Preliminary in vivo investigation of the mesenchymal stromal cell secretome as a novel treatment for methicillin-resistant Staphylococcus aureus in equine skin wounds.

Objective: We aimed to study the antimicrobial and pro-healing potential of equine mesenchymal stromal cell secreted products (i.e. secretome), collected as conditioned media (mesenchymal stromal cell-conditioned media, MSC CM), in a novel in vivo model of methicillin-resistant Staphylococcus aureus (MRSA)-inoculated equine thorax wounds.

Degradation of lubricating molecules in synovial fluid alters chondrocyte sensitivity to shear strain.

Articular joints facilitate motion and transfer loads to underlying bone through a combination of cartilage tissue and synovial fluid, which together generate a low-friction contact surface. Traumatic injury delivered to cartilage and the surrounding joint capsule causes secretion of proinflammatory cytokines by chondrocytes and the synovium, triggering cartilage matrix breakdown and impairing the ability of synovial fluid to lubricate the joint. Once these inflammatory processes become chronic, posttraumatic osteoarthritis (PTOA) development begins.

Application of a variational autoencoder for clustering and analyzing in situ articular cartilage cellular response to mechanical stimuli.

In various biological systems, analyzing how cell behaviors are coordinated over time would enable a deeper understanding of tissue-scale response to physiologic or superphysiologic stimuli. Such data is necessary for establishing both normal tissue function and the sequence of events after injury that lead to chronic disease. However, collecting and analyzing these large datasets presents a challenge-such systems are time-consuming to process, and the overwhelming scale of data makes it difficult to parse overall behaviors.

Connexin 43 Regulates Intercellular Mitochondrial Transfer from Human Mesenchymal Stromal Cells to Chondrocytes.

Background: The phenomenon of intercellular mitochondrial transfer from mesenchymal stromal cells (MSCs) has shown promise for improving tissue healing after injury and has potential for treating degenerative diseases like osteoarthritis (OA). Recently MSC to chondrocyte mitochondrial transfer has been documented, but the mechanism of transfer is unknown. Full-length connexin43 (Cx43, encoded by ) and the truncated internally translated isoform GJA1-20k have been implicated in mitochondrial transfer between highly oxidative cells, but have not been explored in orthopaedic tissues.

Synthesis of Chitosan-Silver Nanocomposite and Its Evaluation as an Antibacterial Coating for Mobile Phone Glass Protectors.

An easy and environment-friendly route for antibacterial coating suited for mobile phone glass protectors was successfully demonstrated. In this route, freshly prepared chitosan solution in 1% v/v acetic acid was added with 0.1 M silver nitrate solution and 0.

Synovial fluid mitochondrial DNA concentration reflects the degree of cartilage damage after naturally occurring articular injury.

Objective: To evaluate mitochondrial DNA (mtDNA) release from injured chondrocytes and investigate the utility of synovial fluid mtDNA concentration in early detection of posttraumatic osteoarthritis.

Method: We measured mtDNA release using four models of osteoarthritis: in vitro interleukin-1β stimulation of cultured equine chondrocytes, ex vivo mechanical impact of bovine cartilage explants, in vivo mechanical impact of equine articular cartilage, and naturally occurring equine intraarticular fracture. In our in vivo model, one group was treated with an intraarticular injection of the mitoprotective peptide SS-31 following cartilage injury.

Mesenchymal stromal cells donate mitochondria to articular chondrocytes exposed to mitochondrial, environmental, and mechanical stress.

Articular cartilage has limited healing capacity and no drugs are available that can prevent or slow the development of osteoarthritis (OA) after joint injury. Mesenchymal stromal cell (MSC)-based regenerative therapies for OA are increasingly common, but questions regarding their mechanisms of action remain. Our group recently reported that although cartilage is avascular and relatively metabolically quiescent, injury induces chondrocyte mitochondrial dysfunction, driving cartilage degradation and OA.

STRAINS: A big data method for classifying cellular response to stimuli at the tissue scale.

Cellular response to stimulation governs tissue scale processes ranging from growth and development to maintaining tissue health and initiating disease. To determine how cells coordinate their response to such stimuli, it is necessary to simultaneously track and measure the spatiotemporal distribution of their behaviors throughout the tissue. Here, we report on a novel SpatioTemporal Response Analysis IN Situ (STRAINS) tool that uses fluorescent micrographs, cell tracking, and machine learning to measure such behavioral distributions.

Human mesenchymal stromal cells release functional mitochondria in extracellular vesicles.

Cartilage and other skeletal soft tissues heal poorly after injury, in part due to their lack of vascularity and low metabolic rate. No pharmacologic approaches have proven effective in preventing chronic degenerative disease after joint injury. Mesenchymal stromal cells (MSCs) have been investigated for their ability to treat pain associated with osteoarthritis (OA) and preserve articular cartilage.

Surgery of the Equine Urinary Tract.

Urinary surgery in the horse may be challenging. More straightforward procedures, such as urinary bladder or urachal defects, do not usually require specialized equipment or imaging, although laboratory work is helpful. Congenital or acquired conditions of the ureters or kidneys may necessitate advanced diagnostic work-ups including advanced imaging /or and minimally invasive procedures.

Amnion and Umbilical Cord-Derived Products in Sports Medicine: From Basic Science to Clinical Application.

Background: Birth tissue products from amnion, chorion, umbilical cord, amniotic fluid, or cord blood are frequently marketed as viable sources of stem cells and growth factors. It can be difficult for health care professionals to differentiate implied from explicit conclusions in reported product analyses.

Purpose: To provide an educational platform for health care professionals to interpret data presented in the promotion of birth tissue products.

Proteomic Analysis and Cell Viability of Nine Amnion, Chorion, Umbilical Cord, and Amniotic Fluid-Derived Products.

Objective: Amnion products are used in various musculoskeletal surgeries and as injections for joint pain with conflicting reports of cell viability and protein contents. The objective of this study was to determine the full proteome and examine cell viability in 9 commercial amnion products using an unbiased bottom-up shotgun proteomics approach and confocal microscopy.

Design: Products were subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis and searched against a UniProt database.

Cartilage articulation exacerbates chondrocyte damage and death after impact injury.

Posttraumatic osteoarthritis (PTOA) is typically initiated by momentary supraphysiologic shear and compressive forces delivered to articular cartilage during acute joint injury and develops through subsequent degradation of cartilage matrix components and tissue remodeling. PTOA affects 12% of the population who experience osteoarthritis and is attributed to over $3 billion dollars annually in healthcare costs. It is currently unknown whether articulation of the joint post-injury helps tissue healing or exacerbates cellular dysfunction and eventual death.

Integrin α10β1-Selected Mesenchymal Stem Cells Mitigate the Progression of Osteoarthritis in an Equine Talar Impact Model.

Background: Early intervention with mesenchymal stem cells (MSCs) after articular trauma has the potential to limit progression of focal lesions and prevent ongoing cartilage degeneration by modulating the joint environment and/or contributing to repair. Integrin α10β1 is the main collagen type II binding receptor on chondrocytes, and MSCs that are selected for high expression of the α10 subunit have improved chondrogenic potential. The ability of α10β1-selected (integrin α10) MSCs to protect cartilage after injury has not been investigated.

Biological Mechanisms for Cartilage Repair Using a BioCartilage Scaffold: Cellular Adhesion/Migration and Bioactive Proteins.

. BioCartilage is a desiccated, particulated cartilage allograft used for repair of focal cartilage defects. It is mixed with a biologic such as bone marrow concentrate (BMC), pressed into a contained defect, and sealed with fibrin glue.

Synovial fluid lubricin and hyaluronan are altered in equine osteochondral fragmentation, cartilage impact injury, and full-thickness cartilage defect models.

The objectives of this study were to evaluate temporal changes in lubricin, hyaluronan (HA), and HA molecular weight (MW) distributions in three distinct models of equine joint injury affecting the carpal (wrist), tarsal (ankle), and femoropatellar (knee) joints. To establish ranges for lubricin, HA, and HA MW distributions across multiple joints, we first evaluated clinically healthy, high-motion equine joints. Synovial fluid was collected from high-motion joints in horses without clinical signs of joint disease (n = 11 horses, 102 joints) and from research horses undergoing carpal osteochondral fragmentation (n = 8), talar cartilage impact injury (n = 7), and femoral trochlear ridge full-thickness cartilage injury (n = 22) prior to and following arthroscopically induced joint injury.

Mitoprotective therapy prevents rapid, strain-dependent mitochondrial dysfunction after articular cartilage injury.

Posttraumatic osteoarthritis (PTOA) involves the mechanical and biological deterioration of articular cartilage that occurs following joint injury. PTOA is a growing problem in health care due to the lack of effective therapies combined with an aging population with high activity levels. Recently, acute mitochondrial dysfunction and altered cellular respiration have been associated with cartilage degeneration after injury.

Intra-articular anaesthesia of the equine stifle improves foot lameness.

Background: Equine diagnostic anaesthesia can be a useful tool in challenging lameness examinations. However, anaesthetics diffuse over time leading to nonspecific desensitisation of periarticular structures. Nerves that convey sensation from the distal limb to the central nervous system pass in close proximity to the caudal stifle joint capsule.

Microscale frictional strains determine chondrocyte fate in loaded cartilage.

Mounting evidence suggests that altered lubricant levels within synovial fluid have acute biological consequences on chondrocyte homeostasis. While these responses have been connected to increased friction, the mechanisms behind this response remain unknown. Here, we combine a frictional bioreactor with confocal elastography and image-based cellular assays to establish the link between cartilage friction, microscale shear strain, and acute, adverse cellular responses.

Mitoprotective therapy preserves chondrocyte viability and prevents cartilage degeneration in an ex vivo model of posttraumatic osteoarthritis.

Unlabelled: No disease-modifying osteoarthritis (OA) drugs are available to prevent posttraumatic osteoarthritis (PTOA). Mitochondria (MT) mediate the pathogenesis of many degenerative diseases, and recent evidence indicates that MT dysfunction is a peracute (within minutes to hours) response of cartilage to mechanical injury. The goal of this study was to investigate cardiolipin-targeted mitoprotection as a new strategy to prevent chondrocyte death and cartilage degeneration after injury.