Sungho Jin

Sungho Jin

The Jin lab currently designs materials incorporating metallic nanostructures for a variety of applications from energy and data storage to biomedical implants and drug delivery. These are only a subset of the types of materials Prof. Jin has studied; over the course of his long career, including over 20 years at Bell Labs, he has also contributed to major advances in display technology, touch-sensitive materials, superconductors, diamond processing, and fiber optics, among other areas. Since he joined UC San Diego in 2002, his research group’s major discoveries and inventions include strongly nonlinear acoustic materials for sound absorption or acoustic scrambling, dye-sensitized solar cells that are less expensive but as efficient as those currently produced, and rare earth-free magnets.

Most research in the Jin lab within the biomedical arena concerns either bone implant materials or magnetically controlled drug carriers. Their work on bone implants focuses on titanium, already widely used in the clinic for this purpose. As roughening the titanium surface had previously been shown to promote integration with existing bone, they have examined the effects of structuring with titanium oxide (TiO2) nanotubes, a more defined and reproducible surface modification, on osteoblast proliferation, elongation, and mineralization. Several years of research has shown that multiple processes of creating nanotubes of varying diameter promote bone formation on the titanium surface. Even more fundamentally, the Jin group has found that nanotubes of >70 nm diameter are sufficient to direct mesenchymal stem cells to an osteoblast fate, without the need for osteogenic factors. This concept is currently being commercialized by a startup, Nasseo, established by recent lab graduates.

bone nodules on TiO2 nanotubes
TiO2 nanotubes, with or without tantalum coating, support bone nodule (raised structures) formation by human osteoblasts. SEM micrographs at 1000x following 3 weeks of culture. Scale bar = 20 μm. From Frandsen et al., Acta Biomater 2014.

The Jin group has also employed metallic nanostructures to enable remote control over drug delivery vehicles, both to guide them to target tissues and to trigger drug release. Incorporating iron oxide (Fe3O4) nanoparticles into the core of hollow silica nanocapsules allows them to be guided to a particular site, such as a tumor, using a low-frequency magnet, and release of co-encapsulated drug by magnetic heating using a radio-frequency magnetic field. This system has been shown to release sufficient quantities of camptothecin to significantly reduce tumor cell proliferation in vitro, and to accumulate ~2 orders of magnitude more efficiently within tumors than non-magnetically guided particles. Further, the same system has been used to penetrate the blood-brain barrier, which generally excludes nanoparticles.

Affiliations

Key publications

Kong SD, Zhang W, Lee JH, Brammer KS, Lal R, Karin M, Jin SH. Magnetically vectored nanocapsules for tumor penetration and remotely switchable on-demand drug release. Nano Lett 2010; 10(12): 5088–92.

Oh S, Brammer KS, Li YSJ, Engler AJ, Chien S, Jin SH. Stem cell fate dictated solely by altered nanotube dimension. Proc Nat Acad Sci USA 2009; 106(7): 2130-35.

Oh SH, Finones R, Daraio C, Chen LH, Jin SH. Growth of nano-scale hydroxyapatite using chemically treated titanium oxide nanotubes. Biomaterials 2005; 26(24): 4938-43.