Growth factors profile in conditioned medium human adipose tissue-derived mesenchymal stem cells (CM-hATMSCs)

Umbilical cord mesenchymal stem cells and lung cancer: We should be hopeful or hopeless?

Lung cancer (LC) is one of the leading causes of cancer-caused death that possesses a poor prognosis and low survival rate worldwide. In general, LC is classified into small-cell (SCLC) and non-small-cell carcinoma (NSCLC) (involving 80% of patients). Although chemotherapy, radiotherapy, surgery, and molecular-targeted therapy are considered standard approaches for LC treatment, these options have low success with detrimental effects on the life quality of patients. Ergo, recommending treatment with maximum effectiveness and minimum side effects for LC patients has been a substantial challenge for researchers and clinicians in the present era. Recently, mesenchymal stem cells (MSCs)-based strategies have sparked much interest in preventing or treating numerous illnesses. These multipotent stem cells can be isolated from diverse sources, such as umbilical cord, bone marrow, and adipose tissue. Among these sources, umbilical cord mesenchymal stem cells (UC-MSCs) have been in the spotlight of MSCs-based therapies thanks to their considerable advantages, such as high proliferation ability, low immune reactions and tumorigenesis, and easiness in collection and isolation. Some experimental studies have investigated the functionality of intact UC-MSCs and extracellular vesicles, exosomes, and conditioned medium derived from UC-MSCs, as well as genetically engineered UC-MSCs. In this review, we aimed to highlight the influences of these UMSCs-based methods in LC treatment with cellular and molecular insights.

Human Mesenchymal Stem Cells on Size-Sorted Gelatin Hydrogel Microparticles Show Enhanced In Vitro Wound Healing Activities

The demand for innovative therapeutic interventions to expedite wound healing, particularly in vulnerable populations such as aging and diabetic patients, has prompted the exploration of novel strategies. Mesenchymal stem cell (MSC)-based therapy emerges as a promising avenue for treating acute and chronic wounds. However, its clinical application faces persistent challenges, notably the low survivability and limited retention time of engraftment in wound environments. Addressing this, a strategy to sustain the viability and functionality of human MSCs (hMSCs) in a graft-able format has been identified as crucial for advanced wound care. Hydrogel microparticles (HMPs) emerge as promising entities in the field of wound healing, showcasing versatile capabilities in delivering both cells and bioactive molecules/drugs. In this study, gelatin HMPs (GelMPs) were synthesized via an optimized mild processing method. GelMPs with distinct diameter sizes were sorted and characterized. The growth of hMSCs on GelMPs with various sizes was evaluated. The release of wound healing promoting factors from hMSCs cultured on different GelMPs were assessed using scratch wound assays and gene expression analysis. GelMPs with a size smaller than 100 microns supported better cell growth and cell migration compared to larger sizes (100 microns or 200 microns). While encapsulation of hMSCs in hydrogels has been a common route for delivering viable hMSCs, we hypothesized that hMSCs cultured on GelMPs are more robust than those encapsulated in hydrogels. To test this hypothesis, hMSCs were cultured on GelMPs or in the cross-linked methacrylated gelatin hydrogel (GelMA). Comparative analysis of growth and wound healing effects revealed that hMSCs cultured on GelMPs exhibited higher viability and released more wound healing activities in vitro. This observation highlights the potential of GelMPs, especially those with a size smaller than 100 microns, as a promising carrier for delivering hMSCs in wound healing applications, providing valuable insights for the optimization of advanced therapeutic strategies.

Recent Advances of Adipose-Tissue-Derived Mesenchymal Stem Cell-Based Therapy for Retinal Diseases

With the rapid development of stem cell research in modern times, stem cell-based therapy has opened a new era of tissue regeneration, becoming one of the most promising strategies for currently untreatable retinal diseases. Among the various sources of stem cells, adipose tissue-derived mesenchymal stem cells (ADSCs) have emerged as a promising therapeutic modality due to their characteristics and multiple functions, which include immunoregulation, anti-apoptosis of neurons, cytokine and growth factor secretion, and antioxidative activities. Studies have shown that ADSCs can facilitate the replacement of dying cells, promote tissue remodeling and regeneration, and support the survival and growth of retinal cells. Recent studies in this field have provided numerous experiments using different preclinical models. The aim of our review is to provide an overview of the therapeutic strategies, modern-day clinical trials, experimental models, and potential clinical use of this fascinating class of cells in addressing retinal disorders and diseases.

Ocular instillation of conditioned medium from mesenchymal stem cells is effective for dry eye syndrome by improving corneal barrier function

Dry eye syndrome (DES) is a chronic ocular disease that induces epithelial damage to the cornea by decreasing tear production and quality. Adequate treatment options have not been established for severe DES such as Sjogren's syndrome due to complicated pathological conditions. To solve this problem, we focused on the conditioned medium of human adipose-derived mesenchymal stem cells (hAdMSC-CM), which have multiple therapeutic properties. Here, we showed that hAdMSC-CM suppressed Benzalkonium Chloride (BAC)-induced cytotoxicity and inflammation in human corneal epithelial cells (hCECs). In addition, hAdMSC-CM increased the expression level and regulated the localisation of barrier function-related components, and improved the BAC-induced barrier dysfunction in hCECs. RNA-seq analysis and pharmacological inhibition experiments revealed that the effects of hAdMSC-CM were associated with the TGFβ and JAK-STAT signalling pathways. Moreover, in DES model rats with exorbital and intraorbital lacrimal gland excision, ocular instillation of hAdMSC-CM suppressed corneal epithelial damage by improving barrier dysfunction of the cornea. Thus, we demonstrated that hAdMSC-CM has multiple therapeutic properties associated with TGFβ and JAK-STAT signalling pathways, and ocular instillation of hAdMSC-CM may serve as an innovative therapeutic agent for DES by improving corneal barrier function.

Thymoquinone-treated mouse mesenchymal stem cells-derived conditioned medium inhibits human breast cancer cells in vitro

Breast cancer is now the most prevalent cancer in females, therefore, it is essential to identify factors affecting its initiation and progression. Mesenchymal stem cells (MSCs) have received considerable attention in stem cell-based therapies and drug delivery applications. Because the therapeutic potential of MSCs is primarily achieved by their paracrine effects, thus identifying and employing bioactive molecules that promote the paracrine activity of MSCs is crucial for their efficient use in cancer treatment. Thymoquinone (TQ) has many biomedical properties, including anti-inflammatory, anti-diabetic, anti-aging, anti-cancer, etc. In addition, it has been found that TQ affects the self-renewal and immunomodulatory properties of MSCs. The present study aimed to investigate the effect of TQ-treated mouse bone marrow-derived MSCs conditioned medium (TQ-MSC-CM) on the biological characteristics of breast cancer cell line MCF7. MSCs were cultured and treated with TQ for 24 h. The TQ-MSC-CM and MSC-CM were collected, and their effects were investigated on ROS production, mitochondrial membrane potential (MMP), cell death, cell cycle, and migration of MCF7 cells by DCFDA-cellular ROS assay, Rhodamine-123 MMP assay, Annexin-PI staining and Caspase-3/7 activity assays, PI-staining and flow-cytometry, and in vitro wound healing assay, respectively. Moreover, the effects of TQ-MSC-CM and MSC-CM were studied on Cdk4, Sox2, c-Met, and Bcl2 gene expression by real-time PCR. Results demonstrated that MSC-CM and TQ-MSC-CM did not have a significant effect on the apoptosis induction in MCF7 cells; however, they significantly stimulated necrosis in the cells. Although TQ-MSC-CM promoted ROS production in MCF7 cells, it decreased the MMP of the cells. TQ-MSC-CM also induced Bcl2 anti-apoptosis gene expression and Casp-3/7 activity in cells. In addition, although MSC-CM induced MCF7 cells to enter the cell cycle, TQ-MSC-CM inhibited its progression. TQ-MSC-CM also downregulated the Cdk4 and Sox2 gene expression. Furthermore, TQ-MSC-CM induced the migration potential of MCF7 in a c-Met-independent manner. Altogether, we conclude that TQ may induce programmed necrosis and inhibits the proliferation and migration of the breast cancer cells by affecting the paracrine activity of MSCs.

The therapeutic and commercial landscape of stem cell vesicles in regenerative dermatology

Extracellular vesicles (EVs) are lipid enveloped nanoparticles that are naturally produced by cells and function in the intercellular transfer of biological material such as proteins, RNAs and metabolites. They have been shown to act in an autocrine and paracrine manner to alter the functions of local and distant recipient cells, with a growing body of evidence highlighting their wide-ranging functions in regenerative processes such as stem cell maintenance, tissue repair and immune modulation. EVs offer several potential advantages over stem cell therapies such as improved safety profiles, scalability, and enhanced storage and quality control of the final product. In fact, many of the pro-regenerative outcomes of stem cell therapies have been attributed to the release of mesenchymal stem cell-derived EVs (MSC-EVs) and their potent effects on extracellular matrix turnover, local cell recruitment, proliferation and angiogenesis is now well described. These positive outcomes have led to clinical trials assessing the safety of MSC-EVs for applications in wound healing and the treatment of cutaneous ulcers, as well as the emergence of multiple commercial MSC-EV sources marketed for topical application in cosmetic medicine. However, regenerative EV therapeutics remain in their infancy and pertinent questions regarding product standardisation, potency and the regulatory landscape surrounding the development of these promising nano-therapeutics must be addressed to ensure safe and effective clinical adoption. In this article we provide an overview of the emerging landscape of MSC-EVs in regenerative dermatology and cosmetic science, highlighting the underlying biological mechanisms pertinent to their application and providing a perspective on current safety considerations, regulation and future directions in the field.

Mesenchyme Stem Cell-Derived Conditioned Medium as a Potential Therapeutic Tool in Idiopathic Pulmonary Fibrosis

Mesenchyme Stem Cells (MSCs) are the most used types of stem cells in regenerative medicine. Regenerative medicine is a rapidly emerging medicine section that creates new methods to regrow, restore, and replace diseased and damaged tissues, organs, and cells. Scholars have shown a positive correlation between MSCs-based therapies and successful treatment of diseases like cardiac ischemia, cartilage problems, bone diseases, diabetes, and even neurological disorders. Although MSCs have several varying features that make them unique, their immuno-regulatory effects in tissue repair emerge from their secretion of paracrine growth factors, exosomes, and cytokines. These cells secrete a secretome, which has regenerative and reparative properties that lead to injury amelioration, immune modulation, or fibrosis reduction. Recent studies have shown that the administration MCSs derived conditioned medium (MSCs-CM) in acute doses in humans is safe and well-tolerated. Studies from animal models and human clinical trials have also shown that they are efficacious tools in regenerative medicine. In this review, we will explore the therapeutic potential of MSCs-CM in pulmonary fibrosis, with further insight into the treatment of Idiopathic Pulmonary Fibrosis (IPF).

Osteogenic effect of electromagnetic fields on stem cells derived from rat bone marrow cultured in osteogenic medium versus conditioned medium in vitro

OBJECTIVES

This study assessed possible osteogenic differentiation caused by electromagnetic fields (EMF) on rat bone-marrow-derived stem cells (rBMSCs) cultured in osteogenic medium (OM) or in human adipose-stem cell-conditioned medium (hADSC-CM).

MATERIALS AND METHODS

The rBMSCs were divided into negative and positive control groups, cultured in α-MEM plus 10% FBS or OM respectively. CM and CM + EMF  groups, cultured cells in hADSCs-CM or exposed to EMF (50 Hz, 1 mT) for 30 min/day plus hADSCs-CM, respectively. Cells from the OM + EMF were simultaneously cultured in OM and exposed to EMF. Osteogenesis was investigated through alkaline phosphatase activity, alizarin red staining and real-time PCR.

RESULTS

A meaningfully higher level of ALP activity was observed in the OM + EMF group compared to the other groups. There was a considerable increase in Runx2 expression in the CM + EMF group compared to the positive control and CM groups and a significant increase in Runx2 expression in the OM + EMF in comparison with all other groups after 21 days. Runx2 expression increased significantly in the CM, CM + EMF and positive control groups on day 21 compared to the same groups on day 14. From days 14-21, Ocn expression increased in the CM and CM + EMF groups, but both groups showed a significant decrease compared to the positive controls. CM and EMF had no effect on Ocn expression. On day 21, Ocn expression was significantly higher in the OM + EMF group than in the positive control group.

CONCLUSION

The synergistic effect of EMF and OM increased the expression of Runx2 and Ocn in rBMSCs.

Mesenchymal stem cell-encapsulated cellulose nanofiber microbeads and enhanced biological activities by hyaluronic acid incorporation

Cell microencapsulation is a process to entrap viable and functional cells within a biocompatible and semi-permeable matrix to provide a favorable microenvironment to the cells. Cellulose nanofiber (CNF), a low-cost and sustainable cellulose-derived natural polymer, has been studied as a matrix for 3D stem cell culture in the form of a bulk hydrogel. Here, the preparation of CNF microbeads for the long-term 3D culture of human adipose-derived stem cells (hADSCs) was demonstrated. Furthermore, hyaluronic acid (HA) was physically incorporated into the stem cell encapsulated CNF microbeads with various molecular weights and concentrations to investigate its potential in enhancing the cellular bioactivities. The beneficial effects of HA incorporation on encapsulated cells were significant compared to CNF microbeads, especially with 700 kDa molecular weight and 0.2% in concentration in terms of cell proliferation (~2 times) and VEGF secretion (~2 times) while maintaining their stemness. All the results demonstrated that the HA-incorporated CNF microbeads could serve as a promising microencapsulation matrix for hADSCs.

Evaluating the effect of conditioned medium from endometrial stem cells on endometriosis-derived endometrial stem cells

Endometriosis is a common, benign gynecological disease which is determined as an overspreading of endometrial tissue in exterior region of the uterine cavity. Evidence suggests that retrograde menstrual blood which contains mesenchymal stem cells with differential gene expression compared to healthy women may play a role in endometriosis creation. We aimed to identify whether the conditioned medium (CM) from menstrual blood-derived mesenchymal stem cells (MenSCs) of healthy women can affect the expression level of inflammatory and stemness genes of MenSCs from endometriosis women. Endometriosis-derived MenSCs (E-MenSCs) were treated with CM derived from healthy women’s MenSCs (non-endometriosis derived MenSCs [NE-MenSCs]). Some CD markers were analyzed by flow cytometer before and after treatment compared with NE-MenSCs, and the expression level of inflammatory and stemness genes was evaluated by real-time PCR. E-MenSCs show different morphology in vitro culture in comparison with NE-MenSCs, which were changed in the presence of CM, into a morphology more similar to normal cells and showed significant decrease expression of CD10 after CM treatment. In our results, the interleukin-1, cyclooxygenase-2, and hypoxia-inducible factor 1α as inflamaturay genes and octamer-binding transcription factor 4, NANOG, and sex determining region Y-box 2 as stemness genes showed significantly different expression level in E-MenSCs after treating with CM. Our study indicates that the expression level of some inflammatory- and stemness-related genes which have differential expression in E-MenSCs compared with NE-MenSCs, could be changed to normal status by using CM derived from NE-MenSCs.

Cell secretomes for wound healing and tissue regeneration: Next generation acellular based tissue engineered products

Wound represents a significant socioeconomic burden for both affected individuals and as a whole healthcare system. Accordingly, stem cells have garnered attention due to their differentiation capacity and ability to aid tissue regeneration by releasing biologically active molecules, found in the cells’ cultivated medium which known as conditioned medium (CM) or secretomes. This acellular approach provides a huge advantage over conventional treatment options, which are mainly used cellular treatment at wound closure. Interestingly, the secretomes contained the cell-secreted proteins such as growth factors, cytokines, chemokines, extracellular matrix (ECM), and small molecules including metabolites, microvesicles, and exosomes. This review aims to provide a general view on secretomes and how it is proven to have great potential in accelerating wound healing. Utilizing the use of secretomes with its secreted proteins and suitable biomaterials for fabrications of acellular skin substitutes can be promising in treating skin loss and accelerate the healing process.

Adipose derived mesenchymal stem cell secretome formulation as a biotherapeutic to inhibit growth of drug resistant triple negative breast cancer

In the present study, a protocol was developed for processing of human adipose derived mesenchymal stem cell secretome formulation of varying concentration. Its molecular composition was evaluated, and its effectiveness in vitro using breast cancer cell lines, and in vivo in a nude mice breast cancer model was studied to determine its role in suppressing triple negative breast cancer in a dose dependent manner. Because the secretome could have value as an add-on therapy along with a current drug, the effectiveness of the secretome both in monotherapy and in combination therapy along with paclitaxel was evaluated. The results showed significant cell kill when exposed to the secretome above 20 mg/ml at which concentration there was no toxicity to normal cells. 70 mg/ml of SF showed 90 ± 10% apoptosis and significant decrease in CD44⁺/CD24⁻, MDR1+ and PDL-1+ cancer cells. In vivo, the tumor showed no growth after daily intra tumor injections at 50 mg/ml and 100 mg/ml doses whereas substantial tumor growth occurred after saline intra tumor injection. The study concludes that SF is a potential biotherapeutic for breast cancer and could be used initially as an add-on therapy to other standard of care to provide improved efficacy without other adverse effects.

Secretome Analysis of Rabbit and Human Mesenchymal Stem and Endothelial Progenitor Cells: A Comparative Study

Human adipose tissue-derived mesenchymal stem cells (AT-MSCs) have been studied several years for their immunomodulatory effect through the paracrine mechanism and cytokine secretion. In combination with endothelial progenitor cells (EPCs), MSCs have great therapeutical potential for the repair of endothelium and wound healing. However, little is known about the cytokine profile of rabbit AT-MSCs or even EPCs. The aim of this study was to analyze the secretomes of these rabbit stem/progenitor cells. A large-scale human cytokine array (up to 80 cytokines) was used to identify and compare cytokines secreted into conditioned media of human and rabbit AT-MSCs as well as HUVECs and rabbit EPCs. Few cytokines were highly expressed by human AT-MSCs (TIMP-2, TIMP-1), HUVECs (MCP-1, TIMP-2, GRO, Angiogenin, IL-8, TIMP-1), or by rabbit EPCs (TIMP-2). Several cytokines have moderate expression by human (MCP-1, GRO, Angiogenin, TGF-β 2, IL-8, LIF, IL-6, Osteopontin, Osteoprotegerin) and rabbit AT-MSCs (TIMP-2, TGF-β 2, LIF, Osteopontin, IL-8, IL-5, IL-3) or by HUVECs (IL-6, MIF, TGF-β 2, GCP-2, IGFBP-2, Osteoprotegerin, EGF, LIF, PDGF-BB, MCP-3, Osteopontin, Leptin, IL-5, ENA-78, TNF-β) and rabbit EPCs (TGF-β 2, Osteopontin, GRO, LIF, IL-8, IL-5, IL-3). In conclusion, the proposed method seems to be useful for the secretome analysis of rabbit stem/progenitor cells.

In vitro effects of conditioned medium from bioreactor cultured human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on skin-derived cell lines

Introduction

When stem cells are grafted into tissues, they differentiate and form specialized cells. However, the proficiency of stem cells to endure and assimilate the host cell is dependent on various growth factors and cytokines. According to various studies, these factors are available in the spent media of harvested stem cells, which can be used for treatment in regenerative medicine and cosmetic products. There are differences in cytokine secretion depending on the culture environment, which are clarified in this paper.

Methods

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) were cultured either in a bioreactor or in a flask. The conditioned medium from the hUC-MSC cultures in the flask and in the bioreactor was designated as “FM” and “BM”, respectively. We assessed the effects of FM and BM on UVB-induced oxidative stress, anti-aging, and melanogenic properties. The amount of growth factors, cell viability, hyaluronic acid (HA), pro-collagen, and pro-melanin were quantitatively evaluated in the FM and BM treated groups. The induction of HA and collagen synthesis was measured in CCD-986SK cells. For melanogenesis, the effects of FM and BM on melanin content and tyrosinase activity were measured in SK-MEL-31 cells.

Results

In the present study, the secretion of growth factors, HA, and pro-collagen was significantly higher in the BM treatment, compared to that in the FM treatment. BM protected CCD-986SK cells against death from UVB induced oxidative stress. BM increased the promoter activity of the anti-oxidant genes SOD1, CAT, and GP; and downregulated the accelerating collagen decomposition gene, MMP-1, induced by UVB irradiation. In α-melanocyte-stimulating hormone (α-MSH) stimulated SK-MEL-31 cells, BM reduced melanin production and decreased the levels of MITF, tyrosinase, TRP-1, and TRP-2. These results suggest that BM could be used as a skin protection agent, because of its anti-apoptotic, anti-aging, and anti-melanogenic properties. This could be attributed to the differences in culturing methods; it is difficult to maintain the temperature and sterility in FM culture, when compared to that in the automated culturing conditions of the BM system.

Conclusions

Collectively, our results indicate that using BM-conditioned hUC-MSC medium is very efficient process for producing raw materials for developing functional cosmetics.

Characterization of Scleraxis and SRY-Box 9 from Adipose-Derived Stem Cells Culture Seeded with Enthesis Scaffold in Hypoxic Condition

The use of mesenchymal stem cells can add local improvements potential to enthesis tissue regeneration based on tropical activity through secretions of growth factors, cytokines, and vesicles (e.g. exosomes), collectively known as secretomes. This study aims to analyze secretomes characterization from adipose-derived mesenchymal stem cells seeded with enthesis tissue scaffold in hypoxic conditions and to analyze the influence of hypoxic environment to the characterization of secretomes. This is an in-vitro study using a Randomized Control Group Post-Test Only design. This study using Adipose Stem Cells (ASCs) were cultured in hypoxia (Oxygen 5%) and Normoxia (21%) condition. The scaffolds are fresh-frozen enthesis tissue and was seeded in the treatment group and compared to control. The evaluation of Scleraxis (Scx) and SRY-box (Sox9) was measured using ELISA on the 2nd, 4th, and 6th days. Comparison of Scx levels between each evaluation time showed a positive trend in a group with scaffold in hypoxia condition although it has no significant differences (p=0.085), with the highest level on day 6, that is 13,568 ng/ml. Conversely, the comparison of Sox9 showed significant differences (p=0.02) in a group with scaffold in hypoxia condition, with the highest level on day 4, that is 28,250 ng/ml. The use of enthesis scaffold seeded in adipose-derived mesenchymal stem cells in hypoxic conditions shows a positive trend as regenerative effort of injured enthesis tissue through Scleraxis and Sox9 secretomes induction.

A Review on Mesenchymal Stem Cells for Treatment of Retinal Diseases

Mesenchymal Stem Cells (MSCs) have been studied extensively for the treatment of several retinal diseases. The therapeutic potential of MSCs lies in its ability to differentiate into multiple lineages and secretome enriched with immunomodulatory, anti-angiogenic and neurotrophic factors. Several studies have reported the role of MSCs in repair and regeneration of the damaged retina where the secreted factors from MSCs prevent retinal degeneration, improve retinal morphology and function. MSCs also donate mitochondria to rescue the function of retinal cells and exosomes secreted by MSCs were found to have anti-apoptotic and anti-inflammatory effects. Based on several promising results obtained from the preclinical studies, several clinical trials were initiated to explore the potential advantages of MSCs for the treatment of retinal diseases. This review summarizes the various properties of MSCs that help to repair and restore the damaged retinal cells and its potential for the treatment of retinal degenerative diseases.

Adipose-Derived Stem Cells Secretome and Its Potential Application in "Stem Cell-Free Therapy"

Adipose-derived stem cells (ASCs) secrete many cytokines, proteins, growth factors, and extracellular vesicles with beneficial outcomes that can be used in regenerative medicine. It has great potential, and the development of new treatment strategies using the ASCs secretome is of global interest. Besides cytokines, proteins, and growth factors, the therapeutic effect of secretome is hidden in non-coding RNAs such as miR-21, miR-24, and miR-26 carried via exosomes secreted by adequate cells. The whole secretome, including ASC-derived exosomes (ASC-exos) has been proven in many studies to have immunomodulatory, proangiogenic, neurotrophic, and epithelization activity and can potentially be used for neurodegenerative, cardiovascular, respiratory, inflammatory, and autoimmune diseases as well as wound healing treatment. Due to limitations in the use of stem cells in cell-based therapy, its secretome with emphasis on exosomes seems to be a reasonable and safer alternative with increased effectiveness and fewer side effects. Moreover, the great advantage of cell-free therapy is the possibility of biobanking the ASCs secretome. In this review, we focus on the current state of knowledge on the use of the ASCs secretome in stem cell-free therapy.

Adipose-Derived Stromal/Stem Cell Culture: Effects of Different Concentrations of Human Platelet Lysate in Media

Adipose-derived stromal/stem cells (ASCs) are being tested as a possible treatment for a wide range of diseases to exploit the immunomodulatory and regenerative potential demonstrated in vitro. Pooled human platelet lysate (pHPL) has replaced fetal bovine serum (FBS) as the preferred growth supplement because of its xeno-free origin and improved cell proliferation. Much has been done toward reducing the concentration of pHPL required when expanding ASCs. However, little is known on how increasing the concentration of pHPL affects ASC potency, which could lead to changes with possible beneficial applications. This study investigated the effect of 5, 10, or 20% pHPL in culture media on ASC proliferation and phenotypic marker expression, including chemokine receptors CXCR2, CXCR3, CXCR4, and VLA-4. Adipogenic and osteogenic properties, as well as immunosuppressive properties, including the ability to induce indoleamine-pyrrole 2,3-dioxygenase 1 (IDO1) and suppress T cell proliferation, were also examined. We observed a significant increase in cell yield (approximately 2-fold) and a corresponding reduction in population doubling time and cell volume when doubling the concentration of pHPL in the growth media. ASCs maintained expression of phenotypic surface markers CD73, CD90, and CD105 and were negative for CD45 and CD31. The ability to induce IDO1 and suppress T cell proliferation was observed as well. Adipogenesis and osteogenesis, however, seem to be increased at higher concentrations of pHPL (20% > 10% > 5%), while expression of chemokine receptors CXCR2 and CXCR3 was lower. In conclusion, increasing the pHPL concentration to 20% could be used to optimize culture conditions when producing cells for clinical treatments and may even be used to enhance beneficial ASC properties depending on the desired therapeutic effect.

Expression Analysis of GDNF/RET Signaling Pathway in Human AD-MSCs Grown in HEK 293 Conditioned Medium (HEK293-CM)

Mesenchymal stem cells have been considered as the suitable source for the repair of kidney lesions. The study and identification of novel approaches could improve the efficiency of these cells in the recovery of kidney. In the present study, the effect of HEK 293 conditioned medium (HEK293-CM) was evaluated on the expression of GDNF/RET signaling pathway and their downstream genes in the human adipose-derived mesenchymal stem cells (AD-MSCs). For this purpose, the human AD-MSCs were cultured in the medium containing HEK293-CM. After the RNA extraction and cDNA synthesis, the expression level of GFRA1, GDNF, SPRY1, ETV4, ETV5, and CRLF1 genes were determined by SYBR Green Real time PCR. The obtained results indicated that the GDNF and GFRA1 expression enhanced in the AD-MSCs following treatment with 10% HEK293-CM-5%FBS as compared to the untreated AD-MSCs. These results were consistent with the decreased expression of SPRY1. The significant increased expression of ETV4, ETV5, and CRLF1 genes also showed that HEK293-CM activated the GDNF/RET signaling pathway in the AD-MSCs (P < 0.05). The obtained data suggested that the treatment with HEK293-CM activated the GDNF/RET signaling pathway in the human AD-MSCs.

Preventive Effects of Intrauterine Injection of Bone Marrow-Derived Mesenchymal Stromal Cell-Conditioned Media on Uterine Fibrosis Immediately after Endometrial Curettage in Rabbit

Uterine fibrosis is an acquired disorder leading to menstrual irregularities, implantation impairment, and abortion. Mesenchymal stromal cells (MSCs) have antifibrotic properties through chemokine secretion. MSC-conditioned media (MSC-CM) contain paracrine components—exosomes—with a great potential for repairing damaged tissue or preventing fibrosis. The main goal of this study was to evaluate the preventive effects of bone marrow-derived MSC-CM (BM-MSC-CM) on uterine fibrosis after uterine curettage in rabbits. This study included 12 female rabbits (24 uterine horns in total). Excised uteri of each of the 12 female rabbits were randomly divided into four groups of intact negative control, curettage positive control, BM-MSC injection, and BM-MSC-CM injection in the way that two corresponding uteri from a rabbit were allocated to different groups. The MSC-CM were collected from cultivated BM-MSCs 48 hours after having been washed three times and replaced in serum-free media. Through a surgical approach, the caudal parts of the uteri were submitted to traumatic endometrial curettage, except for the intact negative uteri. After suturing the uterine walls, BM-MSCs or BM-MSC-CM were injected in the curettage site. Endometrial regeneration was histologically evaluated 30 days after treatment. Based on the evaluation of histomorphometric indices, curettage with or without preventive injections increased the growth of endometrial layers. However, the amount of fibrotic tissue in the CM and the BM-MSC injection groups was the same as the normal control groups, and all were less than the curettage group. A single injection of CM of MSCs after 30 days prevented the fibrotic tissue formation induced by curettage in endometrial layers of rabbits. Injecting BM-MSC-CM immediately after curettage prevented and reduced the uterine fibrosis similar to BM-MSCs in a rabbit model.

Bioengineering Approaches for Corneal Regenerative Medicine

BACKGROUND

Since the cornea is responsible for transmitting and focusing light into the eye, injury or pathology affecting any layer of the cornea can cause a detrimental effect on visual acuity. Aging is also a reason for corneal degeneration. Depending on the level of the injury, conservative therapies and donor tissue transplantation are the most common treatments for corneal diseases. Not only is there a lack of donor tissue and risk of infection/rejection, but the inherent ability of corneal cells and layers to regenerate has led to research in regenerative approaches and treatments.

METHODS

In this review, we first discussed the anatomy of the cornea and the required properties for reconstructing layers of the cornea. Regenerative approaches are divided into two main categories; using direct cell/growth factor delivery or using scaffold-based cell delivery. It is expected delivered cells migrate and integrate into the host tissue and restore its structure and function to restore vision. Growth factor delivery also has shown promising results for corneal surface regeneration. Scaffold-based approaches are categorized based on the type of scaffold, since it has a significant impact on the efficiency of regeneration, into the hydrogel and non-hydrogel based scaffolds. Various types of cells, biomaterials, and techniques are well covered.

RESULTS

The most important characteristics to be considered for biomaterials in corneal regeneration are suitable mechanical properties, biocompatibility, biodegradability, and transparency. Moreover, a curved shape structure and spatial arrangement of the fibrils have been shown to mimic the corneal extracellular matrix for cells and enhance cell differentiation.

CONCLUSION

Tissue engineering and regenerative medicine approaches showed to have promising outcomes for corneal regeneration. However, besides proper mechanical and optical properties, other factors such as appropriate sterilization method, storage, shelf life and etc. should be taken into account in order to develop an engineered cornea for clinical trials.

Topical cell-free conditioned media harvested from adipose tissue-derived stem cells promote recovery from corneal epithelial defects caused by chemical burns

Corneal chemical burns can lead to blindness following serious complications. As most of these complications are caused by failure of reepithelization during the acute phase, treatment at this stage is critical. Although there have been some studies on corneal injury recovery using adipose tissue-derived stem cells (ADSCs), none has reported the effect of topical cell-free conditioned culture media (CM) derived from ADSCs on corneal epithelial regeneration. Here, the best conditions for CM were selected and used for in vitro and in vivo experiments. Corneal burn in rats was induced using 100% alcohol. The chosen CM was administered to corneal burn rats (CM-treated [CT] group) four times a day for three days and this group was compared with the normal control and corneal burn (CB) groups. Biomicroscopic fluorescence images and the actual physical corneas were taken over time and used for analysis. mRNA levels of hepatocyte growth factor and epidermal growth factor (EGF) were significantly increased, whereas those of vascular endothelial growth factor, interleukin (IL)-1β, IL-6, IL-10, and matrix metalloproteinase-9 were significantly decreased in the CT group compared with those in the CB group. The numbers of proliferating cell nuclear antigen- and zonular occludens-1-positive cells in the CT group were significantly higher than those in the CB group. The macrophage-infiltrating corneas in the CT group expressed significantly more of the M2 marker arginase than corneas in the CB group. Optimal CM (× 0.5 concentration) treatment significantly accelerated the migration of corneal epithelial cells and induced upregulation of the expression of IL-6, EGF, and C-X-C chemokine receptor type 4 mRNAs. Overall, in this study, topical administration of cell-free CM promoted regeneration of the corneal epithelium after induction of chemical burns.

Therapeutic Effects of Lyophilized Conditioned-Medium Derived from Corneal Mesenchymal Stromal Cells on Corneal Epithelial Wound Healing

Objectives: The conditioned-medium derived from corneal mesenchymal stromal cells (cMSCs) has been shown to have wound healing and immunomodulatory effects in corneal injury models. Here, the therapeutic effects of lyophilized cMSC conditioned-medium were compared with fresh conditioned-medium. Methods: The epithelial wound healing effects of fresh and lyophilized cMSC conditioned-medium were compared with conditioned-medium from non-MSC cells (corneal epithelial cells) using scratch assay. To evaluate the anti-inflammatory effects of fresh and lyophilized cMSC conditioned-media, macrophages were stimulated by a Toll-Like Receptor (TLR) ligand followed by treatment with the conditioned-media and measuring the expression of inflammatory genes. In vivo wound healing effects of fresh and lyophilized cMSC conditioned-media were assessed in a murine model of cornea epithelial injury. Results: Both fresh and lyophilized cMSCs-derived conditioned-medium induced significantly faster closure of in vitro epithelial wounds compared to conditioned-medium from non-MSC cells (P < .0001). Treating stimulated macrophages with fresh or lyophilized cMSCs-derived conditioned-media significantly decreased the expression of inflammatory genes compared to control (P < .0001). Murine corneal epithelial wounds were healed by 87.6 ± 2.7% and 86.2 ± 4.6% following treatment with fresh and lyophilized cMSC conditioned-media, respectively, while the control was healed by 64.7 ± 16.8% (P < .05). Conclusion: Lyophilized cMSC-derived conditioned-medium is as effective as fresh conditioned-medium in promoting wound healing and modulating inflammation. The results of this study support the application of lyophilized cMSCs-derived conditioned-medium, which allows for more extended storage, as a promising non-invasive option in the treatment of corneal wounds.

Biological activity of mesenchymal stem cells secretome as a basis for cell-free therapeutic approach

Mesenchymal stem (stromal) cells (MSCs) are self-renewing, cultured adult stem cells which secrete a complex set of multiple soluble biologically active molecules such as chemokines, and cytokines, cell adhesion molecules, lipid mediators, interleukins (IL), growth factors (GFs), hormones, micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs), exosomes, as well as microvesicles, the secretome. MSCs of various origin, including adipose-derived stem cells (ASCs), bone marrow derived mesenchymal stem cells (BM-MSCs), human uterine cervical stem cells (hUCESCs), may be good candidates for obtaining secretome-derived products. Different population of MSCs can secret different factors which could have anti-inflammatory, anti-apoptotic, anti-fibrotic activities, a neuroprotective effect, could improve bone, muscle, liver regeneration and wound healing. Therefore, the paracrine activity of conditioned medium obtained when cultivating MSCs, due to a plethora of bioactive factors, was assumed to have the most prominent cell-free therapeutic impact and can serve as a better option in the field of regenerative medicine in future.

The topography of fibrous scaffolds modulates the paracrine function of Ad-MSCs in the regeneration of skin tissues

Injuries to the skin are common in daily life, and a certain type or size of defect is not easily restored using conventional dressings or naturally. The repair of these defects requires restoration of function in regenerated tissues. In this study, a tissue engineered skin was designed and fabricated using a bio-3D printing system. Polycaprolactone and bacterial cellulose comprised the scaffold, due to their excellent biocompatibility and multifunctionality. Adipose-derived mesenchymal stem cells (Ad-MSCs) were seeded onto the scaffold to functionalize it as an artificial skin. The finished artificial skin had mechanical properties similar to that of natural skin, and its fibrous structure providing a unique micro-environment that could regulate the paracrine function of the Ad-MSCs. This effect could be greatly increased by changes in the characteristics of the biomaterials. The artificial skin exhibited high biological activity, strong induction of cell recruitment, migration, growth and up-regulation of gene expression of relevant factors, resulting in excellent wound healing characteristics. This study clarified novel design aspects of cell-material interactions in which the topographical characteristics of materials can be further developed to establish cell signaling or communication networks that take advantage of the paracrine actions of Ad-MSCs to promote specific tissue regeneration or repair characteristics.

Biocompatibility assessment of sub-5 nm silica-coated superparamagnetic iron oxide nanoparticles in human stem cells and in mice for potential application in nanomedicine

Ultrasmall superparamagnetic iron oxide nanoparticles with a size <5 nm are emerging nanomaterials for their excellent biocompatibility, chemical stability, and tunable surface modifications. The applications explored include dual-modal or multi-modal imaging, drug delivery, theranostics and, more recently, magnetic resonance angiography. Good biocompatibility and biosafety are regarded as the preliminary requirements for their biomedical applications and further exploration in this field is still required. We previously synthesized and characterized ultrafine (average core size of 3 nm) silica-coated superparamagnetic iron oxide fluorescent nanoparticles, named sub-5 SIO-Fl, uniform in size, shape, chemical properties and composition. The cellular uptake and in vitro biocompatibility of the as-synthesized nanoparticles were demonstrated in a human colon cancer cellular model. Here, we investigated the biocompatibility of sub-5 SIO-Fl nanoparticles in human Amniotic Mesenchymal Stromal/Stem Cells (hAMSCs). Kinetic analysis of cellular uptake showed a quick nanoparticle internalization in the first hour, increasing over time and after long exposure (48 h), the uptake rate gradually slowed down. We demonstrated that after internalization, sub-5 SIO-Fl nanoparticles neither affect hAMSC growth, viability, morphology, cytoskeletal organization, cell cycle progression, immunophenotype, and the expression of pro-angiogenic and immunoregulatory paracrine factors nor the osteogenic and myogenic differentiation markers. Furthermore, sub-5 SIO-Fl nanoparticles were intravenously injected into mice to investigate the in vivo biodistribution and toxicity profile for a time period of 7 weeks. Our findings showed an immediate transient accumulation of nanoparticles in the kidney, followed by the liver and lungs, where iron contents increased over a 7-week period. Histopathology, hematology, serum pro-inflammatory response, body weight and mortality studies demonstrated a short- and long-term biocompatibility and biosafety profile with no apparent acute and chronic toxicity caused by these nanoparticles in mice. Overall, these results suggest the feasibility of using sub-5 SIO-Fl nanoparticles as a promising agent for stem cell magnetic targeting as well as for diagnostic and therapeutic applications in oncology.

Can supernatant from immortalized adipose tissue MSC replace cell therapy? An in vitro study in chronic wounds model

Background

Mesenchymal stem cells (MSCs) secrete a cocktail of growth factors and cytokines, which could promote tissue regeneration and wound healing. Therefore, in clinical practice, post-culture MSC supernatant treatment could be a more attractive alternative to autologous stem cell transplantation. In this study, we compared the regenerative properties of supernatants harvested from four newly established human adipose tissue mesenchymal stem cell lines (HATMSCs) derived from chronic wound patients or healthy donors.

Methods

HATMSC supernatants were produced in a serum-free medium under hypoxia and their content was analyzed by a human angiogenesis antibody array. The regenerative effect of HATMSCs supernatants was investigated in an in vitro model of chronic wound, where cells originating from human skin, such as microvascular endothelial cells (HSkMEC.2), keratinocytes (HaCaT), and fibroblasts (MSU-1.1), were cultured in serum-free and oxygen-reduced conditions. The effect of supernatant treatment was evaluated using an MTT assay and light microscopy. In addition, fibroblasts and HATMSCs were labeled with PKH67 and PKH26 dye, respectively, and the effect of supernatant treatment was compared to that obtained when fibroblasts and HATMSCs were co-cultured, using flow cytometry and fluorescent microscopy.

Results

A wide panel of angiogenesis-associated cytokines such as angiogenin, growth-regulated oncogene (GRO), interleukin-6 and 8 (IL-6, IL-8), vascular endothelial growth factor (VEGF), insulin growth factor 1 (IGF-1), and matrix metalloproteinase (MMP) were found in all tested HATMSCs supernatants. Moreover, supernatant treatment significantly enhanced the survival of fibroblasts, endothelial cells, and keratinocytes in our chronic wound model in vitro. Importantly, we have shown that in in vitro settings, HATMSC supernatant treatment results in superior fibroblast proliferation than in the case of co-culture with HATMSCs.

Conclusions

Our results suggest that therapy based on bioactive factors released by the immortalized atMSC into supernatant has important effect on skin-derived cell proliferation and might preclude the need for a more expensive and difficult cell therapy approach to improve chronic wound healing.

Secretome of Adipose Tissue-Derived Stem Cells (ASCs) as a Novel Trend in Chronic Non-Healing Wounds: An Overview of Experimental In Vitro and In Vivo Studies and Methodological Variables

Wound healing is a complex process with a linear development that involves many actors in a multistep timeline commonly divided into four stages: Hemostasis, inflammation, proliferation, and remodeling. Chronic non-healing wounds fail to progress beyond the inflammatory phase, thus precluding the next steps and, ultimately, wound repair. Many intrinsic or extrinsic factors may contribute to such an occurrence, including patient health conditions, age-related diseases, metabolic deficiencies, advanced age, mechanical pressure, and infections. Great interest is being focused on the adipose tissue-derived stem cell’s (ASC) paracrine activity for its potential therapeutic impact on chronic non-healing wounds. In this review, we summarize the results of in vitro and in vivo experimental studies on the pro-wound healing effects of ASC-secretome and/or extracellular vesicles (EVs). To define an overall picture of the available literature data, experimental conditions and applied methodologies are described as well as the in vitro and in vivo models chosen in the reported studies. Even if a comparative analysis of the results obtained by the different groups is challenging due to the large variability of experimental conditions, the available findings are undoubtedly encouraging and fully support the use of cell-free therapies for the treatment of chronic non-healing wounds.

Preparation and Characterization of Human Adipose Tissue-Derived Extracellular Matrix, Growth Factors, and Stem Cells: A Concise Review

Background

Human adipose tissue is routinely discarded as medical waste. However, this tissue may have valuable clinical applications since methods have been devised to effectively isolate adipose-derived extracellular matrix (ECM), growth factors (GFs), and stem cells. In this review, we analyze the literature that devised these methods and then suggest an optimal method based on their characterization results.

Methods

Methods that we analyze in this article include: extraction of adipose tissue, decellularization, confirmation of decellularization, identification of residual active ingredients (ECM, GFs, and cells), removal of immunogens, and comparing structural/physiological/biochemical characteristics of active ingredients.

Results

Human adipose ECMs are composed of collagen type I-VII, laminin, fibronectin, elastin, and glycosaminoglycan (GAG). GFs immobilized in GAG include basic fibroblast growth factor (bFGF), transforming growth factor beta 1(TGF-b1), insulin like growth factor 1 (IGF-1), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), BMP4 (bone morphogenetic protein 4), nerve growth factor (NGF), hepatocyte growth factor (HGF), and epithermal growth factor (EGF). Stem cells in the stromal-vascular fraction display mesenchymal markers, self-renewal gene expression, and multi-differentiation potential.

Conclusion

Depending on the preparation method, the volume, biological activity, and physical properties of ECM, GFs, and adipose tissue-derived cells can vary. Thus, the optimal preparation method is dependent on the intended application of the adipose tissue-derived products.