Collagen enhances stability and viability of diced cartilage as an injectable implant: An experimental study in rabbits

Abstract

The use of diced cartilage has become increasingly popular in rhinoplasty; however, the viability of the graft can vary. This study aimed to investigate the use of fillers for diced cartilage, evaluate their morphology and viability, and provide a foundation for their clinical use. Six rabbits were used in this experiment. Ear cartilage was excised and diced into pieces and mixed with different fillers, including collagen (COLD), hyaluronic acid (HAD), and normal saline (NSD), or used alone (COND) as a control. They were embedded in the backs of rabbits. After 3 months, the weight and volume of grafts were measured. The cellular viability and morphology were assessed. The HAD group showed the most significant volume change, followed by the NSD group. There was no significant weight change between the COLD and COND groups. Grossly, the COLD group appeared as a smooth block, while the COND and NSD groups appeared rough. Microscopically, fibrous tissue and collagen were arranged regularly in the COLD and HAD groups, and chondrocytes were arranged neatly. By contrast, collagen was less and arranged messily in the NSD and COND groups. There was better cell viability and angiogenesis around cartilage in the COLD group than in the HAD and NSD groups. When mixed with collagen, diced cartilage can maintain its basic shape and smooth appearance, and there is better cell viability and angiogenesis than when mixed with hyaluronic acid or normal saline, or used alone. These findings may provide implications for the clinical use of diced cartilage as injectable implants.