Stromal vascular fraction (SVF) is a diverse collection of cells obtained from a person’s own fat tissue. This mixture is being explored for its potential in regenerative medicine. SVF contains various cell types that contribute to tissue repair and regeneration, with research continuing into its applications across different medical fields.
Composition and Origin of SVF
Stromal vascular fraction originates from fat tissue, an accessible source of diverse cells. Adipose-derived stem cells (ADSCs) are a primary component within SVF, recognized for their multipotent ability to differentiate into various cell types, including bone, cartilage, and muscle cells.
SVF also contains endothelial cells, which line blood vessels and support vascular health, alongside endothelial progenitor cells instrumental in forming new blood vessels (angiogenesis). Immune cells, such as T cells and macrophages, are present, regulating inflammation and immune responses. Fibroblasts, which provide structural support by producing extracellular matrix components like collagen, also contribute to tissue remodeling and repair.
The Extraction and Preparation Process
Obtaining stromal vascular fraction begins with mini-liposuction. This involves harvesting a small amount of fat tissue, commonly from the abdomen or thighs. A sample of around 50 cubic centimeters is sufficient for processing.
After harvesting, the fat tissue undergoes processing to isolate SVF. One common method is enzymatic digestion, using enzymes like collagenase to break down the extracellular matrix and release cells. Mechanical disruption methods like mincing or filtration can also be used, though enzymatic methods often yield more regenerative cells.
The cells are then subjected to centrifugation, which spins the mixture at high speeds. This separates the denser SVF cells, which form a pellet at the bottom, from lighter fat cells and oil. This entire procedure is performed as a single, in-clinic, point-of-care process, allowing for immediate application of the isolated cells.
Therapeutic and Cosmetic Applications
SVF is explored across various medical disciplines due to its regenerative properties. In orthopedics, SVF shows promise for treating conditions such as knee osteoarthritis, where it helps reduce pain, improve joint function, and potentially aid cartilage repair by modulating inflammation. It is also investigated for other joint, muscle, and tendon injuries, such as rotator cuff tears.
In aesthetic medicine, SVF is used for facial rejuvenation, reducing fine lines and wrinkles, improving skin quality, and stimulating collagen production. It also enhances the survival of fat grafts in procedures like breast and buttock augmentation or facial contouring, improving long-term aesthetic outcomes. SVF also treats various types of scars, including those from burns, acne, and surgical procedures.
SVF also plays a role in chronic wound healing, accelerating repair by promoting new blood vessel formation, remodeling the extracellular matrix, and encouraging healing cell migration. Studies indicate SVF can improve healing rates in non-healing ulcers. Beyond these areas, SVF is under investigational use for a broader range of conditions, including cardiovascular diseases like myocardial ischemia, pulmonary diseases, Crohn’s disease, neurological conditions such as multiple sclerosis, and reproductive disorders.
How SVF Promotes Healing and Regeneration
The therapeutic effects of SVF stem from the collective actions of its diverse cell populations. Adipose-derived stem cells, along with other cell types like endothelial cells, pericytes, immune cells, and fibroblasts, work together to promote tissue repair. This is largely mediated through several biological mechanisms.
One primary mechanism is paracrine signaling, where SVF cells release bioactive molecules, including growth factors (VEGF, FGF, HGF, PDGF), cytokines, and chemokines. These secreted factors act as chemical messengers, instructing local tissue cells to initiate repair, promote cell survival, encourage cell migration to injury sites, and stimulate proliferation. This signaling also reduces scarring.
SVF also promotes angiogenesis, the formation of new blood vessels. Endothelial progenitor cells, pericytes, and macrophages within SVF secrete pro-angiogenic factors and can differentiate into endothelial cells, contributing to new vasculature. This improved blood supply ensures injured tissues receive oxygen and nutrients for healing.
Immunomodulation is another pathway through which SVF exerts its effects, regulating inflammation and immune responses. Immune cells in SVF can suppress pro-inflammatory cytokines, shift macrophages towards an anti-inflammatory M2 phenotype, and induce regulatory T cells, creating an environment conducive to repair. Adipose-derived stem cells in SVF can also differentiate into various tissue-specific cells to replace damaged structures. Fibroblasts and macrophages contribute to extracellular matrix remodeling by secreting collagen and metalloproteinases, essential for structural repair and new vessel growth.
Regulatory and Safety Considerations
The regulatory landscape for SVF therapies varies, particularly concerning the U.S. Food and Drug Administration (FDA). The FDA regards SVF, especially when isolated using enzymes, as “more than minimally manipulated” under 21 CFR 1271. This classification means SVF products are regulated as drugs or biologics, requiring FDA approval for their intended uses. The “same surgical procedure” exemption, which allows certain human cells, tissues, and cellular products to be used without extensive oversight, does not apply to SVF due to processing that alters the original tissue.
Many SVF therapy applications are still investigational, undergoing clinical trials to establish their safety and effectiveness. Despite this, autologous SVF (derived from a patient’s own body) carries a low risk of immune rejection. Common, mild side effects include temporary discomfort, swelling, or bruising at the fat tissue harvest or SVF injection site.
While rare, serious complications have been reported in specific contexts, such as retinal detachment following intravitreal injections, which led to changes in clinical protocols. Patients considering SVF treatments should consult qualified medical professionals to understand the current regulatory status, potential risks, and whether the application is part of an approved clinical trial or still investigational.