Mapping global research landscape and trend of nano-drug delivery system for urological cancers: a bibliometric analysis

<b>Aim:</b> We conducted a bibliometric analysis to quantitatively study the development pathway, research hotspots and evolutionary trends of nano-drug delivery systems (NDDS) in treating urological tumors. <b>Materials &amp; methods:</b> We used the Web of Science Core Collection to retrieve the literature related to NDDS in the urological tumors up to November 1, 2023. Bibliometric analysis and visualization were conducted using CiteSpace, VOSviewer and R-Bibliometrix. The major aspects of analysis included contributions from different countries/regions, authors' contributions, keywords identification, citation frequencies and overall research trends. <b>Results:</b> We included 3,220 articles. The analysis of annual publication trends revealed significant growth in this field since 2010, which has continued to the present day. The United States and China have far exceeded other countries/regions in the publication volume of papers in this field. The progression of the shell structure of NDDS in the urinary system has gradually transitioned from non-biological materials to biocompatible materials and ultimately to completely biocompatible materials. Mucoadhesive NDDS for intravesical drug delivery is a hotspot and a potential research material for bladder cancer. <b>Conclusion:</b> The field of NDDS in urological tumors has emerged as a research hotspot. Future research should focus on synergistic effects of NDDS with other treatment modalities. NDDS studies for prostate, kidney and bladder cancers began to increase around 2010 and the number of studies has subsequently shown a steady increase. The United States and China have made major contributions to NDDS research in urologic tumors, including prostate, kidney, bladder, testicular and penile cancers. In the field of prostate cancer NDDS research, the largest research cluster was magnetic nanoparticles, while drug delivery represented an ongoing theme of research. The progression of the shell structure of NDDS in the urinary system has gradually transitioned from non-biological materials to biocompatible materials and ultimately to completely biocompatible materials. Early research in this field of renal cancer NDDS focused on cancer chemotherapy, cells, cytotoxicity, apoptosis and tissue distribution, whereas more recent studies have primarily concentrated on kidney microenvironment and survival benefits. Bladder cancer-related NDDS studies have focused on their penetration of the urinary epithelium and the retention time of therapeutic agents in the bladder. The evolution of NDDS is a significant hallmark of the continuous progress and optimization in the field of drug delivery, providing novel insights and directions for future drug development and therapy. A combination of multimodal synergistic therapy of NDDS with dynamic therapies or with radiotherapy, chemotherapy, immunotherapy and other treatment modalities could bring breakthroughs to treating urological tumors.