Comparison between AuNP and TiO2NP Nanocarriers for the Treatment of Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is one of the most fatal diseases in the world, leading to lung tissue damage and persistent inflammation. Patients with COPD are typically treated with a bronchodilator and steroids to alleviate bronchoconstriction and inflammation; however, the steroids have limited effects. Inhaled nanomedicine utilizes small agents that facilitate pulmonary-targeted delivery, which improves the absorption and potency of the medication. Over a century ago, Paul Ehrlich proposed the 'magic bullet' theory—targeting diseases precisely while minimizing side effects. Recently, nanomedicine has emerged to support Ehrlich’s theory by fostering nanoparticle drug delivery systems, such as gold (AuNPs) and titanium dioxide nanoparticles (TiO2NPs). Thus, this literature review aims to analyze and compare gold and titanium dioxide nanoparticles as carriers for COPD treatment for pulmonary and systemic applications. An analysis of over 60 PubMed research studies from the last twenty years compared the biodistribution, immunotoxicity, inflammation-causing abilities, and cellular interactions of AuNPs and TiO2NPs. The findings suggest that positively charged, small AuNPs are distributed and cleared quicker than other nanoparticles. However, smaller AuNPs can also cause toxic effects in the digestive and vascular systems. In contrast, TiO2NPs have been shown to cause strong pulmonary inflammation with immune cell accumulation, which occurs through repeated exposure and correlates with size and agglomeration. Ultimately, both AuNPs and TiO2NPs have benefits, but AuNPs demonstrate greater potential for safe and effective COPD treatment, promoting further clinical trials and research on their targeted drug deliveries.