Crosslinked, degradable polymers and uses thereof

A cross-linked poly(beta-amino ester) prepared by a method comprising steps of:

• combining a poly(beta-amino ester) with a photoinitiator or thermal initiator to form a mixture;
• and
• exposing the mixture to light or heating the mixture to a temperature ranging from 30° C. to 200° C.:
• wherein the poly(beta-amino ester) before cross-linking is of the formula:
• or a salt thereof, wherein:
• linker A and linker B are each independently selected from the group consisting of carbon chains of 1 to 30 carbon atoms, heteroatom-containing carbon chains of 1 to 30 atoms, and carbon chains and heteroatom-containing carbon chains optionally substituted with a group selected from the group consisting of branched and unbranched, substituted or unsubstituted, cyclic or acyclic aliphatic;
• branched and unbranched, substituted or substituted, cyclic or acyclic heteroaliphatic;
• substituted or unsubstituted acyl;
• substituted or unsubstituted aryl;
• substituted or unsubstituted heteroaryl;
• amino, alkylamino, dialkylamino, trialkylamino, aryl, ureido, heterocyclic, aromatic heterocyclic, cyclic, aromatic cyclic, halogen, hydroxyl, alkoxy, cyano, amide, carbamoyl, carboxylic acid, ester, carbonyl, carbonyldioxyl, alkylthioether, and thiol groups;
• R1, R2, R3, R4, R5, R6, R7, and R8 are each independently selected from the group consisting of hydrogen;
• branched and unbranched, substituted or unsubstituted, cyclic or acyclic aliphatic;
• branched and unbranched, substituted or unsubstituted, cyclic or acyclic heteroaliphatic;
• substituted or unsubstituted acyl;
• substituted or unsubstituted aryl;
• substituted or unsubstituted heteroaryl;
• halogen, hydroxyl, alkoxy, carbamoyl, carboxyl ester, carbonyldioxyl, amide, thiohydroxyl, alkylthioether, amino, alkylamino, dialkylamino, trialkylamino, cyano, ureido, a substituted alkanoyl group, cyclic, cyclic aromatic, heterocyclic, and aromatic heterocyclic groups, each of which may be substituted with at least one substituent selected from the group consisting of branched and unbranched alkyl, branched and unbranched alkenyl, branched and unbranched alkynyl, amino, alkylamino, dialkylamino, trialkylamino, aryl, ureido, heterocyclic, aromatic heterocyclic, cyclic, aromatic cyclic, halogen, hydroxyl, alkoxy, cyano, amide, carbamoyl, carboxylic acid, ester, carbonyl, carbonyldioxyl, alkylthioether, and thiol groups;
• and
• n is an integer between 5 and 10,000;
• wherein at least one cross-link between polymer chains is formed between terminal acrylate moieties and is a carbon-carbon cross-link selected from the group consisting of:
• wherein the cross-linked poly(beta-amino ester) exhibits an elastic modulus ranging from approximately 4 to approximately 350 MPa.