Andrographolide-loaded silk fibroin nanoparticles.

Andrographolide (AP) is a diterpenoid separated from with a wide spectrum of biological activities including anti-inflammatory, anticancer, hepatoprotective, and antihyperlipidemic. However, its poor water solubility and instability result in lower bioavailability, which seriously limit its pharmacological function. In this study, the attempt to use regenerated silk fibroin (RSF) as a drug-carrier to encapsulate AP was reported. The AP-loaded RSF nanoparticles were prepared by a facile and clean method without any toxic agents. Moreover, special attention was paid to the optimization of formulation. Finally, the sizes of the AP-loaded RSF nanoparticles ranged from 200 to 1000 nm, and the nanoparticles were spherically shaped, as seen by transmission electron microscopy. The drug loading and encapsulation efficiency were about 25.9% and 87.3%, respectively. Furthermore, the release time of AP-loaded RSF nanoparticles was about 3 days. The particle size and drug release behaviour could be adjusted by treating with glycol amine. The cytotoxicity studies demonstrated that the RSF nanoparticles showed negligible cytotoxicity to cells, and the anti-proliferative activity of AP-loaded RSF nanoparticles showed that the AP-loaded RSF nanoparticles can adhere to Hela cells and MDA-MB-231 cells easily. All these results imply that this biomacromolecule drug nanocarrier has great potential for chemotherapy in clinical applications.