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Aims. The efficacy of saline irrigation for treatment of implant-associated infections is limited in the presence of porous metallic implants. This study evaluated the therapeutic efficacy of antibiotic doped bioceramic (vancomycin/tobramycin-doped polyvinyl alcohol composite (PVA-VAN/TOB-P)) after saline wash in a mouse infection model implanted with titanium cylinders. Methods. Air pouches created in female BalBc mice by subcutaneous injection of air. In the first of two independent studies, pouches were implanted with titanium cylinders (400, 700, and 100 µm pore sizes) and inoculated with Staphylococcus aureus (1 × 10. 3. or 1 × 10. 6. colony-forming units (CFU)/pouch) to establish infection and biofilm formation. Mice were killed after one week for microbiological analysis. In the second study, pouches were implanted with 400 µm titanium cylinders and inoculated with S. aureus (1 × 10. 3. or 1 × 10. 6. CFU/pouch). Four groups were tested: 1) no bacteria; 2) bacteria without saline wash; 3) saline wash only; and 4) saline wash plus PVA-VAN/TOB-P. After seven days, the pouches were opened and washed with saline alone, or had an additional injection of PVA-VAN/TOB-P. Mice were killed 14 days after pouch wash. Results. The first part of the study showed that low-grade infection was more significant in 400 µm cylinders than cylinders with larger pore sizes (p < 0.05). The second part of the study showed that saline wash alone was ineffective in eradicating both low- and high-grade infections. Saline plus PVA-VAN/TOB-P eradicated the titanium cylinder-associated infections, as manifested by negative cultures of the washouts and supported by scanning electron microscopy and histology. Conclusion. Porous titanium cylinders were vulnerable to bacterial infection and biofilm formation that could not be treated by saline irrigation alone. Application of PVA-VAN/TOB-P directly into the surgical site alone or after saline wash represents a feasible approach for prevention and/or treatment of porous implant-related infections. Cite this article: Bone Joint Res 2024;13(11):622–631


Bone & Joint Research
Vol. 12, Issue 12 | Pages 722 - 733
6 Dec 2023
Fu T Chen W Wang Y Chang C Lin T Wong C

Aims

Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration.

Methods

A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials – acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC – were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses.


Bone & Joint Research
Vol. 11, Issue 6 | Pages 349 - 361
9 Jun 2022
Jun Z Yuping W Yanran H Ziming L Yuwan L Xizhong Z Zhilin W Xiaoji L

Aims

The purpose of this study was to explore a simple and effective method of preparing human acellular amniotic membrane (HAAM) scaffolds, and explore the effect of HAAM scaffolds with juvenile cartilage fragments (JCFs) on osteochondral defects.

Methods

HAAM scaffolds were constructed via trypsinization from fresh human amniotic membrane (HAM). The characteristics of the HAAM scaffolds were evaluated by haematoxylin and eosin (H&E) staining, picrosirius red staining, type II collagen immunostaining, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Human amniotic mesenchymal stem cells (hAMSCs) were isolated, and stemness was verified by multilineage differentiation. Then, third-generation (P3) hAMSCs were seeded on the HAAM scaffolds, and phalloidin staining and SEM were used to detect the growth of hAMSCs on the HAAM scaffolds. Osteochondral defects (diameter: 3.5 mm; depth: 3 mm) were created in the right patellar grooves of 20 New Zealand White rabbits. The rabbits were randomly divided into four groups: the control group (n = 5), the HAAM scaffolds group (n = 5), the JCFs group (n = 5), and the HAAM + JCFs group (n = 5). Macroscopic and histological assessments of the regenerated tissue were evaluated to validate the treatment results at 12 weeks.


Bone & Joint Research
Vol. 10, Issue 7 | Pages 411 - 424
14 Jul 2021
Zhao D Ren B Wang H Zhang X Yu M Cheng L Sang Y Cao S Thieringer FM Zhang D Wan Y Liu C

Aims

The use of 3D-printed titanium implant (DT) can effectively guide bone regeneration. DT triggers a continuous host immune reaction, including macrophage type 1 polarization, that resists osseointegration. Interleukin 4 (IL4) is a specific cytokine modulating osteogenic capability that switches macrophage polarization type 1 to type 2, and this switch favours bone regeneration.

Methods

IL4 at concentrations of 0, 30, and 100 ng/ml was used at day 3 to create a biomimetic environment for bone marrow mesenchymal stromal cell (BMMSC) osteogenesis and macrophage polarization on the DT. The osteogenic and immune responses of BMMSCs and macrophages were evaluated respectively.


Bone & Joint Research
Vol. 9, Issue 9 | Pages 601 - 612
1 Sep 2020
Rajagopal K Ramesh S Walter NM Arora A Katti DS Madhuri V

Aims

Extracellular matrix (ECM) and its architecture have a vital role in articular cartilage (AC) structure and function. We hypothesized that a multi-layered chitosan-gelatin (CG) scaffold that resembles ECM, as well as native collagen architecture of AC, will achieve superior chondrogenesis and AC regeneration. We also compared its in vitro and in vivo outcomes with randomly aligned CG scaffold.

Methods

Rabbit bone marrow mesenchymal stem cells (MSCs) were differentiated into the chondrogenic lineage on scaffolds. Quality of in vitro regenerated cartilage was assessed by cell viability, growth, matrix synthesis, and differentiation. Bilateral osteochondral defects were created in 15 four-month-old male New Zealand white rabbits and segregated into three treatment groups with five in each. The groups were: 1) untreated and allogeneic chondrocytes; 2) multi-layered scaffold with and without cells; and 3) randomly aligned scaffold with and without cells. After four months of follow-up, the outcome was assessed using histology and immunostaining.


Bone & Joint Research
Vol. 7, Issue 5 | Pages 357 - 361
1 May 2018
Shin T Lim D Kim YS Kim SC Jo WL Lim YW

Objectives

Laser-engineered net shaping (LENS) of coated surfaces can overcome the limitations of conventional coating technologies. We compared the in vitro biological response with a titanium plasma spray (TPS)-coated titanium alloy (Ti6Al4V) surface with that of a Ti6Al4V surface coated with titanium using direct metal fabrication (DMF) with 3D printing technologies.

Methods

The in vitro ability of human osteoblasts to adhere to TPS-coated Ti6Al4V was compared with DMF-coating. Scanning electron microscopy (SEM) was used to assess the structure and morphology of the surfaces. Biological and morphological responses to human osteoblast cell lines were then examined by measuring cell proliferation, alkaline phosphatase activity, actin filaments, and RUNX2 gene expression.