Recent Advances in Nanomaterials with Inherent Optical and Magnetic Properties for Bioimaging and Imaging-Guided Nucleic Acid Therapy

Advancements in Nanoporous Materials for Biomedical Imaging and Diagnostics

This review explores the latest advancements in nanoporous materials and their applications in biomedical imaging and diagnostics. Nanoporous materials possess unique structural features, including high surface area, tunable pore size, and versatile surface chemistry, making them highly promising platforms for a range of biomedical applications. This review begins by providing an overview of the various types of nanoporous materials, including mesoporous silica nanoparticles, metal-organic frameworks, carbon-based materials, and nanoporous gold. The synthesis method for each material, their current research trends, and prospects are discussed in detail. Furthermore, this review delves into the functionalization and surface modification techniques employed to tailor nanoporous materials for specific biomedical imaging applications. This section covers chemical functionalization, bioconjugation strategies, and surface coating and encapsulation methods. Additionally, this review examines the diverse biomedical imaging techniques enabled by nanoporous materials, such as fluorescence imaging, magnetic resonance imaging (MRI), computed tomography (CT) imaging, ultrasound imaging, and multimodal imaging. The mechanisms underlying these imaging techniques, their diagnostic applications, and their efficacy in clinical settings are thoroughly explored. Through an extensive analysis of recent research findings and emerging trends, this review underscores the transformative potential of nanoporous materials in advancing biomedical imaging and diagnostics. The integration of interdisciplinary approaches, innovative synthesis techniques, and functionalization strategies offers promising avenues for the development of next-generation imaging agents and diagnostic tools with enhanced sensitivity, specificity, and biocompatibility.

Fluorescent Peptide Dendrimers for siRNA Transfection: Tracking pH Responsive Aggregation, siRNA Binding, and Cell Penetration

Transfecting nucleic acids into various cells is a key procedure in biological research also envisioned for therapeutic applications. In our effort to obtain simple reagents that would be readily accessible from commercial building blocks, we recently reported peptide dendrimers as single component siRNA transfection reagents accessible in pure form by solid-phase peptide synthesis. Here, we extend our studies of these dendrimers by identifying analogs bearing a coumarin or BODIPY fluorescent label in their core and displaying comparable siRNA transfection efficiencies, pH dependent aggregation, siRNA binding, and secondary structures. Fluorescence resonance energy transfer (FRET) studies show that the dendrimers are tightly associated with siRNA within the formed nanoparticles at pH 7.4 but are released into solution at pH 5.0 and can participate in endosome escape by destabilizing the membrane at this pH value. Colocalization studies furthermore suggest that peptide dendrimers and siRNA remain tightly associated throughout the transfection process.