There is provided a polymer comprising: (i) a repeat unit derived from a compound of formula (I) (Formula (I)) wherein, R1 and R2 are each independently selected from OH, OR′；, SH, SR′；, NH2, NHR′； and NR′；2； R′； is C1-20 hydrocarbyl； each n is independently 0 or an integer between 1 and 6； each m is independently 0 or an integer between 1 and 4, and preferably at least one m is 1； and q is an integer between 1 and 8； and； (ii) a biologically active molecule, wherein said biologically active molecule is covalently bonded to said repeat unit； as well as methods for preparing such polymers, particles comprising said polymers and uses of said polymers and particles including use in the treatment of disease.
