In this work, amphiphilic hyaluronic acid (HA) was synthesized by the chemical bonding of terpenes. The first step concerns the synthesis of functional terpene molecules by thiol−ene addition chemistry initiated by DMPA, which involve carboxylic acid thiols and dihydromyrcenol terpene (Fig. 1a). The terpene was pre-activated by benzoyl chloride to form the reaction intermediate 1 (Fig. 1b) towards the esterification reaction of HA in water/THF (Fig. 1c) The degree of substitution can be controlled by varying the feed ratio of mixed anhydride to HA and up to 36% (mol/mol) can be obtained. The esterification of the polysaccharide occurred under mild reaction conditions, thus no degradation of the polysaccharide was observed. The prepared amphiphilic polymers were characterized by NMR, infrared spectroscopy (FT-IR) and SEC/MALLS. The developed system is proposed for the delivery of hydrophobic molecules for this purpose, curcumin, tocopherol and coenzyme Q10 were used as models; these molecules were loaded into the conjugates. The loading capacity was a clear function of degree of substitution. Furthermore, the derivatives were found to be non-cytotoxic, thus the potential of the prepared delivery systems was demonstrated.
