College of Oral Medicine Students Awarded First and second place in 2024 GTIDEC Paper Competition
Source: College of Oral Medicine
Published on 2025-01-03
Second-year master’s student Li Po-Jui, first-year master’s student Yu Ching-Chieh, and fourth-year bachelor’s student Yang Yu-Hsin, all from the College of Oral Medicine’s School of Dentistry, participated in the 2024 Greater Taipei International Dental Exhibition & Convention (GTIDEC) Paper Competition. Li was awarded first place, while Yu and Yang were awarded second place.

Yu-Hsin Yang (left) and Po-Jui Li (right) attended the competition as representatives.
█ Po-Jui Li: An evaluation of the in vivo bone regeneration effect of EV scaffolds extracted from dental pulp-derived MSCs and optimal EV isolation methods
In dental surgery, guided bone regeneration can enhance teeth and implant stability, as well as facilitate alveolar ridge augmentation and sinus lift procedures. Recent studies in this field have been focused on developing synthetic biomaterials that promote the formation of new bone tissue. Dental pulp stem cells (DPSC) and mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) exhibit significant regeneration potential.
Professor Feng Sheng-Wei, Director of the College of Oral Medicine’s School of Dentistry, guided Li Po-Jui and the rest of Feng’s research group in this study. They compared DPSC-derived small extracellular vesicles (DPSC-sEV) obtained through ultra-high speed centrifugation (UC) and ultrafiltration combined with size exclusion chromatography (SEC) to search for optimal extraction methods. They also studied the impact of EVs on bone regeneration in vivo in rats. The results showed that when the synthetic bone substitute material MBCP® was incorporated with DPSC-EVs extracted via UC or SEC during bone regeneration in vivo in rats, the latter exhibited better performance. In terms of extraction efficiency and economic benefits, the SEC extraction method provides greater advantages.
Li stated that the process of studying EVs is extremely challenging and requires a great deal of patience. Using different separation methods during MSC-EV extraction is of critical importance to the resulting quality of the vesicles and their cellular pathways. This study also provided a better sense of the characteristics of EVs and possibilities for future applications.
█ Ching-Chieh Yu and Yu-Hsin Yang: Establishing a model for in vitro salivary bacteria culturing and “Translational study of Sapindus mukorossi aqueous extract” pilot study for oral bacteria regulation in periodontal disease patients
It is important to Understanding the salivary microbiome composition of patients with periodontal disease and exploring methods to adjust the bacterial balance is crucial. In pursuit of these goals, Yu Ching-Chieh and Yang Yu-Hsin, led by Associate Professor Wang Chin-Wei and Assistant Professor Chang Wei-Min from the College of Oral Medicine’s Research Center of Oral Translational Medicine, collected saliva samples from patients at TMUH. They established an in vitro model, using lysogeny broth as a culture medium to observe the effects of regulatory agents on the growth dynamics of oral bacteria. Then, they tested co-culturing the Sapindus mukorossi seed aqueous extract developed by Associate Dean Huang Haw-Ming with the salivary bacteria, and extracted the bacterial DNA for next-generation sequencing and further analysis.
The results showed that the Sapindus mukorossi seed aqueous extract significantly inhibited the growth of salivary bacteria and greatly reduced the total bacterial count. As for microbiome regulation, the addition of the aqueous extract reduced the number of Porphyromonas and increased that of Veillonella. These trends were observed in the saliva culture of every patient. Both genera are associated with common oral diseases such as periodontitis and dental caries.
The in vitro culture model also demonstrated that the culture medium provides a satisfactory growth environment for Neisseria, Rothia, and Haemophilus, all of which are known to reduce nitric acid and promote oral health. This pilot study reports the first-ever use of this method in the academic community for in vitro culture of salivary bacteria and next-generation sequencing of the cultured bacteria. The in vitro culture model developed by the group was able to retain important bacterial genera from the oral cavity, and verified the ability of Sapindus mukorossi seed aqueous extract to inhibit bacteria growth. This research promises to aid in the development of more treatments aimed at enhancing host immunity and regulating the microbiome.