Fluorescent Polylactides with Rhenium(bisimine) Cores for Tumour Diagnostics

Early tumour detection, for example, by passive delivery of a polymer‐based diagnostic agent, can greatly improve the life expectancy of cancer patients. Here, we present the synthesis of biodegradable 3‐hydroxymethylpyridine‐functionalised polylactides coordinated to Re(CO)3(bisimine) cores [bisimine = bipy (2) phen (3), dppz (4)]. The Re(CO)3(bisimine) polymers 2 and 3 show fluorescence at 560 nm and 572 nm, respectively, with large Stokes shifts, which makes them distinguishable from tissue autofluorescence and therefore suitable diagnostic probes for fluorescence imaging. Re(CO)3(bisimine)Br fluorochromes were coordinated to pyridine‐functionalised polylactides to afford fluorescent polymers,which can be used to passively target tumours. Their properties and usefulness for biological imaging have been investigated.