Cryopreserve at high pressure, and avoid fracturing of tissue (?)
"The form of ice that is created when water is cooled at atmospheric pressure, 'Ice I',has a higher unit volume than the liquid water. As a result, increasing the pressure actually causes ice to melt rather then water to solidify. That is, up to a pressure of about 2000 atm. Above this pressure, other, more dense forms of solid water (Ice II, Ice III, Ice V, Ice VI, and Ice VII) can form." (link1)
These ice forms are denser than water. (link2) So, perhaps they would not damage the cells like ordinary ice does.
For instance, Ice III is formed by cooling water down to 250 K at 300 MPa [Wikipedia:Ice III]. The pressure would occur naturally in the sea, 30 kilometers below the sea level.
"Ice III ... has a density of 1.16 g cm-3 (at 350 MPa where water density = 1.13 g cm-3)." (link about Ice III)
It's a contraction by only 2.65%, versus the usual expansion by 8.33% upon freezing.