A natural pentacyclic triterpenoid arjunolic acid self-assembled hierarchically in aqueous solvents yielding vesicular structures of nano to micrometer diameters affording gels. This self-assembly has been utilized for the entrapment and controlled release of anticancer drugs such as doxorubicin at physiological pH. A gel–gold nanoparticle hybrid material has also been prepared by in situ generated gold nanoparticles at room temperature.