EVQ-218 performance data: Peer-reviewed and independently validated
Published in ACS Omega and Antibiotics. Independently tested at Seattle Children's Research Institute, Charles River, Lovelace Biomedical, and Nelson Laboratories.
Technology overview
EVQ-218 demonstrates particle uniformity and morphological consistency on par with NIST standard reference materials. Published research shows EVQ-218 maintains long-term stability without silver ion emission in aqueous environments.
Shape
The spherical particles exhibit an ultrastable shell structure, as characterized by STEM-EELS analysis in published research. This unique architecture is linked to non-emissive behavior, differing markedly from traditional nanosilver species that undergo oxidative layer formation and subsequent ion emission.
Stability
EVQ-218 demonstrates long-term stability in solution, maintaining particle uniformity for extended periods, as detailed in published research. Comprehensive stability studies confirm the retention of its non-emissive properties throughout multi-year storage under various conditions.
Size
The resulting particle size distribution is narrow and consistent, as evidenced by detailed characterization in published research. This uniformity ensures reliable performance in applications, avoiding the variability often seen in conventional nanosilver materials.
Scalability
Patented high-energy laser ablation manufacturing enables the production of high-purity silver metamaterial at a fraction of the cost of conventional methods, as validated in published research. This scalable process delivers superior quality and consistency while dramatically reducing production expenses compared to traditional nanosilver synthesis techniques.
EVQ-218 is not a traditional silver nanoparticle. EVQ-218 is a novel metamaterial, recognized by the American Chemical Society as a new form of silver. EVQ-218 is stable and has long-lasting antimicrobial characteristics that exhibits no cytotoxicity.
Antimicrobial test data
EVQ-218 has been tested against many deadly pathogens with extremely promising results. Certified laboratory assays demonstrate ≥4-log reduction of select drug-resistant bacterial strains (e.g., MRSA, P. aeruginosa) using EVOQ platform technology across multiple application methods.
Material application methods and testing results
| Application method | Sample | Pathogen | Protocol | Innoculation | Log reduction | Chart |
|---|---|---|---|---|---|---|
| Heat or UV-cured coating | UV-cured hydrophilic coated filaments | MRSA | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Heat or UV-cured coating | Thermal cured hydrophilic coated filaments | Pseudomonas aeruginosa | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Heat or UV-cured coating | UV-cured hydrophilic coated filaments | Pseudomonas aeruginosa | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Heat or UV-cured coating | Thermal cured hydrophilic coated filaments | Staphylococcus aureus | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Heat or UV-cured coating | UV-cured hydrophilic coated filaments | Staphylococcus aureus | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Pellet treatment | Midline Catheters | Pseudomonas aeruginosa | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Pellet treatment | Midline Catheters | Staphylococcus aureus | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Surface infusion | EVQ-218 infused filaments | MRSA | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Surface infusion | EVQ-218 infused filaments | Pseudomonas aeruginosa | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Surface infusion | MicroClave – ICU Medical | Pseudomonas aeruginosa | 3BSA – Contact-based surface antimicrobial test | 10^6 | 4+ | |
| Surface infusion | Ureteral Stents | Pseudomonas aeruginosa | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Surface infusion | EVQ-218 infused filaments | Staphylococcus aureus | Certika Biofilm and Proliferation Assay | 10^6 | 3 | |
| Surface infusion | MaxZero - BD | Staphylococcus aureus | 3BSA – Contact-based surface antimicrobial test | 10^6 | 3.3 | |
| Surface infusion | Ureteral Stents | Staphylococcus aureus | Certika Biofilm and Proliferation Assay | 10^6 | 3 | |
| Surface infusion | Film for platelet/blood bags | Staphylococcus epidermidis | ISO22196 | 10^8 | 4+ | |
| Synthesis phase | TPU film for various devices | Escherichia coli | ISO22196 | 10^4 | 4+ | |
| Synthesis phase | TPU film for various devices | Staphylococcus aureus | ISO22196 | 10^4 | 4+ | |
| Heat or UV-cured coating | UV-cured hydrophilic coated filaments | Escherichia coli | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Surface infusion | Midline Catheters | Escherichia coli | Certika Biofilm and Proliferation Assay | 10^6 | 4+ | |
| Surface infusion | EVQ-218 infused filaments | Escherichia coli | Certika Biofilm and Proliferation Assay | 10^6 | 4+ |
Species breakdown - MIC ranges by drug resistance status
| Pathogen Species | Type | Gram Status | Total Strains | Resistant Strains | Non-Resistant MIC Range (µg/mL) | Resistant MIC Range (µg/mL) | AVG MIC |
|---|---|---|---|---|---|---|---|
| Pseudomonas aeruginosa | Bacteria | Gram negative | 7 | 7 | 0.75-0.75 | 0.25-1 | 0.63 |
| Achromobacter xylosoxidans | Bacteria | Gram negative | 4 | 0 | 0.025-0.75 | N/A | 0.26 |
| Stenotrophomonas maltophilia | Bacteria | Gram negative | 4 | 0 | 0.25-0.5 | N/A | 0.44 |
| Burkholderia cenocepacia | Bacteria | Gram negative | 3 | 0 | 0.125-0.25 | N/A | 0.17 |
| Burkholderia gladioli | Bacteria | Gram negative | 2 | 0 | 0.06-0.125 | N/A | 0.09 |
| Burkholderia multivorans | Bacteria | Gram negative | 2 | 0 | 0.125-0.125 | N/A | 0.13 |
| Haemophilus influenzae | Bacteria | Gram negative | 2 | 0 | 0.25-0.25 | N/A | 0.25 |
| Burkholderia cepacia | Bacteria | Gram negative | 1 | 0 | 0.13 | N/A | 0.125 |
| Burkholderia dolosa | Bacteria | Gram negative | 1 | 0 | 0.25 | N/A | 0.25 |
| Burkholderia vietnamiensis | Bacteria | Gram negative | 1 | 0 | 0.25 | N/A | 0.25 |
| Staphylococcus aureus | Bacteria | Gram positive | 17 | 7 | 1-16 | 2-16 | 5.63 |
| Mycobacterium abscessus/massiliense | Bacteria | Gram positive (Acid-fast) | 9 | 0 | 7.5-10 | N/A | 8 |
| Mycobacterium avium complex | Bacteria | Gram positive (Acid-fast) | 3 | 0 | 2.5-10 | N/A | 5.42 |
| Mycobacterium abscessus subsp. abscessus | Bacteria | Gram positive (Acid-fast) | 1 | 0 | 10.00 | N/A | 10 |
| Mycobacterium smegmatis | Bacteria | Gram positive (Acid-fast) | 1 | 0 | 0.75 | N/A | 0.75 |
| Aspergillus fumigatus | Fungus | N/A | 2 | 0 | 2.5-2.5 | N/A | 2.5 |
| Scedosporium apiospermum | Fungus | N/A | 1 | 0 | 0.50 | N/A | 0.5 |
| Candida albicans | Yeast | N/A | 1 | 0 | 0.13 | N/A | 0.125 |
| Candida parapsilosis | Yeast | N/A | 1 | 0 | 0.13 | N/A | 0.125 |
| Pichia angusta | Yeast | N/A | 1 | 0 | 0.50 | N/A | 0.5 |
Cytotoxicity
ISO 10993-5 MEM Elution cytotoxicity test
An independent ISO 10993-5 MEM elution cytotoxicity study performed by NAMSA (Minneapolis, MN) confirmed that EVQ-218-T and EVQ-218-T/IPA release no detectable cytotoxic leachables. A single extract was prepared in Eagle’s Minimal Essential Medium + 5% FBS at 37 °C for 24 hours and applied to triplicate monolayers of L-929 mouse fibroblasts for 48 hours. Microscopic evaluation showed no evidence of cell lysis or morphological changes (reactivity grade 0 in all replicates), identical to the negative and reagent controls. The test article fully satisfied the ISO 10993-5 acceptance criterion of ≤ grade 2 (mild reactivity), demonstrating that EVQ-218 silver antimicrobial particles are non-cytotoxic under standard medical-device extraction conditions.
| Test/Control Article | Replicate | Reactivity Grade | Description | Overall Result |
|---|---|---|---|---|
| EVQ218-T & EVQ218-T/IPA | 1–3 | 0 | No cell lysis, no morphological changes | Non-cytotoxic |
| Negative control (USP) | 1–3 | 0 | No reactivity | Pass |
| Reagent control | 1–3 | 0 | No reactivity | Pass |
| Positive control | 1–3 | 4 | Nearly complete lysis | Pass (validation) |
Key findings:
- Reactivity Grade : 0 (none) across all three replicates – no evidence of cell lysis or toxicity
- Morphological Response : Identical to negative and reagent controls; no abnormal cell morphology or degeneration observed in L-929 mouse fibroblast monolayers after 48-hour exposure
- Acceptance Criterion Met : Grade ≤ 2 (mild reactivity) per ISO 10993-5 and BS EN ISO 10993-5 – test article fully compliant
- Conclusion : EVQ218-T and EVQ218-T/IPA extracts are non-cytotoxic under standard medical-device elution conditions (24 h extraction at 37 °C in EMEM + 5 % FBS)
Inhalation toxicology test
A nose-only inhalation toxicity study conducted at Lovelace Biomedical (Albuquerque, NM) established the safety of EVQ-218 silver antimicrobial particles via the pulmonary route. Sprague-Dawley rats underwent single-exposure and 7-day repeated-exposure regimens at aerosol concentrations up to 5.0 mg/m³ (presented dose ≥0.143 mg/kg/day; estimated deposited lung dose ≥0.0143 mg/kg/day). No clinical signs of toxicity, body-weight effects, gross pathology, or histopathological changes were observed in the respiratory tract or any other organ at any dose level. The study defined both the maximum tolerated dose (MTD) and no-observed-adverse-effect level (NOAEL) as ≥5.0 mg/m³, demonstrating a wide safety margin relative to the antimicrobial MIC values (typically 0.5–10 µg/mL) required for pulmonary applications.
| Group | Target Concentration (mg/m³) | Presented Dose (mg/kg/day) | Deposited Dose* (mg/kg/day) | Duration |
|---|---|---|---|---|
| 1 | 0.5 | 0.014 | 0.0014 | Single & 7-day repeat |
| 2 | 2.0 | 0.057 | 0.0057 | Single & 7-day repeat |
| 3 | 5.0 | 0.143 | 0.0143 | Single & 7-day repeat |
Key findings:
- Maximum Tolerated Dose (MTD) : >5.0 mg/m³ (highest dose tested) – no clinical signs of toxicity, no body-weight loss, no gross or microscopic pathology in lungs, trachea, or nasal passages after single or 7-day repeated exposure.
- No-Observed-Adverse-Effect Level (NOAEL) : ≥5.0 mg/m³ (≥0.143 mg/kg/day presented, ≥0.0143 mg/kg/day deposited) for both single and 7-day repeat nose-only inhalation.All clinical pathology, organ weights, and histopathology were within normal limits at all dose levels.
Study design and methodology
Independent testing follows OECD guidelines (OECD 436 for acute, OECD 412 for repeat-dose). Sprague-Dawley rats receive nose-only inhalation exposure to aerosolized EVQ-218. Dosimetry calculations account for presented dose (100% deposition fraction) and deposited dose (10% deposition fraction, based on respiratory physiology). Bronchoalveolar lavage (BAL) fluid analysis, lung burden measurements, and full histopathology assess inflammation, particle retention, and tissue response.
Drug resistance test results
Serial passage resistance assessment of EVQ-218
Serial passage assays are a widely accepted in vitro method for evaluating whether repeated exposure to an antimicrobial agent leads to adaptive changes in bacterial susceptibility. These assays involve exposing bacterial populations to sub-inhibitory concentrations of an agent across multiple sequential passages and monitoring changes in minimum inhibitory concentration (MIC) over time. Two independent serial passage studies were conducted to evaluate susceptibility trends associated with EVQ-218 exposure across clinically relevant, antibiotic-resistant organisms.
Study design summary
The baseline 30 passage test used the same concentration of bacteria at each passage. The enhanced 20 passage test used a concentration of bacteria that increased at each passage exposure.
| Study | Duration | Exposure Strategy | Pathogen Panel | Key Observation |
|---|---|---|---|---|
| Baseline Serial Passage | 30 passages (30 days) | Constant sub-lethal concentration (0.156 µg/mL) | Full ESKAPE panel (ATCC strains) | MICs remained stable across all organisms |
| Enhanced Serial Passage | 20 passages (20 days) | Stepwise concentration escalation (0.5 → 4 µg/mL) | Full ESKAPE panel (ATCC strains) | No adaptive MIC shifts detected |
Pathogens evaluated
The studies focused on ESKAPE pathogens, which are recognized as a critical group of antibiotic-resistant bacteria:
- Enterococcus faecium
- Staphylococcus aureus
- Klebsiella pneumoniae
- Acinetobacter baumannii
- Pseudomonas aeruginosa
- Enterobacter cloacae
Across all organisms tested, susceptibility to EVQ-218 remained unchanged from the initial passage through the final passage.
Selected MIC outcomes
Representative MIC data from both studies are shown below to illustrate susceptibility trends across multiple organisms. No increases in MIC were observed for any organism evaluated across either study.
| Organism | Initial MIC (µg/mL) | Final MIC (µg/mL) | Interpretation |
|---|---|---|---|
| E. faecium | 5.0 | 12.5 | Susceptibility |
| S. aureus | 5.0 | 2.5 | Increased susceptibility observed |
| K. pneumoniae | 1.25 | 1.25 | Stable susceptibility |
| A. baumannii | 2.5 | 2.5 | Stable susceptibility |
| P. aeruginosa | 0.625 | 0.625 | Stable susceptibility |
| E. cloacae | 2.5 | 2.5 | Susceptibility |
Comparative Context
Parallel serial passage assays using conventional antibiotics under comparable conditions demonstrated measurable increases in MIC within approximately 10 passages or less. Under the same experimental framework, EVQ-218 exposure did not result in detectable adaptive shifts in susceptibility after up to 30 passages in the baseline study and 20 passages in the enhanced study.
Interpretation
The absence of MIC increases across prolonged and enhanced serial passage conditions indicates sustained antimicrobial activity of EVQ-218 under in vitro testing conditions. Observed susceptibility stability may be associated with EVQ-218’s non-ionic silver metamaterial structure and its interaction with multiple bacterial targets. Mechanistic investigations are ongoing.
Additional testing: Encrustation
EVOQ platform technology has also shown tremendous promise in these early tests for anti-encrustation and anti-thrombogenic properties beyond antimicrobial efficacy.
Encrustation testing summary
Encrustation was evaluated on the outer surface of a device w/ EVQ-218. The procedure was done in a stationary condition for 24 h at 37.5 C. Samples were submerged in 60 mL of 1.5x concentration of artificial urine (Formulation 1 from ASTM F1828-97).
Methodology:
- 2 groups were evaluated:
- Untreated controls
- Filaments w/ EVQ-218 samples as the test subject
- Encrustation was investigated visually though time laps recording to observe any change in the amount of crystals formed on the surface of the stent.
- SEM imaging using FEI Teneo device was used to investigate changes in the shape and morphology of the formed crystals.
Encrustation with EVQ-218
EVOQ metamaterial, along with its antimicrobial properties, has shown promise in providing nucleation sites for smaller crystals. This development in current testing demonstrates significant reduction in crystal formation confirmed via SEM imaging.
Encrustation without EVQ-218
Without EVOQ metamaterial, crystals can form anywhere and are uncontrolled. These larger, more invasive crystal formations are very problematic, especially with consideration to ureteral stents.
Third-party validations and publications
EVOQ platform technology gains endorsement from leading organizations and journals.
- Cystic Fibrosis Foundation Grant : In vitro efficacy against 60+ CF isolates, no resistance.
- American Chemical Society (ACS Omega) : EVQ-218 as a new form of silver.
- Lovelace Biomedical: Animal toxicity study
- Seattle Children's Hospital: In vitro antimicrobial susceptibility testing.
- Galbraith Laboratories, Inc.: ICP-MS analyses of animal study to verify exposure levels, TK values, and relevant tissue levels.