The Combination of Mechanically Isolated Stromal Vascular Fraction and Fibrin Hydrogel: A Processing Protocol

Mechanically isolated stromal vascular fraction (SVF) in combination with a fibrin hydrogel offers an easy and efficient carrier for viable adipose-derived stromal cells for various indications, including tissue engineering and or wound healing purposes. Here, we present the preparation of a mechanical SVF (mSVF)-fibrin hydrogel construct for translational research and clinical application.

The regenerative potential of adipose-derived stromal cells (ASCs) has gained significant attention in regenerative and translational research. In the past, the extraction of these cells from adipose tissue required a multistep enzyme-based process, resulting in a heterogenous cell mix consisting of ACSs and other cells, which are jointly termed the stromal vascular fraction (SVF). More recently introduced mechanical SVF (mSVF) isolation protocols are less time-consuming and bypass regulatory concerns. We recently proposed a protocol that generates mSVF rich in stromal cells based on a combination of emulsification and centrifugation. One current issue in mSVF application for wound therapy application is the lack of a scaffold providing protection from mechanical manipulation and desiccation. Fibrin hydrogels have been shown to be a useful adjunct in cell transfer for wound healing purposes in the past. In the work herein, we delineate the preparation steps of an mSVF-fibrin hydrogel construct as a novel approach for translational research and clinical application.

Over the past few years, regenerative plastic surgery has emerged as an additional pillar of plastic surgery¹. Regenerative plastic surgery aims to restore damaged tissue by transferring soluble factors, cells, and tissue harvested from the patient to promote tissue restoration in a minimally invasive manner². Adipose-derived stem cells (ASCs) have gained attention due to their ability to differentiate into multiple mesenchymal lineages, making them a promising candidate for regenerative medicine research³. Their cytokine profile displays angiogenic, immunosuppressive, and an....

This study was performed in accordance with the Declaration of Helsinki. All adult donors provided written informed consent to allow further use of the collected tissue samples. The protocol follows the guidelines of our institution's human research ethics committee.

1. Harvest of adipose tissue

1. Harvest the adipose tissue by performing a standard liposuction in a conventional fat-harvesting technique described in previous publications²⁶<.......

Resazurin assay
We first examined the in vitro cell viability of the mSVF cells. For this purpose, we conducted a resazurin cell viability assay on days 0, 3, and 7. The cell viability at days 0, 3, and 7 of a total of four samples are shown in Figure 1. The values of day 0 serve as the baseline and were set as 100%. At day 3, the positive control (mSVF) showed a slight decrease to 78.92% (± 5.33%), while the mSVF-fibrin hydrogel combination remained at 9.......

The mechanical isolation of SVF provides an elegant alternative to the traditional enzymatic approach and offers broad access for clinical application²⁹. In fact, mSVF, as proposed in the present manuscript, is already in clinical use for soft tissue treatment of scars or as an adjunct for cosmetic procedures³⁰. The protocol presented here provides a simple method for efficient topical delivery of viable mSVF cells. While the positive control with only mSVF cells showed a t.......

Bong-Sung Kim is supported by the German Research Foundation (KI 1973/2-1) and the Novartis Foundation for Medical-Biological Research (#22A046).