Benchmarking native collagen : evaluation of structural differences between tendon types and across animal models

Abstract

Tendons perform two very distinct functions that require different mechanical properties and are categorized into two types based on these functions: positional (PTs) and energy storing (ESTs). Structural differences between PTs and ESTs enable these distinct functions. Within bovine and equine animal models, both structural and mechanical differences between PTs and ESTs have been noted. However, the extent of these differences is unclear, as is how well conserved any such differences are across species. The present research aimed to understand the structural differences and similarities between the most commonly used PTs and ESTs in three animal models: bovine, ovine, and rat. Tendons were structurally evaluated by four methods: Hydrothermal Isometric Tension (HIT), NaBH4 reduction with HIT, Transmission Electron Microscopy, and scanning Electron Microscopy. Overall, results from all four methods of analysis show that there are distinct differences between tendon types and across models: particularly between large and small animal models.