Observational Analysis of Point-of-Care Lactate Plus™ Meter in Preclinical Trauma Models.

Background/objectives: Blood lactate concentration is often used to assess systemic hypoperfusion, tissue hypoxia, and sepsis in trauma patients and serves as a prognostic indicator and marker of response to therapy. Point-of-care (POC) devices provide rapid lactate measurements with a single drop of blood. In this study, lactate values from whole blood, measured with two POC devices, Abbott i-STAT and the Nova Biomedical Lactate (LA) Plus™ meter, are compared.

Comparison of Intact Fish Skin Graft and Allograft as Temporary Coverage for Full-Thickness Burns: A Non-Inferiority Study.

The extent and depth of burn injury may mandate temporary use of cadaver skin (allograft) to protect the wound and allow the formation of granulation tissue while split-thickness skin grafts (STSGs) are serially harvested from the same donor areas. However, allografts are not always available and have a high cost, hence the interest in identifying more economical, readily available products that serve the same function. This study evaluated intact fish skin graft (IFSG) as a temporary cover to prepare the wound bed for STSG application.

Fish Skin Grafts Affect Adenosine and Methionine Metabolism during Burn Wound Healing.

Burn wound healing is a complex process orchestrated through successive biochemical events that span from weeks to months depending on the depth of the wound. Here, we report an untargeted metabolomics discovery approach to capture metabolic changes during the healing of deep partial-thickness (DPT) and full-thickness (FT) burn wounds in a porcine burn wound model. The metabolic changes during healing could be described with six and seven distinct metabolic trajectories for DPT and FT wounds, respectively.

Assessing multimodal optical imaging of perfusion in burn wounds.

A critical need exists for early, accurate diagnosis of burn wound severity to help identify the course of treatment and outcome of the wound. Laser speckle imaging (LSI) is a promising blood perfusion imaging approach, but it does not account for changes in tissue optical properties that can occur with burn wounds, which are highly dynamic environments. Here, we studied optical property dynamics following burn injury and debridement and the associated impact on interpretation of LSI measurements of skin perfusion.

Accelerated Wound Closure of Deep Partial Thickness Burns with Acellular Fish Skin Graft.

Thermal injuries are caused by exposure to a variety of sources, and split thickness skin grafts are the gold standard treatment for severe burns; however, they may be impossible when there is no donor skin available. Large total body surface area burns leave patients with limited donor site availability and create a need for treatments capable of achieving early and complete coverage that can also retain normal skin function. In this preclinical trial, two cellular and tissue based products (CTPs) are evaluated on twenty-four 5 × 5 deep partial thickness (DPT) burn wounds.

Coming to Consensus: What Defines Deep Partial Thickness Burn Injuries in Porcine Models?

Deep partial thickness burns are clinically prevalent and difficult to diagnose. In order to develop methods to assess burn depth and therapies to treat deep partial thickness burns, reliable, accurate animal models are needed. The variety of animal models in the literature and the lack of precise details reported for the experimental procedures make comparison of research between investigators challenging and ultimately affect translation to patients.

Enzymatic Debridement of Porcine Burn Wounds via a Novel Protease, SN514.

Necrotic tissue generated by a thermal injury is typically removed via surgical debridement. However, this procedure is commonly associated with blood loss and the removal of viable healthy tissue. For some patients and contexts such as extended care on the battlefield, it would be preferable to remove devitalized tissue with a nonsurgical debridement agent.

PEGylated Platelet-Free Blood Plasma-Based Hydrogels for Full-Thickness Wound Regeneration.

To develop a cost-effective and clinically usable therapy to treat full-thickness skin injuries. We accomplished this by preparing a viscoelastic hydrogel using polyethylene glycol (PEG)-modified platelet-free plasma (PEGylated PFP) combined with human adipose-derived stem cells (ASCs). PEGylated PFP hydrogels were prepared by polymerizing the liquid mixture of PEG and PFP±ASCs and gelled either by adding calcium chloride (CaCl) or thrombin.

Spatial frequency domain imaging: a quantitative, noninvasive tool for in vivo monitoring of burn wound and skin graft healing.

There is a need for noninvasive, quantitative methods to characterize wound healing in the context of longitudinal investigations related to regenerative medicine. Such tools have the potential to inform the assessment of wound status and healing progression and aid the development of new treatments. We employed spatial frequency domain imaging (SFDI) to characterize the changes in optical properties of tissue during wound healing progression in a porcine model of split-thickness skin grafts and also in a model of burn wound healing with no graft intervention.

Platelet rich plasma hydrogels promote in vitro and in vivo angiogenic potential of adipose-derived stem cells.

Despite great advances in skin wound care utilizing grafting techniques, the resulting severe scarring, deformity and ineffective vascularization remains a challenge. Alternatively, tissue engineering of new skin using patient-derived stem cells and scaffolding materials promises to greatly increase the functional and aesthetic outcome of skin wound healing. This work focused on the optimization of a polyethylene glycol modified (PEGylated) platelet-rich plasma (PRP) hydrogel for the protracted release of cytokines, growth factors, and signaling molecules and also the delivery of a provisional physical framework for stem cell angiogenesis.

An electrochemically deposited collagen wound matrix combined with adipose-derived stem cells improves cutaneous wound healing in a mouse model of type 2 diabetes.

Chronic wounds complicated by diabetes are a significant clinical issue, and their occurrence is expected to continue to rise due to an increased prevalence of diabetes mellitus, especially type 2 diabetes. Diabetic wounds frequently lead to nonhealing ulcers, and often eventually result in limb amputation due to the high risk of infection of the chronic wound. Here, we present a tissue-engineered treatment that combines a novel electrochemically deposited collagen wound matrix and human adipose-derived stem cells.

PEG-Plasma Hydrogels Increase Epithelialization Using a Human Ex Vivo Skin Model.

In vitro cell culture methods are used extensively to study cellular migration, proliferation, and differentiation, which play major roles in wound healing but the results often do not translate to the in vivo environment. One alternative would be to establish an ex vivo model utilizing human discarded skin to evaluate therapies in a more natural setting. The purpose of this study was to institute such a model by creating 'wounds' in the center of a piece of discarded skin and treating them with three different biomaterials: collagen, polyethylene glycol (PEG)-fibrin, or PEG-platelet free plasma (PFP).

Delivery of Allogeneic Adipose Stem Cells in Polyethylene Glycol-Fibrin Hydrogels as an Adjunct to Meshed Autografts After Sharp Debridement of Deep Partial Thickness Burns.

Harvesting of autografts results in donor site morbidities and is limited in scenarios such as large total body surface area burns. In these instances, coverage is increased by meshing grafts at the expense of delayed biologic closure. Moreover, graft meshing increases the likelihood of contraction and hypertrophic scarring, limits range of motion, and worsens cosmesis.

Tissue Source and Cell Expansion Condition Influence Phenotypic Changes of Adipose-Derived Stem Cells.

Stem cells derived from the subcutaneous adipose tissue of debrided burned skin represent an appealing source of adipose-derived stem cells (ASCs) for regenerative medicine. Traditional tissue culture uses fetal bovine serum (FBS), which complicates utilization of ASCs in human medicine. Human platelet lysate (hPL) is one potential xeno-free, alternative supplement for use in ASC culture.

Microvascular Fragment Transplantation Improves Rat Dorsal Skin Flap Survival.

Background: The development of flap necrosis distally remains a concern during microsurgical flap transfers because, at least in part, of decreased perfusion. Microvascular fragments (MVFs) are microvessels isolated from adipose tissue that are capable of improving tissue perfusion in a variety of tissue defects. The aim of this study was to determine whether the transplantation of MVFs in a dorsal rat skin flap model can improve flap survival.

Temporal genomewide expression profiling of DSS colitis reveals novel inflammatory and angiogenesis genes similar to ulcerative colitis.

Dextran sodium sulfate (DSS)-induced colitis is widely used to study pathological mechanisms and potential treatments of inflammatory bowel disease. Because temporal changes in genome expression profiles remain unknown in this model, we performed whole genome expression profile analysis during the development of DSS colitis in comparison with ulcerative colitis (UC) specimens to identify novel and common responses during disease. Colon tissue from DSS-treated mice was collected at days 0, 2, 4, and 6.

GABA acts as a ligand chaperone in the early secretory pathway to promote cell surface expression of GABAA receptors.

GABA (gamma-aminobutyric acid) is the primary inhibitory neurotransmitter in brain. The fast inhibitory effect of GABA is mediated through the GABA(A) receptor, a postsynaptic ligand-gated chloride channel. We propose that GABA can act as a ligand chaperone in the early secretory pathway to facilitate GABA(A) receptor cell surface expression.

Identification of genes correlated with early-stage bladder cancer progression.

Transitional cell carcinoma (TCC) of the bladder ranks fourth in incidence of all cancers in the developed world, yet the mechanisms of its origin and progression remain poorly understood. There are also few useful diagnostic or prognostic biomarkers for this disease. We have combined a transgenic mouse model for invasive bladder cancer (UPII-SV40Tag mice) with DNA microarray technology to determine molecular mechanisms involved in early TCC development and to identify new biomarkers for detection, diagnosis, and prognosis of TCC.