Biological Reaction to Electrically Polarized Hydroxyapatite

2000 ◽  
Vol 662 ◽  
Author(s):  
Tomoko Sakai ◽  
Masato Ueshima ◽  
Sadao Morita ◽  
Satoshi Nakamura ◽  
Kimihiro Yamashita

AbstractWe have studied the polarized hydroxyapatite (HAp) whose surface was negatively or positively charged. In this study, we assessed the interfaces in vitro and in vivo periodically. As in vitro experiment, samples were immersed in simulated body fluid for 7 days and the surface was examined by scanning electron microscope (SEM). As in vivo experiments, cortical bone defects were created on the femoral trochanters and the condyles of the six Japanese white rabbits and the samples were implanted. The rabbits were sacrificed at 1, 2 and 4 W after the operation to analyze the surfaces by the SEM and the optical microscopy. In this study, a new thick apatite layer was formed on the negatively charged surface (N-surface) after 1week immersion in SBF in vitro. Besides, significant new bone formation was found at 2 weeks after the operation on N-surface in vivo, which was earlier than positively charged or non-polarized HAp surface. From this study negatively charged HAp surface by polarization accelerated the HAp crystal growth or the new bone formation. Thus, this N-surface will be promising for earlier fixation of the prosthesis or better recovery of the bone defect.

2007 ◽  
Vol 539-543 ◽  
pp. 710-715
Author(s):  
Kotaro Kuroda ◽  
Ryoichi Ichino ◽  
Masazumi Okido

Hydroxyapatite (HAp) coatings were formed on cp titanium plates and rods by the thermal substrate method in an aqueous solution that included 0.3 mM Ca(H2PO4)2 and 0.7 mM CaCl2. The coating experiments were conducted at 40-140 oC and pH = 8 for 15 or 30 min. The properties for the coated samples were studied using XRD, EDX, FT-IR, and SEM. All the specimens were covered with HAp, which had different surface morphologies such as net-like, plate-like and needle-like. After cleaning and sterilization, all the coated specimens were subjected to in vivo and vitro testing. In the in vitro testing, the mouse osteoblast-like cells (MC3T3-E1) were cultured on the coated and non-coated specimens for up to 30 days. Moreover, the specimens (φ2 x 5 mm) were implanted in rats femoral for up to 8 weeks, the osseoinductivity on them were evaluated. In in vitro evaluations, there were not significant differences between the different surface morphologies. In in vivo evaluations, however, two weeks postimplantation, new bone formed on both the HAp coated and non-coated titanium rods in the cancellous and cortical bone. The bone-implant contact ratio, which was used for the evaluation of new bone formation, was significantly dependent on the surface morphology of the HAp, and the results demonstrated that the needle-like coating appears to promote rapid bone formation.


2011 ◽  
Vol 5 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Oliver D Schneider ◽  
Dirk Mohn ◽  
Roland Fuhrer ◽  
Karina Klein ◽  
Käthi Kämpf ◽  
...  

Background: The purpose of this preliminary study was to assess the in vivo performance of synthetic, cotton wool-like nanocomposites consisting of a biodegradable poly(lactide-co-glycolide) fibrous matrix and containing either calcium phosphate nanoparticles (PLGA/CaP 60:40) or silver doped CaP nanoparticles (PLGA/Ag-CaP 60:40). Besides its extraordinary in vitro bioactivity the latter biomaterial (0.4 wt% total silver concentration) provides additional antimicrobial properties for treating bone defects exposed to microorganisms. Materials and Methods: Both flexible artificial bone substitutes were implanted into totally 16 epiphyseal and metaphyseal drill hole defects of long bone in sheep and followed for 8 weeks. Histological and histomorphological analyses were conducted to evaluate the biocompatibility and bone formation applying a score system. The influence of silver on the in vivo performance was further investigated. Results: Semi-quantitative evaluation of histology sections showed for both implant materials an excellent biocompatibility and bone healing with no resorption in the adjacent bone. No signs of inflammation were detectable, either macroscopically or microscopically, as was evident in 5 µm plastic sections by the minimal amount of inflammatory cells. The fibrous biomaterials enabled bone formation directly in the centre of the former defect. The area fraction of new bone formation as determined histomorphometrically after 8 weeks implantation was very similar with 20.5 ± 11.2 % and 22.5 ± 9.2 % for PLGA/CaP and PLGA/Ag-CaP, respectively. Conclusions: The cotton wool-like bone substitute material is easily applicable, biocompatible and might be beneficial in minimal invasive surgery for treating bone defects.


2010 ◽  
Vol 654-656 ◽  
pp. 2065-2070
Author(s):  
Ho Yeon Song ◽  
Young Hee Kim ◽  
Jyoti M. Anirban ◽  
In Seon Byun ◽  
Kyung A Kwak ◽  
...  

Calcium phosphate ceramics such as hydroxy apatite (HA), β-tricalcium phosphate (β-TCP) and bicalcium phosphate (BCP) have been used as a bone graft biomaterial because of their good biocompatibility and similarity of chemical composition to natural bones. To increase the mechanical and osteoconductive properties, the granules and spongy type porous bone graft substitutes were prepared by fibrous monolithic process and polyurethane foam replica methods, respectively. The pore sizes obtained using these approaches ranged between 100-600 µm. The cytotoxicity, cellular proliferation, differentiation and ECM deposition on the bone graft substitutes were observed by SEM and confocal microscopy. Moreover, the scaffolds were implanted in the rabbit femur. New bone formation and biodegradation of bone graft were observed through follow-up X-ray, micro-CT analysis and histological findings. After several months (2, 3, 6, 12 and 24 months) of implantation, new bone formation and ingrowths were observed in defect sites of the animal by CaP ceramics and 2 to 3 times higher bone ingrowths were confirmed than that of the normal trabecular bones in terms of total bone volume (BV).


2017 ◽  
Vol 31 (7) ◽  
pp. 1049-1061 ◽  
Author(s):  
Tadahiro Takayama ◽  
Jisen Dai ◽  
Keita Tachi ◽  
Ryutaro Shohara ◽  
Hironori Kasai ◽  
...  

Stromal cell-derived factor-1 (SDF-1) is a cytokine that is important in stem and progenitor cell recruitment in tissue repair after injury. Regenerative procedures using collagen membranes (CMs) are presently well established in periodontal and implant dentistry. The objective of this study is to test the subsequent effects of the released SDF-1 from a CM on bone regeneration compared to platelet-derived growth factor (PDGF) in vitro and in vivo. For in vitro studies, cell proliferation, alkaline phosphatase activity, and osteoblastic differentiation marker genes were assessed after MC3T3-E1 mouse preosteoblasts were cultured with CMs containing factors. In vivo effects were investigated by placement of CMs containing SDF-1 or PDGF using a rat mandibular bone defect model. At 4 weeks after the surgery, the new bone formation was measured using micro-computed tomography (µCT) and histological analysis. The results of in vitro studies revealed that CM delivery of SDF-1 significantly induced cell proliferation, ALP activity, and gene expression of all osteogenic markers compared to the CM alone or control, similar to PDGF. Quantitative and qualitative µCT analysis for volume of new bone formation and the percentage of new bone area showed that SDF-1-treated groups significantly increased and accelerated bone regeneration compared to control and CM alone. The enhancement of bone formation in SDF-1-treated animals was dose-dependent and with levels similar to those measured with PDGF. These results suggest that a CM with SDF-1 may be a great candidate for growth factor delivery that could be a substitute for PDGF in clinical procedures where bone regeneration is necessary.


2012 ◽  
Vol 529-530 ◽  
pp. 266-269
Author(s):  
Tsutomu Minatoya ◽  
Toshitake Furusawa ◽  
Masaaki Sato ◽  
Yuta Matsushima ◽  
Hidero Unuma

A new composition of bioactive glass was proposed that can be drawn into fibers, woven into cloth, and has appropriate alkali-releasing ability for bioactivity. The glass was drawn into fibers and woven into cloth, then the biological efficacy of the cloth was examined in in vivo tests. Bone defects made in tibial bones of Wistar rats were covered with the cloth just like "bandage" for two weeks. The cloth was found to promote new bone formation in the bone defects without causing any adverse effects. In contrast, excessive infection was recognized and new bone was not formed when cloth made of E-glass fibers was used. This was the first successful demonstration that glass cloth made of bioactive glass fibers assisted bone regeneration. The present glass cloth, therefore, is expected to be a promising material for "bone bandage" or porous scaffolds for bone tissue regeneration.


2001 ◽  
Vol 83 (3) ◽  
pp. 364-376 ◽  
Author(s):  
Manjula Viggeswarapu ◽  
Scott D. Boden ◽  
Yunshan Liu ◽  
Gregory A. Hair ◽  
John Louis-Ugbo ◽  
...  

2011 ◽  
Vol 37 (3) ◽  
pp. 403-416 ◽  
Author(s):  
Shih-Kuang Hsu ◽  
Wen-Tao Huang ◽  
Bai-Shuan Liu ◽  
Shih-Miao Li ◽  
Hsien-Te Chen ◽  
...  

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