Search results for "bone"
showing 10 items of 2629 documents
Combination of silica nanoparticles with hydroxyapatite reinforces poly (l-lactide acid) scaffolds without loss of bioactivity
2013
Composite scaffolds of poly(l-lactide acid) and hydroxyapatite are of great interest in bone tissue engineering, but their mechanical properties are typically inferior to scaffolds of pure poly(l-lactide acid) due to agglomeration of the particles and weak interfacial component interaction. Fabrication strategies like double sonication of hydroxyapatite or increasing the amount of this inorganic filler do not effectively enhance the mechanical performance. In this study, poly(l-lactide acid) composites combining two types of fillers, mesoporous silica (SiO2) nanoparticles and hydroxyapatite, were developed to reinforce the poly(l-lactide acid) scaffold without any loss of bioactivity. A 5%…
Improved Bone Regeneration Using Biodegradable Polybutylene Succinate Artificial Scaffold in a Rabbit Model
2022
The treatment of extensive bone loss represents a great challenge for orthopaedic and reconstructive surgery. Most of the time, those treatments consist of multiple-stage surgeries over a prolonged period, pose significant infectious risks and carry the possibility of rejection. In this study, we investigated if the use of a polybutylene succinate (PBS) micro-fibrillar scaffold may improve bone regeneration in these procedures. In an in vivo rabbit model, the healing of two calvarial bone defects was studied. One defect was left to heal spontaneously while the other was treated with a PBS scaffold. Computed tomography (CT) scans, histological and immunohistochemical analyses were performed …
Titanium Lattice Structures Produced via Additive Manufacturing for a Bone Scaffold: A Review
2023
The progress in additive manufacturing has remarkably increased the application of lattice materials in the biomedical field for the fabrication of scaffolds used as bone substitutes. Ti6Al4V alloy is widely adopted for bone implant application as it combines both biological and mechanical properties. Recent breakthroughs in biomaterials and tissue engineering have allowed the regeneration of massive bone defects, which require external intervention to be bridged. However, the repair of such critical bone defects remains a challenge. The present review collected the most significant findings in the literature of the last ten years on Ti6Al4V porous scaffolds to provide a comprehensive summa…
Dual effect of inorganic polymeric phosphate/polyphosphate on osteoblasts and osteoclasts in vitro
2012
Inorganic polymeric phosphate/polyphosphate (polyP) is a natural polymer existing in both pro- and eukaryotic systems. In the present study the effect of polyP as well as of polyP supplied in a stoichiometric ratio of 2 m polyP:1 m CaCl2 [polyP (Ca2+ complex)] on the osteoblast-like SaOS-2 cells and the osteoclast-like RAW 264.7 cells was determined. Both polymers are non-toxic for these cells up to a concentration of 100 µm. In contrast to polyP, polyP (Ca2+ complex) significantly induced hydroxyapatite formation at a concentration > 10 µm, as documented by alizarin red S staining and scanning electron microscopic (SEM) inspection. Furthermore, polyP (Ca2+ complex) triggered in SaOS-2 cell…
Maxillary bone necrosis following the use of bisphosphonates in patients with cancer: management and case series
2008
Bisphosphonates are bone-turnover modulating drugs used to treat various diseases such as certain cancers, bone metastasis, bone- and calcium-related disorders, Paget`s disease, osteoporosis and osteopenia. Recently, several preliminary reports have reported the insurgence of osteonecrosis of the mandible and/or maxilla, associated with intravenously administered bisphosphonates. This case series describes the effects of bisphosphonates used in the treatment of certain cancers on oral bone tissues.
Specific expression of a TRIM-containing factor in ectoderm cells affects the skeletal morphogenetic program of the sea urchin embryo
2011
In the indirect developing sea urchin embryo, the primary mesenchyme cells (PMCs) acquire most of the positional and temporal information from the overlying ectoderm for skeletal initiation and growth. In this study, we characterize the function of the novel gene strim1, which encodes a tripartite motif-containing (TRIM) protein, that adds to the list of genes constituting the epithelial-mesenchymal signaling network. We report that strim1 is expressed in ectoderm regions adjacent to the bilateral clusters of PMCs and that its misexpression leads to severe skeletal abnormalities. Reciprocally, knock down of strim1 function abrogates PMC positioning and blocks skeletogenesis. Blastomere tran…
Association between periodontal disease and non-fatal ischemic stroke: a case-control study
2014
This study aimed to investigate the association between clinical and radiological markers of periodontal disease and ischemic stroke and to assess the potential influence of inflammatory response on the observed associations.A prospective case-control study including a series of 48 cases with a minor ischemic stroke and 47 controls was conducted at the University Hospital of Dijon. Vascular risk factors, clinical dental examination (plaque index, gingival index, percentage of pockets5 mm, percentage of bleeding on probing (BOP) sites), dental panoramic (bone loss) and biological parameters (CRP, total cholesterol, HDL, LDL, fasting glucose) were collected. Conditional regression analyses we…
Bone status in adolescents with type 1 diabetes
2010
Aims The aim of the study was to investigate the potential negative impact of type 1 diabetes on bone status of adolescents. Bone status in adolescents with type 1 diabetes was assessed by means of quantitative ultrasound (QUS) and the influence of metabolic control and other diseaserelated and growth variables was analysed. Methods Group I consisted of 99 pubertal (Tanner ≥2) adolescents (49 female), aged 14.3±2.5 years, diabetes duration 4.6±2.3 years. Controls (group II) were 297 children, matched by sex and age, from a healthy population. The influence of glycated haemoglobin (current: HbA1cD; last year’s mean: HbA1cY; whole duration mean: HbA1cT), diabetes duration, percentage of life …
Platelet, Not Endothelial, P-Selectin Expression Contributes to Generation of Immunity in Cutaneous Contact Hypersensitivity
2010
Leukocyte extravasation is a prerequisite for host defense and autoimmunity alike. Detailed understanding of the tightly controlled and overlapping sequences of leukocyte extravasation might aid development of novel therapeutic strategies. Leukocyte extravasation is initiated by interaction of selectins with appropriate carbohydrate ligands. Lack of P-selectin expression leads to decreased contact hypersensitivity responses. Yet, it remains unclear if this is due to inhibition of leukocyte extravasation to the skin or due to interference with initial immune activation in lymph nodes. In line with previous data, we here report a decreased contact hypersensitivity response, induced by 2,4,-di…
Modulation of platelet activation and initial cytokine release by alloplastic bone substitute materials.
2010
Objectives: Platelet-derived cytokines play a crucial role in tissue regeneration. In regenerative dental medicine, bone substitute materials (BSM) are widely used. However, initial interactions of BSM and platelets are still unknown. The aim of this study was to evaluate the potential of platelet activation and subsequent initial cytokine release by different commercial alloplastic BSM. Material and methods: Eight commercial BSM of different origins and chemical compositions (tricalcium phosphate, hydroxyapatite, bioactive glass: SiO2 and mixtures) were incubated with a platelet concentrate (platelet-rich plasma, PRP) of three healthy volunteers at room temperature for 15 min. Platelet cou…