Animal studies

Rabbits with induced ENS (confirmed by histological and mRNA expression analyses) were randomly divided into six groups:

• turbinate surgery only
• turbinate surgery with collagen hydrogel injection

• three treatment groups - turbinate surgery with hNTSC application at three different doses

• control group: no surgery and no treatment

Human nasal turbinate stem cells (hNTSCs) were isolated from nasal inferior turbinate tissue obtained from a healthy donor. The study also mentions obtaining epithelial cells from a patient with allergic rhinitis who was undergoing nasal surgery, likely used as a reference.

Histological evaluation performed one month after application of hNTSC demonstrated increased epithelial thickness in the treatment groups compared to non-treatment groups. The medium-dose group exhibited the greatest improvement. Despite marked enhancement in epithelial thickness, complete restoration to normal architecture was not fully achieved, though substantial regenerative changes were observed.

To model ENS, turbinoplasty was performed in swine by partially removing the ventral turbinate with turbinectomy scissors followed by electrocauterization. After 56 days, tissue samples were collected for histological and morphological analysis.

The reduced turbinate volume led to expansion of the nasal cavity. Histology showed mucosal epithelial changes similar to those seen in ENS patients, including squamous cell metaplasia, goblet cell metaplasia, submucosal fibrosis, and glandular atrophy. Interestingly, the blood biochemistry values remained within the normal range

This swine model can help researchers evaluate new surgical techniques and mucosal regenerative treatments. Additionally, the model expressed molecular markers similar to those found in ENS patients.