Liquid embolic material composition
A liquid embolic composition of natural polymers, water, and angiographic contrast agents improves neurovascular interventions, making them more reliable, safe, and affordable. The embolic material is made of a single component activated by blood calcium ion, which triggers coagulation, and that offers superior mechanical stability and does not cause fragmentation in the target vessel. The material retains superior long-term mechanical durability after deployment and provides sufficient visualization under fluoroscopy with iodine-based angiographic contrast compounds or other radiopaque compositions. Described herein are aqueous solutions that enable a high concentration gellan gum (greater than 0.5 wt %) to retain sol state even at the range of body temperature (30-40° C.). This discovery means that it is possible to increase the concentration of gellan gum without losing its inject-ability, yet significantly improve its mechanical stability after delivery.
1 . A composition comprising:
(a) 0.8-2.0 wt % gellan gum;
(b) 0.01-20 wt % low molecular weight polyols and/or amino acids, wherein the low molecular weight polyols have a molecular mass less than 1000 Daltons; and
(c) 10-40 wt % radiopaque material.
2 . The composition of claim 1 , wherein the gellan gum of (a) is 0.8-1.0 wt %.
3 . The composition of claim 1 , wherein the low molecular weight polyols and/or amino acids of (b) is 3-10 wt %.
4 . The composition of claim 1 , wherein the composition retains a sol state upon annealing to 30-40° C.
5 . The composition of claim 1 , which is free of alginate.
6 . The composition of claim 1 , further comprising alginate.
7 . The composition of claim 1 , wherein the low molecular weight polyols are selected from the group consisting of: glucose, mannose, glucitol, mannitol, ribose, arabinose, and xylose.
8 . The composition of claim 1 , wherein the low molecular weight amino acids are selected from the group consisting of: glycine, alanine, valine, leucine, β-alanine, sarcosine, glutamate, aspartate, pyroglutamate, proline, serine, betaine, hydroxyproline, and threonine.
9 . A method of preparing a liquid embolic composition, the method comprising combining, at 80-90° C.:
(a) 0.8-2.0 wt % gellan gum solution,
(b) 0.01-20 wt % low molecular weight polyols and/or amino acids; and
(c) 10-40 wt % radiopaque material,
wherein the low molecular weight polyols have a molecular mass less than 1000 Daltons.
10 . The method of claim 9 , wherein the gellan gum of (a) is 0.8-1.0 wt %.
11 . The method of claim 9 , wherein the low molecular weight polyols and/or amino acids of (b) is 3-10 wt %.
12 . A method of embolizing a target blood vessel in a subject, the method comprising:
(a) introducing a catheter into the target blood vessel; and
(b) injecting a composition of claim 1 into the target blood vessel via the catheter.
13 . The method of claim 12 , wherein step (b) is performed under fluoroscopy.
14 . The method of claim 12 , wherein step (b) is performed until complete occlusion of the target blood vessel is confirmed.
15 . The method of claim 12 , wherein the target blood vessel is a cerebral artery.
16 . A composition consisting of:
(a) 0.8-2.0 wt % gellan gum;
(b) 0.01-20 wt % low molecular weight polyols and/or amino acids; and
(c) 10-40 wt % radiopaque material,
wherein the low molecular weight polyols have a molecular mass less than 1000 Daltons.