Inhaled Nanosilver Study

This is a single-center, single-arm pilot study to assess the impact of inhaled silver
nanoparticles (nanosilver or nAg) on immune responses in the lung. Non-smoking, healthy
adults (no lung or cardiovascular conditions), age 18-60 will be recruited to participate;
pregnant or breastfeeding women will be excluded.

Potential participants will be prescreened by telephone and scheduled for a final eligibility
visit that will include vital signs/anthropometry, medical/medication history review,
physical exam, urine tests, blood draw, urine collection, and pulmonary function tests (PFTs;
i.e., spirometry and methacholine challenge test). After eligibility is confirmed, the
participant will be scheduled for a baseline visit, which includes vital signs/anthropometry,
medical/medication history review, physical exam, blood draw, urine collection, and
bronchoscopy (with lavage and brushing). Participants will return 14-40 days between the
baseline visit and study treatment visit, which includes vital signs/anthropometry, blood
draw, urine collection, spirometry, one-time administration of ionic silver via nebulizer,
and instructions to collect urine for 24 hours. The next day after the study treatment visit,
the participant will return for a visit that includes vital signs/anthropometry, blood draw,
providing the 24-hour urine sample, spirometry, and bronchoscopy. During each bronchoscopy
procedure, bronchoalveolar lavage (BAL) fluid and tissue from bronchial brushings will be
collected from the participant to obtain alveolar macrophages and bronchial epithelial cells.

The primary objective of the study is to determine whether exposure to nanosilver alters the
immune responses of lung cells. The primary laboratory analysis will determine whether
exposure to nanosilver mediates a change from baseline in the response of
bronchoscopy-derived, cultured macrophages or epithelial cells to challenge with a toll-like
receptor (TLR) agonist. Additional analyses will assess changes in cytokine levels in BAL
fluid, changes in the lung microbiome, silver penetration into the blood stream, silver
excretion in the urine, and changes in PFT measures.

- INCLUSION CRITERIA:

Participants must meet all of the following criteria for enrollment:

1. Age 18 to 60 years (males and females)

2. Able to understand and provide written consent

3. Able to travel to the NIEHS CRU for required study visits

4. Able to present a valid government-issued form of identification for entry to the
NIEHS campus

5. Able to fast for 6 hours prior to two visits where bronchoscopy occurs

EXCLUSION CRITERIA:

Participants meeting any of the following criteria at screening will not be eligible for
enrollment:

1. Women who are pregnant or breastfeeding

2. Current smoker or significant second-hand smoke exposure (defined by urine cotinine
>200 ng/mL at screening)

3. Body Mass Index (BMI) >35

4. Significant sources of exposure to silver that, in the investigator's opinion, will
compromise the integrity of the study assessments (e.g., regular use of
silver-containing dietary supplements, homeopathic remedies, or cleaning products)

5. FEV1 <80% predicted; or, positive methacholine test [i.e., provocative concentration
of methacholine producing a 20% fall in FEV1 (PC20-FEV1) is reached at a solution of
less than or equal to 4 mg/mL]

6. History of pulmonary or cardiovascular conditions, including the following
comorbidities: chronic obstructive pulmonary disease, cystic fibrosis (CF), non-CF
bronchiectasis, pulmonary fibrosis, sarcoidosis, pulmonary hypertension, unstable
angina

7. Allergy or history of adverse reactions to metals

8. Any condition that, in the investigator's opinion, places the patient at undue risk
for complications associated with required study procedures

9. Bleeding disorders

10. Facial deformity, major facial surgery

11. Allergy or history of adverse reactions to methacholine or lidocain (or other similar
topical anesthetics)

12. Temperature >37.6 C, blood pressure <90/50 or >170/95 mmHg, or pulse rate <50 or >100
beats/minute (if in the investigator s clinical judgment, the exclusionary
condition(s) may resolve, the candidate may be rescreened at a later date)

13. Body weight <50 kg (<110 lbs)

14. The following abnormal lab values on the screening blood work:

- Platelet count <100,000/microliters

- White blood cells count less than or equal to 1000/microliters

- Absolute neutrophil count less than or equal to 500/microliters

- Hematocrit <35% for both female and male

- Hemoglobin less than or equal to 9 g/dL

- Prothrombin Time (PT) / International Normalized Ratio (INR) greater than or
equal to 1.3

- Activated partial prothromboplastin time (aPTT) greater than or equal to 40
seconds

- Serum creatinine greater than or equal to 1.4 mg/dL