Polyhedral oligomeric silsesquioxanes (POSS) have attracted considerable attention in the design of novel organic-inorganic hybrid materials with high performance capabilities. Features such as their well-defined nanoscale structure, chemical tunability, and biocompatibility make POSS an ideal building block to fabricate hybrid materials for biomedical applications. This review highlights recent advances in the application of POSS-based hybrid materials, with particular emphasis on drug delivery, photodynamic therapy and bioimaging. The design and synthesis of POSS-based materials is described, along with the current methods for controlling their chemical functionalization for biomedical applications. We summarize the advantages of using POSS for several drug delivery applications. We also describe the current progress on using POSS-based materials to improve photodynamic therapies. The use of POSS for delivery of contrast agents or as a passivating agent for nanoprobes is also summarized. We envision that POSS-based hybrid materials have great potential for a variety of biomedical applications including drug delivery, photodynamic therapy and bioimaging.

Cancer immunotherapy recently transforms the traditional approaches against various cancer malignancies. Immunotherapy includes systemic and local treatments to enhance immune responses against cancer and involves strategies such as immune checkpoints, cancer vaccines, immune modulatory agents, mimetic antigen‐presenting cells, and adoptive cell therapy. Despite promising results, these approaches still suffer from several limitations including lack of precise delivery of immune‐modulatory agents to the target cells and off‐target toxicity, among others, that can be overcome using nanotechnology. Mesoporous silica nanoparticles (MSNs) are investigated to improve various aspects of cancer immunotherapy attributed to the advantageous structural features of this nanomaterial. MSNs can be engineered to alter their properties such as size, shape, porosity, surface functionality, and adjuvanticity. This review explores the immunological properties of MSNs and the use of MSNs as delivery vehicles for immune‐adjuvants, vaccines, and mimetic antigen‐presenting cells (APCs). The review also details the current strategies to remodel the tumor microenvironment to positively reciprocate toward the anti‐tumor immune cells and the use of MSNs for immunotherapy in combination with other anti‐tumor therapies including photodynamic/thermal therapies to enhance the therapeutic effect against cancer. Last, the present demands and future scenarios for the use of MSNs for cancer immunotherapy are discussed.

Mucin-1 (MUC1), a transmembrane glycoprotein is aberrantly expressed on ∼90% of breast cancer and is an excellent target for nanoparticulate targeted imaging. In this study, the development of a dye-doped NIR emitting mesoporous silica nanoparticles platform conjugated to tumor-specific MUC1 antibody (ab-tMUC1-NIR-MSN) for in vivo optical detection of breast adenocarcinoma tissue is reported. The structural properties, the in vitro and in vivo performance of this nanoparticle-based probe were evaluated. In vitro studies showed that the MSN-based optical imaging nanoprobe is non-cytotoxic and targets efficiently mammary cancer cells overexpressing human tMUC1 protein. In vivo experiments with female C57BL/6 mice indicated that this platform accumulates mainly in the liver and did not induce short-term toxicity. In addition, we demonstrated that the ab-tMUC1-NIR-MSN nanoprobe specifically detects mammary gland tumors overexpressing human tMUC1 in a human MUC1 transgenic mouse model.

Mesoporous silica nanoparticles (MSNs) have been synthesized and loaded with both aluminum chloride phthalocyanine (AlClPc) and cisplatin as combinatorial therapeutics for treating cancer. The structural and photophysical properties of the MSN materials were characterized by different spectroscopic and microscopic techniques. Intracellular uptake and cytotoxicity were evaluated in human cervical cancer (HeLa) cells by confocal laser scanning microscopy (CLSM) and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays, respectively. The CLSM experiments showed that the MSN materials can be readily internalized in HeLa cells. The cytotoxic experiments demonstrated that, after light exposure, the combination of both AlClPc and cisplatin compounds in the same MSN platform potentiate the toxic effect against HeLa cells in comparison to the control AlClPc-MSN and cisplatin-MSN materials. These results show the potential of using MSN platforms as nanocarriers for combination photodynamic and chemotherapies to treat cancer.

Gene therapy offers transformative potential for treating genetic disorders by directly addressing the molecular root causes of diseases. However, the primary challenges of gene therapy involve the efficient delivery of therapeutic genetic material to target cells, crossing biological barriers, managing toxicity and immune responses. Mesoporous silica nanoparticles (MSNs), due to their unique structural features have emerged as a promising platform to overcome these challenges. In recent years, MSNs have gained significant attention as potential nanocarriers for the efficient delivery of various nucleic acids. This review comprehensively examines the role of MSNs in gene therapy, focusing on their capabilities in the targeted delivery of siRNA, DNA, CRISPR‐Cas systems, and other genetic therapeutics. This work explores the modern advancements in MSNs synthesis and functionalization strategies and the impact of structural modifications on their stability, cellular uptake, and controlled release under physiological conditions. Additionally, the review highlights the use of MSNs to develop theranostic systems, where gene delivery is combined with diagnostic imaging for real‐time monitoring and personalized treatment strategies. Finally, this work discusses the future perspectives of MSNs in gene delivery, addressing regulatory challenges, enhancing clinical translation, and expanding their application for treating various genetic disorders and cancers.