Synthesis and characterization of novel biodegradable folate conjugated polyurethanes

In order to obtain targeting polyurethane micelle drug carriers, a series of biodegradable folate conjugated polyurethanes (FPUs) were synthesized using poly(ethylene glycol) (PEG) and poly(ε-caprolactone) (PCL) as soft segments, l-lysine ethyl ester diisocyanate (LDI) and 1,3-propanediol (PDO) as hard segments, and folic acid–ethylenediamine conjugate (FA–EDA) as an end-capping reagent. The resultant FPUs were fully characterized by 1H NMR, Fourier-transform infrared (FTIR) spectroscopy, ultraviolet spectrophotometry (UV), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). These polymers can self-assemble into micelles in aqueous solutions confirmed by dynamic light scattering (DLS), pyrene fluorescence probe techniques, and transmission electron microscopy (TEM). The results indicated that the bulk structures and micellar properties of the prepared polyurethanes could be controlled by varying the PEG content in the soft segments. The present work provides a facile approach to prepare amphiphilic multiblock copolymers with tumor targeting moiety, which is a good candidate as biodegradable carriers for active intracellular drug delivery.

Micellar properties of folate conjugated polyurethane (FPU) could be controlled by varying the PEG content in the soft segments, which makes FPU a possible carrier for active intracellular drug delivery.Figure optionsDownload high-quality image (53 K)Download as PowerPoint slideHighlights
► A novel folate conjugated polyurethane (FPU) has been synthesized using PEG, PCL, and LDI.
► Micellar properties of the FPUs could be controlled by varying the PEG content in the soft segments.
► Our work provides a facile avenue to prepare amphiphilic copolymers with tumor targeting moieties.