Dynamic Cell Seeding of Polymer Scaffolds for Cartilage Tissue Engineering

TLDR

Cell seeding of 3‑D polymer scaffolds is the initial step in engineered tissue cultivation, demanding high yield, rapid attachment, and uniform distribution for clinical implants. The study aims to relate cell seeding kinetics and mechanisms to aggregate formation using a mathematical model to optimize conditions for cartilage tissue engineering. Bovine articular chondrocytes were seeded onto 5–10 mm diameter, 2–5 mm thick highly porous polyglycolic acid scaffolds in well‑mixed spinner flasks. All cells attached throughout the scaffold within one day, and mixing produced 20–32 µm aggregates that accelerated attachment kinetics while preserving uniform distribution.

Abstract

Abstract Cell seeding of three‐dimensional polymer scaffolds is the first step of the cultivation of engineered tissues in bioreactors. Seeding requirements of large scaffolds to make implants for potential clinical use include: (a) high yield, to maximize the utilization of donor cells, (b) high kinetic rate, to minimize the time in suspension for anchorage‐dependent and shear‐sensitive cells, and (c) high and spatially uniform distribution of attached cells, for rapid and uniform tissue regeneration. Highly porous, fibrous polyglycolic acid scaffolds, 5–10 mm in diameter and 2–5 mm thick, were seeded with bovine articular chondrocytes in well‐mixed spinner flasks. Essentially, all cells attached throughout the scaffold volume within 1 day. Mixing promoted the formation of 20–32‐μm diameter cell aggregates that enhanced the kinetics of cell attachment without compromising the uniformity of cell distribution. The kinetics and possible mechanisms of cell seeding were related to the formation of cell aggregates by a simple mathematical model that can be used to optimize seeding conditions for cartilage tissue engineering.