Immunohistochemical Analysis of Nanofat Membrane, Solid PRF, and Stromal Vascular Fraction Gel

Platelet-rich fibrin (PRF) and nanofat have emerged as promising autologous biomaterials in tissue regeneration and facial rejuvenation. Both serve as vehicles for cellular growth factors that promote wound healing and tissue remodeling. This study aims to investigate the presence of endothelial and stem cell markers in nanofat membranes through immunohistochemical analysis.

Eleven patients (nine women, two men) with a mean age of 36.82 ± 5.79 were included in this case-series study. Tissue samples were obtained using a mixture of nanofat and injectable PRF, with two different concentration ratios (2:1 and 1:1), in addition to solid PRF and stromal vascular fraction (SVF) gel membrane for comparison. The samples were fixed in 10% formaldehyde, processed into paraffin blocks, and sectioned (2-5 μm). Immunohistochemical staining was performed using markers CD31 (endothelial cells), CD34 (hematopoietic and adipose-derived stem cells, and endothelial cells), CD163 (macrophages), ERG (endothelial marker), S100 (adipocyte marker), and CD10 (adipose-derived stem cells). Histopathologic examination evaluated endothelial and stem cell presence as well as macrophage infiltration.

Histopathological analysis revealed fragmented adipose tissue with vascular proliferation, as well as platelet and fibrin deposition. Immunohistochemical staining showed the presence of endothelial markers (CD31: 36.82%, CD34: 22.73%, ERG: 19.09%) in the nanofat membrane, indicating vascularization. CD163 staining highlighted macrophages, although they were sparse in the nanofat membrane (<1% of cells). The SVF gel membrane exhibited substantial platelet aggregation but lacked evidence of cellular differentiation. CD34 staining confirmed the presence of adipose-derived stem cells (ADSCs), though in lower-than-expected quantities.

This study demonstrates the presence of endothelial cells and limited macrophages within the nanofat membranes, suggesting potential for vascular neoformation and tissue remodeling. However, the lack of detection of significant adipose-derived stem cells highlights the need for more advanced immunohistochemical markers to fully evaluate regenerative potential. The nanofat membrane provides a viable scaffold for tissue regeneration, with further research needed to optimize protocols for enhanced clinical outcomes.

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