Self-assembled supramolecular material derived from traditional Chinese medicine: Injectable self-assembled natural product gel for drug delivery with biological activity

Injectable self-assembled gels with physicochemical functions have been widely used to deliver chemotherapeutics to achieve an increase in antitumor effects. However, exploration of physiologically functional gel delivery systems has been relatively rare. In such a system, the gel can not only reach the lesion directly, but also play a synergistic effect on the tumor through the gel's own bioactivity, thereby achieving a better therapeutic effect. Here, the bioactive natural compound poricoic acid A (PAA) derived from Poria mushroom (Poria cocos) was developed into the injectable gel by virtue of direct self-assembly capabilities. The PAA gel (PAA/G) was successfully constructed by simple mixing method to initiate self-assembly. Morphological and rheological studies revealed that PAA/G is composed of nanofibers with diameters less than 100 nm and exhibits good injectability. Hydrogen bonding and π-π interactions have been proven to be the driving force for self-assembly via spectroscopy and contact angle analysis. In view of the antitumor activity of PAA, the antitumor drug doxorubicin (DOX) with matching activity was encapsulated into PAA/G (DOX-PAA/G). In vitro and in vivo antitumor studies have shown that the bioactive DOX-PAA/G can not only exert better tumor inhibition (160 % inhibition of free DOX) through synergy, but also improve the overall health of tumor-bearing mice (healthier blood, normal weight, higher SOD levels). The successful development of bioactive gel delivery systems not only provides new strategies for treating tumors, but also provides potential new uses for bioactive natural products as biomaterials.