Advancing human adipose-derived mesenchymal stem cell-derived exosomes for androgenetic alopecia: Appraisal and methodological recommendations

Table 1 Procedural assessment and recommendations for human adipose-derived mesenchymal stem cell-exosome research

Procedures	Current limitations	Recommended improvements	Priority level
Exosome characterization	Incomplete marker information; limited use of negative controls; possible contamination from serum supplements	Include key markers (Alix, TSG101, syntenin), broader negative controls; clarify serum supplementation and collection methods to avoid contamination	Medium
Dose normalization	Only total protein reported; lack of particle count, particle-to-protein ratio; no dose-response analysis; batch variability not addressed	Report both particle count and protein concentration; include particle-to-protein ratio, yield per cell, batch variability; establish dose-response curves with multiple doses; normalize exposure by particle number per area in animal studies	High
Mechanism validation	No direct validation of CDC42 function; mechanism inferred only from changes after treatment; limited depth in Wnt/β-catenin pathway analysis	Demonstrate CDC42’s direct role via knockdown/overexpression and exosome content analysis; assess effects on dermal papilla cells and β-catenin localization; perform rescue experiments and detailed pathway analysis, including target gene expression and reporter activity	High
In vivo model	Phenotypic changes only; limited biochemical measurements; lack of validity safeguards (randomization/blinding); short follow-up duration	Add biochemical measurements (skin/serum dihydrotestosterone, androgen receptor target genes); implement randomization and blinding; extend follow-up to cover a full hair cycle for durability assessment	Medium
Delivery optimization	Microneedle delivery parameters undefined (needle length, density, passes, pressure, intervals); no tracking of distribution or retention	Specify microneedle parameters (length, density, passes, pressure, interval); use imaging techniques to track exosome distribution and optimize dosing	Medium
QC	No minimal QC panel defined; lack of clear release criteria; insufficient disclosure of key variables (size, marker intensity, endotoxin, etc.)	Define a streamlined QC panel early; select key markers from the 232-protein set; disclose criteria (particle size, particle-to-protein ratio, marker intensity, endotoxin level, sterility, residual bovine protein) to ensure reproducibility	Medium
Safety evaluation	Limited safety profiling; no integrated framework; regulatory requirements not fully addressed	Evaluate safety via cytokine panels, pro-fibrotic markers, hemolysis, coagulation, local irritation scores; develop an integrated quality control and safety framework to meet regulatory standards	Low

QC: Quality control.