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Co-corresponding authors: Jian-Guang Zhang and Wei Zhang.
Author contributions: Zhang JG and Zhang W contributed equally as co-corresponding authors. Zhang JG and Zhang W contributed to the conceptualization, writing, reviewing and editing; Wu YF and Zhang W participated in the conceptualization and writing of the original draft; Jiang X assisted with literature collection and manuscript revision; and all authors participated in drafting the manuscript and all have read and approved the final version of the manuscript.
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Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Received: February 24, 2026 Revised: April 8, 2026 Accepted: May 12, 2026 Published online: August 26, 2026 Processing time: 182 Days and 17.1 Hours
Abstract
Adipose tissue-derived stromal vascular fraction (SVF) is a valuable source of regenerative cells for various clinical applications. However, obtaining a sufficient number of cells from patients with limited adipose reserves, particularly from the pediatric population, is a challenge. A study investigated a two-step enzymatic digestion approach to maximize stem cell yield from small adipose tissue samples. Their work demonstrated that the second collagenase digestion of the residual adipose tissue (typically discarded after conventional isolation) yielded a considerable additional population of viable regenerative cells (SVF2). Although SVF1 contained higher absolute cell numbers, SVF2 exhibited superior plating efficiency and higher colony-forming units per 1000 mononucleated cells. This simple modification substantially improved the regenerative cell yield from limited adipose tissue sources. This review offers a critical evaluation of the study methodology and propose future directions, including the integration of artificial intelligence to optimize digestion parameters, and the establishment of standardized potency assays to facilitate its translation into broader clinical practice.
Core Tip: The residual adipose tissue typically discarded after conventional enzymatic digestion contains viable and functionally-potent regenerative cells. The second digestion step yielded stromal vascular fraction 2, which exhibited high clonogenic potential. Although promising, the study’s generalizability is limited by its small sample size and lack of donor diversity. This review critically evaluates the methodology, discusses the impact of donor variability and enzyme lots on reproducibility, and proposes an artificial-intelligence-driven framework for personalizing digestion protocols. These insights aim to accelerate the clinical adoption and optimization of this valuable technique.
