scholarly journals Titania-Containing Bone Cement Shows Excellent Osteoconductivity in A Synovial Fluid Environment and Bone-Bonding Strength in Osteoporosis

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1110
Author(s):  
Tomotoshi Kawata ◽  
Koji Goto ◽  
Masashi Imamura ◽  
Yaichiro Okuzu ◽  
Toshiyuki Kawai ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Bone Cement ◽  
Sodium Succinate ◽  
Fluid Pressure ◽  
Rabbit Model ◽  
Femoral Diaphysis ◽  
Methylprednisolone Sodium Succinate ◽  
Fluid Environment ◽  
Total Knee

Titania bone cement (TBC) reportedly has excellent in vivo bioactivity, yet its osteoconductivity in synovial fluid environments and bone-bonding ability in osteoporosis have not previously been investigated. We aimed to compare the osteoconductivity of two types of cement in a synovial fluid environment and determine their bone-bonding ability in osteoporosis. We implanted TBC and commercial polymethylmethacrylate bone cement (PBC) into rabbit femoral condyles and exposed them to synovial fluid pressure. Rabbits were then euthanized at 6, 12, and 26 weeks, and affinity indices were measured to evaluate osteoconductivity. We generated a rabbit model of osteoporosis through bilateral ovariectomy (OVX) and an 8-week treatment with methylprednisolone sodium succinate (PSL). Pre-hardened TBC and PBC were implanted into the femoral diaphysis of the rabbits in the sham control and OVX + PSL groups. Affinity indices were significantly higher for TBC than for PBC at 12 weeks (40.9 ± 16.8% versus 24.5 ± 9.02%) and 26 weeks (40.2 ± 12.7% versus 21.2 ± 14.2%). The interfacial shear strength was significantly higher for TBC than for PBC at 6 weeks (3.69 ± 1.89 N/mm2 versus 1.71 ± 1.23 N/mm2) in the OVX + PSL group. These results indicate that TBC is a promising bioactive bone cement for prosthesis fixation in total knee arthroplasty, especially for osteoporosis patients.

The Effect of Methylprednisolone Sodium Succinate on Erythrocyte and Haemoglobin Function

1980 ◽  
Vol 59 (3) ◽  
pp. 163-168 ◽  
Author(s):  
M. Brada ◽  
L. A. Robinson ◽  
A. J. Bellingham
Keyword(s):  
Whole Blood ◽  
Sodium Succinate ◽  
Oxygen Affinity ◽  
Whole Cells ◽  
Methylprednisolone Sodium Succinate ◽  
Acid Citrate Dextrose ◽  
Citrate Dextrose ◽  
Therapeutic Doses

1. As it has been suggested that the beneficial effect of methylprednisolone in shock is due to its effect on erythrocyte oxygen affinity, we studied its effect on incubated erythrocytes and on haemoglobin solution. 2. Incubation of fresh whole blood anticoagulated with acid/citrate/dextrose with methylprednisolone (7 mmol/l) produced a significant decrease in oxygen affinity, which was not seen with lower concentrations of methylprednisolone. When either acid/citrate/dextrose blood stored for 10 days or fresh heparinized blood was used, no significant increase in the partial pressure of oxygen at 50% haemoglobin saturation (P50) was demonstrated even with methylprednisolone at 7 mmol/l. At the highest concentration achieved in plasma with standard therapeutic doses (56 μmol/l) there was no increase in P50 under all the conditions studied. 3. Methylprednisolone reduced the oxygen affinity of haemoglobin in solution. The reduction in oxygen affinity was less than that produced by 2,3-diphosphoglycerate and more than that of either sodium succinate or sodium chloride. 4. From the results of this study we conclude that the effect observed in whole cells is probably due to a direct effect of methylprednisolone on haemoglobin. To produce a significant decrease of oxygen affinity of whole blood in vitro requires a plasma concentration of methylprednisolone above that obtained in plasma in vivo, with the currently used therapeutic doses.

scholarly journals Analytical Evaluation of a Vancomycin Immunoassay in Synovial Fluid

Joints ◽  
2017 ◽  
Vol 05 (02) ◽  
pp. 125-126
Author(s):  
Francesca Luceri ◽  
Fiamma Balboni ◽  
Giovanni Balato ◽  
Paola Pezzati ◽  
Nicoletta Cini ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Bone Cement ◽  
Joint Infection ◽  
Standard Of Care ◽  
Joint Space ◽  
Multidrug Resistant ◽  
Cement Matrix ◽  
Clinical Laboratories ◽  
Antibiotic Release

AbstractIn clinical laboratories performing routine activities, the need to answer the burning clinical question in emerging field may be limited by lack of technology support or assays accessibility. Commercially available methods, although originally validated for specific biological matrices, may be employed for other matrices, following appropriate guidelines such as Clinical and Laboratory Standards Institute (CLSI) EP 19. We investigated the use of a vancomycin assay with synovial fluid samples, in view of a possible employment in vancomycin release study. The standard of care of periprosthetic joint infection is a two-stage revision surgery with antibiotic-loaded bone cement implantation. Vancomycin, for its activity against gram-positive bacteria even multidrug-resistant staphylococci, is the most widely used antibiotic. Despite the widespread use of such devices, little is known about the in vivo elution in the joint space. Clinical laboratories equipped with a validated, affordable method to quantify vancomycin in synovial fluid, may support clinical research, and give an important contribution to the study of the pharmacokinetics of antibiotic release from bone cement matrix.

In vitro and in vivo effectiveness of a novel injectable calcitonin-loaded collagen/ceramic bone substitute

2021 ◽  
pp. 088532822198998
Author(s):  
Karl Wu ◽  
Yu-Chun Chen ◽  
Shang M Lin ◽  
Chih-Hung Chang
Keyword(s):  
Calcium Phosphate ◽  
Bone Cement ◽  
Degradation Rate ◽  
Rabbit Model ◽  
Type I ◽  
Calcium Phosphate Bone Cement ◽  
Osteogenic Effect ◽  
Composite Bone

This study aimed to evaluate the effectiveness of a novel calcitonin-loaded calcium phosphate composite bone cement in vitro and in vivo. The novel composite bone cements were composed of NuROs injectable bone graft substitute, type I collagen, and/or salmon calcitonin. The setting time, porosity, wettability, compressive strength, compressive modulus, and crystallographic structures of cement specimens were determined. Degradation rate, calcitonin release rate, and osteoinductivity were assessed in vitro. In addition, osteogenic effect was examined in a rabbit model of femoral defect. The results revealed that addition of collagen/calcitonin did not substantially alter physical properties and degradation rate of bone cement specimens. Calcitonin was released into culture medium in a two-phase manner. Osteogenic effect of conditioned medium derived from calcitonin containing bone cement was observed. Finally, de novo bone growth and bone mineralization across the bone defect area were observed in rabbits after implantation of composite bone cement specimens. In conclusion, this novel calcitonin-loaded composite calcium phosphate bone cement exhibits biocompatibility, bioresorbability, osteoinductivity, and osteoconductivity, which may be suitable for clinical use.

scholarly journals Use of Xylitol To Enhance the Therapeutic Efficacy of Polymethylmethacrylate-Based Antibiotic Therapy in Treatment of Chronic Osteomyelitis

2012 ◽  
Vol 56 (11) ◽  
pp. 5839-5844 ◽  
Author(s):  
Karen E. Beenken ◽  
Laura Bradney ◽  
William Bellamy ◽  
Robert A. Skinner ◽  
Sandra G. McLaren ◽  
...  
Keyword(s):  
Antibiotic Therapy ◽  
Bone Cement ◽  
Therapeutic Efficacy ◽  
Chronic Osteomyelitis ◽  
Rabbit Model ◽  
Bone Infection ◽  
Therapeutic Outcome ◽  
Surgical Debridement ◽  
Pmma Bone Cement

ABSTRACTUsing a rabbit model of postsurgical osteomyelitis, we demonstrate that incorporation of xylitol into polymethylmethacrylate (PMMA) bone cement enhances the elution of daptomycin underin vivoconditions. We also demonstrate that this can be correlated with an improved therapeutic outcome in the treatment of a chronic bone infection following surgical debridement.

Acyl-Enzymes as Thrombolytic Agents in a Rabbit Model of Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 269-274 ◽  
Author(s):  
R A G Smith ◽  
R J Dupe ◽  
P D English ◽  
J Green
Keyword(s):  
Venous Thrombosis ◽  
Active Site ◽  
Fibrinolytic Activity ◽  
Rabbit Model ◽  
Fibrinolytic Agent ◽  
Essential Nature ◽  
Thrombolytic Agents

SummaryA derivative of human lys-plasmin in which the active site has been reversibly acylated (BRL 26920; p-anisoyl human lys-plasmin) has been examined as a fibrinolytic agent in a previously described rabbit model of venous thrombosis and shown to be significantly more active and less fibrinogenolytic than free plasmin. A p-anisoylated derivative of a streptokinase (SK)-activated plasmin preparation was significantly less fibrinogenolytic in vivo than the non-acylated enzyme. Acylation increased the fibrinolytic activity of preparations of SK-plasmin activator complexes. BRL 26921, the active site anisoylated derivative of the primary 2-chain SK-plasminogen complex was the most potent fibrinolytic agent studied. SK-Val442-plasminogen complexes, free or acylated, were biologically inactive in this model and confirm the essential nature of fibrin binding processes for effective thrombolysis in vivo.

scholarly journals Unraveling the molecular pathobiology of vocal fold systemic dehydration using an in vivo rabbit model

PLoS ONE ◽  
2020 ◽  
Vol 15 (7) ◽  
pp. e0236348
Author(s):  
Naila Cannes do Nascimento ◽  
Andrea P. dos Santos ◽  
M. Preeti Sivasankar ◽  
Abigail Cox
Keyword(s):  
Vocal Fold ◽  
Rabbit Model

scholarly journals Evaluation of a bone filler scaffold for local antibiotic delivery to prevent Staphylococcus aureus infection in a contaminated bone defect

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karen E. Beenken ◽  
Mara J. Campbell ◽  
Aura M. Ramirez ◽  
Karrar Alghazali ◽  
Christopher M. Walker ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bone Defect ◽  
Rabbit Model ◽  
In Vivo Studies ◽  
Bovine Bone ◽  
Bone Filler ◽  
Antibiotic Release ◽  
Local Antibiotic ◽  
Antibiotic Delivery

AbstractWe previously reported the development of an osteogenic bone filler scaffold consisting of degradable polyurethane, hydroxyapatite, and decellularized bovine bone particles. The current study was aimed at evaluating the use of this scaffold as a means of local antibiotic delivery to prevent infection in a bone defect contaminated with Staphylococcus aureus. We evaluated two scaffold formulations with the same component ratios but differing overall porosity and surface area. Studies with vancomycin, daptomycin, and gentamicin confirmed that antibiotic uptake was concentration dependent and that increased porosity correlated with increased uptake and prolonged antibiotic release. We also demonstrate that vancomycin can be passively loaded into either formulation in sufficient concentration to prevent infection in a rabbit model of a contaminated segmental bone defect. Moreover, even in those few cases in which complete eradication was not achieved, the number of viable bacteria in the bone was significantly reduced by treatment and there was no radiographic evidence of osteomyelitis. Radiographs and microcomputed tomography (µCT) analysis from the in vivo studies also suggested that the addition of vancomycin did not have any significant effect on the scaffold itself. These results demonstrate the potential utility of our bone regeneration scaffold for local antibiotic delivery to prevent infection in contaminated bone defects.

scholarly journals β-elemene alleviates airway stenosis via the ILK/Akt pathway modulated by MIR143HG sponging miR-1275

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Guoying Zhang ◽  
Cheng Xue ◽  
Yiming Zeng
Keyword(s):  
Cell Cycle ◽  
Cell Viability ◽  
Cell Model ◽  
Protective Efficacy ◽  
Rabbit Model ◽  
Akt Pathway ◽  
Loss Of Function ◽  
Airway Stenosis

Abstract Background We have previously found that β-elemene could inhibit the viability of airway granulation fibroblasts and prevent airway hyperplastic stenosis. This study aimed to elucidate the underlying mechanism and protective efficacy of β-elemene in vitro and in vivo. Methods Microarray and bioinformatic analysis were used to identify altered pathways related to cell viability in a β-elemene-treated primary cell model and to construct a β-elemene-altered ceRNA network modulating the target pathway. Loss of function and gain of function approaches were performed to examine the role of the ceRNA axis in β-elemene's regulation of the target pathway and cell viability. Additionally, in a β-elemene-treated rabbit model of airway stenosis, endoscopic and histological examinations were used to evaluate its therapeutic efficacy and further verify its mechanism of action. Results The hyperactive ILK/Akt pathway and dysregulated LncRNA-MIR143HG, which acted as a miR-1275 ceRNA to modulate ILK expression, were suppressed in β-elemene-treated airway granulation fibroblasts; β-elemene suppressed the ILK/Akt pathway via the MIR143HG/miR-1275/ILK axis. Additionally, the cell cycle and apoptotic phenotypes of granulation fibroblasts were altered, consistent with ILK/Akt pathway activity. In vivo application of β-elemene attenuated airway granulation hyperplasia and alleviated scar stricture, and histological detections suggested that β-elemene's effects on the MIR143HG/miR-1275/ILK axis and ILK/Akt pathway were in line with in vitro findings. Conclusions MIR143HG and ILK may act as ceRNA to sponge miR-1275. The MIR143HG/miR-1275/ILK axis mediates β-elemene-induced cell cycle arrest and apoptosis of airway granulation fibroblasts by modulating the ILK/Akt pathway, thereby inhibiting airway granulation proliferation and ultimately alleviating airway stenosis.

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