Biomedical subjects

Nenad Ignjatović

Publications and source records attributed to Nenad Ignjatović.

3 recordsLinked to original sources

PubMed2007

Substitution of osteoporotic alveolar bone by biphasic calcium phosphate/poly-DL-lactide-co-glycolide biomaterials.

Lost bone tissue due to osteoporosis makes dentistry very difficult. The aim of thisstudy is to reconstruct the bone tissue with composite biomaterials and to estimate the optical density and alveolar ridge height of the mandible. Research is conducted on 30 postmenopausal women aged from 46 to 62 years, with diagnosed osteoporosis and defects in alveolar bones caused by extraction of paradontopathic teeth, enucleation of cysts and periapical changes, extraction of impacted teeth,or by trauma.Biphasic calcium phosphate/poly-DL-lactide-co-glycolide (BCP/PLGA) composite is implanted into the defects of alveolar bones. Six weeks after implantation of BCP/PLGA, the alveolar bone density in the region of premolars on the experimental side of the jaw is found to be lower than that on the untreated, control, side of the jaw. On thecontrary, 24 weeks after implantation, it is significantly higher compared with the density of the control side. A significant increase in optical density of alveolar bones in the region of premolars on the experimental side compared with the control one is noticed. These results indicate a high level of osteoregeneration and osteoblast activity. Synthetic BCP/PLGA composite belongs to the group of biomaterials, which facilitate formation of new bones and rehabilitation of alveolar bones weakened by osteoporosis. Because of its osteoconductive characteristics, BCP/PLGA composite is supposed to be the material of choice for replacement of bone tissue in the future.

Adult↗

PubMed2006

Cytotoxicity and fibroblast properties during in vitro test of biphasic calcium phosphate/poly-dl-lactide-co-glycolide biocomposites and different phosphate materials.

Reconstruction of bone defects is one of the major therapeutic goals in various clinical fields. Bone replacement materials must satisfy a number of criteria. Biological criteria are biocompatibility, controlled biodegradability, and osteoconductive or even osteogenic potential. The material should have a three-dimensional structure with an interconnected pore system so as to permit cell growth and transport of substances. The surface must permit cell adhesion and proliferation. Composite biomaterials have enormous potential for natural bone tissue reparation, filling and augmentation. Calcium hydroxyapatite/polymer composite biomaterials belong to this group of composites and, because of their osteoconductive and biocompatible properties, can be successfully implemented within bone tissue reparations. In this study, possible differences between BCP/DLPLG, pure BCP, and Bio-Oss materials were examined in vitro. During overnight incubations, fibroblast and fibroblast-like cells (L929, MRC5) were able to adhere, spread, and remain viable on BCP, BCP/PLGA, and Bio-Oss discs, as was evidenced by using light- and LVSEM-microscopy. Inhibiting influence over the cell growth is more pronounced in the cases of BCP usage on both cell lines--41.29% for L929 and 43.08% for MRC-5 cells. MRC-5 cells are, within the given experimental conditions, less sensitive on inhibiting effects for the materials BCP/PLGA and Bio-Oss (10.13% and 10.76%, respectively) than for the L929 cell lines (23.02% and 15.44%, respectively).

Animals↗

PubMed2003

Injectable polydimethylsiloxane-hydroxyapatite composite cement.

An injectable polydimethylsiloxane/hydroxyapatite (PDMS/HAp) composite cement was synthesised using linear PDMS and HAp (particles of about 100 nm in size) of different mass fractions. The effect of HAp mass fraction (5-60 mass%) on the hardness of PDMS/HAp composite cement was investigated. The hardness achieved is 25-49 degrees ShA. Differential scanning calorimetry (DSC) was used to study the cross-linking process and the influence of HAp on the temperature and duration of PDMS/HAp cross-linking. The microstructure of composite cement surfaces after 10 days in vivo tests was observed by scanning electron microscopy (SEM). The presence of well-adhered macrophages, fibroblasts and monocytes was found on the implant surface upon its extraction from the organism.

Animals↗