1. Can you briefly describe what you achieved in this article?
Photosensitive drug, Hypocrellin B (HB) can be accumulated effectively in water-solubilized natural polyelectrolyte microcapsules. The complete HB-loaded microcapsules can be taken up by cancer cells. These intracellular microcapsules show biocompatibility under darkness and high cytotoxicity after irradiation which provides the possibility of controlled delivery and release of HB as drugs.

2. Could you explain the significance of your article to the non-specialist?
Most drug carriers are gels, polymeric micelles, liposomes or colloids.  Recently assembled microcapsules have exhibited a potential application for the controlled drug delivery. We demonstrate here that hydrophobic photosensitive drugs like HB can be efficiently encapsulated inside the biocompatible capsules to bring HB into the cells. The microcapsules loaded with HB showed high cytotoxicity after exposure to visible light, indicating that such assembled microcapsules can be considered as efficient anti-cancer agent cargo.

3. What has motivated you to conduct this work? 
We are attempting to develop different types of microcapsules containing lipids, proteins or polyelectrolytes, which will serve as vehicles to deliver drugs into cancer cells. 

4. Where do you see this work developing in the future? 
This is just a preliminary study for such a system. All the control experiments, for instance the targeted recognition for cancer cells without destroying "healthy" cells, are necessary. Otherwise the system is limited. 

5. Are there any particular challenges facing future research in this area? 
One of the challenges is to obtain well dispersed microcapsules and it is still difficult to easily achieve large-scale production. A particular challenge is to perform the experiments in vitro and in vivo.

Junbai Li obtained his B.Sc., M.S., and Ph.D., degrees on Polymer Science from the Jilin University. He then spent several years carrying out postdoctoral research in Colloid and Interface Science at the German Max Planck Institute of Colloids and Interfaces where he now leads an international joint lab. He is currently a full professor in the Institute of Chemistry, Chinese Academy of Sciences. His research interests involve molecular biomimetics based on molecular assembly, molecular mechanisms and structure in the assembled biological systems, microcapsules, and nanostructured materials.

Kewei Wang was born in Hubei, China, in 1982. He received his B.Sc. degree in Chemistry from the Tsinghua University in 2003. He is currently working as a PhD student under the supervision of Professor Li. His research interests include nanostructural assembly, gene transfection and drug delivery.