Aims. This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with
Direct metal printed (DMP) porous
Although multifunctional delivery systems can potentially improve safety and efficacy of therapeutic protein delivery in the biological treatment of injured tissues, ability to track and manipulate protein delivery systems in vivo to ensure localization at the treatment site is still a concern. We hypothesized that incorporating superparamagnetic
Haemophilic arthropathy is characterised by
Recent researches indicate that both M1 and M2 macrophages play vital roles in tissue repair and foreign body reaction processes. In this study, we investigated the dynamics of M1 macrophages in the induced membrane using a mouse femur critical-sized bone defect model. The Masquelet method (M) and control (C) groups were established using C57BL/6J male mice (n=24). A 3mm-bone defect was created in the right femoral diaphysis followed by a Kirschner wire fixation, and a cement spacer was inserted into the defect in group M. In group C, the bone defect was left uninserted. Tissues around the defect were harvested at 1, 2, 4, and 6 weeks after surgery (n=3 in each group at each time point). Following Hematoxylin and eosin (HE) staining, immunohistochemical staining (IHC) was used to evaluate the CD68 expression as a marker of M1 macrophage.
Tendons display poor intrinsic healing properties and are difficult to treat[1]. Prior in vitro studies[2] have shown that, by targeting the Activin A receptor with magnetic nanoparticles (MNPs), it is possible to remotely induce the tenogenic differentiation of human adipose stem cells (hASCs). In this study, we investigated the tenogenic regenerative potential of remotely-activated MNPs-labelled hASCs in an in vivo rat model. We consider the potential for magnetic controlled nanoparticle mediated tendon repair strategies. hASCs were labelled with 250 nm MNPs functionalized with anti-Activin Receptor IIA antibody. Using a rapid curing fibrin gel as delivery method, the MNPs-labelled cells were delivered into a Ø2 mm rat patellar tendon defect. The receptor was then remotely stimulated by exposing the rats to a variable magnetic gradient (1.28T), using a customised magnetic box. The stimulation was performed 1 hour/day, 3 days/week up to 8 weeks. Tenogenesis,
Skeletal muscle tissue engineering has made progress towards production of functional tissues in line with the development in materials science and fabrication techniques. In particular, combining the specificity of 3D printing with smart materials has introduced a new concept called the 4D printing. Inspired by the unique properties of smart/responsive materials, we designed a bioink made of gelatin, a polymer with well-known cell compatibility, to be 3D printed on a magnetically responsive substrate. Gelatin was made photocrosslinkable by the methacrylate reaction (GELMA), and its viscosity was finetuned by blending with alginate which was later removed by alginate lyase treatment, so that the printability of the bioink as well as the cell viability can be finetuned. C2C12 mouse myoblasts-laden bioink was then 3D printed on a magnetic substrate for 4D shape-shifting. The magnetic substrate was produced using silicon rubber (EcoFlex) and carbonyl
Dual mobility (DM) total hip replacements (THRs) were introduced to reduce dislocation risk, which is the most common cause of early revision. Although DM THRs have shown good overall survivorship and low dislocation rates, the mechanisms which describe how these bearings function in-vivo are not fully understood. Therefore, the study aim was to comprehensively assess retrieved DM polyethylene liners for signs of damage using visual inspection and semi-quantitative geometric assessment methods. Retrieved DM liners (n=18) were visually inspected for the presence of surface damage, whereby the internal and external surfaces were independently assigned a score of one (present) or zero (not present) for seven damage modes. The severity of damage was not assessed. The material composition of embedded debris was characterised using energy-dispersive x-ray analysis (EDX). Additionally, each liner was geometrically assessed for signs of wear/deformation [1]. Scratching and pitting were the most common damage modes on either surface. Additionally, burnishing was observed on 50% of the internal surfaces and embedded debris was identified on 67% of the external surfaces. EDX analysis of the debris identified several materials including titanium, cobalt-chrome,
Introduction. Homogenous and consistent preparations of mesenchymal stem cells (MSCs) can be acquired by selecting them for integrin α10β1 (integrin a10-MSCs). Safety and efficacy of intra-articular injection of allogeneic integrin a10-MSCs were shown in two post-traumatic osteoarthritis horse studies. The current study investigated immunomodulatory capacities of human integrin a10-MSCs in vitro and their cell fait after intra-articular injection in rabbits. Method. The concentration of produced immunomodulatory factors was measured after licensing integrin a10-MSCs with pro-inflammatory cytokines. Suppression of T-cell proliferation was determined in co-cultures with carboxyfluorescein N-succinimidyl ester (CFSE) labelled human peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3/CD28 and measuring the CFSE intensity of CD4+ cells. Macrophage polarization was assessed in co-cultures with differentiated THP-1 cells stimulated with lipopolysaccharide and analysing the M2 macrophage cell surface markers CD163 and CD206. In vivo homing and regeneration were investigated by injecting superparamagnetic
Bioabsorbable metals hold a lot of potential as orthopaedic implant materials. Three metal families are currently being investigated:
Introduction. PIEZO mechanoreceptors are increasingly recognized to play critical roles in fundamental physiological processes like proprioception, touch, or tendon biomechanics. However, their gating mechanisms and downstream signaling are still not completely understood, mainly due to the lack of effective tools to probe these processes. Here, we developed new tailor-made nanoswitches enabling wireless targeted actuation on PIEZO1 by combining molecular imprinting concepts with magnetic systems. Method. Two epitopes from functionally relevant domains of PIEZO1 were rationally selected in silico and used as templates for synthesizing molecularly imprinted nanoparticles (MINPs). Highly-responsive superparamagnetic zinc-doped
Tissue engineering and regenerative medicine (TERM) hold the promise to provide therapies for injured tendons despite the challenging cues of tendon niche and the lack of specific factors to guide regeneration. The emerging potential of magnetic responsiveness and magnetic nanoparticles (MNPs) functionalities offers new perspectives to tackle TERM challenges. Moreover, pulsed electromagnetic field (PEMF) is FDA approved for orthopaedics with potential to control inflammation upon injury. We previously demonstrated that magnetic cell-sheets assisted by PEMF trigger the inflammation resolution by modulating cytokine-enriched environments [1]. To further understand the potential of magnetically assisted living patches, we have recently conducted in vivo studies using a rat patellar defect model. After labeling of human adipose stem cells with
Tendon diseases are prevalent health concerns for which current therapies present limited success, in part due to the intrinsically low regenerative ability of tendons. Therefore, tissue engineering presents a potential to improve this outcome. Here, we hypothesize that a concurrent control over both biophysical and biochemical stimuli will boost the tenogenic commitment of stem cells, thus promoting regeneration. To achieve this, we combine molecularly imprinted nanoparticles (MINPs), which act as artificial amplifiers for endogenous growth factor (GF) activity, with bioinspired anisotropic hydrogels. 2. to manufacture 3D tenogenic constructs. MINPs were solid phase-imprinted using a TGF-β3 epitope as template and their affinity for the target was assessed by SPR and dot blot. Magnetically-responsive microfibers were produced by cryosectioning electrospun meshes containing
Over the last decades, biodegradable metals emerged as promising materials for various biomedical implant applications, aiming to reduce the use of permanent metallic implants and, therefore, to avoid additional surgeries for implant removal. However, among the important issue to be solved is their fast corrosion - too high to match the healing rate of the bone tissue. The most effective way to improve this characteristic is to coat biodegradable metals with substituted calcium phosphates. Tricalcium phosphate (β-TCP) is a resorbable bioceramic widely used as synthetic bone graft. In order to modulate and enhance its biological performance, the substitution of Ca2+ by various metal ions, such as strontium (Sr2+), magnesium (Mg2+),
As compared to magnesium (Mg) and
In order to evaluate the feasibility of zinc alloys as future biodegradable bone implant materials, the mechanical properties, corrosion resistance, hemocompatibility, cell activity, proliferation and adhesion, in vivo animal implantation experiments have been employed. The experimental results show that the alloying element magnesium, calcium and strontium can significantly improve the mechanical properties of pure zinc, and further deformation processes can further improve the mechanical properties of zinc alloys. Alloying elements can effectively control the corrosion rates of zinc alloys, which are between the rates of magnesium alloys and
This edition of Cochrane Corner looks at some of the work published by the Cochrane Collaboration, covering pharmacological interventions for the prevention of bleeding in people undergoing definitive fixation or joint replacement for hip, pelvic, and long bone fractures; interventions for reducing red blood cell transfusion in adults undergoing hip fracture surgery: an overview of systematic reviews; and pharmacological treatments for low back pain in adults: an overview of Cochrane Reviews
Intra-synovial tendon injuries affect compressed tendon within a synovial environment (eg Rotator cuff tears of the shoulder) and frequently demonstrate ‘failed healing'. Current therapeutic methods for tendon tears (intra-synovial corticosteroid medication and surgical debridement) offer poor outcomes and new strategies for enhancing repair are needed. We have therefore evaluated two different approaches involving the use of mesenchymal stem cells and scaffolds. Bone marrow- and synovial-derived stem cells were capable of adhering to cut surfaces of tendon in vitro and modulating the release of extracellular matrix into the media. However, when administered in vivo into the digital flexor tendon sheath in naturally-occurring deep digital flexor tendon tears in horses and in an experimental model in sheep, neither cell type was capable of healing the tendon defect. Superparamagnetic
Hematopoietic stem cells (HSCs) reside within a specialised niche area in the bone marrow (BM). They have tremendous clinical relevance, although HSC expansion and culture ex vivo is not currently possible, reducing BM transplant success. This project expands a novel 3D MSC niche model developed in our lab to include HSCs. MSCs were loaded with green fluorescent magnetic
The aim of the work is to develop innovative antibacterial surface modification treatments for titanium capable to limit the bacterial adhesion and proliferation as weel as the biofilm formation while maintaining an high osteointegrative potential. The goal is to contrast the infections which represent a serius complication related to the use of implantable devices. Introduction. Titanium and titanium alloy are considered the golden standard materials for the applications in contact with bone especially for dental and orthopaedic applications. To extend the implantable component lifetime and increase their clinical performance some surface modifications are required, to promote and speed up the osteointegration process increasing the rate of bone bonding. Unfortunately, among the different complications related to the use of titanium implantable devices the infections represent the most serious, often leading to implant failure and revision. The use of surface modification with specific metal ions represents a promising approach to fight implant-related infections. In particular gallium has recently shown efficacy in the treatment of infections: exploiting the chemical similarity of Ga. 3+. with Fe. 3+. , it can interfere in the