Pulmonary drug delivery is a well-suited approach for treating lung infections, providing direct and targeted treatment to infected cells. This method enhances drug concentration in the lungs while reducing the required dosage. However, the physiological characteristics of the lungs constitute a complex barrier to drug delivery. Conventional methods often underperform or fail completely, particularly with poorly soluble drugs and inhaled proteins. This thesis explores the use of mesoporous silica particles (MSPs) as sole excipient in dry powder formulations to improve the treatment of lung infections. This study investigated the use of micron-sized mesoporous silica particles (MSPs) as a drug vehicle for clofazimine (CLZ) to target the lung. In simulated lung fluid (SLF), CLZ was released from the MSPs and subsequently formed nanoparticles. This micro-nano strategy significantly enhanced both extracellular and intracellular bactericidal efficacy in relation to mycobacteria, demonstrating its potential for multidrug-resistant TB. This formulation ensured high local drug retention and minimal side effects, indicating that lower CLZ doses could be administered relative to current oral treatment while sustaining adequate antimicrobial concentrations in the lungs. A second study demonstrated the use of MSPs in formulating proteins, specifically lysozyme (LYS), as a dry powder inhaler (DPI), while also examining aerosolization and release profiles. The observed protein lung deposition and preserved enzymatic activity post-release underscored the versatility of MSPs in this therapeutic application. The toxicological effects of MSPs were evaluated, with a focus on whether silica with varying dissolution characteristics influences cell viability and drug release (CLZ). All types of soluble silica exhibited low immunological responses, emphasizing the potential and safety of amorphous silica for pulmonary drug delivery. A further innovation in this thesis was the design of bioinspired lung surfactantcoated MSPs, aimed at enhancing CLZ dissolution and improving particle interaction and transport in mucus and bronchial tissue. Finally, the MSPs coating concept was refined using bacterial lipids from mycobacteria to assess whether the antimicrobial activity of CLZ against mycobacteria could be improved, presenting a novel approach for treating lung infections. Overall, this thesis highlights the potential of bioinspired coated MSPs as an advanced drug delivery system to address unmet challenges in treating respiratory infections and in overcoming antimicrobial resistance.