Split-thickness skin grafted stent for upper airway patency after medial maxillectomy

Increased mucociliary differentiation of human respiratory epithelial cells on hyaluronan-derivative membranes

The selection of a scaffold to facilitate mucociliary differentiation of respiratory epithelial cells (RECs) is crucial in the development of tissue engineering of respiratory epithelium. However, how the differentiation of RECs is influenced by the biomaterials has never been thoroughly explored. Previously, hyaluronan derivatives were considered as unsuitable biomaterials for culture of respiratory epithelium. In contrast, this study demonstrates that the membranous scaffolds made from benzyl esters of hyaluronic acids are capable of providing a more preferential environment for human RECs than conventionally used collagen-based scaffolds. The proliferation and mucociliary differentiation of RECs were examined by MTT assays, scanning electron microscopy, immunofluorescence, immunoblotting and gene expression. The percentage of ciliated cells in cultured RECs increased from 12.4% on collagen to 20.4% on hyaluronan-derivative membranes with a pseudostratified polarized layer that closely resembled the composition of the native epithelium. The expression levels of MUC5AC and MUC5B mRNA were higher on hyaluronan-based scaffolds than those on collagen. The presence of a hyaluronan-binding domain, CD44 and the receptor for hyaluronan-mediated motility of RECs were also demonstrated. Accordingly, the mucociliary differentiation-promoting effect of hyaluronan-derivative membranes indicates that it may be applied to the tissue engineering of respiratory epithelium.

Airway reconstruction with carrier-free cell sheets composed of autologous nasal squamous epithelium

OBJECTIVES/HYPOTHESIS

Although skin has been the most effective graft material for reconstructing the airway lumen, the use of squamous epithelium has many problems. If autologous airway squamous epithelium could differentiate into mucociliary epithelium after in vivo grafting, it could be an answer to these problems. In this study, we wanted to examine whether carrier-free nasal epithelial cell sheets composed of autologous squamous epithelium could be used as a substitute for skin in airway luminal reconstruction in three maxillectomy patients.

STUDY DESIGN

In vitro biochemical experiments with in vivo applications.

METHODS

We cultured nasal squamous epithelium from three maxillary cancer patients prior to maxillectomy. These squamous cell sheets were grafted on the forearm free flap, and, after maxillectomy, the surgical defect was reconstructed with a prefabricated myocutaneous radial forearm free flap with the cultured nasal squamous epithelium. At 1 and 3 month intervals after the reconstructive surgery, the cultured cell grafted area was investigated with histologic phenotype, comparing the skin grafted area.

RESULTS

The autologous nasal squamous epithelial cell sheet differentiated into mucociliary epithelium without the crust or mucus stagnation that is usually observed in cases in which skin graft is used for airway reconstruction.

CONCLUSIONS

We suggest that autologous cultured nasal squamous epithelium, which differentiates into mucociliary epithelium after in vivo grafting, can be used as a clinically relevant substitute for skin graft in airway luminal reconstruction.

Use of PLGA scaffold for mucociliary epithelium transfer in airway reconstruction: a preliminary study

CONCLUSION

A PLGA biodegradable membrane can be used as a scaffold for mucociliary epithelium transfer.

OBJECTIVES

The aim of this study was to examine the usefulness of the PLGA membrane as a biodegradable scaffold for mucociliary epithelium transfer in order for it to be used as a substitute for a skin graft for restoring mucosal defects in the airway.

METHODS

A PLGA biodegradable membrane was synthesized using the immersion precipitation method, and morphologic characterization was carried out using scanning electron microscopy (SEM). The degradation test was performed by soaking the PLGA membrane in a culture medium, and the morphological changes were observed by SEM. Human nasal basal epithelial (HNBE) cells were cultured on the newly synthesized PLGA membrane, and the morphological changes were analyzed using SEM. The MUC5AC and MUC8 mRNA levels were analyzed by RT-PCR.

RESULTS

The PLGA membrane for the mucociliary epithelium transfer was successfully fabricated. It had a 24 mm diameter, a 50 microm thickness, and many pores with diameters of approximately 3 microm. The PLGA membrane began to degrade from 7 days after it was soaked in the culture medium. It rapidly degraded from 3 weeks and severe destruction of the pore structure was noted from 4 to 6 weeks of soaking. The HNBE cells were well differentiated into the mucociliary epithelium on the PLGA membrane both phenotypically and genotypically.