Functionalized Low-Dimensional Nanomaterials in Antibacterial Activity and Drug Delivery

Abstract

The rise in multi-drug-resistant bacterial infections is a major health concern of the 21st-century. Overuse of traditional antibiotics in medical, agricultural, and veterinary practices has led to numerous drug-resistant bacterial strains. Small molecule-based antibiotics, targeting crucial bacterial processes, face resistance as bacteria adapt. Notably, antibiotics like Daptomycin (2003), Retapamulin (2007), and Fidaxomicin (2011) encountered resistant species shortly after their discovery, emphasizing the urgent need for new solutions. In this regard, nanomaterial-based antibiotics present a promising alternative. Their unique antibacterial mechanisms confuse bacteria's natural defenses system. Physicochemical properties like shape, size, and surface chemistry directly influence their antibacterial effectiveness. Across 0-D to 3-D structures, nanomaterials have shown promise in diagnosing and treating bacterial infections. The primary focus of this thesis was centered on the bioengineering of nanomaterials, particularly emphasizing the development of antibacterial materials through surface modifications. By employing synthetic ligands, I aimed to enable targeted interactions with biomolecules. My investigation focused on understanding how surface functionality influences the antibacterial activity of nanomaterials. Specifically, I concentrated on various quantum dots (0-D nanomaterials) and nanosheet (2D-nanomaterials), seeking insights into their impact on biomolecular interfaces. My research involved synthesizing ligands containing amino acids to modify the surface of MoS2 quantum dots, examining their effect on antibacterial activity. Additionally, I have explored how incorporating hydrophobic ligands on sulfur quantum dots alters their antibacterial properties. I have pursued the production of sulfur nanosheets through sonication, utilizing diverse thiol ligands. Moreover, my efforts extended to crafting liposomes (3-D nanomaterial) designed for targeted interaction with bacterial membranes, facilitating the delivery of antibacterial agents. Additionally, I aimed to explore the inhibition of enzymes through metallo-supramolecular assembly (3-D nanomaterial) to impede bacterial growth. With this mindset, my journey commenced toward crafting antibacterial materials, uncovering intriguing properties that are extensively discussed in the subsequent chapters.