Effect of Granulocyte Colony-Stimulating Factor (G-Csf) and Botulinum Toxin Type a on Fat Graft Retention in a Rat Model Publisher



Farahani Nik Z ; Abadi FNA ; Sabetghadam M
Source: Aesthetic Plastic Surgery Published:2026

Abstract

Background: Autologous fat grafting is widely used in reconstructive and aesthetic surgery; however, unpredictable graft survival remains a major limitation. Various biological modifiers have been proposed to improve graft retention. This study aimed to evaluate the effects of Granulocyte Colony-Stimulating Factor (G-CSF) and Botulinum Toxin Type A (BoNT-A), alone and in combination, on fat graft survival in a rat model. Methods: In this experimental animal study, 20 Wistar rats were randomly allocated into four groups: Group 1 (BoNT-A + G-CSF), Group 2 (BoNT-A), Group 3 (G-CSF), and Group 4 (control). Autologous inguinal fat was harvested and transplanted into the subcutaneous scalp region. Grafts were evaluated after four weeks for weight and volume retention, angiogenesis (CD34), macrophage infiltration (CD68), collagen deposition, and adipocyte viability using histopathological and immunohistochemical analyses. Statistical analysis was performed using one-way ANOVA with a significance level of p < 0.05. This study was approved by the Ethics Committee of Imam Khomeini Hospital Complex, Tehran University of Medical Sciences (Approval No: IR.TUMS.IKHC.REC.1398.287) and was conducted in accordance with the principles of the Declaration of Helsinki for animal research. Results: The BoNT-A group demonstrated significantly higher angiogenesis, adipocyte viability, and graft retention compared to all other groups (p < 0.05). The G-CSF group showed significantly increased macrophage infiltration and fibrosis, with reduced graft volume and weight retention. The combination group demonstrated intermediate outcomes without synergistic benefit. No significant differences in body weight were observed among groups. Conclusion: Botulinum toxin significantly improves fat graft survival by enhancing angiogenesis and maintaining adipocyte viability, while local administration of G-CSF alone may adversely affect graft retention due to increased inflammation and fibrosis. These findings suggest that BoNT-A may serve as an effective adjunct in fat grafting procedures. No Level Assigned: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. © Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery 2026.