Strategies to Mitigate Variability in Engineering Human Nasal Cartilage

Stephen H J Andrews,Martin Osswald,Aillette Mulet-Sierra,Khalid Ansari,Adetola B Adesida,Melanie Kunze,Lynn Williams

doi:10.1038/s41598-017-06666-2

Abstract

Skin cancer and its associated treitments can have devastating consequences for survivors; this is particularly true when cancer occurs on the nose. Recent work has applied cell-based tissue engineering (TE) strategies to develop nasal cartilage constructs for reconstruction of the nose. In this study, we have generated human nasal cartilage on a clinically approved collagen scaffold to investigate the donor-to-donor variability of TE cartilage and evaluated strategies to mitigate it. We also evaluated the gene expression of the family of fibroblast growth factor receptors (FGFR1-4) and their association with tissue quality. FGFR1 was significantly positively correlated with GAG/DNA; a measure of chondrogenic capacity. We implemented two strategies: hypoxic culture and co-culture with mesenchymal stromal cells (MSCs) to increase tissue quality. Total glycosaminoglycan (GAG) content varied significantly between donors initially, with >10–fold difference between the best and worst donor tissue. Our co-culture strategy was able to increase TE construct quality from poor quality donor tissue while supressing hypertrophy relative to MSCs alone. However, no differences were observed with the use of hypoxic culture. Tissues generated using co-culture with MSCs became vascularized and calcified in vivo, demonstrating a non-stable cartilage phenotype in co-culture and MSCs cartilage constructs.

Highlights

Skin cancer and its associated treitments can have devastating consequences for survivors; this is true when cancer occurs on the nose
When GAG content was normalized to DNA content (GAG/DNA) in each scaffold, the average GAG/DNA content varied considerably with an average of 23.3 ± 7.7 μg/μg
Neither total GAG nor the GAG/DNA was significantly correlated with donor age

Summary

Introduction

Skin cancer and its associated treitments can have devastating consequences for survivors; this is true when cancer occurs on the nose. The nasal septum is primary structural cartilage in the centre of the nose and is of paramount importance, as it is primarily responsible for setting the dorsal and caudal projection of the external nose in 3-dimensional space When these cartilages are sacrificed during the treatment of a nasal tip skin cancer with surgery or radiation or both, it can be extremely challenging to replicate or even emulate this complex cartilaginous structure with standard reconstructive techniques[2, 5]. Nasal chondrocytes can be isolated and harvested from a biopsy of the nasal septum These cells can be expanded in in vitro culture with growth factors that enhance their capacity to redifferentiate and express the functional extracellular matrix of native nasal cartilage[11]. To determine the clinical translatability of our culture techniques using BM-MSC and hypoxia, we evaluated the phenotypic stability of our cartilage constructs through subcutaneous implantation in a nude mouse model (Objective 3)

Objectives

Methods

Results

Conclusion