Expandible microparticle intracellular delivery system
First Claim
1. A microparticle comprising a pH-sensitive hydrogel in a collapsed state and containing a compound to be delivered to the interior of a cell, wherein the microparticle is of a size, in the collapsed state, which allows uptake of the microparticle via a clathrin-coated pit on the cell surface, and wherein the pH-sensitive hydrogel expands at a pH less than 7 to result in a microparticle comprising the pH-sensitive hydrogel in an expanded state.
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Accused Products
Abstract
The present invention relates to methods and compositions for delivery of a compound, most preferably a polynucleotide, into the cytoplasm of a cell by means of a microparticle, fabricated from a pH-sensitive hydrogel in collapsed phase, and having a size and physical characteristics compatible with uptake via a clathrin-coated pit on the cell surface. The trigger pH at which the hydrogel expands is lower than the physiological pH of the extracellular environment, allowing the microparticle, which comprises the compound to be delivered, to maintain its compact size prior to cellular uptake, thereby providing the additional benefit of protecting the comprised compound from degradation. This protective feature is particularly beneficial in embodiments in which a polynucleotide or a peptide is being delivered. Following uptake via a clathrin-coated pit, the microparticle then enters the intracellular endocytic pathway, where it is subjected to a progressive decrease in pH. Once the trigger pH for the hydrogel is reached, the microparticle increases its water content and expands, bursting its containing vesicle, and allowing its comprised compound to enter the cytoplasm. According to the invention, microparticle expansion and drug release may be achieved by natural mechanisms without requiring the addition of exogenous compounds, or the application of electric fields, etc. Moreover, with regard to embodiments involving polynucleotides, the present invention provides a means for traversing the plasma membrane and delivering the polynucleotide into the cytoplasm; in conventional transfection methods the plasma membrane, as well as intracellular membranes as occur in endosomes or lysosomes, constitute a formidable barrier to entry.
78 Citations
45 Claims
- 1. A microparticle comprising a pH-sensitive hydrogel in a collapsed state and containing a compound to be delivered to the interior of a cell, wherein the microparticle is of a size, in the collapsed state, which allows uptake of the microparticle via a clathrin-coated pit on the cell surface, and wherein the pH-sensitive hydrogel expands at a pH less than 7 to result in a microparticle comprising the pH-sensitive hydrogel in an expanded state.
- 24. A method for delivering a compound to the interior of a cell, comprising introducing a microparticle containing the compound into the endocytic pathway of the cell, wherein the microparticle comprises a pH-sensitive hydrogel in a collapsed state prior to its introduction into the endocytic pathway, but which assumes an expanded state within the endocytic pathway, thereby delivering the compound into the interior of the cell.
Specification
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- Resources
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Current AssigneeAntigenics Inc. (Agenus Inc.)
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Original AssigneeJames Edward Rothman
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InventorsRothman, James Edward
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Primary Examiner(s)KETTER, JAMES S
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Application NumberUS09/156,739Time in Patent Office362 DaysField of Search435/172.3, 435/320.1, 524/560, 526/329.7US Class Current435/459CPC Class CodesA61P 25/00 Drugs for disorders of the ...A61P 31/00 Antiinfectives, i.e. antibi...A61P 35/00 Antineoplastic agentsA61P 37/00 Drugs for immunological or ...C12N 15/87 Introduction of foreign gen...Y10S 977/905 Specially adapted for trave...Y10S 977/906 Drug deliveryY10S 977/92 Detection of biochemical
