# US 12,214,078 B2 · Artificial beta cells and methods of use thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,078 B2 - Document ID: US12214078B2 - Status: Granted - Kind: B2 - Application number: 17/812,254 - Filed: 2022-07-13 - Published: 2023-04-27 - Granted: 2025-02-04 - Earliest claimed: 2017-09-18 - Assignees: North Carolina State University - Applicants: North Carolina State University - Inventors: Zhen Gu; Zhaowei Chen - Web page: https://patentgrep.com/patent/US12214078B2 ## CPC - A61K 9/127: Synthetic bilayered vehicles, e.g. liposomes or liposomes with cholesterol as the only non-phosphatidyl surfactant - A61K 47/6911: {the form being a liposome} - A61K 38/28: Insulins - A61K 47/42: Proteins; Polypeptides; Degradation products thereof; Derivatives thereof, e.g. albumin, gelatin or zein (oligopeptides having up to five amino acids {A61K47/183}; polyamino acids A61K47/34) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) ## Abstract Disclosed herein is a particle containing an inner liposomal vesicle (ILV) encapsulating a therapeutic agent; an outer liposomal vesicle (OLV) encapsulating the ILV; a membrane fusion-promoting agent; and a pH-altering agent. Also disclosed are methods of delivering a therapeutic agent to a subject comprising: a) providing a herein disclosed particle b) triggering ILV and OLV fusion; and c) releasing the therapeutic agent outside of the OLV. Also disclosed are methods for treating a disease in a subject in need thereof comprising: administering to a subject a herein disclosed particle. Also disclosed are methods to release insulin to an environment comprising increased glucose levels, the method comprising exposing to the environment a herein disclosed particle. ## Claims ### Claim 1 A method of delivering a therapeutic agent to a subject comprising: a. providing a particle comprising: an inner liposomal vesicle (ILV) encapsulating insulin or a biologically active compound derived from insulin; an outer liposomal vesicle (OLV) encapsulating the ILV; a membrane fusion-promoting agent, wherein said membrane fusion-promoting agent selectively facilitates membrane fusion in response to changes in pH within the particle; and a pH-altering agent, wherein said pH-altering agent is a glucose-responsive enzyme inside the OLV but not inside an ILV; b. triggering ILV and OLV fusion; and c. releasing the insulin or biologically active compound derived from insulin outside of the OLV. ### Claim 2 (depends on 1) The method of claim 1, wherein the membrane fusion-promoting agent comprises a SNARE polypeptide, a Peptide-K, a Peptide-E, or combinations thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein the membrane fusion-promoting agent comprises a first membrane fusion-promoting agent attached to the OLV and a second membrane fusion-promoting agent attached to the ILV. ### Claim 4 (depends on 1) The method of claim 1, wherein the glucose-responsive enzyme comprises a glucose oxidase. ### Claim 5 (depends on 1) The method of claim 1, wherein the OLV further comprises a glucose membrane transporter. ### Claim 6 (depends on 5) The method of claim 5, wherein the glucose membrane transporter transports glucose into the OLV. ### Claim 7 (depends on 5) The method of claim 5, wherein the glucose membrane transporter comprises a Glucose Transporter 2 (GLUT2) polypeptide. ### Claim 8 (depends on 1) The method of claim 1, wherein the OLV further comprises a proton transporter. ### Claim 9 (depends on 8) The method of claim 8, wherein the proton transporter comprises a Gramicidin A polypeptide. ### Claim 10 (depends on 1) The method of claim 1, wherein the particle further comprises a peroxide-metabolizing enzyme. ### Claim 11 (depends on 10) The method of claim 10, wherein the peroxide-metabolizing enzyme comprises a catalase (CAT) polypeptide. ### Claim 12 (depends on 1) The method of claim 1, wherein the ILV further comprises a membrane fusion-inhibiting agent which shields access to the membrane fusion-promoting agent. ### Claim 13 (depends on 12) The method of claim 12, wherein the membrane fusion-inhibiting agent comprises a polyethylene glycol (PEG) molecule. ### Claim 14 (depends on 13) The method of claim 13, wherein the polyethylene glycol (PEG) molecule comprises an acid-degradable polyethylene glycol (PEG) molecule. ### Claim 15 (depends on 1) The method of claim 1, further comprising inhibiting ILV-OLV fusion by blocking access to the membrane fusion-promoting agent. ### Claim 16 (depends on 1) The method of claim 1, further comprising oxidizing glucose in the particle. ### Claim 17 (depends on 16) The method of claim 16, wherein the oxidizing step reduces the pH of the OLV. ### Claim 18 (depends on 17) The method of claim 17 wherein the reduced pH of the OLV deshields the membrane fusion-promoting agent. ### Claim 19 (depends on 1) The method of claim 1, wherein the triggering step b) is facilitated by binding of the membrane fusion-promoting agent. ### Claim 20 (depends on 1) The method of claim 1, wherein the triggering step b) is preceded by binding of a first membrane fusion-promoting agent attached to the OLV to a second membrane fusion-promoting agent attached to the ILV.