Botulinum toxin type A plays a role in inhibiting one of the most serious breast surgery complications, capsular contracture. It does so through the TGF-β/Smad signaling pathway, according to a new study.
Researchers treated cultured human fibroblasts in vitro with TGF-β1 and/or botulinum toxin type A. Then they looked at collagen, matris metalloproteinase and Smad expression, according to the abstract.
They found that botulinum toxin type A treatment inhibited Smad 2 phosphorylation and expression of collagen types 1 and 3. But the same treatment enhanced matrix metalloproteinase-2 and matrix metalloproteinase-9. They found that, in vivo, treatment with the neurotoxin reduced capsule thickness and Smad2 phosphorylation in silicone-induced capsules, according to the abstract.
"If validated in the clinical setting, then this may be another use for Botox. It could lead to Botox being used to treat capsular contracture…, which can occur after breast augmentation or breast reconstruction. Current uses for Botox include treating facial rhytides, blepharospasm, masseter hypertrophy and hyperhidrosis. Before we know for sure though, further clinical testing will be needed," says Cindy Wu, M.D., assistant professor and director of research in plastic and reconstructive surgery at The University of North Carolina, Chapel Hill, N.C. Dr. Wu is not affiliated with the study.
Related: Toxin vs toxin: How do you choose?
In a clinical practice update on capsular contracture after breast augmentation published in 2015 in the Archives of Plastic Surgery authors wrote about botulinum toxin A’s potential role, suggesting it had been shown to be effective at reducing keloid scarring, which is histologically similar to implant capsules.
They cited an animal study in which researchers injected 0.5 mL of botulinum toxin A into implant pockets and found the treatment resulted in reduced capsular thickness, decreased inflammatory cells and decreased TGF-β1 expression. The experimental group had a loose, well organized collagen pattern compared to controls. A later study on mice confirmed those results.
Like the researchers in this latest study, the practice update authors wrote that more research (especially on patients) needs to be done to draw any conclusions.