Intraureteral injection of NASHA/Dx gel under direct ureteroscopic visualization for the treatment of primary high-grade vesicoureteral reflux

Bio-Revitalization: Effects of NASHA on Genes Involving Tissue Remodeling

BACKGROUND

The "non-animal stabilized hyaluronic acid" (NASHA) is a widely used product in bio-revitalization injective procedures in esthetic medicine. The present research aimed to quantitatively evaluate the therapeutic effect of one of the more used bio-revitalization products on cultured dermal fibroblasts. RT-PCR was used for gene expression profiling of some proteins known to be relevant in skin homeostasis.

METHODS

Human dermal fibroblasts were seeded on a culture medium enriched with a product for dermal bio-revitalization, consisting of stabilized hyaluronic acid gel 20 mg/ml. After 24, 48, and 72 h of exposure, the cDNA was amplified by real-time PCR. Gene expression was quantified with the delta/delta calculation method.

RESULTS

In this study, the gene of metalloproteinase (MMP)-13 is strongly expressed after NASHA incubation. The MMP-2 encoding gene instead is less expressed, but both evidence the same temporal trend, being progressively up-regulated after 24 and 48 h, thereafter the expression decreases, whereas MMP-3 maintains the same up-regulation at 72 h. Hyaluronan synthase 1 and desmoplakin are progressively up-regulated and increase at 24, 48, and 72 h. Hyaluronidase 1 and neutrophil elastase genes are overexpressed, but at 72 h they both exhibit the same behavior as the other degradative enzymes MMP-13 and MMP-2.

CONCLUSIONS

Skin bio-revitalization by injecting the tested NASHA gel produces an enhancement in the expression of some genes involved in extracellular matrix degradation and organization. In this study, a time-dependent behavior, different for genes encoding degradative compared to synthesis proteins, was demonstrated.

[Histopathological study of experimental intrapalpebral injection of hyaluronic acid gel]

Hyaluronic acid gel (HAG) fillers are successfully used in the treatment of many eyelid disorders. It is considered that the effect of HAG injection lasts for 6 months on average. However, in our experience volume augmentation persists longer, suggesting that the presence of the filler in the eyelid may be associated with certain tissue reactions. The objective of the study was to investigate morphological features of HAG biodegradation.

MATERIAL AND METHODS

Seven adult Chinchilla rabbits (14 eyes) received a single 0.1 ml HAG (Restylane, Q-Med AB, Sweden) subcutaneous upper eyelid injection followed by contouring of the skin for 1.5 mm on average. Tissue samples containing HAG were collected for histopathological examination with morphometric analysis on day 0, week 2, months 1, 2, 4, 6, and 9.

RESULTS

HAG persisted subcutaneously in the eyelid during the 9 months of the study in the form of a sponge-like structure with compartments of varying shape and size. Its total volume diminished gradually, nevertheless at the end of the study the filler could still be found in some compartments, mainly peripheral. In the central area of the depot residual HAG was surrounded by optically transparent spaces.

CONCLUSION

After being injected subcutaneously into the eyelids of experimental animals HAG formed a sponge-like structure causing a significant increase in eyelids volume. Gradual biodegradation of HAG was accompanied by neocollagenogenesis and 9 months later the process was still ongoing.