Particles

Abstract

Particles comprising a branched polymer and either a block copolymer or a linear dendritic hybrid represent a category of useful materials. They may be used in for example drug delivery applications. They may be prepared by a method comprising the steps of: dissolving the branched polymer and block copolymer or linear dendritic hybrid, and optionally other component(s), in a solvent to form a solution; adding said solution to a different liquid; and removing said solvent to form a dispersion of co-precipitated particles.

1 . Particles comprising both a branched polymer and a block copolymer. 
     
     
         2 . Particles as claimed in  claim 1  wherein the block copolymer is a diblock copolymer. 
     
     
         3 . Particles as claimed in  claim 1  wherein the block copolymer comprises a vinyl polymer block. 
     
     
         4 . Particles as claimed in  claim 1  wherein the branched polymer is a branched vinyl polymer. 
     
     
         5 . Particles as claimed in  claim 1  wherein the branched polymer is a branched vinyl polymer and wherein the block copolymer comprises a vinyl polymer block. 
     
     
         6 . Particles as claimed in  claim 1  prepared by co-precipitation. 
     
     
         7 . Particles as claimed in  claim 1  wherein the branched polymer is a branched vinyl polymer, wherein the block copolymer comprises a vinyl polymer block, and wherein the particles are prepared by co-precipitation. 
     
     
         8 . Particles as claimed in  claim 3  wherein the vinyl polymer block comprises HPMA, nBuMA, tBuMA, DEAEMA or styrene. 
     
     
         9 . Particles as claimed in  claim 1  wherein the block copolymer comprises a PEG block. 
     
     
         10 . Particles as claimed in  claim 1  wherein the branched vinyl polymer comprises one or more of the monomers HPMA, nBuMA, tBuMA, styrene, and DEAEMA, and/or wherein the branched vinyl polymer comprises a brancher selected from EGDMA and BDME. 
     
     
         11 . Particles as claimed in  claim 1  wherein the branched polymer is a branched vinyl polymer comprising: HPMA and EGDMA; or HPMA, nBuMA and EGDMA; or HPMA, tBuMA and EGDMA; or nBuMA and EGDMA; and the block copolymer is a diblock copolymer comprising HPMA and PEO. 
     
     
         12 . Particles as claimed in  claim 1  further comprising a drug, prodrug or other biologically active component. 
     
     
         13 . Particles as claimed in  claim 12  wherein the drug is an HIV antiretroviral, anticancer drug, or ibuprofen. 
     
     
         14 . Particles as claimed in  claim 1  which are nanoparticles. 
     
     
         15 . Particles as claimed in  claim 1  in solid form. 
     
     
         16 . A composition containing particles as claimed in  claim 1  dispersed in water or an aqueous phase. 
     
     
         17 . A method of drug delivery comprising administering a therapeutically effective amount of the particles of  claim 12  to a patient in need thereof. 
     
     
         18 . A method of treating HIV or cancer comprising administering a therapeutically effective amount of the particles of  claim 12  to a patient in need thereof. 
     
     
         19 . A method of preparing particles as defined in  claim 1  comprising:
 dissolving the branched polymer and block copolymer, and optionally other component(s), in a solvent to form a solution; 
 adding said solution to a different liquid; and 
 removing said solvent to form a dispersion of co-precipitated particles. 
 
     
     
         20 . A method as claimed in  claim 19  further comprising the following subsequent steps, one or more times:
 adding further solution (of the branched polymer and the block copolymer, and optionally the other component(s), in the solvent) to the liquid; and 
 removing the solvent.