Dr. Sandhya Samarasinghe, Professor

Centre for Geospatial and Computing Technologies, Lincoln University, Christchurch, New Zealand

Biography

Dr. Sandhya Samarasinghe is a Professor in Computational Systems Biology and AI at Lincoln University, New Zealand. She holds a PhD and MSc (Engineering) from Virginia Tech, USA, and MSc (Engineering) from Peoples’ Friendship University in Russia. Her research interests include AI and Machine Learning to understand genomics data and model protein interaction networks to understand biological function and disease mechanisms. She has been invited as a Visiting Scientist at Oxford University, UK, and Princeton and Stanford University in the USA. She has published over 200 research publications including books, book chapters, research articles and conference papers.

Topic

AI Modelling of Protein Networks – Mammalian Cell Cycle

Abstract

Proteins are vital to life as they carry out all biological functions. Proteins form networks or pathways to accomplish these tasks. However, these networks are complex due to many proteins interacting in complex ways making it a challenge to understand how they function and how they succumb to diseases. AI and Machine Learning have emerged as contenders to model complexity of protein-protein interaction (PPI) networks and understand their behaviour. In this talk, a Neural Networks based AI model of the core PPI network underlying the operation of the mammalian cell cycle is presented highlighting model’s ability to accurately mimic the temporal behaviour of all proteins in the network over the course of cell cycle. The success of the model suggests its potential to apply to other PPI networks and other contexts.

Dr. Wenbin Zhong, Professor

College of Food Science & Technology, Nanchang University, Nanchang, China

Biography

Dr. Zhong Wenbin is a Professor at the College of Food Science & Technology, Nanchang University. He joined the precision nutrition laboratory led by Prof. Wan Hao. He received his Ph.D. in 2020 from Nanyang Technological University (NTU), Singapore. From March 2015 to January 2016, he worked as exchange scientist at the Koch Institute for Integrative Cancer Research at the Massachusetts Institute of Technology (MIT), and from November 2020 to March 2025, he worked as a postdoctoral fellow at NTU. His research focuses on the design and regulation of biomedical polymers, precision delivery of probiotics, and modulation of the disease microenvironment, along with the development of related products. He has published nine papers as first author/co-first author/corresponding author in top-tier journals including PNAS, Angewandte Chemie International Edition, Biomaterials, and ACS Materials Letters. He holds five granted patents across China, the United States, Japan, and the WIPO system. Dr. Zhong has played a key role in multiple industry-academia collaboration projects. He co-developed a novel antibacterial detergent with Fortune Global 500 company Procter & Gamble (P&G), which has progressed to pilot-scale production, and completed a patent transfer agreement with Mitsui & Co. His research has also been featured in a documentary series by Channel NewsAsia (CNA), Singapore, which received the Silver Dolphin Award at the 13th Cannes Corporate Media & TV Awards.

Topic

Designer Broad-Spectrum Antimicrobial Polymeric System

Abstract

For a myriad of different reasons most antimicrobial peptides (AMPs) have failed to reach clinical application. Different AMPs have different shortcomings including but not limited to toxicity issues, potency, limited spectrum of activity, or reduced activity in situ. We synthesized several cationic peptide mimics, main-chain cationic polyimidazoliums (PIMs), and discovered that, although select PIMs show little acute mammalian cell toxicity, they are potent broad-spectrum antibiotics with activity against even pan-antibiotic-resistant gram-positive and gram-negative bacteria, and mycobacteria. We selected PIM1, a particularly potent PIM, for mechanistic studies. Our experiments indicate PIM1 binds bacterial cell membranes by hydrophobic and electrostatic interactions, enters cells, and ultimately kills bacteria. Unlike cationic AMPs, such as colistin (CST), PIM1 does not permeabilize cell membranes. We show that a membrane electric potential is required for PIM1 activity. In laboratory evolution experiments with the gram-positive Staphylococcus aureus, we obtained PIM1-resistant isolates most of which had menaquinone mutations, and we found that a site-directed menaquinone mutation also conferred PIM1 resistance. In similar experiments with the gram-negative pathogen Pseudomonas aeruginosa, PIM1-resistant mutants did not emerge. Although PIM1 was efficacious as a topical agent, intraperitoneal administration of PIM1 in mice showed some toxicity. We synthesized a PIM1 derivative, PIM1D, which is less hydrophobic than PIM1. PIM1D did not show evidence of toxicity but retained antibacterial activity and showed efficacy in murine sepsis infections. Our evidence indicates the PIMs have potential as candidates for development of new drugs for treatment of pan-resistant bacterial infections.