Date: February 3, 2015 (Tuesday)
Time: 12:45 p.m. to 1:45 p.m.
Venue: Lounge (Room 7A09), 7/F, The Prince Philip Dental Hospital
Presenter: Miss Yu Xiaolin, PhD Candidate (12:45 p.m. to 1:15 p.m.)
Title: Oral microbiota in periodontal/peri-implant niches
Abstract: Periodontitis is a progressive infectious-inflammatory disease that destroys the soft and hard tissues supporting the teeth. It is prevalent in global populations, leading to a significant healthcare burden. Initiation and progression of this disease are caused by a combination of various factors including the oral microbiota, host factors and external factors. Among these, a complex assortment of bacterial pathogens are regarded as the dominant causative factors. To date, dental implants and implant-supported restorations have become routine and essential treatments for partially or fully edentulous patients. However, biological complications; typically peri-implantitis and peri-implant mucositis have been reported after a period of functional loading. It is widely agreed that peri-implantitis and peri-implant mucositis are mainly associated with microbial plaque accumulation and bacterial infections, and present a high risk in subjects with a history of periodontitis. In my PhD studies, I will use next-generation sequencing approaches to investigate periodontal/peri-implant microbiota in subjects with both healthy and inflamed sites. Moreover, I will mainly focus on oral bacteria belonging to the Treponema and Synergistetes phyla. The complete genome sequences of selected poorly-chraracterized oral treponeme isolates will be analyzed to investigate taxonomy and phylogeny, and to identify pathogenic genes. As the vast majority of oral Synergistetes taxa are uncultivable, targeted single-gene clone-library approaches will be performed to investigate the diversity of genotypes and phylotypes present in subgingival plaque sampled from diseased and healthy sites.
Presenter: Miss Li Xuan, PhD Candidate (1:15 p.m. to 1:45 p.m.)
Title: Mesoporous silica nanoparticles-encapsulated TCMs inhibit oral pathogens and modulate inflammatory responses in human gingival epithelial cells
Abstract: Due to the porous structure and stable physical/chemical characteristics, mesoporous silica nanoparticles (MSNs) have emerged as a ‘hot’ biomedical agent that can be used as cell markers, imaging moieties, gene and drug vehicles. Meanwhile, several selected traditional Chinese medicines (TCMs) show potent anti-microbial and anti-inflammatory effects, such as Scutellariae Radix and green tea. Periodontitis results from plaque biofilms-induced uncontrolled immuno-inflammatory response that leads to substantial periodontal destruction and eventually teeth loss. Currently, two forms of MSNs (SR2 and M1) in different morphologies have been successfully synthesized, and their surfaces have been modified by amine and fluorescent dye. In the coming studies, the extracts ofScutellariae Radix and green tea would be loaded into the synthesized MSNs, and their loading efficiency and release profiles are tested. The anti-microbial effects via a prolong release manner on selected oral microbes are determined. The sub-localization of fluorescent SR2 and M1 in human gingival epithelial cells (HGECs) would be analyzed. Next, the potential anti-inflammatory effects of SR2 and M1-encapsulated TCMs are investigated in P. gingivalis and E. coli lipopolysaccharides(LPS)-treated HGECs. The underlying signaling mechanisms involved in the effects are explored by determining relevant profiles of genes and proteins.