Surface-modified nanocarriers in the design of targeted drug delivery systems for parasitic diseases: a comprehensive review.

Parasitic diseases such as malaria, leishmaniasis, and schistosomiasis remain difficult to treat due to the pathogens' complex life cycles, intracellular niches, and resistance to conventional therapies. Traditional drug delivery methods often lack specificity, resulting in limited efficacy and off-target effects. Recent advances in nanotechnology, especially surface-modified nanocarriers, offer a promising solution by enabling targeted, site-specific delivery and improved therapeutic outcomes. This review explores the design principles, surface functionalisation strategies, and therapeutic applications of nanocarriers in treating parasitic diseases. The main nanocarrier platforms discussed include liposomes, polymeric nanoparticles, and micelles. It focuses on surface modifications such as PEGylation, ligand conjugation, and antibody attachment. These alterations enhance drug specificity, prolong circulation time, and reduce systemic toxicity. Additionally, we address key challenges, including scalability, regulatory concerns, and limited clinical validation. Although surface-modified nanocarriers demonstrate promise in preclinical settings, their clinical application remains limited. Future efforts should aim to enhance large-scale manufacturing, conduct long-term safety evaluations, and standardise regulatory procedures. By summarising recent advances, challenges, and future opportunities, we highlight the vital role of surface-engineered nanocarriers in improving parasitic disease management and emphasise the need for ongoing research to translate laboratory success into clinical practice.