Faculty Spotlight

Dr. Hongli Sun joined the University of Iowa College of Dentistry in 2018. He is an associate professor in the Iowa Institute for Oral Health Research and the Department of Oral and Maxillofacial Surgery. Prior to coming to Iowa, Dr. Sun was an assistant professor in the Department of Biomedical Engineering at the University of South Dakota at Vermillion.

Dr. Sun's research seeks to develop novel biomaterials-based strategies to improve challenged bone (e.g., large, aged or irradiated bone defects) tissue regeneration by mimicking the natural bone healing process. They are particularly interested in understanding the underlying the mechanisms by which osteogenic differentiation of the resident adult stem cells is regulated by microenvironmental cues during tissue injury and repair. Inspired by these fundamental findings, Dr. Sun's team is devoted to developing novel nano-biomaterials/drug delivery-based translational strategies for tissue engineering and regenerative medicine. Their long-term goal is to develop novel therapeutics for musculoskeletal related diseases, including large bone defects, vascular ossification, and cancer bone metastasis.

Dr. Sun's current research interests include:

1. Promote endogenous bone formation by developing bio-mimicking nanofibrous 3D scaffolds;
2. Promote challenged bone repair by targeting angiogenesis/inflammation via local drug delivery (small molecule drugs);
3. Study the role of adult stem cells and 3D microenvironment in bone metastasis.

 

Dr. Sun’s research group includes three postdoctoral fellows, Drs. Jue Hu, Jacob Miszuk, and Zhuozhi Wang, and one BME graduate student Jessica Faber. They have collaborators from many different fields, including, Drs. Brad Amendt, Liu Hong, Kyle Stein, Jin Xie, Erliang Zeng, Jeff Banas, Shaoping Zhang, Tae-Hong Lim, and Alexei Tivanski.

In September 2018 Dr. Sun was awarded a nearly $300,000 multiyear grant for a project entitled, “Functionalized Nanofibrous Scaffold for Endogenous Bone Regeneration.” The long-term goal of Dr. Sun’s research is to develop an effective strategy to repair and regeneration large bone defects. This particular project is a step toward designing an effective strategy—a biomimetic gelatin nanofibrous scaffold—for delivering therapeutic molecules at a designated location so that one can more effectively bring out the natural regenerative properties of these tissues. More particularly, Dr. Sun’s team will investigate whether this innovative scaffold can modulate endogenous bone morphogenetic proteins and angiogenic signals so that bone defects are repaired and regenerated.

In July 2020, the NIH/NIDCR awarded Dr. Sun a five-year R01 grant totaling over $1.7 million for his research project, “Rejuvenating aged bone regeneration by innovative nanomaterials-mediated drug delivery.” Typically, when bones or joints are seriously damaged, such as in multiple or complex fractures or in bones that are seriously damaged by age, disease, infection, and/or injury, the most common treatment is a bone-graft using one’s own bone material. A less invasive and potentially more effective approach, especially for older populations, is to harness a body’s own bodily repair processes to quickly and efficiently repair and regenerate bone, even for older adults with significant bone damage. Emerging research uses deferoxamine, a drug that treats iron poisoning, to activate the hypoxia-induced factor-1α, which in turn promotes angiogenesis and bone regeneration. The biggest obstacle to this line of research has been safety concerns and complicating factors, such as chronic inflammation, which are common among older individuals. To reduce inflammation and promote endogenous bone regeneration, Dr. Sun’s team uses a small molecule, phenamil, and to address the safety concerns, the research team has engineered a novel nanomaterial scaffold that mimics bone matrix and delivers deferoxamine and phenamil locally and effectively. These two innovations could pave the way for treatments to rejuvenate and repair significant bone damage, even for older adults.