Injectable hydrogel compositions
In accordance with one aspect of the invention, injectable compositions are provided, which contain temperature-sensitive hydrogel particles. The hydrogel particles may be provided in dry form, or they may be provided in hydrated form in an aqueous fluid. The temperature-sensitive hydrogel particles may have an upper critical solution temperature (UCST) below normal body temperature, they may have a lower critical solution temperature (LCST) above normal body temperature, or they may have a LCST that changes from below normal body temperature to above normal body temperature after injection into a subject.
1. An injectable medical composition comprising temperature sensitive hydrogel particles that comprise a crosslinked polymer and a therapeutic agent, said hydrogel particles having an ex vivo lower critical solution temperature (LCST) that is below normal body temperature and whose LCST increases in vivo after injection into a subject from below normal body temperature to above body temperature, wherein 95 vol % of the hydrogel particles have a longest linear cross-sectional dimension between 30 μm and 5000 μm.
2. The injectable medical composition of claim 1 , wherein the LCST increases after injection due to hydrolysis.
3. The injectable medical composition of claim 1 , wherein the hydrogel particles comprise a copolymer chain that comprises N-(2-hydroxypropyl) methacrylamide dilactate and N-isopropyl acrylamide.
4. The injectable medical composition of claim 3 , wherein said hydrogel particles are suspended in an aqueous fluid.
5. A method of treatment comprising injecting the injectable medical composition of claim 4 into a subject, wherein the hydrogel particles have an ex vivo LCST that is below injection temperature and below normal body temperature, wherein said method of treatment is a tissue bulking treatment or an embolization treatment.
6. The injectable medical composition of claim 1 , wherein the hydrogel particles comprise a copolymer chain that comprises N-(2-hydroxypropyl) methacrylamide dilactate, N-(2-hydroxypropyl) methacrylamide monolactate, and N-isopropylacryamide monomers.
7. The injectable medical composition of claim 1 , wherein the hydrogel particles comprise a block copolymer that comprises a poly(ethylene oxide) chain and a copolymer chain that comprises N-(2-hydroxypropyl) methacrylamide dilactate, N-(2-hydroxypropyl) methacrylamide monolactate, and N-isopropylacryamide monomers.
8. The injectable medical composition of claim 1 , wherein said hydrogel particles are suspended in an aqueous fluid.
9. A method of treatment comprising injecting the injectable medical composition of claim 8 into a subject, wherein the hydrogel particles have an ex vivo LCST that is below injection temperature and below normal body temperature, wherein said method of treatment is a tissue bulking treatment or an embolization treatment.
10. A method of treatment comprising injecting the injectable medical composition of claim 8 into a subject, wherein the hydrogel particles have an ex vivo LCST that is above injection temperature and below normal body temperature, wherein said method of treatment is a tissue bulking treatment or an embolization treatment.
11. The injectable medical composition of claim 1 , wherein the microparticles are in dry form.
12. The injectable medical composition of claim 1 , wherein the injectable medical composition comprises a tonicity adjusting agent.
13. The injectable medical composition of claim 1 , wherein the injectable medical composition is disposed within a glass container or a preloaded syringe.
14. The injectable composition of claim 1 , wherein the therapeutic agent is selected from an antineoplastic agent, an antiproliferative agent and an antimitotic agent.
15. The injectable composition of claim 1 , wherein the therapeutic agent is a radionuclide.
16. The injectable composition of claim 1 , wherein the therapeutic agent is selected from narcotic analgesics, non-narcotic analgesics and local anesthetic agents.