Growth and Phenotype of Low-density Nasal Septal Chondrocyte Monolayers

Abstract

To analyze the growth patterns and differentiation of human septal chondrocyte monolayers of different seeding densities. Chondrocytes from 8 donors were plated at densities ranging from 20,000 cells/cm(2) (high density) to 300 cells/cm(2) (very low density). Confluency, cellularity, and glycosaminoglycan content were determined from days 1 to 15. Confluency was attained at 5.8, 8.3, 11.0, and 14.8 days for high-, intermediate-, low-, and very low-density monolayers, respectively (P < 0.001). Regression growth curves showed typical lag, logarithmic, and stationary phases. Confluent monolayers attained similar cellularity (power = 0.94) and differentiation (power = 0.88), regardless of initial density. Human septal chondrocyte monolayers reach confluency from very low initial densities. Growth patterns, cellularity, and differentiation are similar to other starting densities. Very low-density monolayers expanded cell number 838-fold in 1 passage and therefore are sufficient for tissue-engineering purposes. This is important because of the requirement of maintaining differentiation and the limitation of small tissue harvest specimens.