SYNTHESIS AND CHARACTERIZATION OF MAGNETIC METAL OXIDE (Fe3O4, Gd2O3) NANOPARTICLES AND THEIR THERANOSTIC APPLICATIONS.

Ph.DDOCTOR OF PHILOSOPH

Wirelessly operated bioelectronic sutures for the monitoring of deep surgical wounds

Monitoring surgical wounds post-operatively is necessary to prevent infection, dehiscence and other complications. However, the monitoring of deep surgical sites is typically limited to indirect observations or to costly radiological investigations that often fail to detect complications before they become severe. Bioelectronic sensors could provide accurate and continuous monitoring from within the body, but the form factors of existing devices are not amenable to integration with sensitive wound tissues and to wireless data transmission. Here we show that multifilament surgical sutures functionalized with a conductive polymer and incorporating pledgets with capacitive sensors operated via radiofrequency identification can be used to monitor physicochemical states of deep surgical sites. We show in live pigs that the sutures can monitor wound integrity, gastric leakage and tissue micromotions, and in rodents that the healing outcomes are equivalent to those of medical-grade sutures. Battery-free wirelessly operated bioelectronic sutures may facilitate post-surgical monitoring in a wide range of interventions

A wireless and battery-free wound infection sensor based on DNA hydrogel

The confluence of wireless technology and biosensors offers the possibility to detect and manage medical conditions outside of clinical settings. Wound infections represent a major clinical challenge in which timely detection is critical for effective interventions, but this is currently hindered by the lack of a monitoring technology that can interface with wounds, detect pathogenic bacteria, and wirelessly transmit data. Here, we report a flexible, wireless, and battery-free sensor that provides smartphone-based detection of wound infection using a bacteria-responsive DNA hydrogel. The engineered DNA hydrogels respond selectively to deoxyribonucleases associated with pathogenic bacteria through tunable dielectric changes, which can be wirelessly detected using near-field communication. In a mouse acute wound model, we demonstrate that the wireless sensor can detect physiologically relevant amounts of Staphylococcus aureus even before visible manifestation of infection. These results demonstrate strategies for continuous infection monitoring, which may facilitate improved management of surgical or chronic wounds.Agency for Science, Technology and Research (A*STAR)Ministry of Health (MOH)National Medical Research Council (NMRC)Published versionJ.S.H. acknowledges support from grants from the National Research Foundation Singapore (NRFF2017-07 and AISG-GC-2019-002), Ministry of Education Singapore (MOE2016-T3-1-004), and Institute for Health Innovation and Technology. D.L.B. acknowledges support from the Agency for Science, Technology and Research (A*STAR) under its Industry Alignment Fund–Pre-Positioning Programme (IAF-PP) grant (H17/01/a0/0C9) as part of the Wound Care Innovation for the Tropics Programme, IAF-PP grant (H17/01/a0/004), and Skin Research Institute of Singapore, Phase 2: SRIS@Novena. H.L. acknowledges support from the Wound Care Innovation for the Tropics Programme, A*STAR IAF-PP grant (H19/01/a0/0GG9), Skin Innovation grant (SIG18005), MOE AcRF Tier 1 grant (R-143-000-B79-114), and Singapore Ministry of Health’s National Medical Research Council OF-IRG (MOH-000612-00). W.L. acknowledges support from MOE AcRF Tier 1 grant (R-221-000-093-133). B.C.K.T. acknowledges support from National University of Singapore Startup Grant (NUS-2017-01) and Agency of Science Technology and Research Singapore (A18A1B0045). H. Yao acknowledges Research Scholarship from NUS Materials Science and Engineering. Y.G. acknowledges support from the EMULSION Programme H18/01/A0/017 (IAF-PP, A*STAR). S.M.P.K. acknowledges support from the National Research Foundation Singapore, under its NRF Large Equipment Grants–Grant Addendum 3: Operations of the Singapore Synchrotron Light Source (SSLS)