Permselective structurally robust membrane material
View Patent ↗A biocompatible multipolymer, having a backbone comprising about 10 to 45 wt % of at least one hard segment and about 55 to 90 wt % of soft segments. The soft segments are divided into three groups, 5 to 25 wt %, of total soft segment weight, of an oxygen permeable soft segment; 5 to 25 wt %, of total soft segment weight, of a hydrophilic soft segment; and 50 to 90 wt %, of total soft segment weight, of a biostable, relatively hydrophobic soft segment.
1. A biocompatible multipolymer, having a backbone comprising:
(a) about 10 to 45 wt % of at least one hard segment;
(b) about 55 to 90 wt % of soft segments, including:
(i) 5 to 25 wt %, of total soft segment weight, of an oxygen permeable soft segment;
(ii) 5 to 25 wt %, of total soft segment weight, of a hydrophilic soft segment;
(iii) 50 to 90 wt %, of total soft segment weight, of a biostable, hydrophobic soft segment; and
(c) having water absorption of from 2 to 25% of weight in membrane form.
2. The multipolymer of claim 1 , wherein said biostable, hydrophobic soft segment is a polycarbonate.
3. The multipolymer of claim 1 , wherein said hydrophilic soft segment has the chemical form O(CH 2 ) N , where N<4.
4. The multipolymer of claim 3 , wherein said hydrophilic soft segment is polyethylene oxide.
5. The multipolymer of claim 1 , wherein said oxygen-permeable soft segment is polydimethylsiloxane.
6. The multipolymer of claim 1 , further comprising capping end groups.
7. The multipolymer of claim 6 , wherein said capping end groups comprise less than about 10 wt % of the total weight of said multi polymer.
8. The multipolymer of claim 1 , capable of forming a membrane having a tensile strength of from 300 to 1,000 psi.
9. The multipolymer of claim 1 , capable of forming a membrane having an ultimate elongation of 100 to 1,000%.
10. A glucose sensor, which senses glucose by way of oxidation and which includes a membrane that is permselective of oxygen and glucose, said membrane comprising:
a biocompatible multipolymer having water absorption of from 2 to 25% of dry weight in membrane form, and having a backbone comprising about 55 to 90 wt % of soft segments including:
(i) 5 to 25 wt %, of total soft segment weight, of an oxygen permeable soft segment;
(ii) 5 to 25 wt %, of total soft segment weight, of a hydrophilic soft segment; and
(iii) 50 to 90 wt %, of total soft segment weight, of a biostable, hydrophilic soft segment.