| 摘要 |
A process is disclosed in which high purity protamine-DNA complexes are prepared by collecting nucleoprotamines specific developmental stages of a life form, specifically, amphibian, egg by low temperature processing. The process also includes the steps of sequential homogenization in a high concentration aqueous salt solution at a buffered low pH, followed by ultracentrifugation to remove insoluble matter. Either a crude mixture or pure isolate of the complexes may be produced. Pure isolates require aqueous chloroform extraction to isolate protein and to remove lipids. Lyophilization then removes chloroform and excess water. The isolate is then fractionated by single pass alumina chromatography. Dialysis against pure water removes salts. Repeated lyophilization removes excess water and concentrates single protamines and protamine-like proteins. The mixture may then be reconstituted with 5% weight/volume heterologous or homologous DNA, in order to shield from charge toxicity. Crude mixtures may be produced by precipitating the supernate of ultracentrifugation in pure water, followed by ultracentrifugation to sediment in solids. Lyophilization then removes any water from the damp solids. The crude solids are suitable for oral use, especially if utilized in gelatin capsules. Sterile filtration to injection quality aqueous form. Following isolation of the protamine-DNA complex, encapsulation of the prepared solid or aqueous protamine-DNA complexes in a specific carrier substance may be accomplished, depending upon the target tissue for the protamine. Several encapsulation carriers are known from prior art literature, such as, for example, liposomes and nanoparticles. The protamine-DNA complexes of the present invention are useful in inhibiting tumor growth, among other uses.
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