METHOD AND APPARATUS FOR RUPTURING TARGETED CELLS

A probe contacts targeted tissue, sometimes while positioned adjacent to nontargeted live tissues. In preferred forms, the probe includes a support that only minimally conducts heat from nontargeted tissues. A very conductive targeted-tissue-contacting element, at an end of the support, is immersed in a liquid cryogen (preferably nitrogen) and then removed for contacting with (e. g., insertion into) the targeted tissue. An ultrathin highly thermoconductive polymeric tubing holds both a very conductive, cold material, forming the targeted-tissue-contacting element, and fine insulating material (e. g. highly insulating elastomer) forming part of the support. The targeted-tissue-contacting element is fashioned to fit the targeted tissue in at least one dimension, and the support to fit nontargeted live tissues (if any) adjacent to which the probe is positioned while contacting the targeted tissue. The probe provides for confined heat exchange with the targeted tissue - as by matching dimensions of probe and targeted tissue, or of support and nontargeted tissue, or insulating the support against heat flow into the probe or from nontargeted tissues; and preferably all of these. The best targeted-tissue-contacting element is a solid cryogen, roughly at liquid-nitrogen temperature; ideally it is solid carbon dioxide, particularly super-sublimated carbon dioxide - cooled to a temperature range characterized by extremely tight crystal bonds.