Protein Profiling of Mechanically Processed Lipoaspirates: Discovering Wound Healing and Antifibrotic Biomarkers in Nanofat.

BACKGROUND: Nanofat is an injectable oily emulsion, rich in adipose-derived stem cells and growth factors. It is prepared from lipoaspirates through mechanical emulsification and filtration. Despite being successfully used in several procedures in regenerative medicine such as scar attenuation, skin rejuvenation, and treatment of chronic wounds, little is known about exactly how nanofat induces regeneration in treated skin at the molecular level. METHODS: Microfat and nanofat samples were isolated from 18 healthy patients. Proteomic profiling was performed through untargeted mass spectrometry proteomics and multiplex antibody arrays. Pathway enrichment analysis of differentially expressed proteins between microfat and nanofat was performed using Gene Ontology, Reactome, and Kyoto Encyclopaedia of Genes and Genomes as reference databases. RESULTS: Untargeted proteomics showed that up-regulated genes in nanofat are involved in innate immunity responses, coagulation, and wound healing, whereas down-regulated genes were linked to cellular migration and extracellular matrix production. Secretome array screening of microfat and nanofat samples showed no significantly different expression, which strongly suggests that the mechanical emulsification step does not affect the concentration of tissue regeneration biomarkers. The identified proteins are involved in wound healing, cellular migration, extracellular matrix remodeling, angiogenesis, stress response, and immune response. CONCLUSIONS: Mechanical processing of lipoaspirates into nanofat significantly influences the proteome profile by enhancing inflammation, antimicrobial, and wound healing pathways. Nanofat is extremely rich in tissue repair and tissue remodeling factors. This study shows that the effects of microfat and nanofat treatment are based on up-regulated inflammation, antimicrobial, and wound healing pathways. Mechanical emulsification does not alter the concentration of tissue regeneration biomarkers. CLINICAL RELEVANCE STATEMENT: In addition to adipose-derived stems cells, nanofat contains distinct tissue repair and remodelling factors, which explains its beneficial effects on tissue regeneration.