Star polymers, methods of preparation thereof, and uses thereof

A composition, comprising:

• a loaded star polymer comprising a water soluble biodegradable amphiphilic star polymer and a hydrophobic biologically active material occluded therein, the star polymer comprising a living microgel core of crosslinked polymeric material and 6 or more independent polymer arms covalently linked to the core, the 6 or more arms each comprising a hydrophilic polymer chain segment and a hydrophobic polymer chain segment, wherein i) the core includes 6 or more sites capable of further synthetic transformation, ii) each of the 6 or more sites includes a functional group selected from the group consisting of alcohols, amines, carboxylic acids, azides, alkynes, alkenes, halogen groups, and combinations thereof, iii) each individual metal selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, radium, aluminum, gallium, indium, thallium, germanium, tin, lead, arsenic, antimony, bismuth, tellurium, polonium, and metals of Groups 3 to 12 of the Periodic Table has a concentration in the star polymer of greater than or equal to 0 parts per million and less than or equal to 100 parts per million, iv) the microgel core is a polymer selected from the group consisting of polyesters, polycarbonates, polycarbamates, polyureas, polythiocarbamates, polythiocarbonates, polydithiocarbonates, and combinations thereof, v) the biologically active material is bound by noncovalent interactions with the microgel core and/or with the 6 or more independent polymer arms, vi) the biologically active material is selected from the group consisting of drugs, genes, dyes, image contrast enhancing materials, and combinations thereof.

A method, comprising:

• agitating a mixture comprising i) a polymer arm precursor comprising an initiator group, a hydrophobic polymer chain segment, and a hydrophilic polymer chain segment, ii) a core precursor material comprising two or more polymerizable cyclic carbonyl groups, iii) an organocatalyst, iv) an optional accelerator, and v) an optional solvent, thereby forming a water soluble biodegradable amphiphilic star polymer by an organocatalyzed ring opening polymerization of the core precursor material;
• wherein a) the star polymer comprises a crosslinked living microgel core comprising a polymer segment selected from the group consisting of polyesters, polycarbonates, polycarbamates, polyureas, polythiocarbamates, polythiocarbonates, polydithiocarbonates, and combinations thereof, b) the star polymer comprises 6 or more independent polymer arms covalently linked to the core, the 6 or more polymer arms being derived from the polymer arm precursor, and the 6 or more arms each comprising a hydrophilic polymer chain segment and a hydrophobic polymer chain segment, and c) each individual metal selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, radium, aluminum, gallium, indium, thallium, germanium, tin, lead, arsenic, antimony, bismuth, tellurium, polonium, and metals of Groups 3 to 12 of the Periodic Table has a concentration in the star polymer of greater than or equal to 0 parts per million and less than or equal to 100parts per million.

A method, comprising:

• forming a mixture of a water soluble biodegradable amphiphilic star polymer and a hydrophobic biologically active material in an organic solvent;
• and
• injecting the mixture into water, the water being a non-solvent for the biologically active material, thereby forming nanoparticles of a loaded star polymer comprising the star polymer and the biologically active material occluded therein;
• wherein i) the star polymer comprises a crosslinked living microgel core and 6 or more independent polymer arms covalently linked to the core, ii) the 6 or more polymer arms each comprise a hydrophobic polymer chain segment and a hydrophilic polymer chain segment, iii) each individual metal selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, radium, aluminum, gallium, indium, thallium, germanium, tin, lead, arsenic, antimony, bismuth, tellurium, polonium, and metals of Groups 3 to 12 of the Periodic Table has a concentration in the star polymer of greater than or equal to 0 parts per million and less than or equal to 100 parts per million, iv) the microgel core comprises a polymer chain segment selected from the group consisting of polyesters, polycarbonates, polycarbamates, polyureas, polythiocarbamates, polythiocarbonates, polydithiocarbonates, and combinations thereof, and v) the biologically active material is bound by noncovalent interactions with the microgel core and/or with the 6 or more independent polymer arms, and vi) the biologically active material is selected from the group consisting of drugs, genes, dyes, image contrast enhancing materials, and combinations thereof.

An aqueous mixture comprising a loaded star polymer, the loaded star polymer comprising:

• a water soluble biodegradable amphiphilic star polymer;
• and
• a hydrophobic biologically active material occluded therein, wherein i) the star polymer comprises a crosslinked living microgel core and 6 or more independent polymer arms covalently linked to the core, the 6 or more arms each comprising a hydrophilic polymer chain segment and a hydrophobic polymer chain segment, wherein each individual metal selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, radium, aluminum, gallium, indium, thallium, germanium, tin, lead, arsenic, antimony, bismuth, tellurium, polonium, and metals of Groups 3 to 12 of the Periodic Table has a concentration in the star polymer of greater than or equal to 0 parts per million and less than or equal to 100 parts per million, ii) the biologically active material is bound by noncovalent interactions with the microgel core and/or with the 6 or more independent polymer arms, iii) the biologically active material selected from the group consisting of drugs, genes, dyes, image contrast enhancing materials, and combinations thereof, and iv) the microgel core comprises a polymer segment selected from the group consisting of polyesters, polycarbonates, polycarbamates, polyureas, polythiocarbamates, polythiocarbonates, polydithiocarbonates, and combinations thereof.