Nanotheranostics—where nanoscale materials serve both diagnostic and therapeutic functions—are rapidly transforming gene therapy by tackling critical delivery challenges. This review explores the design and engineering of various nanoparticle systems (lipid-based, polymeric, inorganic, and hybrid) to enhance stability, targeting, and endosomal escape of genetic payloads. We discuss how real-time imaging capabilities integrated into these platforms enable precise localization and controlled release of genes, improving treatment efficacy while reducing off-target effects. Key strategies to overcome delivery barriers (such as proton sponge effect and photothermal disruption) and to achieve nuclear localization are highlighted, along with recent advances in stimuli-responsive systems that facilitate spatiotemporal control of gene expression. Clinical trials and preclinical studies demonstrate the expanding role of nanotheranostics in managing cancer, inherited disorders, and cardiovascular and neurological diseases. We further address regulatory and manufacturing hurdles that must be overcome for the widespread clinical adoption of nanoparticle-based gene therapies. By synthesizing recent progress and ongoing challenges, this review underscores the transformative potential of nanotheranostics for effective, targeted, and image-guided gene delivery.

Research in nanostructured materials has led to the development of different applications of relevance in the fields of medicine and biomedical engineering. In this regard, the field of drug delivery has probably benefited the most due to the possibility to engineer vehicles of high potency and increased activity and selectivity toward selected intracellular targets. Such vehicles can therefore potentially address one of the major cornerstones of modern pharmacology, which is increasing the bioavailability of drugs of low permeability. Our research group has developed cell-penetration nanobioconjugates by interfacing several nanomaterials (e.g., chitosan, gelatin nanoparticles, graphene oxide, and magnetite) with translocating peptides. The obtained nanobioconjugates have demonstrated facilitated cell internalization and endosomal escape abilities. To improve cell penetration even further, we encapsulated the magnetite-based nanobioconjugates into liposomes (to form magnetoliposomes) with very appealing results. Our plan is to expand the available nanoplatforms by combining the attributes of magnetite and polymeric nanoparticles through a core-shell system comprised of magnetite (core) and chitosan (shell). The encapsulation process has been successfully accomplished with the aid of passive micromixers with different channel geometries to favor intimate contact between the dispersed phase (nanoparticles) and the continuous phase (phospholipid solution). To model the encapsulation process, we implemented an Eulerian simulation in the software COMSOL Multiphysics^® 6.0 (COMSOL Inc, Stockholm, Sweden) where mixing required the Navier-Stokes equations as governing equations of momentum transport, turbulence, eddy viscosity, and damping functions to approximate turbulence using the κ-ε turbulence model near the walls. The simulation was conducted for the different geometries (i.e., SARS, chambers, and serpentine) and for Reynolds numbers ranging from 0.2 to 10 Also, we tested a low Reynolds turbulent model using the κ-ε model given in the Euler-Euler module. The Euler-Euler approach showed that the encapsulation reaches higher encapsulation efficiency (EE%) values compared with the previously implemented mixture model. Our encapsulation results indicate that including the κ-ε turbulence model with a low Reynolds turbulence model near the walls provides a higher agreement between in-silico and experimental approaches. Future work will be dedicated to evaluating the performance of our previously tested magnetophoretic separators with the newly developed encapsulates, to assure sufficient purity for further biocompatibility testing.