The influence of static magnetic fields on canine and equine mesenchymal stem cells derived from adipose tissue

Application of magnetism in tissue regeneration: recent progress and future prospects

Tissue regeneration is a hot topic in the field of biomedical research in this century. Material composition, surface topology, light, ultrasonic, electric field and magnetic fields (MFs) all have important effects on the regeneration process. Among them, MFs can provide nearly non-invasive signal transmission within biological tissues, and magnetic materials can convert MFs into a series of signals related to biological processes, such as mechanical force, magnetic heat, drug release, etc. By adjusting the MFs and magnetic materials, desired cellular or molecular-level responses can be achieved to promote better tissue regeneration. This review summarizes the definition, classification and latest progress of MFs and magnetic materials in tissue engineering. It also explores the differences and potential applications of MFs in different tissue cells, aiming to connect the applications of magnetism in various subfields of tissue engineering and provide new insights for the use of magnetism in tissue regeneration.

Static magnetic fields in regenerative medicine

All organisms on Earth live in the weak but ubiquitous geomagnetic field. Human beings are also exposed to magnetic fields generated by multiple sources, ranging from permanent magnets to magnetic resonance imaging (MRI) in hospitals. It has been shown that different magnetic fields can generate various effects on different tissues and cells. Among them, stem cells appear to be one of the most sensitive cell types to magnetic fields, which are the fundamental units of regenerative therapies. In this review, we focus on the bioeffects of static magnetic fields (SMFs), which are related to regenerative medicine. Most reports in the literature focus on the influence of SMF on bone regeneration, wound healing, and stem cell production. Multiple aspects of the cellular events, including gene expression, cell signaling pathways, reactive oxygen species, inflammation, and cytoskeleton, have been shown to be affected by SMFs. Although no consensus yet, current evidence indicates that moderate and high SMFs could serve as a promising physical tool to promote bone regeneration, wound healing, neural differentiation, and dental regeneration. All in vivo studies of SMFs on bone regeneration and wound healing have shown beneficial effects, which unravel the great potential of SMFs in these aspects. More mechanistic studies, magnetic field parameter optimization, and clinical investigations on human bodies will be imperative for the successful clinical applications of SMFs in regenerative medicine.

The Role of Mesenchymal Stem Cell Secretome (Extracellular Microvesicles and Exosomes) in Animals' Musculoskeletal and Neurologic-Related Disorders

The advances in regenerative medicine are very important for the development of medicine and the discovery of stem cells has shown a greater capacity to raise the level of therapeutic quality while their use becomes more accessible, especially in their mesenchymal form. In veterinary medicine, it is not different. The use of those cells, as well as recent advances related to the use of their extracellular vesicles, demonstrates a great opportunity to enhance therapeutic methods and ensure more life quality for patients, which can be in clinical or surgical treatments. Knowing the advances in these modalities and the growing clinical and surgery research and demands for innovations in orthopedic and neurology medicines, this paper aimed to review the literature about the methodologies of use and applications such as the pathways of action and the advances that were postulated for microvesicles and exosomes derived from mesenchymal stem cells in veterinary medicine, especially for musculoskeletal disorders and related injuries.

Effects of MRI on stemness properties of Wharton's jelly-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs), derived from various tissues, are served as a promising source of cells in clinic and regenerative medicine. Umbilical cord-Wharton's jelly (WJ-MSCs)-derived MSCs exhibit advantages over those from adult tissues, such as no ethical concerns, shorter population doubling time, broad differentiation potential, readily available non-invasive source, prolonged maintenance of stemness properties. The aim of this study was to evaluate the effect of MRI (1.5 T, 10 min) on stemness gene expression patterns (OCT-4, SOX-2, NANOG) of WJ-MSCs. Additionally, we assessed cell viability, growth kinetics and apoptosis of WJ-MSCs after MRI treatment. The quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) data showed that transcript levels of SOX-2, NANOG in MRI-treated WJ-MSCs were increased 32- and 213-fold, respectively. MTT assay was performed at 24, 48, and 72 h post-treatment and the viability was not significantly different between the two groups. The doubling time of the MRI group was markedly higher than the control group. In addition, the colony formation ability of WJ-MSCs after MRI treatment significantly increased. Furthermore, no change in apoptosis was seen before or after MRI treatment. Our results suggest that the use of MRI can improve the quality of MSCs and enhance the efficacy of mesenchymal stem cell-based therapies.

The current status of stimuli-responsive nanotechnologies on orthopedic titanium implant surfaces

With the continuous innovation and breakthrough of nanomedical technology, stimuli-responsive nanotechnology has been gradually applied to the surface modification of titanium implants to achieve brilliant antibacterial activity and promoted osteogenesis. Regarding to the different physiological and pathological microenvironment around implants before and after surgery, these surface nanomodifications are designed to respond to different stimuli and environmental changes in a timely, efficient, and specific way/manner. Here, we focus on the materials related to stimuli-responsive nanotechnology on titanium implant surface modification, including metals and their compounds, polymer materials and other materials. In addition, the mechanism of different response types is introduced according to different activation stimuli, including magnetic, electrical, photic, radio frequency and ultrasonic stimuli, pH and enzymatic stimuli (the internal stimuli). Meanwhile, the associated functions, potential applications and developing prospect were discussion.

Static magnetic field: A potential tool of controlling stem cells fates for stem cell therapy in osteoporosis

Osteoporosis is a kind of bone diseases characterized by dynamic imbalance of bone formation and bone absorption, which is prone to fracture, and seriously endangers human health. At present, there is a lack of highly effective drugs for it, and the existing measures all have some side effects. In recent years, mesenchymal stem cell therapy has brought a certain hope for osteoporosis, while shortcomings such as homing difficulty and unstable therapeutic effects limit its application widely. Therefore, it is extremely urgent to find effective and reliable means/drugs for adjuvant stem cell therapy or develop new research techniques. It has been reported that static magnetic fields(SMFs) has a certain alleviating and therapeutic effect on varieties of bone diseases, also promotes the proliferation and osteogenic differentiation of mesenchymal stem cells derived from different tissues to a certain extent. Basing on the above background, this article focuses on the key words "static/constant magnetic field, mesenchymal stem cell, osteoporosis", combined literature and relevant contents were studied to look forward that SMFs has unique advantages in the treatment of osteoporosis with mesenchymal stem cells, which can be used as an application tool to promote the progress of stem cell therapy in clinical application.

Production enhancement of human adipose-derived mesenchymal stem cells by low-intensity ultrasound stimulation

Low-intensity ultrasound (LIUS) enhances the proliferation rate of various mammalian stem cells through mechanical stimulation. This study quantitively finds suitable LIUS stimulation parameters for increasing the proliferation rate of human adipose-derived mesenchymal stem cells (hAdMSCs) for mass production. Various stimulation conditions of LIUS were assessed based on the beam pattern of the ultrasonic transducer and the attenuation of the sound waves. Using optimal LIUS stimulation parameters for enhancing proliferation of hAdMSCs taken from bromodeoxyuridine (BrdU) incorporation assay, long-term culture of hAdMSCs was performed for 16 days. The resultant hAdMSCs were characterized for various biomarkers such as CD34-, CD45-, CD73+, CD95+, CD105+ and cytological staining and a cytokine array assay. LIUS stimulation parameters found for enhancing the hAdMSCs proliferation were the frequency of 5 MHz, an intensity of 300 mWcm^-2, a duration of 10 min per day, and continuous waves with a 100% duty cycle. The LIUS stimulated hAdMSCs group showed a 3.25-fold increase in the cell number compared to the control group after 16 days of culture. By confirming the effects of quantitatively measured LIUS stimulation on the enhancement of hAdMSCs proliferation, this study may be a foundation for the applications of LIUS stimulation in the industrial-scale production of hAdMSCs.

Selected Techniques for Physiotherapy in Dogs

Simple Summary

Animal physiotherapy is widely addressed in many scientific reports. Although the effectiveness of physiotherapy has been repeatedly proven in both human and animal models, a small percentage of animal keepers decide to implement physiotherapy as part of treatment programs for their pets. After horses, dogs are the second group of animals that are most frequently subjected to physiotherapy treatments. The present study compiles the current knowledge of canine physiotherapy methods. An attempt was made to systematize this knowledge through selection and description of the most important aspects of canine physiotherapy. Most of the physiotherapeutic methods have been transferred from human treatment protocols. A key issue in the achievement of therapy success is the proper selection of physiotherapeutic procedures and close cooperation between the veterinarian and the physiotherapist.

Abstract

Physiotherapy is a new dynamically developing field of science in which the original idea was to improve the care for convalescent patients. Its positive effects observed in humans suggested the need for the adaptation and implementation of human physiotherapy techniques in animal care. Dogs are the second group of animals that undergo physiotherapy most frequently. These animals are diagnosed with a number of locomotor system problems, which may be congenital and are often related to the breed or acquired. The aim of the study was to collect and systematize knowledge of animal physiotherapy with emphasis on the selection and description of the most important aspects of canine physiotherapy. The review material consisted of 59 publications, with 230 selected for the review. Physiotherapeutic treatments are applied not only for rehabilitation of animals but also in healthy animals to upgrade their sports performance and improve their welfare. A majority of physiotherapeutic approaches have been transferred from human protocols. A key issue in the achievement of therapy success is the proper selection of physiotherapeutic procedures and close cooperation between the veterinarian and the physiotherapist.

Magnetic exposure using Samarium Cobalt (SmCO5) increased proliferation and stemness of human Umbilical Cord Mesenchymal Stem Cells (hUC-MSCs)

Despite the extensive reports on the potential hazard of magnetic field (MF) exposures on humans, there are also concurrently reported on the improved proliferative property of stem cells at optimum exposure. However, the effect on mesenchymal stem cells (MSCs) remains unknown. Therefore, we aimed to investigate the impact of induced static MF (SMF) on human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) using Samarium Cobalt (SmCO5). At passage 3, hUC-MSCs (1 × 10⁴) were exposed to 21.6 mT SMF by a direct exposure (DE) showed a significantly higher cell count (p < 0.05) in the growth kinetics assays with the shortest population doubling time relative to indirect exposure and negative control. The DE group was committed into the cell cycle with increased S phase (55.18 ± 1.38%) and G2/M phase (21.75 ± 1.38%) relative to the NC group [S-phase (13.54 ± 2.73%); G2/M phase (8.36 ± 0.28%)]. Although no significant changes were observed in the immunophenotype, the DE group showed an elevated expression of pluripotency-associated markers (OCT4, SOX2, NANOG, and REX1). These results suggest that the MFs could potentially induce proliferation of MSCs, a promising approach to promote stem cells propagation for clinical therapy and research without compromising the stemness of hUC-MSCs.

Angiogenic Effects and Crosstalk of Adipose-Derived Mesenchymal Stem/Stromal Cells and Their Extracellular Vesicles with Endothelial Cells

Adipose-derived mesenchymal stem/stromal cells (ASCs) are an adult stem cell population able to self-renew and differentiate into numerous cell lineages. ASCs provide a promising future for therapeutic angiogenesis due to their ability to promote blood vessel formation. Specifically, their ability to differentiate into endothelial cells (ECs) and pericyte-like cells and to secrete angiogenesis-promoting growth factors and extracellular vesicles (EVs) makes them an ideal option in cell therapy and in regenerative medicine in conditions including tissue ischemia. In recent angiogenesis research, ASCs have often been co-cultured with an endothelial cell (EC) type in order to form mature vessel-like networks in specific culture conditions. In this review, we introduce co-culture systems and co-transplantation studies between ASCs and ECs. In co-cultures, the cells communicate via direct cell-cell contact or via paracrine signaling. Most often, ASCs are found in the perivascular niche lining the vessels, where they stabilize the vascular structures and express common pericyte surface proteins. In co-cultures, ASCs modulate endothelial cells and induce angiogenesis by promoting tube formation, partly via secretion of EVs. In vivo co-transplantation of ASCs and ECs showed improved formation of functional vessels over a single cell type transplantation. Adipose tissue as a cell source for both mesenchymal stem cells and ECs for co-transplantation serves as a prominent option for therapeutic angiogenesis and blood perfusion in vivo.

Magnetic stimulation of the angiogenic potential of mesenchymal stromal cells in vascular tissue engineering

The growing prevalence of vascular diseases worldwide has emphasized the need for novel tissue-engineered options concerning the development of vascularized 3D constructs. This study reports, for the first time, the use of external magnetic fields to stimulate mesenchymal stromal cells (MSCs) to increase the production of vascular endothelial growth factor-A (VEGF-A). Polyvinylalcohol and gelatin-based scaffolds, containing iron oxide nanoparticles, were designed for optimal cell magnetic stimulation. While the application of static magnetic fields over 24 h did not impact on MSCs proliferation, viability and phenotypic identity, it significantly increased the production of VEGF-A and guided MSCs morphology and alignment. The ability to enhance MSCs angiogenic potential was demonstrated by the increase in the number of new vessels formed in the presence of MSCs conditioned media through in vitro and in vivo models. Ultimately, this study uncovers the potential to manipulate cellular processes through short-term magnetic stimulation.

Adipose-Derived Stromal/Stem Cells from Large Animal Models: from Basic to Applied Science

Adipose-derived stem cells (ASCs) isolated from domestic animals fulfill the qualitative criteria of mesenchymal stem cells, including the capacity to differentiate along multiple lineage pathways and to self-renew, as well as immunomodulatory capacities. Recent findings on human diseases derived from studying large animal models, have provided evidence that administration of autologous or allogenic ASCs can improve the process of healing. In a narrow group of large animals used in bioresearch studies, pigs and horses have been shown to be the best suited models for study of the wound healing process, cardiovascular and musculoskeletal disorders. To this end, current literature demonstrates that ASC-based therapies bring considerable benefits to animal health in both spontaneously occurring and experimentally induced clinical cases. The purpose of this review is to provide an overview of the diversity, isolation, and characterization of ASCs from livestock. Particular attention has been paid to the functional characteristics of the cells that facilitate their therapeutic application in large animal models of human disease. In this regard, we describe outcomes of ASCs utilization in translational research with pig and horse models of disease. Furthermore, we evaluate the current status of ASC-based therapy in veterinary practice, particularly in the rapidly developing field of equine regenerative medicine. In conclusion, this review presents arguments that support the relevance of animal ASCs in the field of regenerative medicine and it provides insights into the future perspectives of ASC utilization in animal husbandry.

Applications, challenges, and strategies in the use of nanoparticles as feed additives in equine nutrition

The rapid expansion of nanotechnology has been transforming the food industry by increasing market share and expenditure. Although nanotechnology offers promising benefits as feed additives, their usage in equines is primarily geared toward immunotherapy, hyper-immunization techniques, drug delivery systems, grooming activities, and therapeutic purposes. Nanoparticles could be engaged as alternatives for antibiotic feed additives to prevent foal diarrhea. Gold nanoparticles are proved to provide beneficial effects for racehorses by healing joint and tendon injuries. Because of the poor bioavailability of micro-sized mineral salts, the usage of nano-minerals is highly encourageable to improve the performance of racehorses. Nano-Vitamin E and enzyme CoQ10 for equines are no longer a simple research topic because of the increased commercial availability. Employing nanotechnology-based preservatives may offer a promising alternative to other conventional preservatives in preserving the quality of equine feed items, even during an extended storage period. While nanoparticles as feed additives may provide multitudinous benefits on equines, they could elicit allergic or toxic responses in case of improper synthesis aids or inappropriate dosages. The safety of nano-feed additives remains uninvestigated and necessitates the additional risk assessment, especially during their usage for a prolonged period. To adopt nano-feed additives in horses, there is an extreme paucity of information regarding the validity of various levels or forms of nanoparticles. Further, the currently available toxicological database on the topic of nano-feed additives is not at all related to equines and even inadequate for other livestock species. This review aims to provide new insights into possible future research pertaining to the usage of nano-feed additives in equines.

Static magnetic field-enhanced osteogenic differentiation of human umbilical cord-derived mesenchymal stem cells via matrix vesicle secretion

METHODS

In methodology, WJMSCs were treated with a 0.4-T SMF. The cell viability was tested using the MTT assay. For the osteogenic analysis, the alkaline phosphatase activity assay and alizarin red S staining were performed. The osteogenic-related gene expression of ALP, BMP-2, and Runx2 was examined using real-time polymerase chain reaction. Scanning electron microscopy combined with energy-dispersive X-ray spectroscopy was used to analyze matrix vesicle secretion.

RESULTS

The cell viability showed no significant difference between the SMF-treated group and the sham-exposed cells. However, the SMF-treated group exhibited significantly more mineralized nodule formation and higher ALP activity than their control counterparts (p < .05). The expressions of osteogenic-related markers, ALP, BMP-2, and Runx2, were also significantly higher in the SMF-treated WJMSCs. The scanning electron microscopy results showed much more matrix vesicle secretion in the SMF-treated cells than in the sham-treated cells. A mineralized sheath was noted in the SMF-treated cells, along with a sporadic accumulation of spherical mineralized deposits on the cell surface.

CONCLUSIONS

The results suggest that 0.4-T SMF treatment enhances the osteogenesis of WJMSCs at the early-to-middle stage of osteogenic differentiation by increasing the matrix vesicle secretion and mineralization.

Static Magnetic Field (SMF) as a Regulator of Stem Cell Fate - New Perspectives in Regenerative Medicine Arising from an Underestimated Tool

Tissue engineering and stem cell-based therapies are one of the most rapidly developing fields in medical sciences. Therefore, much attention has been paid to the development of new drug-delivery systems characterized by low cytotoxicity, high efficiency and controlled release. One of the possible strategies to achieve these goals is the application of magnetic field and/or magnetic nanoparticles, which have been shown to exert a wide range of effects on cellular metabolism. Static magnetic field (SMF) has been commonly used in medicine as a tool to increase wound healing, bone regeneration and as a component of magnetic resonance technique. However, recent data shed light on deeper mechanism of SMF action on physiological properties of different cell populations, including stem cells. In the present review, we focused on SMF effects on stem cell biology and its possible application as a tool for controlled drug delivery. We also highlighted the perspectives, in which SMF can be used in future therapies in tissue engineering due to its easy application and a wide range of possible effects on cells and organisms.

Metformin Increases Proliferative Activity and Viability of Multipotent Stromal Stem Cells Isolated from Adipose Tissue Derived from Horses with Equine Metabolic Syndrome

In this study, we investigated the influence of metformin (MF) on proliferation and viability of adipose-derived stromal cells isolated from horses (EqASCs). We determined the effect of metformin on cell metabolism in terms of mitochondrial metabolism and oxidative status. Our purpose was to evaluate the metformin effect on cells derived from healthy horses (EqASCHE) and individuals affected by equine metabolic syndrome (EqASCEMS). The cells were treated with 0.5 μM MF for 72 h. The proliferative activity was evaluated based on the measurement of BrdU incorporation during DNA synthesis, as well as population doubling time rate (PDT) and distribution of EqASCs in the cell cycle. The influence of metformin on EqASC viability was determined in relation to apoptosis profile, mitochondrial membrane potential, oxidative stress markers and BAX/BCL-2 mRNA ratio. Further, we were interested in possibility of metformin affecting the Wnt3a signalling pathway and, thus, we determined mRNA and protein level of WNT3A and β-catenin. Finally, using a two-tailed RT-qPCR method, we investigated the expression of miR-16-5p, miR-21-5p, miR-29a-3p, miR-140-3p and miR-145-5p. Obtained results indicate pro-proliferative and anti-apoptotic effects of metformin on EqASCs. In this study, MF significantly improved proliferation of EqASCs, which manifested in increased synthesis of DNA and lowered PDT value. Additionally, metformin improved metabolism and viability of cells, which correlated with higher mitochondrial membrane potential, reduced apoptosis and increased WNT3A/β-catenin expression. Metformin modulates the miRNA expression differently in EqASCHE and EqASCEMS. Metformin may be used as a preconditioning agent which stimulates proliferative activity and viability of EqASCs.

Iron oxide nanoparticles promote the migration of mesenchymal stem cells to injury sites

Background

Developing new methods to deliver cells to the injured tissue is a critical factor in translating cell therapeutics research into clinical use; therefore, there is a need for improved cell homing capabilities.

Materials and methods

In this study, we demonstrated the effects of labeling rat bone marrow-derived mesenchymal stem cells (MSCs) with fabricated polydopamine (PDA)-capped Fe₃O₄ (Fe₃O₄@PDA) superparticles employing preassembled Fe₃O₄ nanoparticles as the cores.

Results

We found that the Fe₃O₄@PDA composite superparticles exhibited no adverse effects on MSC characteristics. Moreover, iron oxide nanoparticles increased the number of MSCs in the S-phase, their proliferation index and migration ability, and their secretion of vascular endothelial growth factor relative to unlabeled MSCs. Interestingly, nanoparticles not only promoted the expression of C-X-C chemokine receptor 4 but also increased the expression of the migration-related proteins c-Met and C-C motif chemokine receptor 1, which has not been reported previously. Furthermore, the MSC-loaded nanoparticles exhibited improved homing and anti-inflammatory abilities in the absence of external magnetic fields in vivo.

Conclusion

These results indicated that iron oxide nanoparticles rendered MSCs more favorable for use in injury treatment with no negative effects on MSC properties, suggesting their potential clinical efficacy.

Nanocrystalline Hydroxyapatite Loaded with Resveratrol in Colloidal Suspension Improves Viability, Metabolic Activity and Mitochondrial Potential in Human Adipose-Derived Mesenchymal Stromal Stem Cells (hASCs)

In response to the demand for new multifunctional materials characterized by high biocompatibility, hydrogel (HG) nanocomposites as a platform for bioactive compound delivery have been developed and fabricated. A specific crosslinking/copolymerization chemistry was used to construct hydrogels with a controlled network organization. The hydrogels were prepared using 3,6-anhydro-α-l-galacto-β-d-galactan (galactose hydrogel) together with resveratrol (trans-3,5,4'-trihydroxystilbene) and calcium hydroxyapatite nanoparticles. The resveratrol was introduced in three different concentrations of 0.1, 0.5, and 1 mM. Nanosized calcium hydroxyapatite was synthesized by a microwave-assisted hydrothermal technique, annealed at 500 °C for 3 h, and introduced at a concentration 10% (m/v). The morphology and structural properties of Ca10(PO₄)₆(OH)₂ and its composite were determined by using XRPD (X-ray powder diffraction) techniques, as well as the absorption and IR (infrared) spectroscopy. The average nanoparticle size was 35 nm. The water affinity, morphology, organic compound release profile, and cytocompatibility of the obtained materials were studied in detail. The designed hydrogels were shown to be materials of biological relevance and of great pharmacological potential as carriers for bioactive compound delivery. Their cytocompatibility was tested using a model of human multipotent stromal cells isolated from adipose tissue (hASCs). The biomaterials increased the proliferative activity and viability of hASCs, as well as reduced markers of oxidative stress. In light of the obtained results, it has been thought that the designed materials meet the requirements of the tissue engineering triad, and may find application in regenerative medicine, especially for personalized therapies.

The Potential of Intrinsically Magnetic Mesenchymal Stem Cells for Tissue Engineering

The magnetization of mesenchymal stem cells (MSC) has the potential to aid tissue engineering approaches by allowing tracking, targeting, and local retention of cells at the site of tissue damage. Commonly used methods for magnetizing cells include optimizing uptake and retention of superparamagnetic iron oxide nanoparticles (SPIONs). These appear to have minimal detrimental effects on the use of MSC function as assessed by in vitro assays. The cellular content of magnetic nanoparticles (MNPs) will, however, decrease with cell proliferation and the longer-term effects on MSC function are not entirely clear. An alternative approach to magnetizing MSCs involves genetic modification by transfection with one or more genes derived from Magnetospirillum magneticum AMB-1, a magnetotactic bacterium that synthesizes single-magnetic domain crystals which are incorporated into magnetosomes. MSCs with either or mms6 and mmsF genes are followed by bio-assimilated synthesis of intracytoplasmic magnetic nanoparticles which can be imaged by magnetic resonance (MR) and which have no deleterious effects on MSC proliferation, migration, or differentiation. The stable transfection of magnetosome-associated genes in MSCs promotes assimilation of magnetic nanoparticle synthesis into mammalian cells with the potential to allow MR-based cell tracking and, through external or internal magnetic targeting approaches, enhanced site-specific retention of cells for tissue engineering.

Transfer of cells with uptaken nanocomposite, magnetite-nanoparticle functionalized capsules with electromagnetic tweezers

Targeted cell delivery via electromagnetic tweezers.

The Effect of Low-Magnitude Low-Frequency Vibrations (LMLF) on Osteogenic Differentiation Potential of Human Adipose Derived Mesenchymal Stem Cells

Introduction

In the current study, we investigated the effect of low magnitude, low frequency (LMLF) mechanical vibrations on the osteogenic differentiation potential of human adipose derived mesenchymal stem cells (hASC), taken from elderly patients.

Methods

During 21 days in osteogenic culture medium, cells were periodically exposed to three different frequencies (25, 35 and 45 Hz) of continuous sinusoidal oscillation, using a vibration generator. We measured cell proliferation, cell morphology, calcium and phosphorus deposition using Almar Blue assay, fluorescence microscopy, scanning electron microscopy, and a EDX detector, respectively. Osteogenic differentiation was measured by assessing protein and mRNA levels. Osteogenesis was confirmed by detection of specific markers with alkaline phosphatase and enzyme-linked immunosorbent assays for: bone morphogenetic protein 2 (BMP-2), osteocalcin (OCL) and osteopontin (OPN).

Results

We found that 25 Hz vibrations had the greatest impact on hASC morphology, ultrastructure, and proliferation. We observed the formation of osteocyte- and hydroxyapatite-like structures, an increased quantity of calcium and phosphorus deposits, and increased differentiation in the stimulated groups.

Conclusions

Our findings suggest that LMLF vibrations could be used to enhance cell-based therapies for treatment of bone deficits, particularly in elderly patients, where the need is greatest.

Magnetic targeting as a strategy to enhance therapeutic effects of mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) have been extensively investigated in the field of regenerative medicine. It is known that the success of MSC-based therapies depends primarily on effective cell delivery to the target site where they will secrete vesicles and soluble factors with immunomodulatory and potentially reparative properties. However, some lesions are located in sites that are difficult to access, such as the heart, spinal cord, and joints. Additionally, low MSC retention at target sites makes cell therapy short-lasting and, therefore, less effective. In this context, the magnetic targeting technique has emerged as a new strategy to aid delivery, increase retention, and enhance the effects of MSCs. This approach uses magnetic nanoparticles to magnetize MSCs and static magnetic fields to guide them in vivo, thus promoting more focused, effective, and lasting retention of MSCs at the target site. In the present review, we discuss the magnetic targeting technique, its principles, and the materials most commonly used; we also discuss its potential for MSC enhancement, and safety concerns that should be addressed before it can be applied in clinical practice.

The Effect of Co0.2Mn0.8Fe2O4 Ferrite Nanoparticles on the C2 Canine Mastocytoma Cell Line and Adipose-Derived Mesenchymal Stromal Stem Cells (ASCs) Cultured Under a Static Magnetic Field: Possible Implications in the Treatment of Dog Mastocytoma

Cobalt manganese ferrite nanoparticles have application potential in the biomedical field, however there is limited information concerning the biological response. The aim of this work was to investigate the cytotoxic potential of cobalt-manganese ferrite nanoparticles in canine mastocytoma tumor cells (C2) and adipose-derived mesenchymal stromal stem cells (ASCs) cultured under a static magnetic field (MF). In this study, we investigated the viability and proliferation rate of ASC and C2 cells cultured with Co0.2Mn0.8Fe2O4 nanoparticles under 0.5T MF. We observed cells morphology and measured intracellular ROS generation. Thermal observations were used to characterize the thermotrophic cell behavior in different condition and RNA level of heat shock proteins and apoptotic genes was measured. Nanoparticles reduced cell viability, caused cell damage, i.e., through the formation of reactive oxygen species (ROS) and increased transcriptional level of apoptotic genes (Bcl-2, Bax, p53, p21). In addition, we have found that C2 mastocytoma cells cultured with metal oxide nanoparticles under MF exhibited unexpected biological responses, including thermotolerance and apoptotic response induced by the expression of heat shock proteins and ROS produced under a MF. Our results suggest that stimulation using MF and Co0.2Mn0.8Fe2O4 nanoparticles is involved in mechanisms associated with controlling cell proliferative potential signaling events. We can state that significant differences between normal and cancer cells in response to nanoparticles and MF are apparent. Our results show that nanoparticles and MF elevate the temperature in vitro in tumor cells, thereby increasing the expression of ROS as well as heat shock proteins.

Equine metabolic syndrome impairs adipose stem cells osteogenic differentiation by predominance of autophagy over selective mitophagy

Adipose‐derived mesenchymal stem cells (ASC) hold great promise in the treatment of many disorders including musculoskeletal system, cardiovascular and/or endocrine diseases. However, the cytophysiological condition of cells, used for engraftment seems to be fundamental factor that might determine the effectiveness of clinical therapy. In this study we investigated growth kinetics, senescence, accumulation of oxidative stress factors, mitochondrial biogenesis, autophagy and osteogenic differentiation potential of ASC isolated from horses suffered from equine metabolic syndrome (EMS). We demonstrated that EMS condition impairs multipotency/pluripotency in ASCs causes accumulation of reactive oxygen species and mitochondria deterioration. We found that, cytochrome c is released from mitochondria to the cytoplasm suggesting activation of intrinsic apoptotic pathway in those cells. Moreover, we observed up‐regulation of p21 and decreased ratio of Bcl‐2/BAX. Deteriorations in mitochondria structure caused alternations in osteogenic differentiation of ASC_EMS resulting in their decreased proliferation rate and reduced expression of osteogenic markers BMP‐2 and collagen type I. During osteogenic differentiation of ASC_EMS, we observed autophagic turnover as probably, an alternative way to generate adenosine triphosphate and amino acids required to increased protein synthesis during differentiation. Downregulation of PGC1α, PARKIN and PDK4 in differentiated ASC_EMS confirmed impairments in mitochondrial biogenesis and function. Hence, application of ASC_EMS into endocrinological or ortophedical practice requires further investigation and analysis in the context of safeness of their application.

Static magnetic field enhances the viability and proliferation rate of adipose tissue-derived mesenchymal stem cells potentially through activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway

The aim of this work was to investigate the effects of 0.5T static magnetic field (sMF) on the viability and proliferation rate of human adipose-derived mesenchymal stromal stem cells (hASCs) via activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathway. In a 7-d culture we examined cell growth kinetic and population doubling time (PDT). We also examined cell morphology and the cellular senescence markers level. Exposure to sMF enhanced the viability of these cells. However, the effect was blocked by treating the cells with LY294002, a P13K inhibitor. We compared this effect by Western Blot analysis of Akt protein expression. We also examined whether the cell response on sMF stimulation is dependent on integrin engagement and we measured integrin gene expression. Our results suggest that stimulation using sMF is a viable method to improve hASC viability. sMF is involved in mechanisms associated with controlling cell proliferative potential signaling events.

Low-frequency, low-magnitude vibrations (LFLM) enhances chondrogenic differentiation potential of human adipose derived mesenchymal stromal stem cells (hASCs)

The aim of this study was to evaluate if low-frequency, low-magnitude vibrations (LFLM) could enhance chondrogenic differentiation potential of human adipose derived mesenchymal stem cells (hASCs) with simultaneous inhibition of their adipogenic properties for biomedical purposes. We developed a prototype device that induces low-magnitude (0.3 g) low-frequency vibrations with the following frequencies: 25, 35 and 45 Hz. Afterwards, we used human adipose derived mesenchymal stem cell (hASCS), to investigate their cellular response to the mechanical signals. We have also evaluated hASCs morphological and proliferative activity changes in response to each frequency. Induction of chondrogenesis in hASCs, under the influence of a 35 Hz signal leads to most effective and stable cartilaginous tissue formation through highest secretion of Bone Morphogenetic Protein 2 (BMP-2), and Collagen type II, with low concentration of Collagen type I. These results correlated well with appropriate gene expression level. Simultaneously, we observed significant up-regulation of α3, α4, β1 and β3 integrins in chondroblast progenitor cells treated with 35 Hz vibrations, as well as Sox-9. Interestingly, we noticed that application of 35 Hz frequencies significantly inhibited adipogenesis of hASCs. The obtained results suggest that application of LFLM vibrations together with stem cell therapy might be a promising tool in cartilage regeneration.

Inhibition of Viability, Proliferation, Cytokines Secretion, Surface Antigen Expression, and Adipogenic and Osteogenic Differentiation of Adipose-Derived Stem Cells by Seven-Day Exposure to 0.5 T Static Magnetic Fields

After seven-day exposure to 0.5-Tesla Static Magnetic Field (SMF), Adipose-derived Stem Cells (ASCs) and those labeled by superparamagnetic iron oxide (SPIO) nanoparticles were examined for viability by methyl thiazol tetrazolium (MTT) assay, proliferation by cell counting and bromodeoxyuridine (BrdU) incorporation, DNA integrity by single cell gel electrophoresis, surface antigen by flow cytometry analysis, and the expression of cytokines and genetic markers by reverse transcription-PCR and underwent adipogenic and osteogenic differentiation assessed by quantifying related specific genes expression. The SMF slightly reduced cell viability and proliferation and inhibited the expression of CD49d, CD54, and CD73 but did not damage DNA integrity. The SMF slightly downregulated the expression of cytokines including Vascular Endothelial Growth Factor (VEGF), Insulin-like Growth Factor-1 (IGF-1), Transforming Growth Factor Beta 1 (TGF-β1), genetic markers comprising Stem Cell Antigen-1 (Sca1), Octamer-4 (Oct-4), ATP-binding Cassette Subfamily B Member 1 (ABCB1), adipogenic marker genes containing Lipoprotein Lipase (LPL), Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ), and osteogenic marker genes including Secreted Phosphor-protein 1 (SPP1) and Osterix (OSX). Exposure to 0.5 T SMF for seven days inhibited viability, proliferation, surface antigen expression, cytokine secretion, stem cell genetic marker expression, and adipogenic and osteogenic differentiation but did not affect the DNA integrity in ASCs with or without SPIO labeling.

Equine Metabolic Syndrome Affects Viability, Senescence, and Stress Factors of Equine Adipose-Derived Mesenchymal Stromal Stem Cells: New Insight into EqASCs Isolated from EMS Horses in the Context of Their Aging

Currently, equine metabolic syndrome (EMS), an endocrine disease linked to insulin resistance, affects an increasing number of horses. However, little is known about the effect of EMS on mesenchymal stem cells that reside in adipose tissue (ASC). Thus it is crucial to evaluate the viability and growth kinetics of these cells, particularly in terms of their application in regenerative medicine. In this study, we investigated the proliferative capacity, morphological features, and accumulation of oxidative stress factors in mesenchymal stem cells isolated from healthy animals (ASCN) and horses suffering from EMS (ASCEMS). ASCEMS displayed senescent phenotype associated with β-galactosidase accumulation, enlarged cell bodies and nuclei, increased apoptosis, and reduced heterochromatin architecture. Moreover, we observed increased amounts of nitric oxide (NO) and reactive oxygen species (ROS) in these cells, accompanied by reduced superoxide dismutase (SOD) activity. We also found in ASCEMS an elevated number of impaired mitochondria, characterized by membrane raptures, disarrayed cristae, and vacuole formation. Our results suggest that the toxic compounds, accumulating in the mitochondria under oxidative stress, lead to alternations in their morphology and may be partially responsible for the senescent phenotype and decreased proliferation potential of ASCEMS.

Endurance Exercise Mobilizes Developmentally Early Stem Cells into Peripheral Blood and Increases Their Number in Bone Marrow: Implications for Tissue Regeneration

Endurance exercise has been reported to increase the number of circulating hematopoietic stem/progenitor cells (HSPCs) in peripheral blood (PB) as well as in bone marrow (BM). We therefore became interested in whether endurance exercise has the same effect on very small embryonic-like stem cells (VSELs), which have been described as a population of developmentally early stem cells residing in BM. Mice were run daily for 1 hour on a treadmill for periods of 5 days or 5 weeks. Human volunteers had trained in long-distance running for one year, six times per week. FACS-based analyses and RT-PCR of murine and human VSELs and HSPCs from collected bone marrow and peripheral blood were performed. We observed that endurance exercise increased the number of VSELs circulating in PB and residing in BM. In parallel, we observed an increase in the number of HSPCs. These observations were subsequently confirmed in young athletes, who showed an increase in circulating VSELs and HSPCs after intensive running exercise. We provide for the first time evidence that endurance exercise may have beneficial effects on the expansion of developmentally early stem cells. We hypothesize that these circulating stem cells are involved in repairing minor exercise-related tissue and organ injuries.

The Effect of Age on Osteogenic and Adipogenic Differentiation Potential of Human Adipose Derived Stromal Stem Cells (hASCs) and the Impact of Stress Factors in the Course of the Differentiation Process

Human adipose tissue is a great source of autologous mesenchymal stem cells (hASCs), which are recognized for their vast therapeutic applications. Their ability to self-renew and differentiate into several lineages makes them a promising tool for cell-based therapies in different types of degenerative diseases. Thus it is crucial to evaluate age-related changes in hASCs, as the elderly are a group that will benefit most from their considerable potential. In this study we investigated the effect of donor age on growth kinetics, cellular senescence marker levels, and osteogenic and adipogenic potential of hASCs. It also has been known that, during life, organisms accumulate oxidative damage that negatively affects cell metabolism. Taking this into consideration, we evaluated the levels of nitric oxide, reactive oxygen species, and superoxide dismutase activity. We observed that ROS and NO increase with aging, while SOD activity is significantly reduced. Moreover cells obtained from older patients displayed senescence associated features, for example, β-galactosidase activity, enlarged morphology, and p53 protein upregulation. All of those characteristics seem to contribute to decreased proliferation potential of those cells. Our results suggest that due to aging some cellular modification may be required before applying aged cells efficiently in therapies such as tissue engineering and regenerative medicine.

Effect of Metformin on Viability, Morphology, and Ultrastructure of Mouse Bone Marrow-Derived Multipotent Mesenchymal Stromal Cells and Balb/3T3 Embryonic Fibroblast Cell Line

Metformin, a popular drug used to treat diabetes, has recently gained attention as a potentially useful therapeutic agent for treating cancer. In our research metformin was added to in vitro cultures of bone marrow-derived multipotent mesenchymal stromal cells (BMSCs) and Balb/3T3 fibroblast at concentration of 1 mM, 5 mM, and 10 mM. Obtained results indicated that metformin negatively affected proliferation activity of investigated cells. The drug triggered the formation of autophagosomes and apoptotic bodies in all tested cultures. Additionally, we focused on determination of expression of genes involved in insulin-like growth factor 2 (IGF2) signaling pathway. The most striking finding was that the mRNA level of IGF2 was constant in both BMSCs and Balb/3T3. Further, the analysis of IGF2 concentration in cell supernatants showed that it decreased in BMSC cultures after 5 and 10 mM metformin treatments. In case of Balb/3T3 the concentration of IGF2 in culture supernatants decreased after 1 and 5 mM and increased after 10 mM of metformin. Our results suggest that metformin influences the cytophysiology of somatic cells in a dose- and time-dependent manner causing inhibition of proliferation and abnormalities of their morphology and ultrastructure.

Adipose tissue derived mesenchymal stem cells for musculoskeletal repair in veterinary medicine

Adipose tissue derived stem cells (ASCs) are mesenchymal stem cells which can be obtained from different adipose tissue sources within the body. It is an abundant cell pool, which is easy accessible and the cells can be obtained in large numbers, cultivated and expanded in vitro and prepared for tissue engineering approaches, especially for skeletal tissue repair. In the recent years this cell population has attracted a great amount of attention among researchers in human as well as in veterinary medicine. In the meantime ASCs have been well characterized and their use in regenerative medicine is very well established. This review focuses on the characterization of ASCs for their use for tissue engineering approaches especially in veterinary medicine and also highlights a selection of clinical trials on the basis of ASCs as the relevant cell source.

Adipose-derived stem cells in veterinary medicine: characterization and therapeutic applications

Mesenchymal stem cells, considered one of the most promising cell types for therapeutic applications due to their capacity to secrete regenerative bioactive molecules, are present in all tissues. Stem cells derived from the adipose tissue have been increasingly used for cell therapy in humans and animals, both as freshly isolated, stromal vascular fraction (SVF) cells, or as cultivated adipose-derived stem cells (ASCs). ASCs have been characterized in different animal species for proliferation, differentiation potential, immunophenotype, gene expression, and potential for tissue engineering. Whereas canine and equine ASCs are well studied, feline cells are still poorly known. Many companies around the world offer ASC therapy for dogs, cats, and horses, although in most countries these activities are not yet controlled by regulatory agencies. This is the first study to review the characterization and clinical use of SVF and ASCs in spontaneously occurring diseases in veterinary patients. Although a relatively large number of studies investigating ASC therapy in induced lesions are available in the literature, a surprisingly small number of reports describe ASC therapy for naturally affected dogs, cats, and horses. A total of seven studies were found with dogs, only two studies in cats, and four in horses. Taken as a whole, the results do not allow a conclusion on the effect of this therapy, due to the generally small number of patients included, diversity of cell populations used, and lack of adequate controls. Further controlled studies are clearly needed to establish the real potential of ASC in veterinary medicine.

The osteogenic properties of multipotent mesenchymal stromal cells in cultures on TiO₂ sol-gel-derived biomaterial

The biocompatibility of the bone implants is a crucial factor determining the successful tissue regeneration. The aim of this work was to compare cellular behavior and osteogenic properties of rat adipose-derived multipotent stromal cells (ASCs) and bone marrow multipotent stromal cells (BMSCs) cultured on metallic substrate covered with TiO2 sol-gel-derived nanolayer. The morphology, proliferation rate, and osteogenic differentiation potential of both ASCs and BMSCs propagated on the biomaterials were examined. The potential for osteogenic differentiation of ASCs and BMSCs was determined based on the presence of specific markers of osteogenesis, that is, alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCL). Additionally, the concentration of calcium and phosphorus in extracellular matrix was determined using energy-dispersive X-ray spectroscopy (SEM-EDX). Obtained results showed that TiO2 layer influenced proliferation activity of ASCs, which manifested by shortening of population doubling time and increase of OPN secretion. However, characteristic features of cells morphology and growth pattern of cultures prompted us to conclude that ultrathin TiO2 layer might also enhance osteodifferentiation of BMSCs. Therefore in our opinion, both populations of MSCs should be used for biological evaluation of biomaterials compatibility, such results may enhance the area of investigations related to regenerative medicine.

In Vitro and In Vivo Effects of Metformin on Osteopontin Expression in Mice Adipose-Derived Multipotent Stromal Cells and Adipose Tissue

Metformin is applied not only as antidiabetic drug, but also in the treatment of obesity or as antiaging drug. The first part of the research discussed the effect of metformin at concentrations of 1 mM, 5 mM, and 10 mM on the morphology, ultrastructure, and proliferation potential of mice adipose-derived multipotent mesenchymal stromal cells (ASCs) in vitro. Additionally, we determined the influence of metformin on mice adipose tissue metabolism. This study has shown for the first time that metformin inhibits the proliferative potential of ASCs in vitro in a dose- and time-dependent manner. In addition, we have found a significant correlation between the activity of ASCs and osteopontin at the mRNA and protein level. Furthermore, we have demonstrated that 5 mM and 10 mM metformin have cytotoxic effect on ASCs, causing severe morphological, ultrastructural, and apoptotic changes. The reduced level of OPN in the adipose tissue of metformin-treated animals strongly correlated with the lower expression of Ki67 and CD105 and increased caspase-3. The metformin influenced also circulating levels of OPN, which is what was found with systemic and local action of metformin. The results are a valuable source of information regarding the in vitro effect of metformin on adipose-derived stem cells.

Static magnetic field enhances synthesis and secretion of membrane-derived microvesicles (MVs) rich in VEGF and BMP-2 in equine adipose-derived stromal cells (EqASCs)-a new approach in veterinary regenerative medicine

The aim of this work study was to evaluate the cytophysiological activity of equine adipose-derived stem cells (ASCs) cultured under conditions of static magnetic field. Investigated cells were exposed to a static magnetic field (MF) with the intensity of 0.5 T. In order to investigate the effects of magnetic field on stem cell signaling, the localization and density and content of microvesicles (MVs) as well as morphology, ultrastructure, and proliferation rate of equine ASCs were evaluated. Results showed that potential of equine adipose-derived mesenchymal stem cells was accelerated when magnetic field was applied. Resazurin-based assay indicated that the cells cultured in the magnetic field reached the population doubling time earlier and colony-forming potential of equine ASCs was higher when cells were cultured under magnetic field conditions. Morphological and ultrastructural examination of equine ASCs showed that the exposure to magnetic field did not cause any significant changes in cell morphology whereas the polarity of the cells was observed under the magnetic field conditions in ultrastructural examinations. Exposition to MF resulted in a considerable increase in the number of secreted MVs—we have clearly observed the differences between the numbers of MVs shed from the cells cultured under MF in comparison to the control culture and were rich in growth factors. Microvesicles derived from ASCs cultured in the MF condition might be utilized in the stem cell-based treatment of equine musculoskeletal disorders and tendon injuries.