Engineering transplantable human lymphatic and blood capillary networks in a porous scaffold.

Due to a relative paucity of studies on human lymphatic assembly in vitro and subsequent in vivo transplantation, capillary formation and survival of primary human lymphatic (hLEC) and blood endothelial cells (hBEC) ± primary human vascular smooth muscle cells (hvSMC) were evaluated and compared in vitro and in vivo. hLEC ± hvSMC or hBEC ± hvSMC were seeded in a 3D porous scaffold in vitro, and capillary percent vascular volume (PVV) and vascular density (VD)/mm assessed. Scaffolds were also transplanted into a sub-cutaneous rat wound with morphology/morphometry assessment.

Brain Computer Interfaces for Improving the Quality of Life of Older Adults and Elderly Patients.

All people experience aging, and the related physical and health changes, including changes in memory and brain function. These changes may become debilitating leading to an increase in dependence as people get older. Many external aids and tools have been developed to allow older adults and elderly patients to continue to live normal and comfortable lives.

Spatial and temporal distribution of E. coli contamination on three inland lake and recreational beach systems in the upper Midwestern United States.

Swimming advisories are commonly posted at public beaches across the United States every year. In Iowa, weekly monitoring of public swimming areas at state and county beaches have resulted in the impairment of numerous lakes for fecal indicator bacteria (FIB) contamination, as detected by E. coli.

Selenium nanoparticles as anti-infective implant coatings for trauma orthopedics against methicillin-resistant and : in vitro and in vivo assessment.

 Bacterial infection is a common and serious complication in orthopedic implants following traumatic injury, which is often associated with extensive soft tissue damage and contaminated wounds. Multidrug-resistant bacteria have been found in these infected wounds, especially in patients who have multi trauma and prolonged stay in intensive care units.Purpose: The objective of this study was to develop a coating on orthopedic implants that is effective against drug-resistant bacteria.

Bio-engineering a tissue flap utilizing a porous scaffold incorporating a human induced pluripotent stem cell-derived endothelial cell capillary network connected to a vascular pedicle.

Tissue flaps are used to cover large/poorly healing wounds, but involve complex surgery and donor site morbidity. In this study a tissue flap is assembled using the mammalian body as a bioreactor to functionally connect an artery and vein to a human capillary network assembled from induced pluripotent stem cell-derived endothelial cells (hiPSC ECs). In vitro: Porous NovoSorb™ scaffolds (3 mm × 1.

Melatonin promotes survival of nonvascularized fat grafts and enhances the viability and migration of human adipose-derived stem cells via down-regulation of acute inflammatory cytokines.

Nonvascularized fat grafting is a valuable technique for soft tissue reconstruction but poor survival of fat in the host environment remains a problem. A process known as cell-assisted transfer is used to enhance fat graft retention by adding stromal vascular fraction, an adipose-derived stem cell (ASC) rich content to lipoaspirate. We have recently shown that the use of melatonin, a reactive oxygen species scavenger, protects human ASCs from hydrogen peroxide-induced oxidative stress and cell death in vitro but its role as a pharmacological adjunct in clinical fat grafting has not been studied.

Indomethacin Enhances Fat Graft Retention by Up-Regulating Adipogenic Genes and Reducing Inflammation.

Background: Cell-assisted lipotransfer has been promisingly applied to restore soft-tissue defects in plastic surgery; however, the harvesting of stromal vascular fraction increases morbidity and poses potential safety hazards. The authors investigated whether adding indomethacin, an antiinflammatory proadipogenic drug, to the fat graft at the time of transplantation would enhance the final graft volume compared with cell-assisted lipotransfer.

Methods: In vitro, human adipose-derived stem cells were cultured in conditioned growth media supplemented with various doses of indomethacin to investigate adipogenesis and the expression of the adipogenic genes.

Macrophage phenotype in response to implanted synthetic scaffolds: an immunohistochemical study in the rat.

Macrophages predominate among the cells that directly interact with biomaterials and are key orchestrators of host-biomaterial interactions. However, the macrophage response to synthetic scaffolds in particular has not been well studied. The aim of this study was therefore to characterise the macrophage response to several synthetic scaffolds in the rat using immunohistological techniques for a panel of markers of macrophage subclass or activation, including ED1 (CD68), ED2 (CD163), CD80, mannose receptor and inducible nitric oxide synthase (iNOS).

Porous PLGA microspheres tailored for dual delivery of biomolecules via layer-by-layer assembly.

Tissue engineering is a complex and dynamic process that requires varied biomolecular cues to promote optimal tissue growth. Consequently, the development of delivery systems capable of sequestering more than one biomolecule with controllable release profiles is a key step in the advancement of this field. This study develops multilayered polyelectrolyte films incorporating alpha-melanocyte stimulating hormone (α-MSH), an anti-inflammatory molecule, and basic fibroblast growth factor (bFGF).

The adipogenic potential of various extracellular matrices under the influence of an angiogenic growth factor combination in a mouse tissue engineering chamber.

The extracellular matrix (ECM) Matrigel™ has frequently and successfully been used to generate new adipose tissue experimentally, but is unsuitable for human application. This study sought to compare the adipogenic potential of a number of alternative, biologically derived or synthetic ECMs with potential for human application, with and without growth factors and a small fat autograft. Eight groups, with six severe combined immunodeficient (SCID) mice per group, were created with bilateral chambers (silicone tubes) implanted around the epigastric vascular pedicle, with one chamber/animal containing a 5mg fat autograft.

Genetic overlap between evoked frontocentral theta-band phase variability, reaction time variability, and attention-deficit/hyperactivity disorder symptoms in a twin study.

Background: Electrophysiological and hemodynamic activity is altered in attention-deficit/hyperactivity disorder (ADHD) during tasks requiring cognitive control. Frontal midline theta oscillations are a cortical correlate of cognitive control influencing behavioral outcomes including reaction times. Reaction time variability (RTV) is consistently increased in ADHD and is known to share genetic effects with the disorder.

Enhanced liver progenitor cell survival and differentiation in vivo by spheroid implantation in a vascularized tissue engineering chamber.

Liver tissue engineering is hampered by poor implanted cell survival due to inadequate vascularization and cell-cell/cell-matrix interactions. Here, we use liver progenitor cell (LPC) spheroids to enhance cell-cell/cell-matrix interactions, with implantation into an angiogenic in vivo mouse chamber. Spheroids were generated in vitro in methylcellulose medium.

Preparation of an adipogenic hydrogel from subcutaneous adipose tissue.

The ability to generate controlled amounts of adipose tissue would greatly ease the burden on hospitals for reconstructive surgery. We have previously shown that a tissue engineering chamber containing a vascular pedicle was capable of forming new fat; however, further refinements are required to enhance fat formation. The development and maintenance of engineered adipose tissue requires a suitable source of growth factors and a suitable scaffold.

The in vitro preconditioning of myoblasts to enhance subsequent survival in an in vivo tissue engineering chamber model.

The effects of in vitro preconditioning protocols on the ultimate survival of myoblasts implanted in an in vivo tissue engineering chamber were examined. In vitro testing: L6 myoblasts were preconditioned by heat (42 °C; 1.5 h); hypoxia (<8% O(2); 1.

Coating and release of an anti-inflammatory hormone from PLGA microspheres for tissue engineering.

Many biomaterials used in tissue engineering cause a foreign body response in vivo, which left untreated can severely reduce the effectiveness of tissue regeneration. In this study, an anti-inflammatory hormone α-melanocyte stimulating hormone (α-MSH) was physically adsorbed to the surface of biodegradable poly (lactic-co-glycolic) acid (PLGA) microspheres to reduce inflammatory responses to this material. The stability and adsorption isotherm of peptide binding were characterized.

A prevascularized tissue engineering chamber supports growth and function of islets and progenitor cells in diabetic mice.

Recent studies have shown that type 1 diabetes can be reversed in a murine model by islet transplantation to a vascularized tissue engineering chamber. In preliminary experiments using a prevascularized chamber we observed that islet grafts not functioning initially can show a delayed onset of function several weeks after implantation. We sought to characterize this phenomenon.

An "off the shelf" vascular allograft supports angiogenic growth in three-dimensional tissue engineering.

Objectives: Dense angiogenic sprouting occurs from arteriovenous loops (AVLs) incorporating autologous vein grafts inserted into empty plastic chambers in vivo. The purpose of this study was to determine if angiogenesis from the AVL was limited by substituting an "off the shelf" cold-stored allograft vein instead of an autologous vein.

Methods: Four Sprague Dawley rat groups (two AVL configurations × two chamber types) were established for both 2-week and 6-week harvest.

Expansion and hepatocytic differentiation of liver progenitor cells in vivo using a vascularized tissue engineering chamber in mice.

Current cell-based treatment alternatives to organ transplantation for liver failure remain unsatisfactory. Hepatocytes have a strong tendency to dedifferentiate and apoptose when isolated and maintained in culture. In contrast, liver progenitor cells (LPCs) are robust, easy to culture and have been shown to replace damaged hepatocytes in liver disease.

Epoxy-amine synthesised hydrogel scaffolds for soft-tissue engineering.

Highly porous and biodegradable hydrogels based on poly(ethylene glycol) (PEG) and cystamine (Cys) were fabricated using epoxy-amine chemistry and investigated as scaffolds for soft-tissue engineering. Whereas the application of fused-salt templates provided a comprehensive interconnecting pore morphology, the incorporation of a specially designed poly(epsilon-caprolactone) (PCL) cross-linker provided enhanced mechanical function without adversely effecting the scaffolds positive biological interactions. The addition of only 1.

Implanted myoblast survival is dependent on the degree of vascularization in a novel delayed implantation/prevascularization tissue engineering model.

In in vivo tissue engineering, many implanted cells die because of hypoxic conditions immediately postimplantation. The aim of this study was to determine whether delayed myoblast implantation, at day 4 or 7, improves myoblast survival compared with implantation at day 0 in an in vivo arterio-venous loop (AB loop) chamber model. In adult inbred Sprague-Dawley rats, an AB loop was inserted into a plastic chamber (day 0).

Angiogenic growth factor synergism in a murine tissue engineering model of angiogenesis and adipogenesis.

De novo tissue generation stimulated by three angiogenic growth factors administered in a factorial design was studied in an in vivo murine tissue engineering chamber. A silicone chamber was implanted around the epigastric pedicle and filled with Matrigel with 100 ng/ml of recombinant mouse vascular endothelial growth factor-120 (VEGF120), recombinant human basic fibroblastic growth factor (FGF-2), or recombinant rat platelet-derived growth factor-BB (PDGF-BB) added as single, double, or triple combinations. Angiogenesis, supporting tissue ingrowth, and adipogenesis were assessed at 2 and 6 weeks by immunohistochemistry and morphometry.