Controlling the morphology and outgrowth of nerve and neuroglial cells: The effect of surface topography

Unlike other tissue types, like epithelial tissue, which consist of cells with a much more homogeneous structure and function, the nervous tissue spans in a complex multilayer environment whose topographical features display a large spectrum of morphologies and size scales. Traditional cell cultures, which are based on two-dimensional cell-adhesive culture dishes or coverslips, are lacking topographical cues and mainly simulate the biochemical microenvironment of the cells. With the emergence of micro- and nano-fabrication techniques new types of cell culture platforms are developed, where the effect of various topographical cues on cellular morphology, proliferation and differentiation, can be studied. Different approaches (regarding the material, fabrication technique, topographical charactertistics, etc.) have been implemented. The present review paper aims at reviewing the existing body of literature on the use of artificial micro- and nano-topographical features to control neuronal morphology, outgrowth and neural network topology. The cell responses from phenomenology to investigation of the underlying mechanisms- on the different topographies, including both deterministic and random ones, are summarized

Cryopreservation of implantable human skeletal muscle-derived cell-microcarrier combinations for use in clinical regenerative medicine

Regenerative medicine therapies include tissue engineered constructs to restore tissue and organ function. Among the different approaches, implantable polymeric microcarriers have been proposed for delivery of anchorage-dependent cells to target tissue locations. Cell-microcarrier combinations produced as fresh advanced therapy medicinal products (ATMP) face significant challenges in terms of manufacturing and in time distribution. In the current study, we have explored the feasibility cryopreservation for human skeletal muscle-derived cell (SMDC) – implantable microcarrier combinations. Existing and novel cryoprotectant formulations combined with slow cooling were investigated, along with rapid and slow thawing regimens. Under specific conditions following cryopreservation and thawing, most SMDC cells were viable and remained attached to the microcarriers. Furthermore, the capacity of human SMDC to differentiate into myotubes was unaffected. The cryopreservation process did not alter the physico-mechanical properties of the microcarriers enabling them to retain their primary function of an implantable cell substrate. Overall, these findings pave the way to use cold-chain product supply for future clinical studies with the implantable cell-microcarrier technology

Modular Orthopaedic Tissue Engineering With Implantable Microcarriers and Canine Adipose-Derived Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSC) hold significant potential for tissue engineering applications. Modular tissue engineering involves the use of cellularized “building blocks” that can be assembled via a bottom-up approach into larger tissue-like constructs. This approach emulates more closely the complexity associated hierarchical tissues compared with conventional top-down tissue engineering strategies. The current study describes the combination of biodegradable porous poly(DL-lactide-co-glycolide) (PLGA) TIPS microcarriers with canine adipose-derived MSC (cAdMSC) for use as implantable conformable building blocks in modular tissue engineering applications. Optimal conditions were identified for the attachment and proliferation of cAdMSC on the surface of the microcarriers. Culture of the cellularized microcarriers for 21 days in transwell insert plates under conditions used to induce either chondrogenic or osteogenic differentiation resulted in self-assembly of solid 3D tissue constructs. The tissue constructs exhibited phenotypic characteristics indicative of successful osteogenic or chondrogenic differentiation, as well as viscoelastic mechanical properties. This strategy paves the way to create in situ tissue engineered constructs via modular tissue engineering for therapeutic applications

The acute effects of different high-intensity conditioning activities on sprint performance differ between sprinters of different strength and power characteristics

The purpose of the present study was to examine the effect of different conditioning activities (CAs) on short-term increase in sprint performance. In twelve male sprinters (21.1±2.6 years, 100 m performance: 11.5±0.6 s) their body composition, half squat maximum strength, 100 m sprinting and countermovement jump performances were evaluated. The performance of a 50 m sprint (splits at 10 m, 30 m and 50 m) was evaluated before and 5, 10 and 15 min after four postactivation performance enhancement CAs on different occasions: [1] 3 sets x 4 s maximum isometric half squat (IHF), [2] 3 sets x 3 consecutive countermovement jumps (cCMJs), [3] 3 repetitions x 30 m overspeed sprinting (OVSP) and [4] dynamic submaximal half squat (2 sets x 2 reps x 90% of 1-RM half squat; HSQ). Significant improvements of sprinting performance were found 10 and 15 min following the cCMJs, OVSP and HSQ’s interventions, in all distances (p.05). Significant inter-individual differences were found in the magnitude of sprint performance improvements as well as in the optimal time window (p<.05), with the stronger sprinters responding better after HSQs, while the more powerful sprinters after cCMJs and OVSPs. In conclusion, it seems that cCMJs, OVSP and HSQ can acutely increase sprinting performance after 10 min, but CA’s induced increases in sprinting performance are highly related to the strength and power characteristics of each sprinter

Cell Patterning via Laser Micro/nano Structured Silicon Surfaces

The surface topography of biomaterials can have an important impact on cellular adhesion, growth and proliferation. Apart from the overall roughness, the detailed morphological features, at all length scales, significantly affect the cell-biomaterial interactions in a plethora of applications including structural implants, tissue engineering scaffolds and biosensors. In this study, we present a simple, one-step direct laser patterning technique to fabricate nanoripples and dual-rough hierarchical micro/nano structures to control SW10 cell attachment and migration. It is shown that, depending on the laser processing conditions, distinct cell-philic or cell-repellant patterned areas can be attained with a desired motif. We envisage that our technique could enable spatial patterning of cells in a controllable manner, giving rise to advanced capabilities in cell biology research

Nanotechnology in peripheral nerve repair and reconstruction

The recent progress in biomaterials science and development of tubular conduits (TCs) still fails in solving the current challenges in the treatment of peripheral nerve injuries (PNIs), in particular when disease-related and long-gap defects need to be addressed. Nanotechnology-based therapies that seemed unreachable in the past are now being considered for the repair and reconstruction of PNIs, having the power to deliver bioactive molecules in a controlled manner, to tune cellular behavior, and ultimately guide tissue regeneration in an effective manner. It also offers opportunities in the imaging field, with a degree of precision never achieved before, which is useful for diagnosis, surgery and in the patientâ s follow-up. Nanotechnology approaches applied in PNI regeneration and theranostics, emphasizing the ones that are moving from the lab bench to the clinics, are herein overviewed.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for the financial support provided to Joaquim M. Oliveira (IF/01285/2015) and Joana Silva-Correia (IF/00115/2015) under the program “Investigador FCT”.info:eu-repo/semantics/publishedVersio

Controlling the Outgrowth and Functions of Neural Stem Cells: The Effect of Surface Topography

Neural stem cells (NSCs) are self-renewing cells that generate the major cell types of the central nervous system, namely neurons, astrocytes and oligodendrocytes, during embryonic development and in the adult brain. NSCs reside in a complex niche where they are exposed to a plethora of signals, including both soluble and physical signals such as compressive and shear stresses, but also discontinuities and differences in morphology of the extracellular environment, termed as topographical features. Different approaches that incorporate artificial micro- and nano-scale surface topographical features have been developed aiming to recapitulate the in vivo NSC niche discontinuities and features, particularly for in vitro studies. The present review article aims at reviewing the existing body of literature on the use of artificial micro- and nano-topographical features to control NSCs orientation and differentiation into neuronal and/or neuroglial lineage. The different approaches on the study of the underlying mechanism of the topography-guided NSC responses are additionally revised and discussed

Project An-Akalyptos: uncovering the potential of Exarcheia's, Athens, urban voids

Project: An-Akalyptos, examines the urban landscape of Athens and proposes a new strategy to address the issue of the lack of green communal spaces in the densely packed city, which suffers from the Heat Island Phenomenon. Athenian public spaces derive from an urban strategy that prioritises individualism over collectivism. As a result the city has a fragmented urban environment with no cohesive public spaces, numerous useless urban voids and limited green parks. It is crucial to implement effective planning strategies to reshape the city's urban environment, in order to provide a higher quality of life in the city centre. An-Akalyptos, is a non-greek-word, inspired from the project. It comes from the verb Anakalypto (Ανακαλύπτω), which means Uncover, in greek, and Akalyptos (Ακάλυπτος), which is the urban void. This study aims to uncover Athens' urban voids potential in order to revitalise them and change Athenians’ perspective about them. Its a theoretical design approach, that focuses on taking advantage of these currently abandoned spaces, in the neighbourhood of Exarcheia, called ‘Akalyptos’, and repurpose them as Urban Patios. The idea of the mediterranean patio house is adapted to the remnants of the athenian residential block, as domestic gardens in the city. Starting the transformation from the heart of the block, the vision is to reform the whole city as an open garden. These neglected spaces can be the extension of each house, the outdoor terrace, a green oasis that is missing from the athenian flat. Analysing the different case studies and the urban landscape of Exarcheia, the research provides data on the 151 Akalyptos of the district and triggers to reimagine the voids as an exit-oasis of the city. This collection of elements focus on improving the microclimate, increasing the urban attractiveness and strengthening the social inclusion of the communities