Philadelphia – Penn Dental Medicine faculty member Dr. Yuan Liu and postdoctoral fellow Dr. Zhi Ren have been recognized for their excellence in research, recently receiving top awards from the American Association for Dental, Oral, and Craniofacial Research (AADOCR) and the International Association for Dental Research (IADR). The awards were presented as part of the AADOCR/IADR/Canadian Association for Dental Research (CADR) General Session, held virtually in July. Also recognized at the General Session was Penn Dental Medicine DScD candidate and periodontics resident Dr. Dennis Sourvanos (GD’23).
IADR Joseph Lister Award for New Investigators
Dr. Yuan Liu, a Research Associate in the Division of Restorative Dentistry at Penn Dental Medicine, is the 2021 recipient of the IADR Joseph Lister Award for New Investigators. An annual IADR award supported by Johnson & Johnson Consumer Inc., this competition recognizes young investigators with original research in oral disease prevention or oral health promotion.
Through her research, as part of the research lab of Dr. Michel Koo in the Department of Orthodontics and Divisions of Community Oral Health and Pediatric Dentistry, Dr. Liu is working to understand caries etiopathology and develop novel anti-caries approaches. Among her recent areas of study was a new bi-functional nanotechnology combining natural enzymes with catalytic nanoparticles (termed nanohybrid) that can precisely disrupt cariogenic biofilms and prevent caries onset.
“Through this nanohybrid system, we would like to introduce a concept of exploiting the natural settings found in pathological conditions (high sugar and acidic pH) to trigger self-generating chemical weapons used by commensals to fight against pathogenic bacteria to deter cariogenic biofilm establishment,” says Dr. Liu.
She helped to develop a dual-catalytic nanohybrid by integrating glucose-oxidase and dextran-coated nanoparticles with peroxidase-like activity. Glucose oxidase can self-fuel the hybrid system in a controlled manner, she explains, by boosting intrinsic H2O2 production using readily available glucose that can be converted to free radicals by a nanoparticle core with high catalysis at acidic pH.
“It precisely kills the cariogenic pathogen Streptococcus mutans and degrades the extracellular matrix while sparing commensals such as Streptococcus oralis in a low-pH environment, resulting in localized biofilm disruption,” says Dr. Liu. “Our findings demonstrate therapeutic precision of a bi-functional nanotechnology against a biofilm-related disease in a controlled-manner activated when pathological conditions arise in the oral cavity.”
2021 AADOCR and IADR Hatton Awards
Dr. Zhi Ren has the unique distinction of being a double winner of both the 2021 Hatton Awards in the AADOCR and the IADR. The Hatton Awards are IADR’s longest running and the most competitive award that recognizes outstanding young dental researcher talents. The IADR Hatton Competition is designed to provide an opportunity for the best junior investigators from all IADR Divisions and Sections around the globe to present their research at the annual IADR General Session. Dr. Ren was one of the winners of the AADOCR Hatton Award, which qualified him to compete against worldwide competitors at the IADR Hatton Competition, where he won again representing the IADR American Division (AADOCR).
As a dentist-scientist, Dr. Ren joined the lab of Dr. Michel Koo at Penn Dental Medicine in 2019 as a postdoctoral fellow. His research focuses on understanding how bacterial and fungal pathogens interact in the oral cavity to form a sticky plaque (biofilm) on teeth, which gives rise to early childhood caries (ECC), a severe tooth decay affecting millions of children worldwide. In his recent project, for which he received the AADOCR and IADR Hatton Awards, Dr. Ren discovered a new microbial consortium naturally present in the saliva of children that have ECC, where the fungi and bacteria behave as a single unit, acting in concert to protect themselves from antimicrobials and to strengthen their ability to initiate disease-causing biofilms.
“This work may have significant therapeutic implications as the pathogens ‘united’ into a single structure are stickier and harder to eradicate, which could change the way we prevent and treat ECC,” says Dr. Ren. “Our next step is to seek innovative therapeutic strategies that target this mixed-kingdom structure in saliva to fight this painful and costly disease for toddlers worldwide.”
“It is incredibly difficult to win both the AADOCR and the IADR Hatton Awards; he may be the first postdoc fellow from Penn Dental Medicine to achieve this,” says Dr. Koo. “Kudos to Zhi for his creative mind, hard-work, and great presentation skills.”
The research development of both Drs. Ren and Liu has been supported by the Colgate-Palmolive Pediatric Dentistry DScD Fellowship at Penn Dental Medicine, which provides financial support for a student pursuing a Doctor of Science in Dentistry (DSCD) degree or engaged in postdoctoral research studies through the Penn Dental Medicine Division of Pediatric Dentistry. Dr. Ren is currently a Colgate Fellow and Dr. Liu was the inaugural recipient of the fellowship in 2017, earning her DScD in 2019 and joining the research faculty in 2020. “We are grateful to Colgate-Palmolive for helping develop the next-generation dentist-scientists for careers dedicated to the advancement of dental research and oral health care innovation,” says Dr. Koo.