Histological Assessment of the Effectiveness of Microneedling Device-Assisted Filler Delivery.

Background: Microneedling is used to enhance transcutaneous drug delivery. However, the extent to which microneedling devices impact filler delivery and whether this varies by filler type, microneedling device type, and treatment sequence is not known.

Objective: To histologically assess and quantify the delivery of commonly used fillers through microneedling, using both a microneedling pen and a microneedling roller. In addition, the authors investigated whether there is a variation in filler delivery based on the sequence of microneedling in relation to topical filler application.

Methods: Ex vivo human abdominal skin samples were subjected to microneedling pen or microneedling roller treatment. Black tissue marking ink, hyaluronic acid, poly- l -lactic acid, or undiluted calcium hydroxyapatite was topically applied before or immediately after microneedling treatment.

Results: Histological evaluation revealed a notable presence of black ink within channels formed by both microneedling treatments (15.5%-98.1%), whereas there was limited presence of the various filler types tested (0%-6.6%) in all settings. Topical application before microneedling treatment led to relatively higher filler/ink deposition within the channels formed by the microneedling treatments compared with topical application after microneedling.

Conclusion: Transcutaneous delivery of fillers was not significantly helped by microneedling treatment, whereas the microneedling devices demonstrated effective delivery of an aqueous solution.