A systematic review of autologous adipose-derived stromal vascular fraction (SVF) for the treatment of acute cutaneous wounds

Improvement in Early Scar Maturation by Nanofat Infiltration: Histological and Spectrophotometric Preliminary Results From a Split Scar-Controlled, Randomized, Double-Blinded Clinical Trial

Background

The regenerative properties of stromal vascular fraction (SVF) in wound healing and scar formation are a subject of increasing clinical interest.

Objectives

Although preclinical studies have confirmed the angiogenetic, proliferative, and antifibrotic properties of SVF, there is limited clinical evidence from randomized controlled clinical trials.

Methods

Twelve patients who underwent abdominoplasty were included in this clinical study. Nanofat was mechanically obtained intraoperatively and infiltrated intradermally in the sutured surgical wound, randomly assigned to either the left or the right side. The abdominal scar was evaluated with the Patient and Observer Scar Assessment Scale, whereas erythema and pigmentation were measured with a reflectance spectrophotometry device (Mexameter, Courage + Khazaka electronic GmbH, Köln,Germany). Histological analysis and electron scan microscopy of tissue biopsies were performed at 8 months.

Results

The treated side of the scar showed significantly less erythema at 3- and 6-month follow-ups, but this difference reduced after 12 months. Patients reported better scar scores at the 6-month follow-up with a significantly better color at the treated side. Observers reported better overall scar scores at the treated side at 3-, 6-, and 12-month follow-ups, with better vascularization, pigmentation, and thickness. There was no statistically significant difference in terms of histological analysis between the 2 groups. There was no difference in the occurrence of adverse events between both sides.

Conclusions

Infiltration of nanofat exhibited promising results in surgical scar maturation characterized by less erythema and better texture. More clinical trials with a larger sample size are warranted to better elucidate the possible benefits of SVF on surgical scar formation.

Level of Evidence 5

N,N-Dimethylglycine Sodium Salt Exerts Marked Anti-Inflammatory Effects in Various Dermatitis Models and Activates Human Epidermal Keratinocytes by Increasing Proliferation, Migration, and Growth Factor Release

N,N-dimethylglycine (DMG) is a naturally occurring compound being widely used as an oral supplement to improve growth and physical performance. Thus far, its effects on human skin have not been described in the literature. For the first time, we show that N,N-dimethylglycine sodium salt (DMG-Na) promoted the proliferation of cultured human epidermal HaCaT keratinocytes. Even at high doses, DMG-Na did not compromise the cellular viability of these cells. In a scratch wound-closure assay, DMG-Na augmented the rate of wound closure, demonstrating that it promotes keratinocyte migration. Further, DMG-Na treatment of the cells resulted in the upregulation of the synthesis and release of specific growth factors. Intriguingly, DMG-Na also exerted robust anti-inflammatory and antioxidant effects, as assessed in three different models of human keratinocytes, mimicking microbial and allergic contact dermatitis as well as psoriasis and UVB irradiation-induced solar dermatitis. These results identify DMG-Na as a highly promising novel active compound to promote epidermal proliferation, regeneration, and repair, and to exert protective functions. Further preclinical and clinical studies are under investigation to prove the seminal impact of topically applied DMG-Na on relevant conditions of the skin and its appendages.

A Closed-system Technology for Mechanical Isolation of High Quantities of Stromal Vascular Fraction from Fat for Immediate Clinical Use

Adipose tissue stromal vascular fraction (SVF) is increasingly used in the clinic. SVF separation from fat by enzymatic disruption is currently the gold standard for SVF isolation. However, enzymatic SVF isolation is time-consuming (~1.5 h), costly and significantly increases the regulatory burden of SVF isolation. Mechanical fat disruption is rapid, cheaper, and less regulatory challenging. However, its reported efficacy is insufficient for clinical use. The current study evaluated the efficacy of a novel rotating blades (RBs) mechanical SVF isolation system.

Methods

SVF cells were isolated from the same lipoaspirate sample (n = 30) by enzymatic isolation, massive shaking (wash), or engine-induced RBs mechanical isolation. SVF cells were counted, characterized by flow cytometry and by their ability to form adipose-derived stromal cells (ASCs).

Results

The RBs mechanical approach yielded 2 × 10⁵ SVF nucleated cells/mL fat, inferior to enzymatic isolation (4.17 × 10⁵) but superior to cells isolating from fat by the "wash" technique (0.67 × 10⁵). Importantly, RBs SVF isolation yield was similar to reported yields achieved via clinical-grade enzymatic SVF isolation. RBs-isolated SVF cells were found to contain 22.7% CD45^-CD31^-CD34⁺ stem cell progenitor cells (n = 5) yielding quantities of multipotent ASCs similar to enzymatic controls.

Conclusions

The RBs isolation technology provided for rapid (<15 min) isolation of high-quality SVF cells in quantities similar to those obtained by enzymatic digestion. Based on the RBs platform, a closed-system medical device for SVF extraction in a rapid, simple, safe, sterile, reproducible, and cost-effective manner was designed.

Efficacy and safety of stromal vascular fraction on scar revision surgery: a prospective study

BACKGROUND

Cell-based therapies are popular in the field of reconstructive surgery. The stromal vascular fraction (SVF), comprised of mature adipocytes or blood, reportedly has a regenerative effect; however the mechanism remains unclear. This study aimed to prove the viability and effectiveness of using SVF in scar treatment.

METHODS

This prospective double-blind study involved 20 patients who visited an outpatient clinic for 2 years, from July 2016 to July 2018, and underwent scar revision for traumatic or surgical scars. After scar revision surgery performed by a single surgeon, patient scars were divided into experimental and control sides. The subcutaneous layer of the experimental and control sides were injected with 0.1 mL/cm of SVF and normal saline, respectively. Each side was evaluated using the Patient and Observer Scar Assessment Scale (POSAS) before and six months after the surgery.

RESULTS

Of the 20 patients who underwent scar revision surgery and SVF treatment, 4 dropped out for personal reasons. In 11 of 12 POSAS items, the experimental side showed significant improvements compared to the control side.

CONCLUSIONS

Although more research is needed, autologous SVF is a valuable source of regenerative medicine that can be swiftly and inexpensively prepared from human fat tissue.