Valorisation to biogas of macroalgal waste streams: a circular approach to bioproducts and bioenergy in Ireland.

Seaweeds (macroalgae) have been recently attracting more and more interest as a third generation feedstock for bioenergy and biofuels. However, several barriers impede the deployment of competitive seaweed-based energy. The high cost associated to seaweed farming and harvesting, as well as their seasonal availability and biochemical composition currently make macroalgae exploitation too expensive for energy production only. Recent studies have indicated a possible solution to aforementioned challenges may lay in seaweed integrated biorefinery, in which a bioenergy and/or biofuel production step ends an extractions cascade of high-value bioproducts. This results in the double benefit of producing renewable energy while adopting a zero waste approach, as fostered by recent EU societal challenges within the context of the Circular Economy development. This study investigates the biogas potential of residues from six indigenous Irish seaweed species while discussing related issues experienced during fermentation. It was found that Laminaria and Fucus spp. are the most promising seaweed species for biogas production following biorefinery extractions producing 187-195 mL CH4 gVS-1 and about 100 mL CH4 gVS-1 , respectively, exhibiting overall actual yields close to raw un-extracted seaweed.

Diagnostic and therapeutic yield of a patient-controlled portable EEG device with dry electrodes for home-monitoring neurological outpatients-rationale and protocol of the HOMEONE pilot study.

BACKGROUND: The HOMEONE study is part of the larger HOME project, which aims to provide evidence of diagnostic and therapeutic yield ("change of management") of a patient-controlled portable EEG device with dry electrodes for the purposes of EEG home-monitoring neurological outpatients. METHODS: The HOMEONE study is the first step in the process of investigating whether outpatient EEG home-monitoring changes the diagnosis and treatment of patients in comparison to conventional EEG ("change of management"). Both EEG devices (conventional and portable) will be systematically compared via a two-phase intra-individual assessment.In the first phase (pilot study phase), both EEG devices will be used within neurologist practices (all other things being equal). This pilot study (involving 130 patients) will evaluate the technical usability and efficacy of the new portable dry electrode EEG recorder in comparison to conventional EEG devices. Judgements will be based on technical assessments and EEG record examinations of private practitioners and two experienced neurologists (percent of concordant readings and kappa values).The second phase (feasibility study phase) aims to assess patients' acceptability and feasibility of the EEG home-monitoring and will provide insights into the extent diagnostic and therapeutic yields can be expected.For this purpose, a conventional EEG will be recorded in neurologist practices. Thereafter, the practice staff will instruct the patients on how the portable EEG device functions. The patients will subsequently use the devices in their home environment.The evaluation will compare the before and after documented diagnostic findings and the therapeutic consequences of the private practitioners with those of two experienced neurologists. DISCUSSION: To the best of our knowledge, this will be the first study of its kind to examine new approaches to diagnosing unclear consciousness disorders or other disorders of the CNS or the cardiovascular system through the use of a patient-controlled portable EEG device with dry electrodes for the purpose of home-monitoring neurological outpatients. If the two phases of the HOMEONE study provide sufficient evidence of diagnostic and therapeutic yields, this would justify (indication-specific) full-scale randomized controlled trials or observational studies. TRIAL REGISTRATION: DRKS DRKS00012685. Registered 9 August 2017, retrospectively registered.

Towards functional 3D-stacked electrospun composite scaffolds of PHBV, silk fibroin and nanohydroxyapatite: Mechanical properties and surface osteogenic differentiation.

Bone tissue engineering scaffolds have two challenging functional tasks to fulfil: to encourage cell proliferation, differentiation and matrix synthesis and to provide suitable mechanical stability upon implantation. Composites of biopolymers and bioceramics combine the advantages of both types of materials, resulting in better processability and enhanced mechanical and biological properties through matrix reinforcement. In the present study, novel thick bone composite scaffolds were successfully fabricated using electrospun flat sheets of polyhydroxybutyrate-polyhydroxyvalerate/nanohydroxyapatite/silk fibroin essence (2% nanohydroxyapatite - 2% silk fibroin essence and 5% nanohydroxyapatite - 5% silk fibroin essence, respectively). Their potential asin vitrobone regeneration scaffolds was evaluated using mouse calvarian osteoblast cells (MC3T3-E1), in terms of morphology (scanning electron microscope), cell attachment, cell proliferation, Col type I, osteopontin and bone alkaline phosphatase activity (Quantitative Real Time Polymerase Chain Reaction [qRT-PCR], enzyme-linked immunosorbent assay, immunocytochemistry). Electrospun polyhydroxybutyrate-polyhydroxyvalerate scaffolds were used as reference constructs. The results showed that the compressive and tensile mechanical properties of the scaffolds are dependent on the change in their composition, and the treatment these underwent. Furthermore, methanol-treated and autoclaved (MA) P2 (2% nanohydroxyapatite, 2% silk fibroin essence) samples appeared to exhibit more promising tensile properties. Additionally, the compressive tests results confirmed that the methanol pre-treatment and the autoclaving step lead to an increase in the P2 secant modulus when compared to the non-methanol-treated ones, P2 and P5 (5% nanohydroxyapatite, 5% silk fibroin essence), respectively.Both formulations of polyhydroxybutyrate-polyhydroxyvalerate/nanohydroxyapatite/silk fibroin essence composite promoted greater cell adhesion and proliferation than the corresponding polyhydroxybutyrate-polyhydroxyvalerate control ones. Cells seeded on the composite fibrous scaffolds were extensively expanded and elongated on the fibre surface after one day in culture, whereas those seeded on the polyhydroxybutyrate-polyhydroxyvalerate scaffolds were not completely elongated. In addition, cells grown on P2 and P5 scaffolds had higher alkaline phosphatase activity when compared to those containing no nanohydroxyapatite/silk fibroin essence.

Electrospun composites of PHBV, silk fibroin and nano-hydroxyapatite for bone tissue engineering.

Electrospinning of fibrous scaffolds containing nano-hydroxyapatite (nHAp) embedded in a matrix of functional biomacromolecules offers an attractive route to mimicking the natural bone tissue architecture. Functional fibrous substrates will support cell attachment, proliferation and differentiation, while the role of HAp is to induce cells to secrete extracellular matrix (ECM) for mineralization to form bone. Electrospinning of biomaterials composed of polyhydroxybutyrate-co-(3-hydroxyvalerate) with 2% valerate fraction (PHBV), nano-hydroxyapatite (nHAp), and Bombyx mori silk fibroin essence (SF), Mw=90KDa, has been achieved for nHAp and SF solution concentrations of 2 (w/vol) % each and 5 (w/vol) % each. The structure and properties of the nanocomposite fibrous membranes were investigated by means of Scanning Electron Microscopy in combination with Energy Dispersive X-Ray Analysis (SEM/EDX), Fourier Transformed Infrared Spectroscopy (FT-IR), uniaxial tensile and compressive mechanical testing, degradation tests and in vitro bioactivity tests. SEM images showed smooth, uniform and continuous fibre deposition with no bead formation, and fibre diameters of between 10 and 15 µm. EDX and FT-IR confirmed the presence of nHAp and SF. After one month in deionised water, tests showed less than 2% weight loss with the samples retaining their fibrous morphology, confirming that this material biodegrades slowly. After 28 days of immersion in Simulated Body Fluid (SBF) an apatite layer was visible on the surface of the fibres, proving their bioactivity. Preliminary in vitro biological assessment showed that after 1 and 3 days in culture, cells were attached to the fibres, retaining their morphology while presenting a flattened appearance and elongated shape on the surface of fibres. Young's modulus was found to increase from 0.7 kPa (±0.33 kPa) for electrospun samples of PHBV only to 1.4 kPa (±0.54 kPa) for samples with 2 (w/vol) % each of nHAp and SF. Samples prepared with 5 (w/vol) % each of nHAp and SF did not show a similar improvement.