The dermal filler Sculptra® has been employed to treat facial volume loss and age-related wrinkles in Europe since 1999. Sculptra® injections were administered 87,946 times (increase of 25.7% to 2012) in the USA in 2013. Except for histological analysis and clinical reports, data based on molecular biology or biochemistry, enlightening the mechanisms of action, do not exist to date. In contrast, such data are available for cross-linked hyaluronic acid, which is also administered for facial augmentation. To overcome this gap of knowledge, a comprehensive study about macroscopic to microscopic events occurring after Sculptra® injections was conducted.
The augmentation of facial tissue with Sculptra® is approved; however, as the required repetitive biopsies could not be taken from the face, Sculptra® was injected to the inner side of the upper arms of 21 volunteers. Furthermore, this “off label use” was documented: The effect of the injections on the volunteer’s subjective quality of life was investigated using a questionnaire. For objective evaluation, the upper arms were photographed and sonographic measurements were applied.
Photos of the treated upper arms revealed no changes in their shape during the study course. The amount of Sculptra® administered was not sufficient to augment the upper arms of postmenopausal women. Furthermore, these applied Sculptra® treatments of the upper arm did not improve the volunteers’ quality of life significantly. Upon sonographic measurement, however, a highly significant decrease in echogenicity was retrieved by comparing baseline subepidermal tissue values (t0) with 20 month (t2) values from either arm. Upon comparison of both treated sides, echogenicity was comparable; therefore 22 MHz sonography is an objective non-invasive measure to document the subcutaneous effect of Sculptra®.
Immunofluorescence staining of sections from biopsies characterised the cell infiltrate and collagen type. CD68+ macrophages were found in direct proximity to PLLA, CD90+ fibroblasts aligned adjacently, while αSMA positive structures indicated myofibroblasts and neovascularisation. Substantial collagen type III deposition was detected right next to PLLA particles and collagen type I in the periphery of a given PLLA encapsulation. mRNA expression was strongly up-regulated for collagen type I and III transcripts, as well as for TGFß1 and TIMP1. PLLA particles were still retrievable 28 months after subcutaneous application.
The augmenting effect of Sculptra® is generated by a complex reaction, comprised of various cells, chemokines and cytokines, leading to the proliferation of fibroblasts and their differentiation into myofibroblasts, synthesising a substantial amount of collagen in order to restore subcutaneous volume deficiencies. Degradation of facial and extra facial PLLA particles is considerably slower than described previously. The augmenting effect of Sculptra® diminishes over a period of 18-20 months in the face, but the degradation of PLLA particles seems to be much slower. Whether Sculptra® stimulates the synthesis of other ECM components, such as HA, or rationalises a continuous stimulus for collagen production, at least as long as it is not synthesised, should be analysed in further studies.
| Identifer | oai:union.ndltd.org:uni-osnabrueck.de/oai:repositorium.ub.uni-osnabrueck.de:urn:nbn:de:gbv:700-2015020413042 |
| Date | 04 February 2015 |
| Creators | Stein, Philipp |
| Contributors | apl. Prof. Dr. Nanna Y. Schürer, Prof. Dr. Helmut Wieczorek |
| Source Sets | Universität Osnabrück |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis |
| Format | application/pdf, application/zip |
| Rights | http://rightsstatements.org/vocab/InC/1.0/ |
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