ESWT is a force to be reckoned with

Extracorporeal Acoustic Shock Waves to Treat Complications of Polymethylmethacrylate

BACKGROUND

Polymethylmethacrylate (PMMA) fillers are permanent fillers known for their possible side effects. In case of complications, the only possible treatment is surgical removal, followed by procedures to minimize resulting deformity. The aims of this study were (1) to analyse the morphology of the PMMA material in the nodules, (2) to demonstrate that treatment by acoustic wave therapy (AWT) can help the removal of the nodules, and (3) to present an easy procedure to solve deformities.

METHODS

The data of 9 patients who underwent AWT, surgical PMMA removal, and deformity correction by enriched nanograft and dermagraft injections between April 2021 and May 2024 were presented. The leftover aspirated material was analysed by histology and scanning electron microscopy.

RESULTS

AWT resulted in no complications in all patients. After removal and correction surgeries, minor complications were observed in 5 cases. All the patients were delighted with the aesthetic outcome. In all patients, an important improvement of the deformities, with correction of the volume of the face, was observed. A substantial resolution of the initial clinical symptoms was documented. The ultrastructural analysis highlighted that PMMA appears in the form of laminar or prismatic formations with a paracrystalline structure.

CONCLUSIONS

AWT acted directly on PMMA to facilitate its removal and reduce fibrosis around the PMMA filler. The lack of volume correlated with PMMA removal was resolved with the enriched nanograft and dermagraft injections, which led to very satisfying aesthetic results.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Shock wave-induced permeabilization of mammalian cells

Controlled permeabilization of mammalian cell membranes is fundamental to develop gene and cell therapies based on macromolecular cargo delivery, a process that emerged against an increasing number of health afflictions, including genetic disorders, cancer and infections. Viral vectors have been successfully used for macromolecular delivery; however, they may have unpredictable side effects and have been limited to life-threatening cases. Thus, several chemical and physical methods have been explored to introduce drugs, vaccines, and nucleic acids into cells. One of the most appealing physical methods to deliver genes into cells is shock wave-induced poration. High-speed microjets of fluid, emitted due to the collapse of microbubbles after shock wave passage, represent the most significant mechanism that contributes to cell membrane poration by this technique. Herein, progress in shock wave-induced permeabilization of mammalian cells is presented. After covering the main concepts related to molecular strategies whose applications depend on safer drug delivery methods, the physics behind shock wave phenomena is described. Insights into the use of shock waves for cell membrane permeation are discussed, along with an overview of the two major biomedical applications thereof-i.e., genetic modification and anti-cancer shock wave-assisted chemotherapy. The aim of this review is to summarize 30 years of data showing underwater shock waves as a safe, noninvasive method for macromolecular delivery into mammalian cells, encouraging the development of further research, which is still required before the introduction of this promising tool into clinical practice.