DSPE-PEG-2K-Maleimide is a PEG derivative with a DSPE moiety and maleimide group. The DSPE-PEGs have been FDA approved for medical applications. The hydrophobic properties of the DSPE allow for the encapsulation and congregation of other hydrophobic drugs. The hydrophilic PEG linker increases the water solubility of the overall compound allowing for the delivery of the drug. Maleimide groups can be reacted with thiol groups between pH 6.5 to 7.5.