Preparation of Rat Tail Tendons for Biomechanical and Mechanobiological Studies

Summary

This article describes the experimental procedures used to prepare rat tail tendons for biomechanical and mechanobiological studies. Several features of the main steps in preparation are demonstrated, beginning with extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber.

Abstract

Rat tail tendons (RTTs) are a common biological model used in experimental in vitro studies in the fields of tendon physiology and tendinopathy. Working with those tissues is challenging because they are very fragile, and until now there was no rigorously detailed protocol for their isolation.

Faced with these challenges, we have developed methods and instruments to facilitate manipulation of RTTs and control tissue viability, sterility and integrity. This article describes the experimental procedures used to prepare RTTs for biomechanical and mechanobiological studies. Our work is divided into four main steps: extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber.

At each step, all procedures, materials and manipulations are presented in detail so that they can be easily reproduced. Moreover, the specific instruments developed are presented: a manipulation plate used to segregate RTTs, an optic micrometer to position the tissue during the cross-sectional area measurement and an anchoring system to attach the RTTs onto a bioreactor.

Finally, we describe the results obtained after multiple tests to validate our methods. The viability, sterility and integrity evaluations demonstrate that our procedures are sufficiently rigorous for manipulations of fragile tissues such as rat tail tendons.

Protocol

Prior to any manipulation, you must identify the group of tendons to be used depending on the experiment you are conducting and the apparatus at your disposition. For our purposes, ventral tendons were chosen because they are smaller and thus easier to manipulate when measuring the cross-sectional area and fitting them into the bioreactor chamber.

Please note that all instruments are autoclaved or sterilized with 70% ethanol. Moreover, a spray bottle containing 70% ethanol is placed beside each work station to sterilize the experimenter’s gloves before each operation.

Part 1: Extraction

Discussion

By applying those experimental procedures, we can conduct a wide variety of in vitro studies on this kind of tissues. As for example, a study on tissue degeneration was carried out by the application of under-stimulation to RTTs for a period of ten days. Each day, we evaluated tissue mechanical properties in non-destructive stress relaxation tests. At the end, we were able to observe RTT stress variation and thus analyze the progression of mechanical properties.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
D-PBS	Reagent	Wisent Inc.	311-410-CL	Saline solution
Glucose	Reagent	Wisent Inc.	609-037-EL	Saline solution 1g/L
Antibiotics-antimycotics	Reagent	Invitrogen	15240-062	Saline solution 1%
DMEM	Reagent	Invitrogen	12800-017	Culture solution
Sodium Bicarbonate	Reagent	Wisent Inc.	600-105-CG	Culture solution 3.7g/L
FBS	Reagent	Wisent Inc.	090150	Culture solution 10%
Antibiotics-antimycotics	Reagent	Invitrogen	15240-062	Culture solution 1%
Optic Micrometer	Tool	Custom Made
Manipulation plate	Tool	Custom Made
Bioreactor chamber	Tool	Custom Made