Zentek Ltd. announced further successful pre-clinical testing of the aptamer-based platform technology by the Dr. Matthew Miller Lab. After initial promising results released on July 27th, 2023, which featured an aptamer therapeutic/prophylactic using the novel platform technology developed by the lab of Dr. Yingfu Li and tested by the team of Dr. Matthew Miller, further preclinical testing has been completed supporting this aptamer as a lead therapeutic target. An in vivo preclinicall longevity of protection study was conducted to assess the safety and efficacy of the aptamer-based treatment over a period of 24 hours.

This duration was chosen to mimic a suitable prophylactic use case that balances the convenience of a daily dose while maintaining complete protection. The study successfully demonstrated that the novel aptamer provided 24 hours of neutralizing protection against SARS-CoV-2 and improves the potential of the aptamer as a prophylactic in a setting that is both commercially and clinically relevant. The trial used three test groups of 10 mice, which were administered three separate treatments 24 hours prior to administering the virus: Group 1 - control that was administered saline; Group 2 - received the novel aptamer developed by the Li lab; Group 3 - received the S309 antibody treatment; the most effective antibody against SARS-CoV -2 variants that received emergency use approval.

After 24 hours, all mice received a lethal challenge (10^5 PFU) of the original Wuhan strain of SARS-CoV- 2. Viriral titers were measured and histopathology was performed at the end of the 7-day study. The mice that received the aptamers showed no clinical signs of infection, similar to those that received the S309 antibody. Four separate groups of 10 mice were tested in the experiment: Group 1 - control that received saline; Group 2 - received a 10-fold lower dose (25.8 uM); Group 4 - received a 50-fold lower dose (5.16 uM).

After two hours, mice were challenged with a lethal dose of SARS-CoV - The Group 2 mice that received 258 uM of aptamer were consistent with the previous tests reported on July 27th, where the aptamers provided sterilizing protection. Group 3, which received a ten-fold lower dose (25.,8 uM), showed no clinical markers of infection demonstrating that this lower aptamer dose still provided complete protection against SARS-Co V-2. Group 4 that received the lowest dose showed signs of infection similar to the control group suggesting that animum dosage is in the range of 25.8 uM through this delivery system. Based on these promising results, the next step will be to evaluate the aptamer's ability to protect against infection with the Omicron variant.

Based on the results achieved to date, the aptamer platform developed at the Li Lab has successfully neutralized the SARS-CoV-1 virus at a dose and duration that shows strong therapeutic and prophylactic potential and that suggests the aptamer platform could be an alternative to monoclonal antibodies. This is significant as aptamer-based therapeutics can be developed much more quickly than monoclonal antibodies. A development platform with these attributes could allow for faster and more effective treatment of numerous infectious diseases.

Importantly, it could allow governments and healthcare systems to respond much more quickly to new infectious threats to society, which is crucial for global pandemic preparedness efforts. Zentek's patented technology platform ZenGUARD??, is shown to have 99-per-cent anti-microbial activity and to significantly increase the bacterial and viral filtration efficiency of both surgical masks and HVAC (heating, ventilation, and air conditioning) systems. Zentek's ZenGUARD?? production facility is located located at the Li Lab.