Polycation-functionalized nanoporous silicon carrier for systemic delivery of gene silencing agents

1. A composition for the sustained-release delivery of an active agent to a target cell of a subject in need thereof, comprising:

(a) a population of polycation-functionalized, nanoporous, silicon first-stage particles; and

(b) a population of second-stage particles contained substantially within the interior of the population of the first-stage particles, and wherein the second-stage particles comprise a first active agent;

wherein the polycation comprises poly-arginine, poly-lysine, chitosan, dendrimer, polyethyleneimine, or any combination thereof;

wherein the first active agent is released from the second-stage particles, and self-assembles into one or more nanoparticles, upon contacting an aqueous environment;

wherein the polycation is operably linked to a first portion of the outer surface of the population of first-stage particles by conjugation or by functionalization with 3-aminopropyl-triethoxysilane; and

further wherein the composition is formulated for storage between about 0° C. and about 22° C. for a period of about one week to about six months, without a substantial degradation or a substantial loss of biological activity.

2. The composition of claim 1 , wherein the population of first-stage nanoporous silicon particles is biocompatible and degradable.

3. The composition of claim 1 , formulated for freezing, freeze-drying, dehydration, desiccation, or lyophilization.

4. The composition of claim 1 , formulated for mammalian administration.

5. The composition of claim 4 , formulated for system administration to a human.

6. The composition of claim 1 , further comprising a second, distinct population of nanoparticles or microparticles.

7. A kit comprising: the composition of claim 1 , and a set of instructions for using the composition in the treatment or amelioration of one or more symptoms of a mammalian disease, disorder, or dysfunction.

8. The kit of claim 7 , further comprising: (a) a therapeutic agent; (b) a first diagnostic agent; or (c) a combination of (a) and (b).

9. A method of targeting gene silencing in a mammalian cancer cell, comprising administering to a mammal, an effective amount of the composition of claim 1 .

10. A method of treating or ameliorating at least one symptom of cancer in a mammal, the method comprising administering to the mammal a composition comprising a therapeutically-effective amount of the composition of claim 1 , and for a time effective to treat or ameliorate at least one symptom of the cancer.

11. The method of claim 10 , further comprising administering to the mammal an effective amount of a therapeutic agent selected from the group consisting of a small interfering RNA, an anti-cancer agent, an anti-inflammatory agent, a cytotoxic agent, or any combination thereof.

12. A method of treating, alleviating, or ameliorating at least one symptom of a breast cancer in a human, the method comprising administering to the mammal an amount of the composition of claim 1 , and for a time effective to treat, alleviate, or ameliorate at least one symptom of the breast cancer in the human.

13. The kit of claim 7 , wherein the mammalian disease is cancer.

14. The kit of claim 13 , wherein the mammalian disease is human breast cancer.

15. A pharmaceutical composition comprising:

(1) (a) a population of polycation-functionalized, nanoporous, silicon first-stage particles; and

(b) a population of second-stage particles contained substantially within the interior of the population of the first-stage particles, and wherein the second-stage particles comprise a first active agent; and

(2) a pharmaceutically-acceptable buffer, diluent, solvent, or excipient;

wherein the polycation comprises poly-arginine, poly-lysine, chitosan, dendrimer, polyethyleneimine, or any combination thereof;

wherein the first active agent is released from the second-stage particles, and self-assembles into one or more nanoparticles, upon contacting an aqueous environment;

wherein the polycation is operably linked to a first portion of the outer surface of the population of first-stage particles by conjugation or by functionalization with 3-aminopropyl-triethoxysilane; and

further wherein the composition is formulated for storage between about 0° C. and about 22° C. for a period of about one week to about six months, without a substantial degradation or a substantial loss of biological activity.

16. A method for treating cancer in a mammal, comprising: administering to the mammal a biologically-effective amount of a pharmaceutical composition that comprises:

(1) (a) a population of polycation-functionalized, nanoporous, silicon first-stage particles; and

(b) a population of second-stage particles contained substantially within the interior of the population of the first-stage particles, and wherein the second-stage particles comprise a first active agent; and

(2) a pharmaceutically-acceptable buffer, diluent, solvent, or excipient;

wherein the polycation comprises poly-arginine, poly-lysine, chitosan, dendrimer, polyethyleneimine, or any combination thereof;

wherein the first active agent is released from the second-stage particles, and self-assembles into one or more nanoparticles, upon contacting an aqueous environment;

wherein the polycation is operably linked to a first portion of the outer surface of the population of first-stage particles by conjugation or by functionalization with 3-aminopropyl-triethoxysilane; and

further wherein the composition is formulated for storage between about 0° C. and about 22° C. for a period of about one week to about six months, without a substantial degradation or a substantial loss of biological activity.

17. The method of claim 16 , wherein the mammalian cancer is human breast cancer.