Platelets as circulatory drug carriers: Emerging potential and its advantages over conventional delivery systems

Traditional systemic drug delivery methods are often limited by faster clearance rates and high dose requirements. While innovative drug delivery systems, such as liposomes, polymersomes, and solid lipid nanoparticles etc., offer the ability to carry hydrophilic and hydrophobic drugs. But the lack of specificity in the current delivery systems leads to reduced therapeutic efficacy. To overcome these, functionalization with small molecules like peptides, aptamers, and antibodies is done. But they introduce new immunogenicity, stability, and complexity challenges, making these methods costly and less practical. To address these issues, circulatory cell-based drug delivery systems have gained attention as a promising alternative. Unlike red blood cells (RBCs), which have the Rh factor that can complicate, platelets are devoid of this factor and possess inherent advantages. Their natural properties, including non-immunogenicity, hemostasis, pathogen interaction, tissue regeneration, and wound healing, make them highly effective for targeted drug delivery. Furthermore, platelets can form leaky junctions at tumor sites, enhancing localized drug delivery and improving therapeutic outcomes. Thus, platelet-based drug delivery systems are gaining popularity. Moreover, the lower production costs make platelets an efficient and promising tool for a smart drug delivery system. This review highlights the significant role of platelets in advancing targeted drug delivery and their potential to revolutionize therapeutic strategies.