We used interconnected porous calcium hydroxyapatite ceramic to bridge a rabbit ulnar defect. Two weeks after inducing the defect we percutaneously injected rabbit bone marrow-derived mesenchymal stromal cells labelled with ferumoxide. The contribution of an external magnetic targeting system to attract these cells into the ceramic and their effect on subsequent bone formation were evaluated. This technique significantly facilitated the infiltration of ferumoxide-labelled cells into ceramic and significantly contributed to the enhancement of bone formation even in the chronic phase. As such, it is potentially of clinical use to treat fractures, bone defects, delayed union and nonunion.
Venous thromboembolism (VTE) is a major potential complication following orthopaedic surgery. Subcutaneously administered enoxaparin has been used as the benchmark to reduce the incidence of VTE. However, concerns have been raised regarding the long-term administration of enoxaparin and its possible negative effects on bone healing and bone density with an increase of the risk of osteoporotic fractures. New oral anticoagulants such as rivaroxaban have recently been introduced, however, there is a lack of information regarding how these drugs affect bone metabolism and post-operative bone healing. We measured the migration and proliferation capacity of mesenchymal stem cells (MSCs) under enoxaparin or rivaroxaban treatment for three consecutive weeks, and evaluated effects on MSC mRNA expression of markers for stress and osteogenic differentiation.Objectives
Methods
We have observed clinical cases where bone is formed in the overlaying muscle covering surgically created bone defects treated with a hydroxyapatite/calcium sulphate biomaterial. Our objective was to investigate the osteoinductive potential of the biomaterial and to determine if growth factors secreted from local bone cells induce osteoblastic differentiation of muscle cells. We seeded mouse skeletal muscle cells C2C12 on the hydroxyapatite/calcium sulphate biomaterial and the phenotype of the cells was analysed. To mimic surgical conditions with leakage of extra cellular matrix (ECM) proteins and growth factors, we cultured rat bone cells ROS 17/2.8 in a bioreactor and harvested the secreted proteins. The secretome was added to rat muscle cells L6. The phenotype of the muscle cells after treatment with the media was assessed using immunostaining and light microscopy.Objectives
Materials and Methods
The aim of this study was to investigate the role of miR-126 in the development of osteoarthritis, as well as the potential molecular mechanisms involved, in order to provide a theoretical basis for osteoarthritis treatment and a novel perspective for clinical therapy. Human chondrocyte cell line CHON-001 was administrated by different doses of interleukin (IL)-1β to simulate inflammation. Cell viability, migration, apoptosis, IL-6, IL-8, and tumour necrosis factor (TNF)-α expression, as well as expression of apoptosis-related factors, were measured to assess inflammation. miR-126 expression was measured by quantitative polymerase chain reaction (qPCR). Cells were then transfected with miR-126 inhibitor to assess the effect of miR-126 on IL-1β-injured CHON-001 cells. Expression of B-cell lymphoma 2 (Bcl-2) and the activity of mitogen-activated protein kinase (MAPK) / Jun N-terminal kinase (JNK) signaling pathway were measured by Western blot to explore the underlying mechanism through which miR-126 affects IL-1β-induced inflammation.Objectives
Methods
For the treatment of ununited fractures, we developed
a system of delivering magnetic labelled mesenchymal stromal cells
(MSCs) using an extracorporeal magnetic device. In this study, we
transplanted ferucarbotran-labelled and luciferase-positive bone
marrow-derived MSCs into a non-healing femoral fracture rat model
in the presence of a magnetic field. The biological fate of the
transplanted MSCs was observed using luciferase-based bioluminescence
imaging and we found that the number of MSC derived photons increased
from day one to day three and thereafter decreased over time. The
magnetic cell delivery system induced the accumulation of photons at
the fracture site, while also retaining higher photon intensity
from day three to week four. Furthermore, radiological and histological
findings suggested improved callus formation and endochondral ossification.
We therefore believe that this delivery system may be a promising
option for bone regeneration.
To study the effect of hyaluronic acid (HA) on local anaesthetic
chondrotoxicity Chondrocytes were harvested from bovine femoral condyle cartilage
and isolated using collagenase-containing media. At 24 hours after
seeding 15 000 cells per well onto a 96-well plate, chondrocytes
were treated with media (DMEM/F12 + ITS), PBS, 1:1 lidocaine (2%):PBS,
1:1 bupivacaine (0.5%):PBS, 1:1 lidocaine (2%):HA, 1:1 bupivacaine (0.
5%):HA, or 1:1 HA:PBS for one hour. Following treatment, groups
had conditions removed and 24-hour incubation. Cell viability was
assessed using PrestoBlue and confirmed visually using fluorescence
microscopy.Objective
Methods
Regenerative medicine is an emerging field aimed at the repair and regeneration of various tissues. To this end, cytokines (CKs), growth factors (GFs), and stem/progenitor cells have been applied in this field. However, obtaining and preparing these candidates requires invasive, costly, and time-consuming procedures. We hypothesised that skeletal muscle could be a favorable candidate tissue for the concept of a point-of-care approach. The purpose of this study was to characterize and confirm the biological potential of skeletal muscle supernatant for use in regenerative medicine. Semitendinosus muscle was used after harvesting tendon from patients who underwent anterior cruciate ligament reconstructions. A total of 500 milligrams of stripped muscle was minced and mixed with 1 mL of saline. The collected supernatant was analysed by enzyme-linked immunosorbent assay (ELISA) and flow cytometry. The biological effects of the supernatant on cell proliferation, osteogenesis, and angiogenesis in vitro were evaluated using human mesenchymal stem cells (hMSCs) and human umbilical cord vein endothelial cells (HUVECs).Objectives
Methods
Infection of implants is a major problem in elective and trauma surgery. Heating is an effective way to reduce the bacterial load in food preparation, and studies on hyperthermia treatment for cancer have shown that it is possible to heat metal objects with pulsed electromagnetic fields selectively (PEMF), also known as induction heating. We therefore set out to answer the following research question: is non-contact induction heating of metallic implants effective in reducing bacterial load Titanium alloy cylinders (Ti6Al4V) were exposed to PEMF from an induction heater with maximum 2000 watts at 27 kHz after being contaminated with five different types of micro-organisms: Objectives
Methods
Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis.Objectives
Methods
Adipose-derived mesenchymal stem cells (ADMSCs) are a promising strategy for orthopaedic applications, particularly in bone repair. Human ADMSCs were cultured in medium supplemented with HPL, Hplasma and a combination of HPL and Hplasma (HPL+Hplasma). Characteristics of these ADMSCs, including osteogenesis, were evaluated in comparison with those cultured in fetal bovine serum (FBS).Objectives
Methods
To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone. Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed Objectives
Methods
Mesenchymal stem cells have the ability to differentiate into various cell types, and thus have emerged as promising alternatives to chondrocytes in cell-based cartilage repair methods. The aim of this experimental study was to investigate the effect of bone marrow derived mesenchymal stem cells combined with platelet rich fibrin on osteochondral defect repair and articular cartilage regeneration in a canine model. Osteochondral defects were created on the medial femoral condyles of 12 adult male mixed breed dogs. They were either treated with stem cells seeded on platelet rich fibrin or left empty. Macroscopic and histological evaluation of the repair tissue was conducted after four, 16 and 24 weeks using the International Cartilage Repair Society macroscopic and the O’Driscoll histological grading systems. Results were reported as mean and standard deviation (Objectives
Methods
The objective of this study was to determine if combining variations in mixing technique of antibiotic-impregnated polymethylmethacrylate (PMMA) cement with low frequency ultrasound (LFUS) improves antibiotic elution during the initial high phase (Phase I) and subsequent low phase (Phase II) while not diminishing mechanical strength. Three batches of vancomycin-loaded PMMA were prepared with different mixing techniques: a standard technique; a delayed technique; and a control without antibiotic. Daily elution samples were analysed using flow injection analysis (FIA). Beginning in Phase II, samples from each mix group were selected randomly to undergo either five, 15, 45, or 0 minutes of LFUS treatment. Elution amounts between LFUS treatments were analysed. Following Phase II, compression testing was done to quantify strength. Objectives
Methods
Curettage and packing with polymethylmethacrylate cement is a routine treatment for giant-cell tumour (GCT) of bone. We performed an We found that the cytotoxic effect of eluted drugs depended on their concentration and the time interval, with even the lowest dose of each drug demonstrating an acceptable rate of cytotoxicity. Even in low doses, cytotoxic drugs mixed with polymethylmethacrylate cement could therefore be considered as effective local adjuvant treatment for GCTs.
The objective of this study is to determine an optimal antibiotic-loaded
bone cement (ALBC) for infection prophylaxis in total joint arthroplasty
(TJA). We evaluated the antibacterial effects of polymethylmethacrylate
(PMMA) bone cements loaded with vancomycin, teicoplanin, ceftazidime,
imipenem, piperacillin, gentamicin, and tobramycin against methicillin-sensitive Objectives
Methods
Resveratrol is a polyphenolic compound commonly found in the
skins of red grapes. Sirtuin 1 (SIRT1) is a human gene that is activated
by resveratrol and has been shown to promote longevity and boost
mitochondrial metabolism. We examined the effect of resveratrol
on normal and osteoarthritic (OA) human chondrocytes. Normal and OA chondrocytes were incubated with various concentrations
of resveratrol (1 µM, 10 µM, 25 µM and 50 µM) and cultured for 24,
48 or 72 hours or for six weeks. Cell proliferation, gene expression,
and senescence were evaluated.Background
Methods
When transferring tissue regenerative strategies
involving skeletal stem cells to human application, consideration needs
to be given to factors that may affect the function of the cells
that are transferred. Local anaesthetics are frequently used during
surgical procedures, either administered directly into the operative
site or infiltrated subcutaneously around the wound. The aim of
this study was to investigate the effects of commonly used local anaesthetics
on the morphology, function and survival of human adult skeletal
stem cells. Cells from three patients who were undergoing elective hip replacement
were harvested and incubated for two hours with 1% lidocaine, 0.5%
levobupivacaine or 0.5% bupivacaine hydrochloride solutions. Viability
was quantified using WST-1 and DNA assays. Viability and morphology
were further characterised using CellTracker Green/Ethidium Homodimer-1
immunocytochemistry and function was assessed by an alkaline phosphatase
assay. An additional group was cultured for a further seven days
to allow potential recovery of the cells after removal of the local
anaesthetic. A statistically significant and dose dependent reduction in cell
viability and number was observed in the cell cultures exposed to
all three local anaesthetics at concentrations of 25% and 50%, and
this was maintained even following culture for a further seven days. This study indicates that certain local anaesthetic agents in
widespread clinical use are deleterious to skeletal progenitor cells
when studied
Recent studies have shown that modulating inflammation-related
lipid signalling after a bone fracture can accelerate healing in
animal models. Specifically, decreasing 5-lipoxygenase (5-LO) activity
during fracture healing increases cyclooxygenase-2 (COX-2) expression
in the fracture callus, accelerates chondrogenesis and decreases
healing time. In this study, we test the hypothesis that 5-LO inhibition
will increase direct osteogenesis. Bilateral, unicortical femoral defects were used in rats to measure
the effects of local 5-LO inhibition on direct osteogenesis. The
defect sites were filled with a polycaprolactone (PCL) scaffold
containing 5-LO inhibitor (A-79175) at three dose levels, scaffold
with drug carrier, or scaffold only. Drug release was assessed Objectives
Methods
The nervous system is known to be involved in inflammation and repair. We aimed to determine the effect of physical activity on the healing of a muscle injury and to examine the pattern of innervation. Using a drop-ball technique, a contusion was produced in the gastrocnemius in 20 rats. In ten the limb was immobilised in a plaster cast and the remaining ten had mobilisation on a running wheel. The muscle and the corresponding dorsal-root ganglia were studied by histological and immunohistochemical methods. In the mobilisation group, there was a significant reduction in lymphocytes (p = 0.016), macrophages (p = 0.008) and myotubules (p = 0.008) between three and 21 days. The formation of myotubules and the density of nerve fibres was significantly higher (both p = 0.016) compared with those in the immobilisation group at three days, while the density of CGRP-positive fibres was significantly lower (p = 0.016) after 21 days. Mobilisation after contusional injury to the muscle resulted in early and increased formation of myotubules, early nerve regeneration and progressive reduction in inflammation, suggesting that it promoted a better healing response.
The aim of this study was to investigate the occurrence of tissue hypoxia and apoptosis at different stages of tendinopathy and tears of the rotator cuff. We studied tissue from 24 patients with eight graded stages of either impingement (mild, moderate and severe) or tears of the rotator cuff (partial, small, medium, large and massive) and three controls. Biopsies were analysed using three immunohistochemical techniques, namely antibodies against HIF-1α (a transcription factor produced in a hypoxic environment), BNip3 (a HIF-1α regulated pro-apoptotic protein) and TUNEL (detecting DNA fragmentation in apoptosis). The HIF-1α expression was greatest in mild impingement and in partial, small, medium and large tears. BNip3 expression increased significantly in partial, small, medium and large tears but was reduced in massive tears. Apoptosis was increased in small, medium, large and massive tears but not in partial tears. These findings reveal evidence of hypoxic damage throughout the spectrum of pathology of the rotator cuff which may contribute to loss of cells by apoptosis. This provides a novel insight into the causes of degeneration of the rotator cuff and highlights possible options for treatment.
