Functional transfer of integrin co-receptor CD98hc by small extracellular vesicles improves wound healing in vivo.

Extracellular vesicles (EVs) mediate intercellular communication. EVs are composed of a lipid bilayer and contain cytosolic proteins and RNAs. Studies highlight EVs striking functions in cell-cell crosstalk.

Fibroblast growth factor-2 bound to specific dermal fibroblast-derived extracellular vesicles is protected from degradation.

Fibroblast growth factor-2 (FGF2) has multiple roles in cutaneous wound healing but its natural low stability prevents the development of its use in skin repair therapies. Here we show that FGF2 binds the outer surface of dermal fibroblast (DF)-derived extracellular vesicles (EVs) and this association protects FGF2 from fast degradation. EVs isolated from DF cultured in the presence of FGF2 harbor FGF2 on their surface and FGF2 can bind purified EVs in absence of cells.

Purification of Extracellular Microvesicles Secreted by Dermal Fibroblasts.

Extracellular vesicles (EVs) secreted by all cells are key players in information transfer within a tissue or organism. With their highly cell-specific protein and RNA content, EVs can propagate cellular signals and modulate distant cells' behavior. Dermal fibroblasts are supportive cells for all skin cells and the roles of their EVs start to come to light only recently.

Effects of a novel medial meniscus implant on the knee compartments: imaging and biomechanical aspects.

The altered biomechanical function of the knee following partial meniscectomy results in ongoing articular cartilage overload, which may lead to progressive osteoarthritis (OA). An artificial medial meniscus implant (NUsurface Meniscus Implant, Active Implants LLC., Memphis, TN, USA) was developed to mimic the native meniscus and may provide an effective long-term solution for OA patients, alleviate pain, and restore joint function.

Release of sodium pyruvate from sacral prophylactic dressings: A computational model.

The use of sacral dressings for pressure ulcer prevention is growing rapidly. In addition to their passive biomechanical role in pressure and shear reduction, in the near future, prophylactic dressings may also provide active tissue protection by releasing preventive agents or drugs into skin and deeper tissues. We investigated delivery of sodium pyruvate (NaPy) from an active dressing to potentially protect the sacral skin and underlying tissues in addition.

Measuring Adult Children's Perceptions of Their Parents' Acceptance and Rejection of Their Sexual Orientation: Initial Development of the Parental Acceptance and Rejection of Sexual Orientation Scale (PARSOS).

The Parental Acceptance and Rejection of Sexual Orientation Scale was administered to 256 self-identified lesbian, gay, bisexual, or queer adults who had been out of the closet to their parents for at least 1 year. Principal component analysis revealed a clear two-component solution: parental acceptance and parental rejection. Findings showed that perceived maternal sexual orientation-specific acceptance was higher, and perceived maternal sexual orientation-specific rejection was lower, for gay/bisexual sons compared to their lesbian/bisexual daughters.

Sacral Soft Tissue Deformations When Using a Prophylactic Multilayer Dressing and Positioning System: MRI Studies.

Purpose: The sacrum is the most common location of pressure injuries (PIs) in bedridden patients. The purpose of this study was to measure the effect of specific pressure preventive devices on sacral skeletal muscle, subcutaneous fat, and skin tissue deformations.

Subjects And Setting: The sample comprised 3 healthy adults residing in a community setting in Tel Aviv, Israel.

A Computer Modeling Study to Assess the Durability of Prophylactic Dressings Subjected to Moisture in Biomechanical Pressure Injury Prevention.

The sacral area is the most common site for pressure injuries (PIs) associated with prolonged supine bedrest. In previous studies, an anisotropic multilayer prophylactic dressing was found to reduce the incidence of PIs and redistribute pressure. The purpose of the current study was to further investigate relationships between design features and biomechanical efficacy of sacral prophylactic dressings.

Effects of humidity on skin friction against medical textiles as related to prevention of pressure injuries.

Sustained pressure, shear forces, and friction, as well as elevated humidity/moisture, are decisive physical factors in the development of pressure injuries (PIs). To date, further research is needed in order to understand the influence of humidity and moisture on the coefficient of friction (COF) of skin against different types of medical textiles. The aim of this work was to investigate the effects of moisture caused by sweat, urine, or saline on the resulting COF of skin against different textiles used in the medical setting in the context of PI prevention.

Effects of ambient conditions on the risk of pressure injuries in bedridden patients-multi-physics modelling of microclimate.

Scientific evidence regarding microclimate and its effects on the risk of pressure ulcers (PU) remains sparse. It is known that elevated skin temperatures and moisture may affect metabolic demand as well as the mechanical behaviour of the tissue. In this study, we incorporated these microclimate factors into a novel, 3-dimensional multi-physics coupled model of the human buttocks, which simultaneously determines the biothermal and biomechanical behaviours of the buttocks in supine lying on different support surfaces.

Assessment of the Biomechanical Effects of Prophylactic Sacral Dressings on Tissue Loads: A Computational Modeling Analysis.

The sacrum is the most susceptible anatomical site for developing pressure injuries, including deep tissue injuries, during supine lying. Prophylactic dressings generally are designed to reduce friction, alleviate internal tissue shear, manage the microclimate, and overall cushion the soft tissues subjected to sustained deformations under the sacrum. Using computational modeling, the authors developed a set of 8 magnetic resonance imaging-based, 3-dimensional finite element models of the buttocks of a healthy 28-year-old woman for comparing the biomechanical effects of different prophylactic sacral dressing designs when used during supine lying on a standard hospital foam mattress.

The contribution of a directional preference of stiffness to the efficacy of prophylactic sacral dressings in protecting healthy and diabetic tissues from pressure injury: computational modelling studies.

The sacral region is the most common site for pressure injuries (PIs) associated with lying in bed, and such sacral PIs often commence as deep tissue injuries (DTIs) that later present as open wounds. In complex patients, diabetes is common. Because, among other factors, diabetes affects connective tissue stiffness properties, making these tissues less able to dissipate mechanical loads through physiological deformations, diabetes is an additional biomechanical risk factor for PIs and DTIs.

Beware of the toilet: The risk for a deep tissue injury during toilet sitting.

A pressure injury (PrI) compromises quality of life and can be life-threatening. The fundamental cause of PrIs is sustained deformations in weight-bearing soft tissues, e.g.

Penile compression clamps: A model of the internal mechanical state of penile soft tissues.

Aims: Prostate cancer is the most frequently diagnosed male cancer and urinary incontinence represents a major consequence following surgery. Penile compression clamps (PCCs) which externally occlude the urethra may be used to manage the incontinence. Despite potential complication of PCCs, such as deformation-inflicted tissue damage, to date, there are no reported biomechanical criteria for design of PCCs, in terms of quantitative parameters for evaluating the safety-versus-efficacy of existing or future designs.

A multiscale modeling framework for studying the mechanobiology of sarcopenic obesity.

An inactive sedentary lifestyle is a common risk factor contributing to sarcopenic obesity. At the cell scale, sustained mechanical deformations of the plasma membrane (PM) in adipocytes, characterizing chronic static loading in weight-bearing tissues during prolonged sitting or lying, were found to promote adipogenesis. Taking a mechanobiological perspective, we correlated here the macroscale mechanical deformations of weight-bearing adipose tissues (subcutaneous and intramuscular) with mechanical strains developing in the PMs of differentiating adipocytes.

Computer Modeling Studies to Assess Whether a Prophylactic Dressing Reduces the Risk for Deep Tissue Injury in the Heels of Supine Patients with Diabetes.

Heels are susceptible to pressure ulcer (PU) development. Some evidence suggests dressings may provide mechanical cushioning, reduce friction with support, and lower localized internal tissue loading, which together may minimize the risk for heel ulcers (HUs). To examine the effect of dressing application on pressure ulcer prevention, 20 computer simulations were performed.

Device-related pressure ulcers from a biomechanical perspective.

Pressure ulcers (PUs) in the pediatric population are inherently different from those in adults, in their risk factors and etiology, with more than 50% of the cases related to contact with medical equipment at the care setting. The aims of this study were to: (i) Determine the mechanical loads in the scalp of a newborn lying supine, near a wedged encephalogram electrode or wire, which is deforming the scalp at the occiput. (ii) Evaluate the effect of a doughnut-shaped headrest on the mechanical state of tissues at the same site.

A Computer Modeling Study to Evaluate the Potential Effect of Air Cell-based Cushions on the Tissues of Bariatric and Diabetic Patients.

Sitting-acquired pressure ulcers (PUs) are a potentially life-endangering complication for wheelchair users who are obese and have diabetes mellitus. The increased body weight and diabetes-related alterations in weight-bearing tissue properties have been identified in the literature to increase the risk for PUs and deep tissue injuries (DTIs). A computer modeling study was conducted to evaluate the biomechanical effect of an air cell-based (ACB) cushion on tissues with increased fat mass and diabetes, which causes altered stiffness properties in connective tissues with respect to healthy tissues.

Adjustability and Adaptability Are Critical Characteristics of Pediatric Support Surfaces.

Pressure ulcers (PUs) in newborns and children are remarkably different from those in adults, both in their possible causal factors and in the etiology and biomechanical pathways for tissue damage. Pediatric muscle and fat tissue structures are overall softer than those of adults, making newborns and young children more susceptible to deformation-inflicted injuries at their weight-bearing soft tissues. The unique medical environment of neonatal and pediatric intensive care units, which is overloaded with medical devices, wiring, tubing, electrodes, and so on, is, in fact, an extrinsic risk factor for device-related PUs, since accidently misplaced tubes, wires, or electrodes can become trapped between the skin and the mattress, causing large sustained soft tissue deformations around them.

Pluripotent stem cells as a cellular model for skin: relevance for physiopathology, cell/gene therapy and drug screening.

The skin represents the largest tissue in the human body. Its external part, the epidermis, accomplishes vital functions such as barrier protection, thermoregulation and immune function. The mammalian skin epidermis has been for decades the paradigm for studying the molecular events that occur in tissue homeostasis and repair.

Contoured Foam Cushions Cannot Provide Long-term Protection Against Pressure-Ulcers for Individuals with a Spinal Cord Injury: Modeling Studies.

Objective: To determine changes in internal soft-tissue loads in the buttocks of individuals with a spinal cord injury (SCI), who undergo pathoanatomical changes during the first months and years following the occurrence of the SCI, while sitting on a contoured foam cushion (CFC) that has been fitted close to the time of the injury but has not been replaced in subsequent years.

Design: Internal tissue loads in variant buttocks anatomies on a CFC were analyzed by means of finite element computer simulations. The pathoanatomical changes that are characteristic to SCI and were simulated here are: increase in fat tissue mass, intramuscular fat infiltration, muscle atrophy, and combinations of these conditions.

Alzheimer's disease pathology is attenuated in a CD38-deficient mouse model.

Objective: Alzheimer's disease (AD)-associated dementia is due to tissue damage caused by amyloid β (Aβ) deposition within the brain and by accompanying neuroinflammation. The nicotinamide adenine dinucleotide (NAD) glycohydrolase CD38, which is expressed by neurons, astrocytes, and microglial cells, regulates inflammatory and repair processes in the brain and other tissues by degrading NAD and repressing the activity of other NAD-consuming enzymes and by producing NAD-derived metabolites that regulate calcium signaling and migration of inflammatory cells. Given the role of CD38 in neuroinflammation and repair, we examined the effect of CD38 deletion on AD pathology.

The biomechanical efficacy of dressings in preventing heel ulcers.

The heels are the most common site for facility-acquired pressure ulcers (PUs), and are also the most susceptible location for deep tissue injuries. The use of multilayer prophylactic dressings to prevent heel PUs is a relatively new prevention concept, generally aimed at minimizing the risk for heel ulcers (HUs) through mechanical cushioning and reduction of friction at the dressing-support interface. We used 9 finite element model variants of the posterior heel in order to evaluate the biomechanical performance of a multilayer dressing in prevention of HUs during supine lying.

Computer simulations of efficacy of air-cell-based cushions in protecting against reoccurrence of pressure ulcers.

For individuals with a spinal cord injury (SCI) who depend on a wheelchair for mobility, sitting-acquired pressure ulcers (PUs) are a common and life-endangering complication. In the short time following an SCI, pathoanatomical and pathophysiological changes that affect the weight-bearing tissues of the buttocks may increase the risk for PUs, exposing this already-at-risk population to the additional potential risk caused by soft tissue scarring. In this work, we evaluated the biomechanical efficacies of an air-cell-based (ACB) cushion for individuals with SCI who have previously experienced PUs that healed but left scars in their soft tissues.

Inhibition of glioma progression by a newly discovered CD38 inhibitor.

Glioma, the most common cancer of the central nervous system, has very poor prognosis and no effective treatment. It has been shown that activated microglia/macrophages in the glioma tumor microenvironment support progression. Hence, inhibition of the supporting effect of these cells may constitute a useful therapeutic approach.