Papers by Keyword: Osteogenic

Abstract: The purpose of this study was to analyze the histological, histochemical and radiological findings gained from pre-clinical in vitro and in vivo tests and from implantation of ß-tricalcium phosphate PORESORB^®-TCP (P). (P) is a bioactive, resorbable, inorganic, crystalline, non-metallic material with osseoconductive properties intended for replacement of bone tissue. The (P) granules (size 1-2mm) were implanted into the tibia of dogs for 3 and 6 months. The formation of 53% and 72% of new bone was observed after 3 and 6 months respectively.Material (P) sized 0.3-0.6 mm was used to fill in the periodontal defect and also as a carrier of growth proteins. During the study period, no undesired response to the material used was observed. The values of the plaque index showed standard hygienic conditions – the values of PlI were 0.72, 0.65 and 0.62 before treatment and 6 and 12 months after treatment, respectively.A total of 72 two-stage sinus lifts were performed in 54 patients. The autologous bone was harvested from the mandibular ramus and mixed with the (P) material sized 1-2 mm. The materials were used in a proportion ranging between 1: 1 and 1: 3. The residual allograft area was 16.21 ± 8.78 %. The connective tissue was 44.16 ± 5.85 %.This has been a retrospective review of the healing of bone defects, due to benign tumours or tumour-like lesions, using (P) material sized 1.3 mm, 0.7 mm (0.6-2 mm) as bone graft substitutes. 87 patients with bone defects (average volume 15 cm³; interval 0.4 – 144 cm³) were included. Defects with a volume up to 4 cm³ had the same successful rate of healing both for autologous bone grafts and (P). (P) sized 1.3 mm; 0.7 mm (0.6-2 mm) was successfully used in defects with volume up to 4 cm³. However, it is evident that the ratio of the size of the defect and the size of the applied granule must be kept near to 10/1 for successful treatment.

Abstract: Calcium phosphate is a widely used material as coating for metallic implants. This research describes a biomimetic coating techniques based on deposition of calcium phosphate films on a Ti6Al4V plates that was used to study the effect of strontium additive on the behavior of hMSCs. In this study, strontium additive was homogenously deposited onto calcium phosphate films on a Ti6AlV plates by using a biomimetic techniques. Strontium affected composition and morphology of calcium phosphate deposited on a Ti6Al4V plates to a varying degree, according to concentration of solutions used. The effect of strontium additive on proliferation and differentiation of hMSCs depended on the solution and concentration tested. In general, all individual three coatings showed decreased hMSCs proliferation. Strontium additive demonstrated a significant increase in differentiation into osteogenic lineage when compared with the control and calcium phosphate films without strontium additive. However, no cytotoxic effect of strontium additive in the concentrations tested was detected. The Fourier transform infrared spectra showed that this new coating closely resembles bone mineral. The techniques illustrated in this study mimics bone mineral containing strontium additive, making it constructive for studying basic processes of in vitro bone formation. The results showed in this study can be used for changing bone graft substitutes by addition of strontium additive on implants in order to affect their performance in bone repair and regeneration. Also, the system can aid rapid bone formation around the implant, reducing therewith the patient’s recovery time after surgery.

Abstract: Bone tissue has evolved into hierarchical three-dimensional structures with dimensions ranging from nanometres to metres. The structure varies depending on the site in the body, which is dictated by the loading environment. Medically, bone is one of the most replaced body parts (second only to blood) but replicating these complex living hierarchical structures for the purpose of regenerating defective bone is a challenge that has yet to be overcome. A temporary template (scaffold) is needed that matches the hierarchical structure of native bone as closely as possible that is available ‘off the shelf’ for surgeons to use. After implantation the scaffold must bond to bone and stimulate not only three dimensional (3D) bone growth, but also vascularisation to feed the new bone. There are many engineering design criteria for a successful bone scaffold and bioactive glass foam scaffolds have been developed that can fulfil most of them, as they have a hierarchical porous structure, they can bond to bone, and they release soluble silica species and calcium ions that have been found to up-regulate seven families of genes in osteogenic cells. Other ions have also been incorporated to combat infection and to counteract osteoporosis. Their tailorable hierarchical structure consists of highly interconnected open spherical macropores, further, because the glass is sol-gel derived, the entire structure is nanoporous. The macropores are critical for bone and blood vessel growth, the nanopores for tailoring degradation rates and protein adsorption and for cell attachment. This chapter describes the optimised sol-gel foaming process and how bone cells respond to them. Whatever type of scaffold is used for bone regeneration, it is critically important to be able to quantify the hierarchial pore structure. The nanopore size can be quantified using gas sorption, but to obtain full information of the macropore structure, imaging must be done using X-ray microtomography and the resulting images must be quantified via 3D image analysis. These techniques are reviewed.

Abstract: Nature is full of many interesting things to work with, but many natural resources are also protected. In this view the recycling of aquaculture and fishery residues may lead to the manufacture of new devices and the isolation of new molecules with potential application in medicine. The aim of the present study was to explore the possibility to transform the cuttlefish bone into an hydroxyapatite scaffold suitable for bone tissue engineering application. The mixture of different lamellar porous structure of cuttlefish bone from the species Sepia Officinalis was selected and characterized, according to morphology (including porosity, surface development, surface characteristics) and mechanical properties. The material was transformed into suitable scaffold for bone tissue regeneration, trying to totally or partially convert calcium carbonate (aragonite) into calcium phosphate (hydroxyapatite HA) using hydrothermal transformation. The studies on cell attachment and proliferation (by MTT assay at different experimental times), cell morphology with Scanning Electron Microscopy (SEM), alkaline phosphatase (ALP) and osteocalcin (OC) activities and expressions by mouse osteoblast-like MC3T3-E1 cells on HA were investigated at different experimental times in cultures, in comparison with those observed on titanium specimens used as a control (ET and ST). Cell proliferation was less in HA transformed cuttlefish bone scaffolds than in ET and ST specimens. In contrast, good performance for osteoblasts differentiation was observed on HA transformed cuttlefish bone scaffolds, similar to those observed onto titanium scaffolds.