Comparison between Stromal Vascular Fraction and Adipose Mesenchymal Stem Cells in Remodeling Hypertrophic Scars

Mesenchymal stem cells in the treatment of Cesarean section skin scars: study protocol for a randomized, controlled trial

Background

Cesarean delivery has already become a very common method of delivery around the world, especially in low-income countries. Hypertrophic scars and wound infections have affected younger mothers and frustrated obstetricians for a long time. Mesenchymal stem cells (MSCs) have strong potential for self-renewal and differentiation to multilineage cells. Previous studies have demonstrated that MSCs are involved in enhancing diabetic wound healing. Therefore, this study is designed to investigate the safety and efficacy of using MSCs in the treatment of Cesarean section skin scars.

Methods

This trial is a prospective, randomized, double-blind, placebo-controlled, single-center trial with three parallel groups. Ninety eligible participants will be randomly allocated to placebo, low-dose (transdermal hydrogel MSCs; 3 × 10⁶ cells) or high-dose (transdermal hydrogel MSCs; 6 × 10⁶ cells) groups at a 1:1:1 allocation ratio according to a randomization list, once a day for six consecutive days. Study duration will last for 6 months, comprising a 1 week run-in period and 24 weeks of follow-up. The primary aim of this trial is to compare the difference in Vancouver Scar Scale rating among the three groups at the 6th month. Adverse events, including severe and slight signs or symptoms, will be documented in case report forms. The study will be conducted at the Department of Obstetric of Southern Medical University Affiliated Maternal & Child Health Hospital of Foshan.

Discussion

This trial is the first investigation of the potential for therapeutic use of MSCs for the management of women’s skin scar after Cesarean delivery. The results will give us an effective therapeutic strategy to combat Cesarean section skin scars, even with uterine scarring.

Trial registration

ClinicalTrials.gov, NCT02772289. Registered on 10 May 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2478-x) contains supplementary material, which is available to authorized users.

Mesenchymal stem cells-derived exosomes are more immunosuppressive than microparticles in inflammatory arthritis

Objectives: Mesenchymal stem cells (MSCs) release extracellular vesicles (EVs) that display a therapeutic effect in inflammatory disease models. Although MSCs can prevent arthritis, the role of MSCs-derived EVs has never been reported in rheumatoid arthritis. This prompted us to compare the function of exosomes (Exos) and microparticles (MPs) isolated from MSCs and investigate their immunomodulatory function in arthritis.

Methods: MSCs-derived Exos and MPs were isolated by differential ultracentrifugation. Immunosuppressive effects of MPs or Exos were investigated on T and B lymphocytes in vitro and in the Delayed-Type Hypersensitivity (DTH) and Collagen-Induced Arthritis (CIA) models.

Results: Exos and MPs from MSCs inhibited T lymphocyte proliferation in a dose-dependent manner and decreased the percentage of CD4⁺ and CD8⁺ T cell subsets. Interestingly, Exos increased Treg cell populations while parental MSCs did not. Conversely, plasmablast differentiation was reduced to a similar extent by MSCs, Exos or MPs. IFN-γ priming of MSCs before vesicles isolation did not influence the immunomodulatory function of isolated Exos or MPs. In DTH, we observed a dose-dependent anti-inflammatory effect of MPs and Exos, while in the CIA model, Exos efficiently decreased clinical signs of inflammation. The beneficial effect of Exos was associated with fewer plasmablasts and more Breg-like cells in lymph nodes.

Conclusions: Both MSCs-derived MPs and Exos exerted an anti-inflammatory role on T and B lymphocytes independently of MSCs priming. However, Exos were more efficient in suppressing inflammation in vivo. Our work is the first demonstration of the therapeutic potential of MSCs-derived EVs in inflammatory arthritis.

Autologous adipose-derived regenerative cell therapy modulates development of hypertrophic scarring in a red Duroc porcine model

Background

Effective prevention and treatment of hypertrophic scars (HTSs), a common consequence of deep-partial thickness injury, remain a significant clinical challenge. Previous studies from our group have shown that autologous adipose-derived regenerative cells (ADRCs) represent a promising approach to improve wound healing and, thereby, impact HTS development. The purpose of this study was to assess the influence of local delivery of ADRCs immediately following deep-partial thickness cutaneous injury on HTS development in the red Duroc (RD) porcine model.

Methods

Bilateral pairs of deep-partial thickness excisional wounds (2 mm depth; 58 cm² area) were created using an electric dermatome on RD pigs (n = 12). Autologous ADRCs were isolated from the inguinal fat pad and then sprayed directly onto the wound at a dose of 0.25 × 10⁶ viable cells/cm². The paired contralateral wound received vehicle control. Wound healing and development of HTS were assessed over 6 months using digital imaging, quantitative measurement of skin hardness and pigmentation, and histology.

Results

Data showed that ADRC treatment led to reduced scar hyperpigmentation compared to control (p < 0.05). Using the Durometer, at 2 and 6 months post-injury, skin hardness was 10–20% lower in ADRCs-treated wounds compared to control vehicle (p < 0.05). A similar trend was observed with the skin fibrometer.

ADRC treatment promoted more normal collagen organization, improvement in the number of rete ridges (p < 0.01), longer elastic fiber length (p < 0.01), and reduced hypervascularity (blood vessel density; p < 0.05). ADRC treatment was associated with modulation of IL-6 expression within the wound/scar with upregulation 2 weeks after injury (wound healing phase) and downregulation at 2 months (early scarring phase) post-treatment compared to control

Conclusions

These findings support the potential therapeutic value of autologous ADRC administration for reduction of HTS development following deep-partial cutaneous injury.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0704-1) contains supplementary material, which is available to authorized users.

Adipose tissue-derived stromal vascular fraction in regenerative medicine: a brief review on biology and translation

Adipose/fat tissue provides an abundant source of stromal vascular fraction (SVF) cells for immediate administration and can also give rise to a substantial number of cultured, multipotent adipose-derived stromal cells (ADSCs). Recently, both SVF and ADSCs have gained wide-ranging translational significance in regenerative medicine. Initially used for cosmetic breast enhancement, this mode of treatment has found use in many diseases involving immune disorders, tissue degeneration, and ischaemic conditions. In this review, we try to address several important aspects of this field, outlining the biology, technology, translation, and challenges related to SVF- and ADSC-based therapies. Starting from the basics of SVF and ADSC isolation, we touch upon recently developed technologies, addressing elements of novel methods and devices under development for point-of-care isolation of SVF. Characterisation of SVF cells and ADSCs is also an evolving area and we look into unusual expression of CD34 antigen as an interesting marker for such purposes. Based on reports involving different cells of the SVF, we draw a potential mode of action, focussing on angiogenesis since it involves multiple cells, unlike immunomodulation which is governed predominantly by ADSCs. We have looked into the latest research, experimental therapies, and clinical trials which are utilising SVF/ADSCs in conditions such as multiple sclerosis, Crohn’s disease, peripheral neuropathy, osteoarthritis, diabetic foot ulcer, and so forth. However, problems have arisen with regards to the lack of proper regulatory guidelines for such therapies and, since the introduction of US Food and Drug Administration draft guidelines and the Reliable and Effective Growth for Regenerative Health Options that Improve Wellness (REGROW) Act, the debate became more public with regards to safe and efficacious use of these cells.

Semi-automated extraction and characterization of Stromal Vascular Fraction using a new medical device

INTRODUCTION

The stem cell rich Stromal Vascular Fraction (SVF) can be harvested by processing lipo-aspirate or fat tissue with an enzymatic digestion followed by centrifugation. To date neither a standardised extraction method for SVF nor a generally admitted protocol for cell application in patients exists. A novel commercially available semi-automated device for the extraction of SVF promises sterility, consistent results and usability in the clinical routine. The aim of this work was to compare the quantity and quality of the SVF between the new system and an established manual laboratory method.

MATERIAL AND METHODS

SVF was extracted from lipo-aspirate both by a prototype of the semi-automated UNiStation™ (NeoGenesis, Seoul, Korea) and by hand preparation with common laboratory equipment. Cell composition of the SVF was characterized by multi-parametric flow-cytometry (FACSCanto-II, BD Biosciences). The total cell number (quantity) of the SVF was determined as well the percentage of cells expressing the stem cell marker CD34, the leucocyte marker CD45 and the marker CD271 for highly proliferative stem cells (quality).

RESULTS

Lipo-aspirate obtained from six patients was processed with both the novel device (d) and the hand preparation (h) which always resulted in a macroscopically visible SVF. However, there was a tendency of a fewer cell yield per gram of used lipo-aspirate with the device (d: 1.1×105±1.1×105 vs. h: 2.0×105±1.7×105; p = 0.06). Noteworthy, the percentage of CD34+ cells was significantly lower when using the device (d: 57.3% ±23.8% vs. h: 74.1% ±13.4%; p = 0.02) and CD45+ leukocyte counts tend to be higher when compared to the hand preparation (d: 20.7% ±15.8% vs. h: 9.8% ±7.1%; p = 0.07). The percentage of highly proliferative CD271+ cells was similar for both methods (d:12.9% ±9.6% vs. h: 13.4% ±11.6%; p = 0.74) and no differences were found for double positive cells of CD34+/CD45+ (d: 5.9% ±1.7% vs. h: 1.7% ±1.1%; p = 0.13), CD34+/CD271+ (d: 24.1% ±12.0% vs. h: 14.2% ±8.5%; p = 0.07).

DISCUSSION

The semi-automated closed system provides a considerable amount of sterile SVF with high reproducibility. Furthermore, the SVF extracted by both methods showed a similar cell composition which is in accordance with the data from literature. This semi-automated device offers an opportunity to take research and application of the SVF one step further to the clinic.

Quantitative analysis of rat adipose tissue cell recovery, and non-fat cell volume, in primary cell cultures

BACKGROUND

White adipose tissue (WAT) is a complex, diffuse, multifunctional organ which contains adipocytes, and a large proportion of fat, but also other cell types, active in defense, regeneration and signalling functions. Studies with adipocytes often require their isolation from WAT by breaking up the matrix of collagen fibres; however, it is unclear to what extent adipocyte number in primary cultures correlates with their number in intact WAT, since recovery and viability are often unknown.

EXPERIMENTAL DESIGN

Epididymal WAT of four young adult rats was used to isolate adipocytes with collagenase. Careful recording of lipid content of tissue, and all fraction volumes and weights, allowed us to trace the amount of initial WAT fat remaining in the cell preparation. Functionality was estimated by incubation with glucose and measurement of glucose uptake and lactate, glycerol and NEFA excretion rates up to 48 h. Non-adipocyte cells were also recovered and their sizes (and those of adipocytes) were measured. The presence of non-nucleated cells (erythrocytes) was also estimated.

RESULTS

Cell numbers and sizes were correlated from all fractions to intact WAT. Tracing the lipid content, the recovery of adipocytes in the final, metabolically active, preparation was in the range of 70-75%. Cells showed even higher metabolic activity in the second than in the first day of incubation. Adipocytes were 7%, erythrocytes 66% and other stromal (nucleated cells) 27% of total WAT cells. However, their overall volumes were 90%, 0.05%, and 0.2% of WAT. Non-fat volume of adipocytes was 1.3% of WAT.

CONCLUSIONS

The methodology presented here allows for a direct quantitative reference to the original tissue of studies using isolated cells. We have also found that the "live cell mass" of adipose tissue is very small: about 13 µL/g for adipocytes and 2 µL/g stromal, plus about 1 µL/g blood (the rats were killed by exsanguination). These data translate (with respect to the actual "live cytoplasm" size) into an extremely high metabolic activity, which make WAT an even more significant agent in the control of energy metabolism.