Recent trends in mesoporous silica nanoparticles of rode-like morphology for cancer theranostics: A review

•The shape of nanoparticles is an important factor which affects the drug delivery efficiency.•RMSNs have shown improvements in the targeted delivery of biological agents compared to MSNs.•MSNs with a rode-like shape can be exploited for 3D tomography-based cancer diagnostic imaging.•Colloidal instability, water insolubility, inadequate drug loading capacity, uncontrolled release, and hemolysis may all restrict biomedical applications of RMSNs. The shape has become a determining factor that can tremendously affect drug delivery efficiency. Mesoporous silica nanoparticles (MSNs), and specifically rod-shaped mesoporous silica nanoparticles (RMSNs), have shown advancements in the targeted delivery of biological agents relative to spherical MSNs. These interesting multifunctional nanostructures have been broadly utilized for biological imaging, cancer treatment, and drug/gene delivery. Desirable biocompatibility, low density and toxicity, enhanced surface areas, and superior mechanical and thermal stability are all factors that make RMSNs a perfect nanostructure. The design of RMSNs with many compartments has progressed rapidly during the last decade. Different MSNs-based drug delivery approaches have recently emerged to deliver drugs into the target tissues via transcellular transport, treating various diseases, particularly prostate, lung, bladder, and other cancer types. These tailored nanoplatforms were mainly capped with a pH-sensitive gatekeeper and loaded with anticancer agents (i.e., doxorubicin) to reduce the toxicity of the entrapped drug. Moreover, it has been established that ultra-small nanoparticles within RMSNs can be used for diagnostic imaging of cancer using 3-D tomography. Herein, we discuss bioimaging, chemotherapy, phototherapy, targeted drug/gene delivery, and challenges of utilizing RMSNs as a promising strategy for cancer theranostics.