The present invention is directed to a cryoprotective system that comprises an
aqueous solution containing polymeric nano- and micro-particles that exhibit a
reversible temperature-dependent volume change. It is also directed to a method
for providing cryoprotection to an organism or parts of an organism by pumping
the cryoprotective system into the vasculature of the organism prior to exposing
the organism to a lower, preferably below 0 C., temperature.