Browsing by Subject "Antibacterial"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    The antibacterial effect of a radiopaque double antibiotic paste against both an established multispecies and a single enterococcus faecalis biofilm
    (2019) Haslam, Bryce S.; Spolnik, Kenneth J.; Ehrlich, Ygal; Gregory, Richard L.; Bringas, Josef; Warner, Ned A.
    For regenerative endodontic procedures (REPs) to be successful an elimination of bacteria from the root canal system must be accomplished. Many different medicaments with antibacterial properties have been used to obtain complete disinfection. Double antibiotic paste (DAP) containing a mixture of ciprofloxacin and metronidazole has been shown to be a promising intracanal medicament. The addition of a radiopaque filler such as zirconium oxide to DAP may affect the antibacterial properties of DAP as well as allow precise placement and radiographic visualization of its position in the canal system. The aim of the proposed study was to evaluate the direct antibacterial properties of zirconium oxide radiopacifier combined with DAP (RoDAP) against a multispecies biofilm from a bacterial isolate from an infected immature tooth with a necrotic pulp and a known single species biofilm. 4x4 mm radicular dentin specimens (n = 112) obtained from human extracted teeth were used prepared and sterilized prior to use. A multispecies clinical bacterial isolate from an immature tooth with a necrotic pulp and a single species Enterococcus faecalis isolate were obtained. These bacterial isolates were used to inoculate dentin slabs and grown for 3 weeks. The dentin slabs were treated for 1 week with 1.0-mg/mL and 10- mg/mL RoDAP, 1.0-mg/mL DAP, and two placebo pastes consisting of methyl cellulose (MC) and methyl cellulose combined with zirconium oxide (RoMC), respectively, as well as two no-treatment controls. Following treatment, the grown biofilm was detached and spiral plated. The plated biofilm cells were cultured for 24 hours and each group examined using a colony counter to determine bacterial numbers (CFUs/mL). Data analysis, using a 5.0-percent significance level was conducted using one-way ANOVA followed by pair-wise group comparisons. Both 1.0-mg/mL and 10 mg/mL RoDAP demonstrated significant antibacterial effects against bacterial isolates from an immature tooth with a necrotic pulp as well as an E. faecalis isolate. The precise application of RoDAP confirmed radiographically with its direct antibacterial properties may be beneficial for intracanal disinfection during REPs.
  • Thumbnail Image
    Item
    Expanding Access to Novel Antibacterial Therapeutics in Low- and Middle-Income Countries: Leveraging Donor-Funded Pooled Procurement
    (2024-07) Swenson, Jessica Emily; Archer, Sarah E.; Coburn, Kenneth; Houchens, Christopher
    Antibiotics are one of the most significant advances of modern medicine, however, bacteria continue to evolve faster than new antibacterials are being developed. In 2019, 1.27 million deaths were directly attributable to bacterial antimicrobial resistance (AMR) globally—more than either HIV or malaria that year—with the highest death rates occurring in low- and middle-income countries (LMICs) (Murray et al., 2022). Because of limited returns on investment, multinational pharmaceutical companies have largely abandoned antibacterial development. This void has been filled by smaller product developers vastly located in the United States and Europe who have limited resources and experience in seeking licensure and commercialization in LMICs, where the need is greatest (WHO, 2021). When these smaller developers only seek regulatory approval in the high-income countries where they are located, they often cannot sell enough of their product to avoid bankruptcy because of the low volume of patients with susceptible infections there (Alm & Gallant, 2020). Building on the current body of literature, this study assessed the factors necessary to leverage an existing donor-funded pooled procurement strategy to expand its scope to include novel antibacterial therapeutics, with the goal of expanding access to these products in LMICs. Market access expansion would bring new products to patients where they are needed most while also ensuring financial viability for developers of novel antibacterials who struggle to retain financial solvency. A qualitative case study gathering expertise from individuals familiar with current procurement practices for novel antibacterials and donor-funded global procurement strategies for other infectious disease therapeutics elucidated that the Global Drug Facility (GDF) is the entity best positioned to expand scope to include novel antibacterials for AMR. An eight-stage action plan was developed to provide recommended actions, resource needs, measures of success, and an anticipated timeline over the next decade for GDF and a consortium of technical partners to implement the scope expansion. By pairing a market-driven access expansion initiative with a pragmatic approach to support financial sustainability of product developers, these critical medicines can be available for patients globally, and the AMR pipeline can support the demand for new antibacterials for decades to come.
  • Thumbnail Image
    Item
    An improved dental composite with potent antibacterial function
    (Elsevier, 2019-07) Almousa, Rashed; Wen, Xin; Anderson, Gregory G.; Xie, Dong; Biomedical Engineering, School of Engineering and Technology
    A new BisGMA-based antibacterial dental composite has been formulated and evaluated. Compressive strength and bacterial viability were utilized to evaluate the formed composites. It was found that the new composite exhibited a significantly enhanced antibacterial function along with improved mechanical and physical properties. The bromine-containing derivative-modified composite was more potent in antibacterial activity than the chlorine-containing composite. The modified composites also exhibited an increase of 30–53% in compressive yield strength, 15–30% in compressive modulus, 15–33% in diametral tensile strength and 6–20% in flexural strength, and a decrease of 57–76% in bacterial viability, 23–37% in water sorption, 8–15% in shrinkage, 8–13% in compressive strength, and similar degree of conversion, than unmodified composite. It appears that this experimental composite may possibly be introduced to dental clinics as an attractive dental restorative due to its improved properties as well as enhanced antibacterial function.
  • Thumbnail Image
    Item
    A self-cured glass-ionomer cement with improved antibacterial function and hardness
    (Wiley, 2020) Chen, Yong; Caneli, Gulsah; Almousa, Rashed; Hill, Kayla; Na, Sungsoo; Anderson, Gregory G.; Xie, Dong; Biology, School of Science
    A novel antimicrobial dental self-cured glass-ionomer cement has been developed and evaluated. Alumina filler particles were covalently coated with an antibacterial polymer and blended into a self-cured glass-ionomer cement formulation. Surface hardness and bacterial viability were used to evaluate the modified cements. Results showed that the modified cements exhibited a significantly enhanced antibacterial activity along with improved surface hardness. Effects of antibacterial moiety content, alumina particle size and loading, and total filler content were investigated. It was found that increasing antibacterial moiety content, particle size and loading, and total filler content generally increased surface hardness. Increasing antibacterial moiety, filler loading and total filler content increased antibacterial activity. On the other hand, increasing particle size showed a negative impact on antibacterial activity. The leaching tests indicate no cytotoxicity produced from the modified cements to both bacteria and 3T3 mouse fibroblast cells.