The antimicrobial efficacy of zinc doped phosphate-based glass for treating catheter associated urinary tract infections

Calcium phosphate glasses are a promising new generation of biomaterials that can simultaneously induce tissue regeneration and controlled release of therapeutic molecules. In this work, novel calcium phosphate glasses containing 0, 2, 4, and 6 mol % Cu 2+ were synthesized via room temperature precipitation reaction in aqueous solution. The effect of Cu 2+ addition on the glass properties and structure was investigated using thermal analysis, 31 P solidstate MAS NMR, Raman spectroscopy, and X-ray diffraction. All glasses crystallize at temperature >500°C and are mainly formed by Q 1 groups. The release of P, Ca, and Cu in solution over time was monitored via inductively coupled plasma-optical emission spectroscopy. It was found that with increasing Cu content, the amount of P and Ca released decreases whereas the amount of Cu released increases. The effect of Cu 2+ release on the antibacterial activity against S. aureus, a bacterial strain commonly found in postsurgery infections, has been investigated. The addition of copper has been shown to infer the glasses antibacterial properties. As expected, the antibacterial activity of the glasses increases with increasing Cu 2+ content. Cytocompatibility was assessed by seeding human osteoblast-like osteosarcoma cells Saos-2 (HTB85) on the glass particles. A significant increase in cell number was observed in all the glasses investigated. The copper-doped calcium phosphate glasses have proven to be multifunctional, as they combine bone regenerative properties with antibacterial activity. Therefore, they have great potential as antibacterial bioresorbable materials for hard tissue regeneration.

Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Antibacterial Copper-Doped Calcium Phosphate Glasses for Bone Tissue Regeneration

Foroutan

McGuire

Gupta

et al. 2019

“…In our previous studies, we characterized sodium calcium phosphate glasses doped with 1, 3, 5, and 10% of CoO 1 and ZnO. 11 As expected, an increase in antimicrobial activity was observed with the increasing metal oxide content. A slight cytotoxicity was observed for glasses doped with 10% ZnO.…”

Section: Experimental Sectionsupporting

confidence: 60%

Synergistic Antimicrobial Metal Oxide-Doped Phosphate Glasses; a Potential Strategy to Reduce Antimicrobial Resistance and Host Cell Toxicity

Raja

Worthington

Souza

et al. 2022

Self Cite

The emergence of antimicrobial resistant strains bacteria and a decline in the discovery of new antibiotics has led to the idea of combining various antimicrobials to treat resistant strains and/or polymicrobial infections. Metal oxide-doped glasses have been extensively investigated for their antimicrobial potential; however to date, most experiments have focused on single metal species in isolation. The present study investigates the antimicrobial potential of sodium calcium phosphates (P 2 O 5 ) 50 (Na 2 O) 20 (CaO) 30– X (MO) X , where M is cobalt, copper, or zinc as single species. In addition, this work studied the effect of co-doping glasses containing two different metal ions (Co + Cu, Co + Zn, and Cu + Zn). The antimicrobial efficacy of all glasses was tested against Gram-positive ( Staphylococcus aureus ) and Gram-negative ( Escherichia coli ) bacterial strains, as well as a fungal strain ( Candida albicans ). Minimum inhibitory and bactericidal concentrations and time kill/synergy assays were used to assess the antimicrobial activity. An enhanced antimicrobial effect, at 5 mg/mL concentration, was exhibited by cobalt, copper, and zinc oxide glasses alone and in combinations. A synergistic antimicrobial effect was observed by Cu + Co and Cu + Zn against E. coli and Cu + Zn against S. aureus .

“…It should also be mentioned that Zn is a relatively harmless element; thus, many studies on synthetic Zn-substituted CPs report much higher levels of Zn doping with respect to physiological amounts . Different Zn-substituted CPs such as HAp, β-TCP, and monetite demonstrated superior biological performance; moreover, Zn ions are known for their antibacterial properties. − …”

Section: Introductionmentioning

confidence: 99%

Dissolution–Precipitation Synthesis and Characterization of Zinc Whitlockite with Variable Metal Content

Kizalaitė

Grigoravičiūtė-Puronienė

Stoll

et al. 2021

In the present work, a series of zinc whitlockite (Ca x Zn y (HPO 4 ) 2 (PO 4 ) 12 ) powders was synthesized by a low-temperature dissolution–precipitation process for the first time. The phase conversion from calcium hydroxyapatite to zinc whitlockite occurred in an acidic medium in the presence of Zn 2+ ions. Variable chemical composition of the synthesis products was achieved by changing Ca-to-Zn molar ratio in the reaction mixture. Investigation of the phase evolution as a function of time demonstrated that phase-pure zinc whitlockite powders can be synthesized in just 3 h. It is also demonstrated that single-phase products can be obtained when the Ca-to-Zn ratio in the reaction medium is in the range from 9 to 30. With higher or lower ratios, neighboring crystal phases such as scholzite or calcium hydroxyapatite were obtained. The morphology of the synthesized powders was found to be dependent on the chemical composition, transforming from hexagonal to rhombohedral plates with the increase of Zn content. Thermal stability studies revealed that the synthesized compounds were thermally unstable and decomposed upon heat treatment.