Tissue engineering a model for the human ear: Assessment of size, shape, morphology, and gene expression following seeding of different chondrocytes

Abstract

This study examines the tissue engineering of a human ear model through use of bovine chondrocytes isolated from four different cartilaginous sites (nasoseptal, articular, costal, and auricular) and seeded onto biodegradable poly(l-lactic acid) and poly(L-lactide-epsilon-caprolactone) (50 : 50) polymer ear-shaped scaffolds. After implantation in athymic mice for up to 40 weeks, cell/scaffold constructs were harvested and analyzed in terms of size, shape, histology, and gene expression. Gross morphology revealed that all the tissue-engineered cartilages retained the initial human auricular shape through 40 weeks of implantation. Scaffolds alone lost significant size and shape over the same period. Quantitative reverse transcription-polymerase chain reaction demonstrated that the engineered chondrocyte/scaffolds yielded unique expression patterns for type II collagen, aggrecan, and bone sialoprotein mRNA. Histological analysis showed type II collagen and proteoglycan to be the predominant extracellular matrix components of the various constructs sampled at different implantation times. Elastin was also present but it was found only in constructs seeded with auricular chondrocytes. By 40 weeks of implantation, tissue-engineered cartilage of costal origin became calcified, marked by a notably high relative gene expression level of bone sialoprotein and the presence of rigid, nodular protrusions formed by mineralizing rudimentary cartilaginous growth plates. The collective data suggest that nasoseptal, articular, and auricular cartilages represent harvest sites suitable for development of tissue-engineered human ear models with retention over time of three-dimensional construct architecture, gene expression, and extracellular matrix composition comparable to normal, nonmineralizing cartilages. Calcification of constructs of costal chondrocyte origin clearly shows that chondrocytes from different tissue sources are not identical and retain distinct characteristics and that these specific cells are inappropriate for use in engineering a flexible ear model.

The in vitro and in vivo capacity of culture-expanded human cells from several sources encapsulated in alginate to form cartilage

“…2002; Karlsson et al, 2007;Kusuhara et al, 2009;Lohan et al, 2011;Malicev et al, 2009;Naumann et al, 2004;Panossian et al, 2001;Sakaguchi et al, 2005;Seda Tigli et al, 2009;Tay et al, 2004;van Osch et al, 2004;Vinardell et al, 2012;Xu et al, 2004;Yoshimura et al, 2007;Zhang and Spector, 2009). However, precise comparison of the performance of culture-expanded human cells is lacking.…”

Novel bilayer bacterial nanocellulose scaffold supports neocartilage formation in vitro and in vivo

“…Most studies that have used biodegradable scaffold materials have resulted in poor structural integrity (i.e. shape and size stability) of the auricular scaffold after implantation; caused by the short-lived chemical and mechanical stability [27][28][29][30][31]. On the other hand, recent studies that have investigated the use of non-degradable biomaterials for auricular cartilage reconstruction have reported a better structural integrity of the implant [23,25,32] -likely caused by the chemical stability of the support biomaterial, which translates 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 into long-lasting mechanical properties even after implantation.…”

Biocompatibility of Human Auricular Chondrocytes Cultured onto a Chitosan/Polyvynil Alcohol/Epichlorohydrin-Based Hydrogel for Tissue Engineering Application

“…More experiments should be performed in order to confirm this hypothesis. Elastin is the protein that confers elasticity to elastic cartilage, preventing tissue creeping by stretching under load and recoiling to their original configurations after the load is released (Kusuhara et al, 2009). Immunohistochemical assay showed that an elevated number of auricular chondrocytes from microtia cultured onto CS-PVA-ECH hydrogel were still able to express elastin and type II collagen in concordance with mRNA analysis.…”