HYDROGEL DRUG DELIVERY IMPLANTS
Materials and methods for treating a patient, optionally a patient with an eye disease, comprising providing a collection of particles that comprise a first biodegradable material that is a hydrogel or a xerogel and a therapeutic agent, with the first material, before biodegradation, having a rate of release for the therapeutic agent as measured in physiological solution, and forming a second hydrogel ex vivo or in situ on a tissue of the patient at a site of intended use, optionally at or near an eye, that at least partially coats the collection of particles. The agent is released to treat the patient.
1 . A method of treating a patient comprising
providing a collection of particles that comprise a first biodegradable material that is a hydrogel or a xerogel and a therapeutic agent, with the first material, before biodegradation, having a rate of release for the therapeutic agent as measured in physiological solution, and
forming a second hydrogel in situ on a tissue of the patient that at least partially coats the collection of particles, with the agent being subsequently released to treat the patient.
2 . The method of claim 1 wherein a solids content of the second material is lower than a solids content of the particles, and is in a range from about 2.5% to about 20% w/w.
3 . The method of claim 2 wherein the hydrogel is covalently crosslinked and a molecular weight between crosslinks of the second material is lower than a solids content of the particles or other coated object, and is at least 2000 Da.
4 . The method of claim 3 wherein the second material delays the rate of release of the agent by no more than 10% as measured at the 50% w/w release of the agent.
5 . The method of claim 1 wherein the second material is free of the therapeutic agent until such time as the agent diffuses from the particles into the second hydrogel.
6 . The method of claim 5 wherein the agent is a protein.
7 . The method of claim 1 wherein the particles have a diameter that is within a range from about 1 to about 100 microns diameter.
8 . The method of claim 1 wherein a syringe or catheter is used to deliver the collection particles in a presence of precursors, with the precursors coating the particles and forming the hydrogel in situ.
9 . The method of claim 1 wherein the tissue is an eye and the hydrogel is formed within the eye.
10 . A biomedical sustained release system for use in a patient comprising
a collection of particles that comprise a first biodegradable material that is a hydrogel or a xerogel and a therapeutic agent, with the first material, before biodegradation, having a rate of release for the therapeutic agent as measured in physiological solution, and
a second material that is a hydrogel or xerogel that at least partially coats the collection of particles wherein the second material delays the rate of release of the agent by no more than 20% as measured at the 50% w/w release of the agent.
11 . The system of claim 10 wherein a solids content of the second material is lower than a solids content of the particles, and the solids content of the second material is in a range from about 2.5% to about 20% w/w.
12 . The system of claim 11 wherein the hydrogel is covalently crosslinked and a molecular weight between crosslinks of the second material is lower than a distance between crosslinks of the particles, and is at least 3000.
13 . The system of claim 12 wherein the delay of the rate of the release as measured at the 50% w/w release of the agent is no more than 10%.
14 . The system of claim 12 wherein the therapeutic agent is a protein.
15 . The system of claim 10 wherein the first material comprises a first precursor that comprises first functional groups and a second precursor that comprises second functional groups, with the first functional groups and the second functional groups forming covalent crosslinks, and the second material comprises a third precursor that comprises third functional groups and a fourth precursor that comprises fourth functional groups, with the third functional groups and the fourth functional groups forming covalent crosslinks.
16 . The system of claim 15 wherein the first through fourth functional groups, before reaction, are selected from the group consisting of electrophilic groups and nucleophilic groups.
17 . The system of claim 16 wherein the first through fourth precursors are, before being covalently crosslinked, water soluble.
18 . A biomedical sustained release system for use in a patient comprising
a first biodegradable material that is a hydrogel or a xerogel and a therapeutic agent, with the first material, before biodegradation, having a rate of release for the therapeutic agent as measured in physiological solution, and
a second material that is a hydrogel or xerogel that at least partially coats the first material, wherein the second material delays the rate of release of the agent by no more than 20% as measured at the 50% w/w release of the agent.
19 . The system of claim 18 wherein the first material and the second material are xerogels.
20 . The system of claim 19 wherein the second material comprises precursors that, in response to a physiological solution, react with each other to form a covalently-crosslinked hydrogel.