Strategies for improving adipose-derived stem cells for tissue regeneration

Efficacy of stromal vascular fraction for knee osteoarthritis: A prospective, single-centre, non-randomized study with 2 years follow-up

BACKGROUND

Current osteoarthritis (OA) treatments focus on symptom relief without addressing the underlying disease process. In regenerative medicine, current treatments have limitations. In regenerative medicine, more research is needed for intra-articular stromal vascular fraction (SVF) injections in OA, including dosage optimization, long-term efficacy, safety, comparisons with other treatments, and mechanism exploration.

AIM

To compare the efficacy of intra-articular SVF with corticosteroid (ICS) injections in patients with primary knee OA.

METHODS

The study included 50 patients with Kellgren-Lawrence grades II and III OA. Patients were randomly assigned (1:1) to receive either a single intra-articular SVF injection (group A) or a single intra-articular ICS (triamcinolone) (group B) injection. Patients were followed up at 1, 3, 6, 12, and 24 months. Visual analog score (VAS) and International Knee Documentation Committee (IKDC) scores were administered before the procedure and at all follow-ups. The safety of SVF in terms of adverse and severe adverse events was recorded. Statistical analysis was performed with SPSS Version 26.0, IBM Corp, Chicago, IL, United States.

RESULTS

Both groups had similar demographics and baseline clinical characteristics. Follow-up showed minor patient loss, resulting in 23 and 24 in groups A and B respectively. Group A experienced a notable reduction in pain, with VAS scores decreasing from 7.7 to 2.4 over 24 months, compared to a minor reduction from 7.8 to 6.2 in Group B. This difference in pain reduction in group A was statistically significant from the third month onwards. Additionally, Group A showed significant improvements in knee functionality, with IKDC scores rising from 33.4 to 83.10, whereas Group B saw a modest increase from 36.7 to 45.16. The improvement in Group A was statistically significant from 6 months and maintained through 24 months.

CONCLUSION

Our study demonstrated that intra-articular administration of SVF can lead to reduced pain and improved knee function in patients with primary knee OA. More adequately powered, multi-center, double-blinded, randomised clinical trials with longer follow-ups are needed to further establish safety and justify its clinical use.

Engineered Extracellular Vesicles in Chronic Kidney Diseases: A Comprehensive Review

Chronic kidney diseases (CKD) present a formidable global health challenge, characterized by a deficiency of effective treatment options. Extracellular vesicles (EVs), recognized as multifunctional drug delivery systems in biomedicine, have gained accumulative interest. Specifically, engineered EVs have emerged as a promising therapeutic approach for targeted drug delivery, potentially addressing the complexities of CKD management. In this review, we systematically dissect EVs, elucidating their classification, biogenesis, composition, and cargo molecules. Furthermore, we explore techniques for EV engineering and strategies for their precise renal delivery, focusing on cargo loading and transportation, providing a comprehensive perspective. Moreover, this review also discusses and summarizes the diverse therapeutic applications of engineered EVs in CKD, emphasizing their anti-inflammatory, immunomodulatory, renoprotective, and tissue-regenerating effects. It critically evaluates the challenges and limitations in translating EV therapies from laboratory settings to clinical applications, while outlining future prospects and emerging trends.

Exosomes from adipose-derived stem cells restore fibroblast function and accelerate diabetic wound healing

Background

Diabetes is common yet challenging chronic disease, that affects a wide range of people around the world. Complex cellular environments around diabetic wounds tend to damage the function of effector cells, including vascular endothelial cells (VECs), fibroblasts and epithelial cells. This study aims to analyze the differences between diabetic wounds and normal skin as well as whether adipose-derived stem cell (ADSC) exosome could promote healing of diabetic wound.

Methods

Human diabetic wounds and normal skin were collected and stained with HE, Masson, CD31 and 8-hydroxy-2 deoxyguanosine immunohistochemical staining. RNA-seq data were collected for further bioinformatics analysis. ADSC exosomes were isolated and identified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting. The effect of ADSC exosomes on diabetic wound healing was assessed on full thickness wounds in mice. To further verify the regulative impact of ADSCs exosomes in high glucose treated fibroblasts, we isolated fibroblasts from normal skin tissue and measured the cell viability, apoptosis rate, proliferation and migration of fibroblasts. In addition, collagen formation and fibrosis-related molecules were also detected. To further disclose the mechanism of ADSC exosomes on the function of high glucose treated fibroblasts, we detected the expression of apoptosis related molecules including BCL2, Bax, and cleaved caspase-3.

Results

Histological observation indicated that perilesional skin tissues from diabetic patients showed structural disorder, less collagen disposition and increased injury compared with normal skin. Bioinformatics analysis showed that the levels of inflammatory and collagen synthesis related molecules, as well as oxidative stress and apoptosis related molecules, were significantly changed. Furthermore, we found that ADSC exosomes could not only speed up diabetic wound healing, but could also improve healing quality. ADSC exosomes restored high glucose induced damage to cell viability, migration and proliferation activity, as well as fibrosis-related molecules such as SMA, collagen 1 and collagen 3. In addition, we verified that ADSC exosomes downregulated high glucose induced increased apoptosis rate in fibroblast and the protein expression of Bax as well as cleaved caspases 3.

Conclusions

This study indicated that ADSC exosomes alleviated high glucose induced damage to fibroblasts and accelerate diabetic wound healing by inhibiting Bax/caspase 3.

Role of Hedgehog Signaling Pathways in Multipotent Mesenchymal Stem Cells Differentiation

Multipotent mesenchymal stem cells (MSCs) have high self-renewal and multi-lineage differentiation potentials and low immunogenicity, so they have attracted much attention in the field of regenerative medicine and have a promising clinical application. MSCs originate from the mesoderm and can differentiate not only into osteoblasts, cartilage, adipocytes, and muscle cells but also into ectodermal and endodermal cell lineages across embryonic layers. To design cell therapy for replacement of damaged tissues, it is essential to understand the signaling pathways, which have a major impact on MSC differentiation, as this will help to integrate the signaling inputs to initiate a specific lineage. Hedgehog (Hh) signaling plays a vital role in the development of various tissues and organs in the embryo. As a morphogen, Hh not only regulates the survival and proliferation of tissue progenitor and stem populations but also is a critical moderator of MSC differentiation, involving tri-lineage and across embryonic layer differentiation of MSCs. This review summarizes the role of Hh signaling pathway in the differentiation of MSCs to mesodermal, endodermal, and ectodermal cells.

Transplantation of adipose derived stem cells in diabetes mellitus; limitations and achievements

Objectives

Diabetes mellitus (DM) is a complex metabolic disease that results from impaired insulin secreting pancreatic β-cells or insulin resistance. Although available medications help control the disease, patients suffer from its complications. Therefore, finding effective therapeutic approaches to treat DM is a priority. Adipose Derived Stem Cells (ADSCs) based therapy is a promising strategy in various regenerative medicine applications, but its systematic translational use is still somewhat out of reach. This review is aimed at clarifying achievements as well as challenges facing the application of ADSCs for the treatment of DM, with a special focus on the mechanisms involved.

Methods

Literature searches were carried out on "Scopus", "PubMed" and "Google Scholar" up to September 2022 to find relevant articles in the English language for the scope of this review.

Results

Recent evidence showed a significant role of ADSC therapies in DM by ameliorating insulin resistance and hyperglycemia, regulating hepatic glucose metabolism, promoting β cell function and regeneration, and functioning as a gene delivery tool. In addition, ADSCs could improve diabetic wound healing by promoting collagen deposition, inhibiting inflammation, and enhancing angiogenesis.

Conclusion

Overall, this literature review revealed the great clinical implications of ADSCs for translating into the clinical setting for the treatment of diabetes. However, further large-scale and controlled studies are needed to overcome challenges and confirm the safety and optimal therapeutic scheme before daily clinical application.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01280-8.

Mesenchymal stromal cell biotherapy for Parkinson's disease premotor symptoms

Parkinson's disease (PD) is a neurodegenerative disorder with motor deficits due to nigrostriatal dopamine depletion and with the non-motor/premotor symptoms (NMS) such as anxiety, cognitive dysfunction, depression, hyposmia, and sleep disorders. NMS is presented in at least one-fifth of the patients with PD. With the histological information being investigated, stem cells are shown to provide neurotrophic supports and cellular replacement in the damaging brain areas under PD conditions. Pathological change of progressive PD includes degeneration and loss of dopaminergic neurons in the substantia nigra of the midbrain. The current stem cell beneficial effect addresses dopamine boost for the striatal neurons and gliovascular mechanisms as competing for validated PD drug targets. In addition, there are clinical interventions for improving the patient's NMS and targeting their autonomic dysfunction, dementia, mood disorders, or sleep problems. In our and many others' research using brain injury models, multipotent mesenchymal stromal cells demonstrate an additional and unique ability to alleviate depressive-like behaviors, independent of an accelerated motor recovery. Intranasal delivery of the stem cells is discussed for it is extensively tested in rodent animal models of neurological and psychiatric disorders. In this review, we attempt to discuss the repairing potentials of transplanted cells into parkinsonism pathological regions of motor deficits and focus on preventive and treatment effects. From new approaches in the PD biological therapy, it is believed that it can as well benefit patients against PD-NMS.

OPG gene-modified adipose-derived stem cells improve bone formation around implants in osteoporotic rat maxillae

Background

Osteoporosis is a significant barrier to the use of dental implants in the elderly for the treatment of tooth defects. Adipose derived stem cells (ADSCs) have demonstrated extensive potential for tissue repair and regeneration. The present study aimed to investigate the effectiveness of ADSCs engineered to express high levels of osteoprotegerin (OPG) for the treatment of bone loss in implant dentistry caused by estrogen deficiency.

Methods

A rat model of osteoporosis was established through double oophorectomy, and the rats were treated by gene modified cells Adv-OPG-ADSCs. The effects of the treatment on maxilla tissue changes were evaluated using HE staining and micro-CT. Additionally, ALP and TRAP staining were used to assess osteoblast and osteoclast alterations. Finally, the changes in related osteoblast and osteoclast indicators were measured by RT-qPCR, Western blot, and ELISA.

Results

The successfully generated high-OPG-expressing ADSCs led to increase of cell viability, proliferation, and osteoblast differentiation. Treatment with Adv-OPG-ADSCs significantly ameliorated maxillary morphology, trabecular volume reduction, and bone mineral density decline in the model of estrogen-deficient maxillary implant dentistry. Furthermore, the treatment was beneficial to promoting the generation of osteoblasts and inhibiting the generation of osteoclast. Adv-OPG-ADSCs increased OPG, ALP, OCN, and Runx-2 expressions in the maxilla while suppressing RANKL expression, and also increased the concentration of COL I and PINP, as well as decreased the concentration of CTX-1.

Conclusion

Adv-OPG-ADSCs promote the formation of osteoblasts and inhibit the generation of osteoclasts, thereby inhibiting bone absorption, facilitating bone formation, and promoting the repair of maxillary bone after dental implantation in the presence of osteoporosis-related complications, especially in the setting of estrogen deficiency, providing scientific basis for the application of Adv-OPG-ADSCs in the treatment of implant related osteoporosis.

Magnetic Nanoparticle Coating Decreases the Senescence and Increases the Targeting Potential of Fibroblasts and Adipose-Derived Mesenchymal Stem Cells

Magnetic nanoparticles (MNPs) are intensely scrutinized for applications in emerging biomedical fields. Their potential use for drug delivery, tracking, and targeting agents or for cell handling is tested for regenerative medicine and tissue engineering applications. The large majority of MNPs tested for biomedical use are coated with different lipids and natural or synthetic polymers in order to decrease their degradation process and to increase the ability to transport drugs or bioactive molecules. Our previous studies highlighted the fact that the as-prepared MNP-loaded cells can display increased resistance to culture-induced senescence as well as ability to target pathological tissues; however, this effect tends to be dependent on the cell type. Here, we assessed comparatively the effect of two types of commonly used lipid coatings, oleic acid (OA) and palmitic acid (PA), on normal human dermal fibroblasts and adipose-derived mesenchymal cells with culture-induced senescence and cell motility in vitro. OA and PA coatings improved MNPs stability and dispersibility. We found good viability for cells loaded with all types of MNPs; however, a significant increase was obtained with the as-prepared MNPs and OA-MNPs. The coating decreases iron uptake in both cell types. Fibroblasts (Fb) integrate MNPs at a slower rate compared to adipose-derived mesenchymal stem cells (ADSCs). The as-prepared MNPs induced a significant decrease in beta-galactosidase (B-Gal) activity with a nonsignificant one observed for OA-MNPs and PA-MNPs in ADSCs and Fb. The as-prepared MNPs significantly decrease senescence-associated B-Gal enzymatic activity in ADSCs but not in Fb. Remarkably, a significant increase in cell mobility could be detected in ADSCs loaded with OA-MNPscompared to controls. The OA-MNPs uptake significantly increases ADSCs mobility in a wound healing model in vitro compared to nonloaded counterparts, while these observations need to be validated in vivo. The present findings provide evidence that support applications of OA-MNPs in wound healing and cell therapy involving reparative processes as well as organ and tissue targeting.

3D bioprinting of a gradient stiffened gelatin-alginate hydrogel with adipose-derived stem cells for full-thickness skin regeneration

Current hydrogel-based scaffolds offer a promising approach to accelerate tissue regeneration, but great challenges remain in developing platforms that mimic the physical microenvironment of tissues combined with therapeutic biological cues. Here, a 3D bioprinting gelatin-alginate hydrogel for the construction of gradient composite scaffolds that mimic the dermal stiffness microenvironment was developed for architecture construction by extruding the bioink on calcium-containing substrates to achieve gradient secondary cross-linking, meanwhile, adipose-derived stem cells were encapsulated in the present hydrogels for therapeutic purposes. The gradient-stiffness scaffold exhibited good stability and biocompatibility as well as enhanced proliferation and migration of the adipose-derived stem cells. In addition, the promoted angiogenesis and healing efficiency was demonstrated via the animal wound model and was mainly attributed to the enhanced paracrine secretion of adipose-derived stem cells by the physical microenvironment provided within the gradient stiffness scaffold. The current 3D printed gradient scaffolds provide adipose-derived stem cells with a distinct yet successive architecture rather than the typical uniform microenvironment to accelerate skin regeneration, which may have broader applications in other chronic wounds or tissue defects.