UC Riverside

Pathogenic microbes pose a serious threat to public health. Specifically, antibiotic abuse is creating new strains of antibiotic resistant bacteria and creating a public health crisis. There are many health risks associated with the overuse of antibiotics. Their broad bactericidal effects can disrupt an individual’s symbiotic relationship with beneficial bacteria [1]. Furthermore, antibiotics can be toxic to human and create serious side effects from skin sensitivity to organ failure [2]. In addition to some microbes’ inherent antibiotic resistive genes, microbes evolve and mutate quickly thereby quickly producing antibiotic resistance. Antibiotic sensitive bacteria are able to acquire antibiotic resistance genes via horizontal gene transfer, causing the organism to then become resistant to specific classes of antibiotics, further complicating treatment [3]. It is therefore of great interest in the scientific community to examine other methods of infectious disease prevention and treatment. Since the introduction of the GAIN Act in 2012, there has been new stimulated interest in the battle against bacteria, however no significant strides have been made yet [3]. Growing resistance to antibiotics continues to be a devastating public health problem. Attempts to tackle the problem involve research teams at the Massachusetts Institute of Technology (MIT) who utilize a type of phage therapy to target antibiotic resistance genes directly via the CRISPR (clustered, regularly interspaced short palindromic repeats) Cas9 gene editing technology [3]. The engineered phage (a phage is a virus which infects bacteria) delivers the CRISPR Cas9 RNA tool into resistant bacteria, resulting in genomic expression of the CRISPR Cas9 tool which then programs the bacteria to either become sensitive to drugs or to undergo lysis [4]. The CRISPR Cas9 tool encodes a DNA nuclease (DNA degrading enzyme) that recognizes and cleaves specific genes which code for antibiotic resistance [3]. The phage tool selectively kills bacteria with chromosomally integrated resistance genes, while bacteria with plasmid-integrated resistance genes become sensitive and continue to survive, adding a selective pressure which favors sensitive bacteria to resistant bacteria [4]. The surviving bacteria can then be effectively treated with antibiotics. Ironically, the CRISPR Cas9 system is a part of bacteria’s natural immune defense against phage attacks [3]. While this tool seems very promising in research, gene therapy is very difficult to implement and apply. Furthermore, it does not prevent the development of antibiotic resistance; there will always be too great a pressure for bacteria to evolve further resistance and survive. The common solution to prevent pathogenic infections tends to rely on organic disinfectants or drugs, however this solution may lead to drug resistance and can harm the environment. Since about 80% of microbes are transmitted through surface contact, another approach to preventing the spread of harmful microbes is to develop surface technology which not only is bactericidal, but also overcomes the concern of drug resistance and is safe environment [5]. Naturally occurring structures can serve as templates for such bactericidal applications. It has been reported that the nanoscale structure of dragonfly wings may serve as a bactericidal surface [6]. Their natural structure can rupture adjacent microbial cells thereby killing and preventing bacterial growth. These organic templates can be reproduced synthetically and applied to the development of microbicide technologies. It has been observed that the interaction between synthetic nanoparticles and biological cells can be enough to cause cell lysis and death without any other external forces, chemical nor mechanical [7]. This idea is a promising opportunity for the development of novel bactericidal surface technologies which are effective and safe. Nanomaterials have the capacity to enhance the field of science that relies on public health and sterility, from water treatments, medical devices, and food processing [8]. Metal oxide nanoparticles such as zinc oxide and copper oxide exhibit antimicrobial behavior at different degrees in a variety of materials, forms, and morphologies [6]. The functional activity of nanoparticles is affected by material size, shape, and morphology. Analyzing and characterizing the effects of nanoparticles of varying properties is of current interest in research for biomedical and industrial applications. Medical devices may harbor harmful bacteria which can be deadly for an immune compromised or elderly patient [2]. Bacteria can produce highly resistant biofilms which allow them to survive on such surfaces for long lengths of time. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are commonly acquired hospital infections that may cause deadly bloodstream, urinary tract, lung, heart, and skin infections [9]. These microbes can be very resistant to conventional antibiotics, requiring the need for novel methods of reducing microbial infections. Metallic nanoparticles have been reported to show antimicrobial activity especially towards pathogenic bacteria such as E. coli and S. aureus [7] [10]. Antimicrobial effects of the nanoparticle depend on the particle size, stability, and concentration; with the right preparation and application, these particles can hold a promising future in safely reducing infection. Furthermore, graphene based nanomaterials show promising development in the antimicrobial community [6]. Graphene materials have been shown to interact with biomolecules such as proteins, nucleic acids and membranes; these material-microbial interfaces are worthy of analysis in order to further understand the beneficial application of such materials [6]. Here, an economical, scalable and facile sol-gel method to synthesize a metallic copper nanoparticle embedded carbon matrix material (CMAT) is described. Furthermore, CMAT’s antimicrobial potential is investigated. CMAT possesses hydrophobic properties as well as high flame resistivity and a high absorption ability of oils. These properties generate a spectrum of prospective CMAT applications ranging from environmental decontamination, biomedical antimicrobial coatings, storage solutions, and air filters.