The effect of cryopreservation or heating on the mechanical properties and histomorphology of rat bone-patellar tendon-bone

Abstract

The effects of cryopreservation on tendon allograft have been reported, but remain unclear, particularly the potential effects on mechanical properties and histological changes by ice crystal formation. There are also few studies about effects of heating for sterilization of tendon. We evaluated the effect of cryopreservation or heating on the mechanical properties and histomorphology of rat bone-patellar tendon-bones (BTBs). BTBs were processed by cryopreservation at -80 degrees C for 3 weeks, or heating at 80 degrees C for 10 min. Tensile testing and histomorphological examination were performed. The cryopreservation of tendons showed less influences on their mechanical properties. When cryopreserved BTBs in frozen state were fixed by freeze-substitution method, many spaces were observed in interfibrillar substances. These results suggest that the collagen fibers of cryopreserved tendons were histomorphologically affected by ice crystals. The heating of tendons completely destroyed the collagen fibers of the tendons and is therefore thought to be inappropriate for the sterilization of BTBs.

Repeated freeze–thaw cycles reduce the survival rate of osteocytes in bone-tendon constructs without affecting the mechanical properties of tendons

“…Fresh specimens were pre-fixed with 0.1 M cacodylate buffer containing 4% paraformaldehyde and 2.5% glutaraldehyde, and then post-fixed with 2% osmium tetraoxide in 0.1 M cacodylate buffer and embedded in Quetol 651 resin (Nissin EM Corp., Tokyo, Japan) according to the manufacturer’s instructions. In addition, to evaluate the structure of bone cells in the frozen state, bones were fixed using a freeze-substitution method, as previously described (Park et al 2009). Briefly, bones were first transferred to acetone containing 2% osmium tetroxide (OsO 4 ) cooled at −80°C, and then stored at −80°C for 1 week.…”

“…We therefore hypothesized that repeated freeze–thaw cycles would reduce the number of surviving cells in allografts, and potentially represents a simple method for reducing immunogenicity. Although we previously reported that a single freeze–thaw cycle did not affect the mechanical properties of tendons (Park et al 2009), it is unclear how repeated freeze–thaw treatments would affect tendon mechanics and function.…”

X Ray Diffraction: An Approach to Structural Quality of Biological Preserved Tissues in Tissue Banks

“…In other field, there are many studies showing that the biomechanical behavior of tissue collagen framework, is not altered by effect of cryopreservation / thaw cycle, in vascular (Armentano, 2006;Bia, 2006;Langerak, 2001Langerak, , 2007Pukacki, 2000), tendon , (Woo, 1986;Park, 2009) or bone tissues. (Hamer, 1996).…”

Estudo biomecânico de tração (ex-vivo) em osteotomia da tuberosidade tibial de cães estabilizada com placa fixa por "garfo" ou parafuso

“…As radiografias foram avaliadas quanto a doença óssea ou nutricional, fraturas da crista da tíbia, sinais de artroplastia ou osteotomia da tuberosidade da tíbia. Após remoção de tecidos moles estas foram armazenadas em freezer convencional, com temperatura de -20° Celsius (PARK et al, 2009;GOH et al, 2010;JUNG et al, 2011). As peças foram armazenadas em embalagens plásticas com dimensões de 50 centímetros de altura e 30 centímetros de largura.…”

“…(JUNG et al, 2011). Esta temperatura foi baseada em estudos similares previamente realizados (DENNLER et al, 2006;KOWALESKY;LINS et al, 2009;PARK et al, 2009;ETCHEPAREBORDE et al, 2010;GOH et al, 2010;BUTLER et al, 2011;JUNG et al, 2011 DOVERSPIKE et al, 1993;DUPUIS et al, 1994;CHAUVET et al, 1996;BONFIM;PACCOLA, 2000;INNES et al, 2000;MORRIS;LIPOWITZ, 2001;BOUDRIEAU, 2005;CONZEMIUS et al, 2005;DAMUR, 2005;HOFFMANN et al, 2006;BARAÚNA et al, 2007;TARTARUNAS et al, 2007;STEINS;SCHMOEKEL, 2008;VOSS, et al, 2008;GUERRERO et al, 2009;DYMOND;GOLDSMID;SIMPSON, 2010;BISGARD et al, 2011;KEMPER et al, 2011;STEINBERG et al, 2011). Entretanto é sabido que a avaliação biomecânica pode trazer informações importantes para estudos clínicos futuros.…”