Can cell therapy restore muscle function?
AMELIE (Anchored Muscle cELls for IncontinencE) is a 5-year H2020 EU-funded research project. The consortium will work on a novel regenerative intervention using autologous skeletal muscle derived cells (ASMDC) to restore the function of the sphincter muscle. Scientists at SCERG will attach ASMDC to implantable microcarriers, to improve cell delivery and engraftment in patients with faecal incontinence. This strategy is expected to improve cell viability and increase the likelihood of muscle regeneration, contributing to improved continence.
Minicircle‐based Expression of VEGF in Mesenchymal Stromal Cells from Human Tissues
Mesenchymal stromal cells (MSC) have been exploited for the treatment of ischemic diseases given their angiogenic potential. A recent study published in the Journal of Gene Medicine by BERG and SCERG researchers compares the angiogenic potential of MSC obtained from bone marrow (BM), adipose tissue (AT) and umbilical cord matrix (UCM) that were genetically modified with VEGF‐encoding minicircle vectors. Transfected cells displayed higher in vitro angiogenic potential than non‐transfected controls, as demonstrated by functional in vitro assays, but no significant differences were observed among cells from different sources.
Modeling Rett Syndrome with Human Pluripotent Stem Cells: Mechanistic Outcomes and Future Clinical Perspectives
Rett syndrome (RTT) is a rare neurodevelopmental disorder caused by mutations in the gene encoding for the MeCP2 protein. Among many different roles, MeCP2 has a high phenotypic impact during the different stages of brain development. Thus, it is essential to intensively investigate the function of MeCP2 and its regulated targets. In this review paper, a team of researchers at SCERG-iBB provides a brief summary of the main neurological features of RTT and the impact of MeCP2 mutations in the neuropathophysiology of the disease. Then, it is also provided a thorough revision of the more recent advances and future prospects of RTT modeling using human neural cells derived from pluripotent stem cells obtained using both 2D and organoid culture systems, and its contribution for the current and future clinical trials for RTT.
Transcriptomic Profiling of Human Pluripotent Stem Cell-Derived Cerebellar Organoids
Endogenous human brain tissue is not easily available for studying neurodevelopment and neurodegenerative diseases. However, human pluripotent stem cells (PSCs) have been used to generate a variety of glial and neuronal cells of the central nervous system. Still, reproducible protocols for generating in vitro models of the human cerebellum are scarce. In this context, Silva et al. describe the scalable production of human PSC-derived cerebellar organoids using single-use vertical-wheel bioreactors. The transcriptomic profile of cerebellar organoids derived under dynamic conditions demonstrates a faster cerebellar differentiation combined with significant enrichment of extracellular matrix and upregulation of transcripts involved in angiogenesis when compared with the static protocol. The authors anticipate that large-scale production of cerebellar organoids may help developing models for drug screening, toxicological tests and studying pathological pathways involved in cerebellar degeneration.
Artificial cell matrixes: Why electrospun fibers matter in defining the composition of the extracellular matrix of neural cells?
Looking for a house to rent? How many did you actually clicked with? If you struggled with this, imagine how it feels with neural stem cells when researchers are designing artificial matrices just for them? The right matrices can make a big difference on a neural cell’s differentiation, and even influence the extracellular matrix (ECM) composition these cells produce. Among the various ECM molecules that exist, glycosaminoglycans stand out as the functional bridges/hands between living cells and their environment. Researchers at SCERG-iBB, in collaboration with Rensselaer Polytechnic Institute and Instituto de Telecomunicações, have evaluated the effect of electrospun scaffolds on the glycosaminoglycan profile of differentiating neural stem cells. The use of electrospun scaffolds for neural tissue engineering applications allows a closer mimicry of the native tissue extracellular matrix (ECM), important for the transplantation of cells in vivo. Until now, the effect of such scaffolds on the produced extracellular matrix has not been yet unveiled. In this work REN-VM cells (neural stem cell line) were differentiated on polycaprolactone (PCL) nanofibers, obtained by wet/wet electrospinning, and on flat glass lamellas. Glycosaminoglycan (GAG) analysis, using a highly sensitive liquid chromatography protocol (LC-MS/MS), was successfully used to evaluate the consequent changes in the GAG profile of differentiating cells. Cells cultured on electrospun fibers generate an ECM enriched with chondroitin sulfate, a main component of neural ECM. Moreover, they also secrete higher amounts of hyaluronic acid, possibly of its low molecular weight and a sign of cell plasticity! The authors conclude that REN-VM cells, when cultured on PCL fibers, produce a more neural-friendly ECM, similar to that present in the neural tissue and more suitable for tissue engineering applications.
An electrospun fiber-based platform was optimized for effective electrically stimulation of neural cells! How can a new solvent system impact the properties of polyaniline-based fibers so much?
Building platforms for electrically stimulate neural cells is no easy task. The secret is allying materials science and nanotechnology with regenerative medicine strategies. In the end, we can build better platforms, capable to promote neural stem cell differentiation into matured neurons; an effort that aims to contribute the far reaching aim of transplant off-shelf or customized produced neurons into patients! Inspired by this, researchers at SCERG-iBB, Rensselaer Polytechnic Institute and Instituto de Telecomunicações jointly optimized a method for the production of reliable electrospun platforms for the electrical stimulation of neural stem cells. The platform in question is composed of electrospun fibers of poly(caprolactone), biocompatible and FDA approved, and polyaniline, a well-known electroconductive and biocompatible polymer. The authors developed a new solvent system, comprised a mixture of hexafluoropropanol and trifluoroethanol (1:1), to boost both the electroconductivity (0.2 S cm-1) and the softness (1.6 ± 0.5 MPa) of the fibers, paramount for neural cell culture! The results obtained also suggest HFP promotes polyaniline chain relaxation through pseudo-doping, much like when you’re unwinding a yarn but using molecular interactions between polymers and with the solvent milieu! As a result, neural stem cells can be more effectively electrically stimulated. Using AC electrical current the authors could also induce cell alignment with the direction of the electrical field! Moreover, they managed to improve cell differentiation through the upregulation of neural (DCX, MAP2) and astrocytical (S100β) genes. The authors concluded that electrically stimulating cells can actually reduce the time needed for cells to obtain a matured profile. This in turn can be used to our advantage in developing new in vitro systems to study disease progression and test new drugs. And who knows, maybe one day we’ll transplant these same cells into diseased brains and cure neurodegenerative diseases, such as Alzheimer’s or Parkinson’s.
Electrical stimulation of neural stem cells on electroconductive platforms made of PEDOT:PSS
New frontiers of regenerative medicine are focusing on the generation of specific cell types and tissues upon culture of stem cells under the right cues. There are many cells in the human body that respond to electrical stimuli, prompting the use of electrical stimulation of stem cells to generate fully developed electrical responsive cells, such as neurons.
Ideally, such cues can be applied to cultured cells through electroconductive materials, among which conjugated polymers are the most promising. However, in the literature, there are still open questions about the stimuli application conditions and how they affect the differentiation of neural stem cells into mature neurons. In their most recent work, researchers at SCERG-iBB and IT decided to address these questions. In a first stage, they evaluated the performance of electroconductive platforms made of cross-linked conjugated polymer PEDOT:PSS in terms of conductivity and stability. Two different cross-linkers (GOPS and DVS) were investigated. After this critical step, three different protocols of electrical stimulation, using 3 different electrical currents (AC, DC and pulsatile DC), were compared for neural stem cell differentiation. They found that pulsatile DC assisted best in generating higher number of neurons. This is very important for future regenerative approaches to neurological diseases and highlights the importance of using the correct platform to design scaffolds to regenerate the brain tissue.
Special Issue on “Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine”
João Carlos Silva and Frederico Castelo Ferreira are guest-editing a special issue for the open-access journal “Polymers” entitled “Advanced Polymeric Scaffolds for Stem Cell Engineering and Regenerative Medicine”. Polymer scaffolds play a crucial role in tissue engineering and regenerative medicine applications since they can closely mimic the architecture of a native extracellular matrix (ECM) and improve the biological performance of cells both in vitro and in vivo. This Special Issue welcomes full research papers, communications and reviews on recent exciting developments of polymeric scaffolds for tissue engineering and regenerative medicine applications.