Evaluation of tissue-engineered human acellular vessels as a Blalock-Taussig-Thomas shunt in a juvenile primate model.

Objectives: Palliative treatment of cyanotic congenital heart disease (CCHD) uses systemic-to-pulmonary conduits, often a modified Blalock-Taussig-Thomas shunt (mBTTs). Expanded polytetrafluoroethylene (ePTFE) mBTTs have associated risks for thrombosis and infection. The Human Acellular Vessel (HAV) (Humacyte, Inc) is a decellularized tissue-engineered blood vessel currently in clinical trials in adults for vascular trauma, peripheral artery disease, and end-stage renal disease requiring hemodialysis.

Biological mechanisms of infection resistance in tissue engineered blood vessels compared to synthetic expanded polytetrafluoroethylene grafts.

Objective: Synthetic expanded polytetrafluoroethylene (ePTFE) grafts are known to be susceptible to bacterial infection. Results from preclinical and clinical studies of bioengineered human acellular vessels (HAVs) have shown relatively low rates of infection. This study evaluates the interactions of human neutrophils and bacteria with ePTFE and HAV vascular conduits to determine whether there is a correlation between neutrophil-conduit interactions and observed differences of their infectivity in vivo.

Six-year outcomes of a phase II study of human-tissue engineered blood vessels for peripheral arterial bypass.

Objective: The human acellular vessel (HAV) was evaluated for surgical bypass in a phase II study. The primary results at 24 months after implantation have been reported, and the patients will be evaluated for ≤10 years.

Methods: In the present report, we have described the 6-year results of a prospective, open-label, single-treatment arm, multicenter study.

Arterial reconstruction with human bioengineered acellular blood vessels in patients with peripheral arterial disease.

Objective: Vascular conduit is essential for arterial reconstruction for a number of conditions, including trauma and atherosclerotic occlusive disease. We have developed a tissue-engineered human acellular vessel (HAV) that can be manufactured, stored on site at hospitals, and be immediately available for arterial vascular reconstruction. Although the HAV is acellular when implanted, extensive preclinical and clinical testing has demonstrated that the HAV subsequently repopulates with the recipient's own vascular cells.

Bioengineered human acellular vessels recellularize and evolve into living blood vessels after human implantation.

Traditional vascular grafts constructed from synthetic polymers or cadaveric human or animal tissues support the clinical need for readily available blood vessels, but often come with associated risks. Histopathological evaluation of these materials has shown adverse host cellular reactions and/or mechanical degradation due to insufficient or inappropriate matrix remodeling. We developed an investigational bioengineered human acellular vessel (HAV), which is currently being studied as a hemodialysis conduit in patients with end-stage renal disease.

Elective nodal irradiation with simultaneous integrated boost stereotactic body radiotherapy for pancreatic cancer: Analyses of planning feasibility and geometrically driven DVH prediction model.

Purpose: We evaluate the feasibility of the elective nodal irradiation strategy in stereotactic body radiotherapy (SBRT) for pancreatic cancer.

Methods: Three simultaneous integrated boost (SIB)-SBRT plans (Boost1, Boost2, and Boost3) were retrospectively generated for each of 20 different patients. Boost1 delivered 33 and 25 Gy to PTV1 and PTV2, respectively.

Susceptibility of ePTFE vascular grafts and bioengineered human acellular vessels to infection.

Background: Synthetic expanded polytetrafluorethylene (ePTFE) grafts are routinely used for vascular repair and reconstruction but prone to sustained bacterial infections. Investigational bioengineered human acellular vessels (HAVs) have shown clinical success and may confer lower susceptibility to infection. Here we directly compared the susceptibility of ePTFE grafts and HAV to bacterial contamination in a preclinical model of infection.

Gallbladder toxicity and high-dose ablative-intent radiation for liver tumors: Should we constrain the dose?

Purpose: Little is known about the risk of gallbladder toxicity from hypofractionated (HFXRT) and stereotactic body radiation therapy (SBRT). We report on gallbladder toxicity and attribution to treatment in a prospective series of patients with primary and metastatic liver tumors receiving ablative-intent HFXRT and SBRT with protons.

Methods And Materials: We evaluated 93 patients with intact gallbladders enrolled in either of 2 trials investigating proton HFXRT and SBRT for primary and metastatic liver tumors from 2009 to 2014.

Bioengineered human acellular vessels for dialysis access in patients with end-stage renal disease: two phase 2 single-arm trials.

Background: For patients with end-stage renal disease who are not candidates for fistula, dialysis access grafts are the best option for chronic haemodialysis. However, polytetrafluoroethylene arteriovenous grafts are prone to thrombosis, infection, and intimal hyperplasia at the venous anastomosis. We developed and tested a bioengineered human acellular vessel as a potential solution to these limitations in dialysis access.

A collaborative system to improve compartment syndrome recognition.

Background And Objective: Acute compartment syndrome (ACS) is a rare but serious complication of extremity injury that can cause permanent damage or death. ACS development is variable and unpredictable, and delay in recognition or treatment of ACS can lead to significant morbidity. Our objective was to create a reliable system for recognition of patients at risk and monitoring for ACS that could withstand frequent provider turnover.

Identification of platinum and palladium particles emitted from vehicles and dispersed into the surface environment.

Platinum, palladium, and rhodium are emitted from vehicle catalytic converters. Until now, the form of precious metal particles in road dust and urban waste has not been identified. This study has located, imaged, and analyzed these particles in road dust and gully waste.

An early study on the mechanisms that allow tissue-engineered vascular grafts to resist intimal hyperplasia.

Intimal hyperplasia is one of the prominent failure mechanisms for arteriovenous fistulas and arteriovenous access grafts. Human tissue-engineered vascular grafts (TEVGs) were implanted as arteriovenous grafts in a novel baboon model. Ultrasound was used to monitor flow rates and vascular diameters throughout the study.

Readily available tissue-engineered vascular grafts.

Autologous or synthetic vascular grafts are used routinely for providing access in hemodialysis or for arterial bypass in patients with cardiovascular disease. However, some patients either lack suitable autologous tissue or cannot receive synthetic grafts. Such patients could benefit from a vascular graft produced by tissue engineering.

Bioluminescence imaging of glucose in tissue surrounding polyurethane and glucose sensor implants.

Background: The bioluminescence technique was used to quantify the local glucose concentration in the tissue surrounding subcutaneously implanted polyurethane material and surrounding glucose sensors. In addition, some implants were coated with a single layer of adipose-derived stromal cells (ASCs) because these cells improve the wound-healing response around biomaterials.

Methods: Control and ASC-coated implants were implanted subcutaneously in rats for 1 or 8 weeks (polyurethane) or for 1 week only (glucose sensors).

Platinum-group elements in sewage sludge and incinerator ash in the United Kingdom: assessment of PGE sources and mobility in cities.

Platinum-group element (PGE) concentrations in sewage sludge and incinerator ash compared with average PGE concentrations in road dust show a common pattern, characterized by a negative Rh anomaly. This similarity, found at 9 UK incinerators, suggests that there is a universal characteristic PGE pattern produced by common processes of dispersal of Pt, Pd and Rh derived from automobile catalytic converters. Ninety-one sewage sludge and incinerator ash samples from the sewage treatment facilities in Sheffield, Birmingham and 7 other UK cities were analyzed for PGE.

A further discussion of the factors controlling the distribution of Pt, Pd, Rh and Au in road dust, gullies, road sweeper and gully flusher sediment in the city of Sheffield, UK.

Forty paired road dust and gully sediments from the city of Sheffield in NE England show that high platinum, palladium and rhodium concentrations derived from catalytic converters depend on proximity to both roundabouts rather than traffic lights and to topographic lows. Road dust outside schools and control samples, further away on the same road, show that Pt, Pd and Rh concentrations are dependent on passing traffic flow rather than numbers of stopping vehicles. Highest values of Pt+Pd in road dust are 852 ppb and 694 ppb in gullies.

Dispersal and accumulation of Pt, Pd and Rh derived from a roundabout in Sheffield (UK): From stream to tidal estuary.

The Coisley Hill roundabout, a typical urban source for PGE in stream sediments, has anomalously high values of up to 408 ppb Pt, 444 ppb Pd and 113 ppb Rh in road dust, up to 416 ppb Pt and 278 ppb Pd in gulley sediment and up to 606 ppb Pt and 1050 ppb Pd in verge soil. For samples collected at the same time, the road dust values are much higher than in sediments in the Shire Brook stream, that drains the roundabout, with values of 3-64 ppb Pt, 4-57 ppb Pd and up to 7 ppb Rh. Downstream sediments from rivers Rother and Don have lower values of 2-35 ppb Pt, 2-14 ppb Pd and up to 3 ppb Rh.

IFATS collection: Adipose-derived stromal cells improve the foreign body response.

Many implanted devices fail due to the formation of an avascular capsule surrounding the device. Additionally, fat has long been known to promote healing and vascularization. The goals of this study were to identify potential mechanisms of the provascular actions of adipose-derived stromal cells (ASCs) and to improve implant biocompatibility.

Reduced foreign body response at nitric oxide-releasing subcutaneous implants.

The tissue response to nitric oxide (NO)-releasing subcutaneous implants is presented. Model implants were created by coating silicone elastomer with diazeniumdiolate-modified xerogel polymers capable of releasing NO. The host tissue response to such implants was evaluated at 1, 3, and 6 weeks and compared to that of uncoated silicone elastomer blanks and xerogel-coated controls incapable of releasing NO.

Platinum and palladium variations through the urban environment: evidence from 11 sample types from Sheffield, UK.

Platinum (Pt) and Palladium (Pd) concentrations have been analysed in 194 samples from within the city of Sheffield in the UK. The samples were taken from road dust, gully pots (also known as drains), soils, a motorway drainage pipe, rivers, lakes, sewage sludge, incinerator ash, incinerator ash in landfill, street cleansers and gully cleansers. The introduction of Pt- and Pd-bearing automobile catalysts, has been cited as the cause of a rise in the concentration of urban Pt and Pd accumulations.

Effects of glutamine, glucose, and oxygen concentration on the metabolism and proliferation of rabbit adipose-derived stem cells.

The use of adipose-derived stem cells (ASCs) for tissue engineering involves exposing them to metabolically adverse conditions. This study examined the metabolism, proliferation, and viability of ASCs under various oxygen, glucose, and glutamine concentrations to determine how these cells respond to such environments. ASCs were cultured in each of 8 media preparations containing 4.

Combined bone allograft and adipose-derived stem cell autograft in a rabbit model.

Currently available options for the repair of bony defects have substantial limitations. Much work has looked to the possibility of engineering bone using stem cells. These tissue-engineering efforts have focused on calvarial defect models, which have the advantages of minimal load-bearing and a large surface area.

Adult adipose-derived stem cell attachment to biomaterials.

Attachment of adipose-derived stem cells (ASCs) to biomaterials prior to implantation is a possible strategy for mediating inflammation and wound healing. In this study, the ASC percent coverage was measured on common medical grade biosensor materials subjected to different surface treatments. Cell coverage on silicone elastomer (poly-dimethylsiloxane) was below 20% for all surface treatments.

Randomized trial comparing two fractionation schedules for patients with localized prostate cancer.

Purpose: The optimal radiation dose fractionation schedule for localized prostate cancer is unclear. This study was designed to compare two dose fractionation schemes (a shorter 4-week radiation schedule v a longer 6.5-week schedule).