Multivariate description of gait changes in a mouse model of peripheral nerve injury and trauma.

Objective: Animal models of nerve injury are important for studying nerve injury and repair, particularly for interventions that cannot be studied in humans. However, the vast majority of gait analysis in animals has been limited to univariate analysis even though gait data is highly multi-dimensional. As a result, little is known about how various spatiotemporal components of the gait relate to each other in the context of peripheral nerve injury and trauma.

The multifaceted helical net of amphipathic alpha-helices; the next dimension of the helical peptide wheel.

The amphipathic nature of helical proteins is crucial to their binding features across a broad spectrum of physiological examples, including heat-shock proteins and hyaluronic acid (HA) receptor binding. By taking advantage of the amphipathic balance of amino acids and their presentation in helical faces, novel synthetic peptides can be designed to improve biofunctionality. We present a new approach for designing synthetic alpha helical peptides using a multifaceted analysis, which allows for new bioengineering designs of amphipathic alpha helices.

Peptide discovery across the spectrum of neuroinflammation; microglia and astrocyte phenotypical targeting, mediation, and mechanistic understanding.

Uncontrolled and chronic inflammatory states in the Central Nervous System (CNS) are the hallmark of neurodegenerative pathology and every injury or stroke-related insult. The key mediators of these neuroinflammatory states are glial cells known as microglia, the resident immune cell at the core of the inflammatory event, and astroglia, which encapsulate inflammatory insults in proteoglycan-rich scar tissue. Since the majority of neuroinflammation is exclusively based on the responses of said glia, their phenotypes have been identified to be on an inflammatory spectrum encompassing developmental, homeostatic, and reparative behaviors as opposed to their ability to affect devastating cell death cascades and scar tissue formation.

Blocking antibodies against integrin-α3, -αM, and -αMβ2 de-differentiate myofibroblasts, and improve lung fibrosis and kidney fibrosis.

Fibrosis is involved in 45% of deaths in the United States, and no treatment exists to reverse the progression of lung or kidney fibrosis. Myofibroblasts are key to the progression and maintenance of fibrosis. We investigated features of cell adhesion necessary for monocytes to differentiate into myofibroblasts, seeking to identify pathways key to myofibroblast differentiation.

A class of peptides designed to replicate and enhance the Receptor for Hyaluronic Acid Mediated Motility binding domain.

The extra-cellular matrix (ECM) is a complex and rich microenvironment that is exposed and over-expressed across several injury or disease pathologies. Biomaterial therapeutics are often enriched with peptide binders to target the ECM with greater specificity. Hyaluronic acid (HA) is a major component of the ECM, yet to date, few HA adherent peptides have been discovered.

Autophagy Enhances Longevity of Induced Pluripotent Stem Cell-Derived Endothelium via mTOR-Independent ULK1 Kinase.

Stem cells are enabling an improved understanding of the peripheral arterial disease, and patient-specific stem cell-derived endothelial cells (ECs) present major advantages as a therapeutic modality. However, applications of patient-specific induced pluripotent stem cell (iPSC)-derived ECs are limited by rapid loss of mature cellular function in culture. We hypothesized that changes in autophagy impact the phenotype and cellular proliferation of iPSC-ECs.

Taking the Next Step: a Neural Coaptation Orthotopic Hind Limb Transplant Model to Maximize Functional Recovery in Rat.

Limb transplant in particular and vascularized composite allotransplant (VCA) in general have wide therapeutic promise that have been stymied by current limitations in immunosuppression and functional neuromotor recovery. Many animal models have been developed for studying unique features of VCA, but here we present a robust reproducible model of orthotopic hind limb transplant in rats designed to simultaneously investigate both aspects of current VCA limitation: immunosuppression strategies and functional neuromotor recovery. At the core of the model rests a commitment to meticulous, time-tested microsurgical techniques such as hand sewn vascular anastomoses and hand sewn neural coaptation of the femoral nerve and the sciatic nerve.

Enzymatic Activity in Fractal Networks of Self-Assembling Peptides.

The tissue environment is exceptionally complex, with well-controlled biochemical communication occurring between similar and dissimilar cells as well as between these cells and local extracellular matrices (ECM). To build an artificial ECM that can directly affect regional cell populations, a designer system should allow for controlled degradation, molecular release, and reorganization as related to local cellular function. (RADA) self-assembling peptide (SAP) hydrogels are excellent candidates for precisely tuned ECMs, or nanoscaffolds, with several beneficial qualities.

Towards Developing Bioresponsive, Self-Assembled Peptide Materials: Dynamic Morphology and Fractal Nature of Nanostructured Matrices.

(Arginine-alanine-aspartic acid-alanine)₄ ((RADA)₄) nanoscaffolds are excellent candidates for use as peptide delivery vehicles: they are relatively easy to synthesize with custom bio-functionality, and assemble in situ to allow a focal point of release. This enables (RADA)₄ to be utilized in multiple release strategies by embedding a variety of bioactive molecules in an all-in-one "construct". One novel strategy focuses on the local, on-demand release of peptides triggered via proteolysis of tethered peptide sequences.

Improved 3D Hydrogel Cultures of Primary Glial Cells for In Vitro Modelling of Neuroinflammation.

In the central nervous system, numerous acute injuries and neurodegenerative disorders, as well as implanted devices or biomaterials engineered to enhance function result in the same outcome: excess inflammation leads to gliosis, cytotoxicity, and/or formation of a glial scar that collectively exacerbate injury or prevent healthy recovery. With the intent of creating a system to model glial scar formation and study inflammatory processes, we have generated a 3D cell scaffold capable of housing primary cultured glial cells: microglia that regulate the foreign body response and initiate the inflammatory event, astrocytes that respond to form a fibrous scar, and oligodendrocytes that are typically vulnerable to inflammatory injury. The present work provides a detailed step-by-step method for the fabrication, culture, and microscopic characterization of a hyaluronic acid-based 3D hydrogel scaffold with encapsulated rat brain-derived glial cells.