Doctoral Research: Design and synthesis of hydrogel encapsulated dental biofilm inhibitors

Dental caries represents a pervasive oral health concern characterized by the degradation of tooth enamel due to the acidic milieu generated by acidogenic bacteria thriving within intricate biofilm communities. Among these pathogens, Streptococcus mutans (S. mutans) stands out as a primary culprit. This bacterium secretes glucosyltransferase (Gtf) enzymes, which act as chain producing machines pivotal in catalyzing the synthesis of adhesive glucans, which form a scaffold for bacterial aggregation, culminating in robust biofilm formation. Within this biofilm, S. mutans and its acidogenic cohorts metabolize dietary sugars to produce lactic acid, instigating tooth demineralization. While conventional preventive measures like oral hygiene practices offer some reprieve, biofilm recalcitrance persists, necessitating novel intervention strategies. Mouthwashes are powerful in killing oral bacteria, but they also eliminate beneficial microbiota indiscriminately.

During my doctoral studies, I undertook a targeted approach, aiming to disrupt biofilm formation by inhibiting Gtf activity, thereby impeding glucan synthesis. This strategy, distinct from bactericidal approaches, seeks to render the bacteria disarmed rather than eliminating them outright. Leveraging high-throughput computational screening of extensive compound libraries, we identified small molecule inhibitors of Gtf enzymes, subsequently subjecting them to structure-activity relationship (SAR) studies to optimize efficacy. The efficacy of these lead compounds was evaluated through rigorous in vitro assays involving S. mutans and select commensal species such as S. gordonii, S. sanguinis, and S. parasanguinis, shedding light on their specificity and potential impact on oral microbiota equilibrium. Most promising candidates underwent encapsulation within polymeric nanomaterials to afford pH-responsive delivery, ensuring targeted action within the acidic microenvironment of dental biofilms.

Encouragingly, our encapsulated biofilm inhibitors demonstrated significant efficacy in vivo, as validated through rat models, offering promising prospects for clinical translation. These findings have been disseminated through peer-reviewed publications in esteemed journals such as the ACS Medicinal Chemistry Letters4 and Journal of Medicinal Chemistry, with another manuscript ready to be published to extend our investigations using alternative polymeric matrices for encapsulation.

In essence, my research endeavors epitomize a concerted effort to unravel the intricate dynamics of dental biofilm formation and devise innovative strategies for targeted intervention, poised to alleviate the burden of dental caries while preserving the delicate balance of the oral microbiome.

Specifically, I employ a range of cutting-edge techniques, including molecular cloning, genetic engineering, and CRISPR-based genome editing, to modify microbial systems with precision. By reprogramming these microorganisms, I aim to enhance or introduce capabilities such as the production of high-value chemicals, biotherapeutics, or environmental biosensors. For instance, my work involves designing microorganisms that can efficiently synthesize metabolites, fluorescent proteins, and pigments, which can be used as environmental biosensors. These engineered microorganisms have the potential to detect and respond to environmental changes, providing a powerful tool for monitoring pollution, detecting toxins, or tracking ecosystem health in real time.

My research bridges the gap between fundamental biology and applied science, focusing not only on understanding the molecular mechanisms driving microbial processes but also on leveraging that understanding to create innovative solutions. By combining advanced molecular techniques with a thorough understanding of microbial biology, I strive to contribute to the development of sustainable technologies and transformative innovations that address critical challenges in healthcare, industry, and the environment.