Laser-Assisted Fabrication of Injectable Nanofibrous Cell Carriers.

The use of injectable biomaterials for cell delivery is a rapidly expanding field which may revolutionize the medical treatments by making them less invasive. However, creating desirable cell carriers poses significant challenges to the clinical implementation of cell-based therapeutics. At the same time, no method has been developed to produce injectable microscaffolds (MSs) from electrospun materials. Here the fabrication of injectable electrospun nanofibers is reported on, which retain their fibrous structure to mimic the extracellular matrix. The laser-assisted micro-scaffold fabrication has produced tens of thousands of MSs in a short time. An efficient attachment of cells to the surface and their proliferation is observed, creating cell-populated MSs. The cytocompatibility assays proved their biocompatibility, safety, and potential as cell carriers. Ex vivo results with the use of bone and cartilage tissues proved that NaOH hydrolyzed and chitosan functionalized MSs are compatible with living tissues and readily populated with cells. Injectability studies of MSs showed a high injectability rate, while at the same time, the force needed to eject the load is no higher than 25 N. In the future, the produced MSs may be studied more in-depth as cell carriers in minimally invasive cell therapies and 3D bioprinting applications.

Three-Dimensional Printable Conductive Semi-Interpenetrating Polymer Network Hydrogel for Neural Tissue Applications.

Intrinsically conducting polymers (ICPs) are widely used to fabricate biomaterials; their application in neural tissue engineering, however, is severely limited because of their hydrophobicity and insufficient mechanical properties. For these reasons, soft conductive polymer hydrogels (CPHs) are recently developed, resulting in a water-based system with tissue-like mechanical, biological, and electrical properties. The strategy of incorporating ICPs as a conductive component into CPHs is recently explored by synthesizing the hydrogel around ICP chains, thus forming a semi-interpenetrating polymer network (semi-IPN). In this work, a novel conductive semi-IPN hydrogel is designed and synthesized. The hybrid hydrogel is based on a poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide) hydrogel where polythiophene is introduced as an ICP to provide the system with good electrical properties. The fabrication of the hybrid hydrogel in an aqueous medium is made possible by modifying and synthesizing the monomers of polythiophene to ensure water solubility. The morphological, chemical, thermal, electrical, electrochemical, and mechanical properties of semi-IPNs were fully investigated. Additionally, the biological response of neural progenitor cells and mesenchymal stem cells in contact with the conductive semi-IPN was evaluated in terms of neural differentiation and proliferation. Lastly, the potential of the hydrogel solution as a 3D printing ink was evaluated through the 3D laser printing method. The presented results revealed that the proposed 3D printable conductive semi-IPN system is a good candidate as a scaffold for neural tissue applications.

Repeat Administration of Bone Marrow-Derived Mesenchymal Stem Cells for Treatment of Amyotrophic Lateral Sclerosis.

BACKGROUND The aim of this study was to investigate repeated intrathecal injection of autologous bone marrow-derived mesenchymal stem cells (BM-D MSCs) to patients for treatment of sporadic amyotrophic lateral sclerosis (ALS). MATERIAL AND METHODS Autologous MSCs were isolated from the patients' bone marrow, plated, expanded, harvested, and passaged. Stem cells from a single bone marrow collection were used for 3 injections per patient, given over a 3-month period. Outcomes were measured with the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R). Participants were observed for a minimum of 6 months before transplantation to assess the natural course of ALS and for the same amount of time after transplantation to compare the rate of disease progression, estimated based on average monthly changes in ALSFRS-R scores. Data from 8 of the 15 participants eligible for the study were analyzed. RESULTS The safety of the MSC injections was confirmed and various effects of the therapy were documented. In patients who had ALS with an inherently slow course, there were no significant changes in the rate of disease progression. In patients who had ALS with an inherently rapid course, slowing of the disease was noted following treatment with MSCs. However, because that subgroup was so small, it was not possible to assess whether the changes were statistically significant. CONCLUSIONS Identifying groups of patients who are not responding or potentially responding negatively to injection of MSCs may help prevent it from being offered to individuals who may not benefit from the therapy. One of the limitations of this treatment method is the amount of time required for long-lasting preparation of bone marrow-derived MSCs for a disease that is rapidly progressive. Therefore, it is worth looking for other allogeneic sources of stromal cells for these types of injections.

Intrathecal administration of mesenchymal stem cells in patients with adrenomyeloneuropathy.

Background and objectives: X-linked adrenomyeloneuropathy (AMN) is an inherited neurodegenerative disorder associated with mutations in the ABCD1 gene and the accumulation of very long-chain fatty acids (VLFCAs) in plasma and tissues. Currently, there is no effective treatment for AMN. We have aimed to evaluate the therapeutic effects of mesenchymal stem cell (MSC) transplantation in patients with AMN. Methods: This is a small cohort open-label study with patients with AMN diagnosed and treated at the University Hospital in Olsztyn, Poland. All patients met clinical, biochemical, MRI, and neuropsychological criteria for AMN. MSCs derived from Wharton jelly, 20 × 106 cells, were administered intrathecally three times every 2 months, and patients were followed up for an additional 3 months. The primary outcome measures included a blinded assessment of lower limb muscle strength with the Medical Research Council Manual Muscle Testing scale at baseline and on every month visits until the end of the study. Additional outcomes included measurements of the timed 25-feet walk (T25FW) and VLFCA serum ratio. Results: Three male patients with AMN with an age range of 26-37 years participated in this study. All patients experienced increased muscle strength in the lower limbs at the end of the study versus baseline. The power grade increased by 25-43% at the baseline. In addition, all patients showed an improvement trend in walking speed measured with the T25FW test. Treatment with MSCs in patients with AMN appeared to be safe and well tolerated. Discussion: The results of this study demonstrated that intrathecal administration of WJ-MSC improves motor symptoms in patients with AMN. The current findings lend support to the safety and feasibility of MSC therapy as a potentially viable treatment option for patients with AMN.

Understanding Intra- and Inter-Species Variability in Neural Stem Cells' Biology Is Key to Their Successful Cryopreservation, Culture, and Propagation.

Although clinical trials on human neural stem cells (hNSCs) have already been implemented in the treatment of neurological diseases and they have demonstrated their therapeutic effects, many questions remain in the field of preclinical research regarding the biology of these cells, their therapeutic properties, and their neurorestorative potential. Unfortunately, scientific reports are inconsistent and much of the NSCs research has been conducted on rodents rather than human cells for ethical reasons or due to insufficient cell material. Therefore, a question arises as to whether or which conclusions drawn on the isolation, cell survival, proliferation, or cell fate observed in vitro in rodent NSCs can be introduced into clinical applications. This paper presents the effects of different spatial, nutritional, and dissociation conditions on NSCs' functional properties, which are highly species-dependent. Our study confirmed that the discrepancies in the available literature on NSCs survival, proliferation, and fate did not only depend on intra-species factors and applied environmental conditions, but they were also affected by significant inter-species variability. Human and rodent NSCs share one feature, i.e., the necessity to be cultured immediately after isolation, which significantly maintains their survival. Additionally, in the absence of experiments on human cells, rat NSCs biology (neurosphere formation potential and neural differentiation stage) seems closer to that of humans rather than mice in response to environmental factors.

Minimally Invasive Intradiscal Delivery of BM-MSCs via Fibrous Microscaffold Carriers.

Current treatments of degenerated intervertebral discs often provide only temporary relief or address specific causes, necessitating the exploration of alternative therapies. Cell-based regenerative approaches showed promise in many clinical trials, but limitations such as cell death during injection and a harsh disk environment hinder their effectiveness. Injectable microscaffolds offer a solution by providing a supportive microenvironment for cell delivery and enhancing bioactivity. This study evaluated the safety and feasibility of electrospun nanofibrous microscaffolds modified with chitosan (CH) and chondroitin sulfate (CS) for treating degenerated NP tissue in a large animal model. The microscaffolds facilitated cell attachment and acted as an effective delivery system, preventing cell leakage under a high disc pressure. Combining microscaffolds with bone marrow-derived mesenchymal stromal cells demonstrated no cytotoxic effects and proliferation over the entire microscaffolds. The administration of cells attached to microscaffolds into the NP positively influenced the regeneration process of the intervertebral disc. Injectable poly(l-lactide-co-glycolide) and poly(l-lactide) microscaffolds enriched with CH or CS, having a fibrous structure, showed the potential to promote intervertebral disc regeneration. These features collectively address critical challenges in the fields of tissue engineering and regenerative medicine, particularly in the context of intervertebral disc degeneration.

[Use of adipose tissue as a source of mesenchymal stem cells]. / Wykorzystanie tkanki tluszczowej jako zródla mezenchymalnych komórek macierzystych.

Enormous expectations are associated with stem cells with regard to cell therapy and tissue engineering. Stem cells have unlimited potential for self-renewal and develop into various cell types. For the mesodermal tissue engineering such a source of cells is the bone marrow stroma. However, isolation of the bone marrow requires general or spinal anesthesia and yields low number of mesodermal stem cells (MSCs) upon processing (1 MSC per 105 adherent stromal cells). An alternative source of autologous stem cells seems to be, apart from bone marrow: periosteum, muscular tissue or synovial membrane and adipose tissue. The adipose tissue is derived from the embryonic mesenchyme, contains a large number of stromal stem cells and is relatively easy to obtain in large quantities. It covers a widespread area of human body, and can be classified as white and brown adipose tissue in terms of location and function. Specimens of the adipose tissue are usually obtained from elective, laparoscopic or liposuction surgeries. Stromal stem cells, isolated from this tissue, exhibit characteristics common to mesodermal tissues, including: adherence to plastic, formation of fibroblastic- like colonies, extensive proliferative capacity, ability to differentiate into several mesodermal lineages (including bone, cartilage, muscle and fat), and expression of several common cell surface antigens. Recent evidence suggest that these cells can also form non-mesodermal tissues--neuron-like cells. The aim of this publication is to describe the application of the adipose tissue as a source of mesenchymal stem cells based on current literature data.

Immune Response to COVID-19: Can We Benefit from the SARS-CoV and MERS-CoV Pandemic Experience?

The global range and high fatality rate of the newest human coronavirus (HCoV) pandemic has made SARS-CoV-2 the focus of the scientific world. Next-generation sequencing of the viral genome and a phylogenetic analysis have shown the high homology of SARS-CoV-2 to other HCoVs that have led to local epidemics in the past. The experience acquired in SARS and MERS epidemics may prove useful in understanding the SARS-CoV-2 pathomechanism and lead to effective treatment and potential vaccine development. This study summarizes the immune response to SARS-CoV, MERS-CoV, and SARS-CoV-2 and focuses on T cell response, humoral immunity, and complement system activation in different stages of HCoVs infections. The study also presents the quantity and frequency of T cell responses, particularly CD4+ and CD8+; the profile of cytokine production and secretion; and its relation to T cell type, disease severity, and utility in prognostics of the course of SARS, MERS, and COVID-19 outbreaks. The role of interferons in the therapy of these infections is also discussed. Moreover, the kinetics of specific antibody production, the correlation between humoral and cellular immune response and the immunogenicity of the structural HCoVs proteins and their utility in the development of a vaccine against SARS, MERS, and COVID-19 has been updated.

Influence of Bone Marrow-Derived Mesenchymal Stem Cell Therapy on Oxidative Stress Intensity in Minimally Conscious State Patients.

Neurological disorders, including minimally conscious state (MCS), may be associated with the presence of high concentrations of reactive oxygen species within the central nervous system. Regarding the documented role of mesenchymal stem cells (MSCs) in oxidative stress neutralization, the aim of this study is to evaluate the effect of bone marrow-derived MSC (BM-MSC) transplantation on selected markers of oxidative stress in MCS patients. Antioxidant capacity was measured in cerebrospinal fluid (CSF) and plasma collected from nine patients aged between 19 and 45 years, remaining in MCS for 3 to 14 months. Total antioxidant capacity, ascorbic acid and ascorbate concentrations, superoxide dismutase, catalase, and peroxidase activity were analyzed and the presence of tested antioxidants in the CSF and plasma was confirmed. Higher ascorbic acid (AA) content and catalase (CAT) activity were noted in CSF relative to plasma, whereas superoxide dismutase (SOD) activity and total antioxidant capacity were higher in plasma relative to CSF. Total antioxidant capacity measured in CSF was greater after BM-MSC transplantations. The content of ascorbates was lower and CAT activity was higher both in CSF and plasma after the administration of BM-MSC. The above results suggest that MSCs modulate oxidative stress intensity in MCS patients, mainly via ascorbates and CAT activity.

Safety of intrathecal injection of Wharton's jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy.

Animal experiments have confirmed that mesenchymal stem cells can inhibit motor neuron apoptosis and inflammatory factor expression and increase neurotrophic factor expression. Therefore, mesenchymal stem cells have been shown to exhibit prospects in the treatment of amyotrophic lateral sclerosis. However, the safety of their clinical application needs to be validated. To investigate the safety of intrathecal injection of Wharton's jelly-derived mesenchymal stem cells in amyotrophic lateral sclerosis therapy, 43 patients (16 females and 27 males, mean age of 57.3 years) received an average dose of 0.42 × 106 cells/kg through intrathecal administration at the cervical, thoracic or lumbar region depending on the clinical symptoms. There was a 2 month interval between two injections. The adverse events occurring during a 6-month treatment period were evaluated. No adverse events occurred. Headache occurred in one case only after first injection of stem cells. This suggests that intrathecal injection of Wharton's Jelly-derived mesenchymal stem cells is well tolerated in patients with amyotrophic lateral sclerosis. This study was approved by the Bioethical Committee of School of Medicine, University of Warmia and Mazury in Olsztyn, Poland (approval No. 36/2014 and approval No. 8/2016). This study was registered with the ClinicalTrials.gov (identifier: NCT02881476) on August 29, 2016.

Evaluation of regenerative processes in the pig model of intervertebral disc degeneration after transplantation of bone marrow-derived mesenchymal stem cells.

INTRODUCTION: The pathophysiology of degenerative disc disease (DDD) is complex and not fully understood. While surgical treatment and appropriate rehabilitation offer relief of acute symptoms, there is a need to find tissue engineering strategies for intervertebral disc repair to restore healthy higher and histological structure. The purpose of this study was to estimate the survival rate of transplanted cells and their post-delivery integration level at the damage site. MATERIAL AND METHODS: We used an in vivo porcine model to investigate autogenic bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation for intervertebral disc repair. In our experiment we used a large animal model of DDD induced by percutaneous laser light deliveries. The percutaneous approach has also been used for delivery of BM-MSCs into the intervertebral disc space. RESULTS: After MSC transplantation, we observed a deceleration of the degenerative process in the intervertebral disc, relative to degenerative discs without MSC transplantation. CONCLUSIONS: By using a large animal model that mimicked the development of intervertebral degenerative disc disease, the present results are indicative of the clinical feasibility of this procedure.

Migration of human mesenchymal stem cells stimulated with pulsed electric field and the dynamics of the cell surface glycosylation.

BACKGROUND: The analysis of the stem cells' glycome dynamics at different stages of differentiation and migration makes possible the exploration of the cell surface glycans as markers of the stem cell functional status, and, in the future, compatibility between transplanted cell and host environment. OBJECTIVES: The objective of our study was to develop novel techniques of investigating cell motility and to assess whether the electric field of the therapeutic spinal cord stimulation system used in vivo contributes to the migration of human mesenchymal stem cells (hMSCs) in vitro. MATERIAL AND METHODS: We have investigated the electrotaxis of bone marrow-derived MSCs using pulsed electric field (PEF) in the range of 16-80 mV/mm and the frequency of 130 Hz and 240 Hz. The PEF-related dynamics of the cell surface glycosylation was evaluated using 6 plant lectins recognizing individual glycans. RESULTS: Pulsed electric field at physiological levels (10 mV/mm; 130 Hz) did not influence cellular motility in vitro, which may correspond to the maintenance of the transplanted cells at the lesion site in vivo. An increase of the PEF intensity and the frequency exceeding physiological levels resulted in an increase in the cellular migration rate in vitro. Pulsed electric field elevated above physiological intensity and frequency (40-80 mV/mm; 240 Hz), but not at physiological levels, resulted in changes of the cell surface glycosylation. CONCLUSIONS: We found the described approach convenient for investigations and for the in vitro modeling of the cellular systems intended for the regenerative cell transplantations in vivo. Probing cell surface glycomes may provide valuable biomarkers to assess the competence of transplanted cells.

The feasibility of the CD271+ and CD271- mesenchymal stromal cell enrichment toward nucleus pulposus-like cells.

INTRODUCTION: Factors promoting nerve cell ingrowth are considered responsible for chronic back pain resulting from the intervertebral disc degeneration (IDD). One of the recent exploratory IDD treatments is stem cell transplantation therapy. The CD271 (low-affinity nerve growth factor receptor) has been identified as a mark-er of the most homogeneous mesenchymal stem cell (MSC) subset. It is capable of promoting differentiation along adipogenic, osteogenic and chondrogenic lineages and producing significantly higher levels of cytokines as compared to the total population of plastic adherence-mesenchymal stem cells (PA-MSCs). We investigated the ability of CD271+ MSCs to differentiate into chondrocyte-like cells of the nucleus pulposus (NP) of intervertebral disc. We also examined CD271- MSCs, using PA-MSCs as a control cell population. MATERIAL AND METHODS: Bone marrow derived PA-MSCs and its two subsets, CD271- MSCs and CD271+ MSCs, were seeded in collagen scaffolds. After two weeks of growth in NP-differentiation medium, RNA was isolated from cells-scaffold constructs and was analyzed by q-PCR for expression of NP markers. Glycosaminoglycans were analyzed biochemically directly in cells-scaffold constructs. RESULTS: Expression of NP markers - extracellular matrix components such as aggrecan, collagen type II and glycosaminoglycans on both RNA and the protein levels - was significantly higher in CD271- MSCs compared to the CD271+ MSCs and PA-MSCs cell populations. CONCLUSIONS: CD271- MSCs may be superior candidates for NP restorative treatment compared to CD271+ MSCs and PA-MSCs due to their ability of expressing NP-supporting extracellular matrix components at levels higher than the other two studied MSC subsets.

Corrigendum to "Therapeutic Potential of Olfactory Ensheathing Cells and Mesenchymal Stem Cells in Spinal Cord Injuries".

[This corrects the article DOI: 10.1155/2017/3978595.].

Stem cells as therapy for cardiac disease - a review.

Acute myocardial infarction (AMI) is one of the most significant causes of morbidity and mortality worldwide. Stem cells represent an enormous chance to rebuild damaged heart tissue. Correct definition of the cardiac progenitors is necessary to understand heart development, and would pave the way for the use of cardiac progenitors in the treatment of heart disease. Identifying, purifying and differentiating native cardiac progenitor cells are indispensable if we are to overcome congenital and adult cardiac diseases. To understand their functions, physiology and action, cells are tested in animal models, and then in clinical trials. But because clinical trials yield variable results, questions about proper cardiac stem cells remain unanswered. Transplanted stem cells release soluble factors, acting in a paracrine fashion, which contributes to cardiac regeneration. Cytokines and growth factors have cytoprotective and neovascularizing functions, and may activate resident cardiac stem cells. Understanding all these mechanisms is crucial to overcoming heart diseases.