital radiography of eight distal limbs from two white and one Indian rhinoceroses. Our study demonstrated that bone pathology in rhinoceroses' foot is present and in large numbers, yet none of these were diagnosed ante mortem. Even when the animals were euthanized due to foot problems, the decision was based on soft tissue pathology rather than orthopedic reasons. Even more worrying is the fact that the largest number of osteopathologies was present in one of the white rhinoceroses that showed no discernable related clinical signs. This study describes for the first time the existence of bone pathology in white rhinoceros foot, in addition to the two previously described rhinoceros species--Indian and black rhinoceroses. Furthermore, the chronic foot disease reported for the Indian rhinoceros in our study was not restricted to soft tissue structures as was presumed ante mortem but included severe bone pathology. New evidence suggesting that osteopathology in rhinoceroses' distal limb is more widespread than it was thought before could force us to rethink of radiographic diagnosis in captive megaherbivores as routine examination incorporated into their health management. The anticipated improvements in radiologic examinations in megaherbivores will increase the effectiveness of their management and husbandry and open the way for improved animal welfare and better wildlife conservation