A compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein: each R is independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, (CH 2) j OR 1, (CH 2) i C R 1, (CH 2) j C OR 1, (CH 2) j OC R 1, (CH 2) j NR 2 R 3, (CH 2) j C NR 2 R 3, (CH 2) j OC NR 2 R 3, (CH 2)j C(NR 4)NR 2 R 3, (CH 2) j NR 4 C R 1, (CH 2) j NR 4 C OR 1, (CH 2) j NR 4 C NR 2 R 3, (CH 2) j NR 4 C NR 2 R 3, (CH 2) j NR 4 C NR 2 R 3, (CH 2) j SH, (CH 2) j S k CH 3, (CH 2) j NR 4 S k CH 3, (CH 2) j S k NR 2 R 3 and (CH 2) j NR 4 S k NR 2 R 3, wherein j is an integer independently selected from 0 to 6, k is an integer independently selected from 0 to 2, and wherein each R group is optionally independently substituted with 1-3 substituent groups, each substituent group is independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, perfluoroalkyl, amino, cyano, halogen, hydroxyl, nitro, aryl, arylalkyl, heterocycle, heteroaryl, and heteroarylalkyl; R 1, R 2, R 3 and R 4 are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, wherein each R 1, R 2, R 3 and R 4 group is optionally independently substituted with 1-3 substituent groups, each substituent group is independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, perfluoroalkyl, amino, cyano, halogen, hydroxyl, nitro, aryl, arylalkyl, heterocycle, heteroaryl, and heteroarylalkyl; m is an integer independently selected from 1 to 100,000; n is an integer independently selected from 1 to 100,000; and x is an integer independently selected from 1 to 5,000. each R is independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, (CH 2) j OR 1, (CH 2) i C R 1, (CH 2) j C OR 1, (CH 2) j OC R 1, (CH 2) j NR 2 R 3, (CH 2) j C NR 2 R 3, (CH 2) j OC NR 2 R 3, (CH 2)j C(NR 4)NR 2 R 3, (CH 2) j NR 4 C R 1, (CH 2) j NR 4 C OR 1, (CH 2) j NR 4 C NR 2 R 3, (CH 2) j NR 4 C NR 2 R 3, (CH 2) j NR 4 C NR 2 R 3, (CH 2) j SH, (CH 2) j S k CH 3, (CH 2) j NR 4 S k CH 3, (CH 2) j S k NR 2 R 3 and (CH 2) j NR 4 S k NR 2 R 3, wherein j is an integer independently selected from 0 to 6, k is an integer independently selected from 0 to 2, and wherein each R group is optionally independently substituted with 1-3 substituent groups, each substituent group is independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, perfluoroalkyl, amino, cyano, halogen, hydroxyl, nitro, aryl, arylalkyl, heterocycle, heteroaryl, and heteroarylalkyl; R 1, R 2, R 3 and R 4 are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, wherein each R 1, R 2, R 3 and R 4 group is optionally independently substituted with 1-3 substituent groups, each substituent group is independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, perfluoroalkyl, amino, cyano, halogen, hydroxyl, nitro, aryl, arylalkyl, heterocycle, heteroaryl, and heteroarylalkyl; m is an integer independently selected from 1 to 100,000; n is an integer independently selected from 1 to 100,000; and x is an integer independently selected from 1 to 5,000.