# US 2019/0169374 A1 · Compositions and methods for delivery of active agents

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- Number: US 2019/0169374 A1
- Document ID: US20190169374A1
- Status: Published application
- Kind: A1
- Application number: 16/313,812
- Filed: 2017-06-28
- Published: 2019-06-06
- Earliest claimed: 2016-06-28
- Assignees: Trustees of Tufts College
- Applicants: Trustees of Tufts College
- Inventors: C. Andrew Ramsburg; Christopher S. Martin; Katherine A. Muller
- Web page: https://patentgrep.com/patent/US20190169374A1

## CPC

- B09C 1/00: Reclamation of contaminated soil
- B09C 1/002: {involving in-situ ground water treatment}
- B09C 1/08: chemically
- B01J 13/14: Polymerisation; cross-linking
- B01J 13/20: After-treatment of capsule walls, e.g. hardening
- B09C 2101/00: In situ
- C08J 3/075: Macromolecular gels
- C08J 2301/28: Alkyl ethers
- C08J 2305/04: Alginic acid; Derivatives thereof
- C08J 2305/08: Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
- C08J 2333/26: Homopolymers or copolymers of acrylamide or methacrylamide
- B09C: RECLAMATION OF CONTAMINATED SOIL (gatherers for removing stone or the like from the soil A01B43/00; sterilising soil by steam A01G11/00; removing undesirable matter, e.g. rubbish, from the land E01H15/00)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)

## Abstract

The present disclosure relates to remediation of contaminated environmental sites. In particular, the present disclosure relates to passive control compositions and their use in remediation.

## Claims

### Claim 1

A composition, comprising:
an inactive hydrogel with a core of an active agent surrounded by a polymer shell, wherein said polymer swells and releases said agent in response to a change in environment.

### Claim 2 (depends on 1)

The composition of claim 1, wherein said polymer is selected from the group consisting of chitosan, carboxymethylcellulose, alginate, polyacrylamide, and carrageenan.

### Claim 3 (depends on 1, 2)

The composition of claim 1 or 2, wherein said polymer is cross-linked.

### Claim 4 (depends on 3)

The composition of claim 3, wherein said polymer is cross-linked with a cross-linking agent selected from the group consisting of glutaraldehyde, formaldehyde, and genipin.

### Claim 5 (depends on 1)

The composition of claim 1, wherein said active agent is selected from the group consisting of calcium carbonate, magnesium oxide, and citric acid.

### Claim 6 (depends on 1)

The composition of claim 1, wherein said active agent is a nanoparticle, a micron sized particle, or a droplet.

### Claim 7 (depends on 1)

The composition of claim 1, wherein said change in environment is selected from the group consisting of pH, temperature, and oxidation state.

### Claim 8 (depends on 1)

The composition of claim 1, wherein release of said agent alters the pH of said environment.

### Claim 9 (depends on 1)

The composition of claim 1, wherein said inactive hydrogel is dehydrated or in a colloidal suspension.

### Claim 10 (depends on 1)

A method of remediating an environmental site, comprising:
introducing the composition of claim 1 to an environmental site undergoing remediation under conditions such that said composition releases said active agent only within a defined pH range.

### Claim 11 (depends on 10)

The method of claim 10, wherein said defined pH range is determined by the polymer and crosslinking agent.

### Claim 12 (depends on 10)

The method of claim 10, wherein said environmental site is a groundwater contamination site, surface water body, or a mine.

### Claim 13 (depends on 10)

The method of claim 10, wherein said site is contaminated with a contaminant selected from the group consisting of a chlorinated solvent, a radionuclide, an actinide, and an organic contaminant.

### Claim 14 (depends on 10)

The method of claim 10, wherein said environmental site is undergoing a rededication reaction selected from the group consisting of in situ chemical oxidation, abiotic reduction, and in situ dechlorination.