Cryomilling of Decellularized Tissue: A Technique to Obtain Fine Extracellular Matrix Powder

Cryogenic milling or cryomilling is a technique that allows decellularized tissue specimens to be cooled to extremely low temperatures and ground to a fine powder while retaining their biochemical composition. 

To begin, obtain a lyophilized tissue-derived decellularized extracellular matrix or ECM of interest. Mince it to obtain small fragments.

Next, transfer the minced ECM fragments into a milling jar. Introduce milling balls into the milling jar. Immerse the loaded milling jar in liquid nitrogen to freeze the sample at −196 °C.

Load the cooled jar into a cryomilling system. Subject the frozen sample to cryomilling at an appropriate frequency for the desired duration.

During cryomilling, the milling jar oscillates radially in the horizontal position. In consequence, the inertia of the milling balls facilitates them to impact the frozen sample with high energy at the rounded ends of the jar and pulverize it.

Additionally, the movement of the milling jar coupled with the motion of the milling balls promotes intensive mixing of the sample to obtain a fine powder with uniform particle size distribution.

Now, transfer the cryomilled ECM powder into a glass vial. Seal the vial tightly to prevent exposure to moisture. Desiccate the sample until further use.