26 research outputs found
Soft Perfusable Device to Culture Skeletal Muscle 3D Constructs in Air
Devices for in vitro culture of three-dimensional (3D) skeletal muscle tissues have multiple applications, including tissue engineering and muscle-powered biorobotics. In both cases, it is crucial to recreate a biomimetic environment by using tailored scaffolds at multiple length scales and to administer prodifferentiative biophysical stimuli (e.g., mechanical loading). On the contrary, there is an increasing need to develop flexible biohybrid robotic devices capable of maintaining their functionality beyond laboratory settings. In this study, we describe a stretchable and perfusable device to sustain cell culture and maintenance in a 3D scaffold. The device mimics the structure of a muscle connected to two tendons: TendonâMuscleâTendon (TMT). The TMT device is composed of a soft (E ⌠6 kPa) porous (pore diameter: âŒ650 ÎŒm) polyurethane scaffold, encased within a compliant silicone membrane to prevent medium evaporation. Two tendon-like hollow channels interface the scaffold with a fluidic circuit and a stretching device. We report an optimized protocol to sustain C2C12 adhesion by coating the scaffold with polydopamine and fibronectin. Then, we show the procedure for the soft scaffold inclusion in the TMT device, demonstrating the deviceâs ability to bear multiple cycles of elongations, simulating a protocol for cell mechanical stimulation. By using computational fluid dynamic simulations, we show that a flow rate of 0.62 mL/min ensures a wall shear stress value safe for cells (<2 Pa) and 50% of scaffold coverage by an optimal fluid velocity. Finally, we demonstrate the effectiveness of the TMT device to sustain cell viability under perfusion for 24 h outside of the CO2 incubator. We believe that the proposed TMT device can be considered an interesting platform to combine several biophysical stimuli, aimed at boosting skeletal muscle tissue differentiation in vitro, opening chances for the development of muscle-powered biohybrid soft robots with long-term operability in real-world environments
Testing seed germination from herbaria: Application of seed quality enhancement techniques and implication for plant resurrection and conservation
Herbaria are an important source of data and material useful in many fields, including plant conservation. Seeds preserved in herbarium specimens may have the potential to germinate, although few studies focused on this topic. Here, the first systematic assessment of six techniques, including priming techniques and melatonin application, aimed at improving the germination of seeds from herbarium specimens is presented. Seed germination of 26 species common in Europe, some of which congeneric to extinct species, collected in herbaria and in the wild (20,549 seeds in total, including 19,509 from 297 herbarium specimens from 8 different herbaria) was tested with the following treatments: exogenous melatonin addition to the germination medium, priming with melatonin, osmopriming, hydropriming for 24 and 48 hours, standard soil, heat sterilization and gibberellins addition. More than 85% of the fresh seeds and 1% of the seeds collected in herbaria germinated, including seeds older than 50 years. Data show that treatment with exogenous melatonin had a positive effect on the germination of fresh seeds, but a negative effect on the germination of herbarium-derived seeds. Furthermore, osmopriming treatment had a slightly positive effect on the germination of herbarium-derived seeds. Osmopriming and exogenous melatonin addition seem to be promising techniques that need further investigation and improvement and might be useful for the development of an optimal germination protocol for old and herbarium-derived seeds. The germination of seeds from herbaria could be an important tool in plant conservation, with the aim of reversing the extinction trend of many species through de-extinction, safeguarding biodiversity, and genetic variability. This study provides preliminary data for the development of germination protocols, especially for old seeds of species of conservation interest, to maximise the chance of recovering lost genetic diversity and leading to the first de-extinction ever
At the intersection of cultural and natural heritage: Distribution and conservation of the type localities of Italian endemic vascular plants
We conducted a GIS spatial analysis with the aim of providing the first quantitative large-scale overview of the distribution patterns of 1536 type localities (loci classici) of 1216 Italian endemic vascular plants and their relationship with a set of descriptive variables. Whereas some variables were used to model the presence-absence distribution patterns of the type localities for the whole set of endemics as well as for the subset of narrow endemics, others (e.g., presence inside or outside protected areas and Italian Important Plant Areas) were considered with the purpose of assessing potential assets or risks for conservation.
The largest number of type localities was found within the Mediterranean biogeographic region (1134), followed by the Alpine region (306) and Continental region (96). A total of 670 locations are located on islands, whereas 866 are located on the Italian mainland (139 and 124 in the case of narrow endemics, respectively). A large number of type localities are located in mountainous areas and along the coastline, which can be seen as a potential risk for conservation. On the contrary, we detected a positive correlation with the distance from roads, which might be considered to be an asset. Importantly, 1030 type localities fall inside protected areas, whereas 506 localities fall outside protected areas, with 259 of these unprotected localities on islands.
We propose considering the results of the analysis of the distribution of type localities of Italian endemics to be a strategic tool for conservation planning and resource management. Application of plant micro-reserves and integration of diverse legislation tools are suggested to strengthen efforts and increase conservation success
ï»żNotulae to the Italian flora of algae, bryophytes, fungi and lichens: 14
In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the algal genus Chara, for the bryophyte genera Bryum, Grimmia, Cephaloziella, Hypnum, Nogopterium, Physcomitrium, Polytrichastrum, Rhynchostegiella, Saelania, and Schistostega, the fungal genera Cortinarius, Lentinellus, Omphalina, and Xerophorus, and the lichen genera Acarospora, Agonimia, Candelariella, Cladonia, Graphis, Gyalolechia, Hypogymnia, Lichinella, Megalaria, Nephroma, Ochrolechia, Opegrapha, Peltigera, Placidium, Ramalina, Rhizoplaca, Ropalospora, Strangospora, Toniniopsis, Usnea, and Zahlbrucknerell
Notulae to the Italian native vascular flora: 1
In this contribution, new data concerning the Italian distribution of native vascular flora are presented. It includes new records, exclusions, and confirmations pertaining to the Italian administrative regions for taxa in the genera Arundo, Bromopsis, Cistus, Crocus, Festuca, Galeopsis, Genista, Lamium, Leucanthemum, Nerium, Orobanche, Peucedanum, Pilosella, Polycnemum, Stipa and Viola
Notulae to the Italian alien vascular flora 6
In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions of taxa in the genera Acalypha, Acer, Canna, Cardamine, Cedrus, Chlorophytum, Citrus, Cyperus, Epilobium, Eucalyptus, Euphorbia, Gamochaeta, Hesperocyparis, Heteranthera, Lemna, Ligustrum, Lycium, Nassella, Nothoscordum, Oenothera, Osteospermum, Paspalum, Pontederia, Romulea, Rudbeckia, Salvia, Sesbania, Setaria, Sicyos, Styphnolobium, Symphyotrichum, and Tradescantia. Nomenclature and distribution updates, published elsewhere, and corrigenda are provided as supplementary material
Notulae to the Italian alien vascular flora: 1
In this contribution, new data concerning the Italian distribution of alien vascular flora are presented. It includes new records, exclusions, and confirmations for Italy or for Italian administrative regions for taxa in the genera Agave, Arctotheca, Berberis, Bidens, Cardamine, Catalpa, Cordyline, Cotoneaster, Dichondra, Elaeagnus, Eragrostis, Impatiens, Iris, Koelreuteria, Lamiastrum, Lantana, Ligustrum, Limnophila, Lonicera, Lycianthes, Maclura, Mazus, Paspalum, Pelargonium, Phyllanthus, Pyracantha, Ruellia, Sorghum, Symphyotrichum, Triticum, Tulbaghia and Youngia
Development and test of a biomimetic sensory feedback strategy for bidirectional hand prostheses
The aim of this thesis is to improve the sensibility and dexterity of trans-radial amputees using prostheses with sensory feedback, while eliciting sensations as natural as possible.
A model simulating a population of afferent fibers from the hand has been used as source for the encoded information, the model is able to evaluate responses to touch stimuli according to their spatial and temporal features; multiple modulation strategies have been devised, according to the source of information and the affected stimulation parameter.
The new modulation techniques developed have been evaluated on a subject with a trans-radial amputation and an intraneural implant, the results highlight improved performances in functional tests, enhanced sensibility and, as a result, a reduction of abnormal phantom limb perceptions, suggesting a better embodiment