**3. Validation of packaging for use in tissue cryopreservation.**

#### **3.1 Description of our sample**

A roll of transparent, unprinted seven layers, coextruded plastic:

The room is also equipped with an air conditioning system, its own energy generator, and carbon gas backup as protection against defrosting, as well as a rigorous temperature monitoring system that generates 24-hour printed temperature recordings, and a satellite alarm system, which ensures adequate maintenance of the temperature and early detection

Depending on the results of the analyses, the tissues are transferred to the room designated for materials liberated for use. The maximum cryopreservation period is 5 years for bone

It is vital to maintain sterility and integrity, in order to avoid disposal of any material. This is the purpose of **packaging**, which is aimed at containment and protection. In Brazil, there are no specific regulations for packaging of sterile, cryopreserved tissues for transplants, and in this chapter, we present our experience in the definition and validation of a type of packaging used for this purpose. Our proposal is to characterize a coextruded plastic film structure used for packaging of musculoskeletal tissues at low temperatures, in regard to the aspects sterility, cytotoxicity, migration, mechanical resistance and

Fig. 1. Cryopreservation of tissues at -80 ◦C in drawers, separated by batches.

**3. Validation of packaging for use in tissue cryopreservation.** 

A roll of transparent, unprinted seven layers, coextruded plastic:

**3.1 Description of our sample** 

of any flaws.

oxygen permeability.

tissue and 2 years for soft or tendinous tissues.

Layer 01: LLDPE – 1-octene comonomer Linear Low-Density Polyethylene Layer 02: LLDPE – 1-octene comonomer Linear Low-Density Polyethylene and 1-octene comonomer Linear Low-Density Polyethylene modified with anhydride maleic Layer 03: PA – hexamethylenediamine, adipic acid e caprolactam copolyamide Layer 04: LLDPE – 1-octene comonomer Linear Low-Density Polyethylene and 1-octene comonomer Linear Low-Density Polyethylene modified with anhydride maleic Layer 05: PA – hexamethylenediamine, adipic acid e caprolactamcopolyamide Layer 06: LLDPE – 1-octene comonomer Linear Low-Density Polyethylene and 1-octene comonomer Linear Low-Density Polyethylene modified with anhydride maleic Layer 07: LLDPE – 1-octene comonomer Linear Low-Density Polyethylene

In relation to the physicomechanical and barrier properties characteristics, we investigated the alterations that occurred in the packages after 30, 60, 90, 120, and 150 days of cryopreservation at -80◦C. For the cytotoxicity and sterility analysis, two groups (before and after sterilization by ethylene oxide) were analysed.
