Polyethylene glycol based oligomers for coating nanoparticles, nanoparticles coated therewith, and related methods
In a composition aspect of the invention, a nanoparticle coating comprises repeating polyacrylic acid monomers covalently bound together to form an aliphatic chain having a plurality of carboxylic acid functional groups and modified carboxylic acid functional groups extending therefrom. A first portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal methoxy functional group and a second portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having at least one terminal sulfur moiety.
1. A composition comprising repeating polyacrylic acid monomer units covalently bound together in an aliphatic chain having a plurality of carboxylic acid functional groups and modified carboxylic acid functional groups extending therefrom, wherein a first portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal methoxy functional group and a second portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having at least one terminal sulfur moiety.
2. The composition of claim 1 , wherein the at least one terminal sulfur moiety is formed from thioctic acid.
3. The composition of claim 1 , wherein the at least one terminal sulfur moiety is formed from dihydrolipoic acid.
4. The composition of claim 1 , wherein the PEG oligomer having a terminal methoxy functional group is formed from a Compound 2 having a structure:
wherein n has a value such that an average molecular weight of the PEG oligomer is about 750.
5. The composition of claim 1 , wherein the PEG oligomer having at least one terminal sulfur moiety is formed from a Compound 1 having a structure:
wherein n has a value such that an average molecular weight of the PEG oligomer is about 600.
6. The composition of claim 1 , wherein the PEG oligomer having a terminal methoxy functional group is formed from a Compound 2 and the PEG oligomer having at least one terminal sulfur moiety is formed from a Compound 1; wherein the Compound 2 and the Compound 1 have the following structures:
wherein n has a value such that an average molecular weight of the PEG oligomer is about 750; and
wherein n has a value such that an average molecular weight of the PEG oligomer is about 600.
7. The composition of claim 1 , wherein the PEG oligomer having at least one terminal sulfur moiety is formed from dihydrolipoic acid.
8. The composition of claim 1 , further comprising a third portion of the modified carboxylic acid functional groups, wherein the third portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal azide functional group.
9. The composition of claim 8 , wherein the PEG oligomer having at least one terminal sulfur moiety is formed from a Compound 1 having a structure:
wherein n has a value such that an average molecular weight of the PEG oligomer is about 600.
10. The composition of claim 1 , further comprising a third portion of the modified carboxylic acid functional groups, wherein the third portion of the modified carboxylic acid functional groups are modified by a PEG oligomer having a terminal amine functional group.
11. The composition of claim 10 , wherein the PEG oligomer having at least one terminal sulfur moiety is formed from dihydrolipoic acid.