1. Allogeneic Heart Valve Storage Above the Glass Transition at −80°C
Kelvin G.M. Brockbank, PhD, Gregory J. Wright, BS, Hai Yao, PhD, Elizabeth D. Greene, LATg, Zhen Z. Chen, MS, Katja Schenke- Layland, PhD 
The Annals of Thoracic Surgery 
Volume 91, Issue 6, Pages (June 2011)
DOI: /j.athoracsur
Copyright © 2011 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Gross examination of heart valves in 100 mL volumes at −135°C while in the storage freezer. The VS55 (A) sample shows extensive cracking throughout the cryoprotectant solution while the VS83 (B) sample remains grossly intact. In only one case the cracks observed with VS55 at −135°C damaged the muscle band of the heart valve (not shown).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2011 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
The graph displays differential scanning calorimetry thermograms for VS55 (upper trace) and VS83 (lower trace) during warming from −140°C to −20°C at 5°C/minute after rapid cooling (approximately 40°C/minute). The thermogram for VS55 shows glass transition at −123°C followed by a devitrification peak at −62°C and subsequent melt at −42°C. The devitrification peak at −62°C is indicative of appreciable ice crystallization in the sample at this clinically relevant warming rate. Conversely, devitrification is not observed in the VS83 sample after a glass transition at −119°C.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2011 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Representative stress-strain curve, derived from cryopreserved sample No. 5 after storage at −80°C, from which ultimate stress, ultimate strain, and Young's Modulus were calculated.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2011 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Comparison of viability in (A) leaflet and (B) aortic tissues as well as cardiac muscle of fresh (n = 12) and VS83-preserved aortic heart valves stored at −80°C and −135°C (each n = 6). Data are presented as mean ± standard error. (*, **, *** p < 0.01 versus fresh control valves).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2011 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
Overlays of multiphoton-induced autofluorescence images showing VS83-preserved heart valve tissue components, stored at either −80°C or −135°C, depicting collagen structures (red, 840 nm) and elastic fibers (green, 760 nm). Scale bar equals 40 μm.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2011 The Society of Thoracic Surgeons Terms and Conditions