Superstable and Large-Scalable Organosilica-Micellar Hybrid Nanosystem via a Confined Gelation Strategy for Ultrahigh-Dosage Chemotherapy

sEmerging glucose oxidase-delivering nanomedicines for enhanced tumor therapy

Abnormalities in glucose metabolism have been shown to characterize malignant tumors. Glucose depletion by glucose oxidase (GOD) has shown great potential in tumor therapy by causing tumor starvation. Since 2017, nanomedicines have been designed and utilized to deliver GOD for more precise and effective glucose modulation, which can overcome intrinsic limitations of different cancer therapeutic modalities by remodeling the tumor microenvironment to enhance antitumor therapy. To date, the topic of GOD-delivering nanomedicines for enhancing tumor therapy has not been comprehensively summarized. Herein, this review aims to provide an overview and discuss in detail recent advances in GOD delivery and directly involved starvation therapy strategies, GOD-sensitized various tumor therapy strategies, and GOD-mediated multimodal antitumor strategies. Finally, the challenges and outlooks for the future progress of the emerging tumor therapeutic nanomedicines are discussed. This review provides intuitive and specific insights to a broad audience in the fields of nanomedicines, biomaterials, and cancer therapy.

Tumor microenvironment-responsive engineered hybrid nanomedicine for photodynamic-immunotherapy via multi-pronged amplification of reactive oxygen species

Reactive oxygen species (ROS) is promising in cancer therapy by accelerating tumor cell death, whose therapeutic efficacy, however, is greatly limited by the hypoxia in the tumor microenvironment (TME) and the antioxidant defense. Amplification of oxidative stress has been successfully employed for tumor therapy, but the interactions between cancer cells and the other factors of TME usually lead to inadequate tumor treatments. To tackle this issue, we develop a pH/redox dual-responsive nanomedicine based on the remodeling of cancer-associated fibroblasts (CAFs) for multi-pronged amplification of ROS (ZnPP@FQOS). It is demonstrated that ROS generated by ZnPP@FQOS is endogenously/exogenously multiply amplified owing to the CAFs remodeling and down-regulation of anti-oxidative stress in cancer cells, ultimately achieving the efficient photodynamic therapy in a female tumor-bearing mouse model. More importantly, ZnPP@FQOS is verified to enable the stimulation of enhanced immune responses and systemic immunity. This strategy remarkably potentiates the efficacy of photodynamic-immunotherapy, thus providing a promising enlightenment for tumor therapy.

Review and Future Perspectives of Stimuli-Responsive Bridged Polysilsesquioxanes in Controlled Release Applications

Bridged polysilsesquioxanes (BPSs) are emerging biomaterials composed of synergistic inorganic and organic components. These materials have been investigated as ideal carriers for therapeutic and diagnostic systems for their favorable properties, including excellent biocompatibility, physiological inertia, tunable size and morphology, and their extensive design flexibility of functional organic groups to satisfy diverse application requirements. Stimuli-responsive BPSs can be activated by both endogenous and exogenous stimuli, offering a precise, safe, and effective platform for the controlled release of various targeted therapeutics. This review aims to provide a comprehensive overview of stimuli-responsive BPSs, focusing on their synthetic strategies, biocompatibility, and biodegradability, while critically assessing their capabilities for controlled release in response to specific stimuli. Furthermore, practical suggestions and future perspectives for the design and development of BPSs are presented. This review highlights the significant role of stimuli-responsive BPSs in advancing biomedical research.

Reduction-responsive supramolecular hybridized paclitaxel nanoparticles for tumor treatment

Powerful chemotherapeutics have been used to combat tumor cells, but serious adverse effects and poor therapeutic efficiency restrict their clinical performance. Herein, we developed reduction-responsive supramolecular hybridized paclitaxel nanoparticles (PTX@HOMNs) for improved tumor treatment. The nanocarrier is composed of F127 and strengthened by a disulfide bond linked organosilica network, which ensures the desirable stability during blood circulation and controlled drug release at tumor sites. The as-prepared PTX@HOMNs could effectively accumulate at tumor regions. After entering tumor cells, PTX@HOMNs can respond to intracellular glutathione, and trigger active drug release for chemotherapy. As a result, PTX@HOMNs exhibited potent antitumor activity against ovarian tumors in vitro and in vivo. Our work provides a deep insight into constructing simple and controlled drug delivery nanoplatforms for improved tumor treatment.

Hyaluronic acid-functionalized redox-responsive organosilica nanoparticles for targeted resveratrol delivery to attenuate acrylamide-induced toxicity

The purpose of this study is to construct a redox-responsive and targeted nanoparticle to effectively deliver resveratrol (Res) for alleviating acrylamide (ACR) toxicity. Here, Res-loaded tetrasulfide-containing organosilica nanoparticles (DSMSNs) functionalized with hyaluronic acid on the surface (DSMSNs@Res@HA) were prepared. The DSMSNs@Res@HA nanoparticles were spherical with an encapsulation efficiency of 46.68 ± 1.64 % and a hydrated particle size of about 237.73 nm. As expected, DSMSNs@Res@HA were capable of significantly protecting PC12 cells against ACR-induced damage in oxidative stress, mitochondrial membrane potential decrease, and cell apoptosis compared with free Res and DSMSNs@Res at the equivalent dose. Moreover, DSMSNs@Res@HA could be biodegraded and released Res in response to GSH stimulus. In vivo experiments suggested that DSMSNs@Res@HA significantly reduced histological damage in the brain, liver, and kidney of rats compared with free Res and DSMSNs@Res. After oral administration of DSMSNs@Res@HA, the intestinal flora of ACR-treated rats could be effectively regulated by improving the species uniformity and abundance as well as recovering the species diversity. According to these findings, DSMSNs@Res@HA is worth further investigation as a potential therapeutic nanomedicine to alleviate ACR toxicity and restore gut microbiota diversity.

Dual "Unlocking" Strategy to Overcome Inefficient Nanomedicine Delivery and Tumor Hypoxia for Enhanced Photodynamic-Immunotherapy

Lacking blood vessels is one of the main characteristics of most solid tumors due to their rapid and unrestricted growth, which thus causes the inefficient delivery efficiency of nanomedicine and tumor hypoxia. Herein, a dual "unlocking" strategy to overcome these obstacles is proposed by combining engineered hybrid nanoparticles (named ZnPc@FOM-Pt) with dexamethasone (DXM). It is verified that pretreatment of tumors with DXM can increase intratumorally micro-vessel density (delivery "unlocking") to enhance the tumor delivery efficiency of ZnPc@FOM-Pt and decrease HIF-1α expression. Correspondingly, more Pt can catalyze tumor-overexpressed H₂ O₂ to produce oxygen to further cause hypoxia "unlocking," ultimately achieving boosted ZnPc-based photodynamic therapy in vivo (tumor inhibition rate: 99.1%). Moreover, the immunosuppressive tumor microenvironment is efficiently reversed and the therapeutic effect of anti-PD-L1-based immunotherapy is promoted by this newly designed nanomedicine. This dual "unlocking" strategy provides an innovative paradigm on simultaneously enhancing nanomedicine delivery efficacy and hypoxia relief for tumor therapy.

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

Iron oxide nanoparticles as a drug carrier reduce host immunosuppression for enhanced chemotherapy

Chemotherapy is still regarded as the main modality for cancer treatment. However, it often suppresses the host immune system, resulting in limited therapeutic effects. It is desirable to design a novel chemotherapeutic agent to reduce the level of immunosuppression. Herein, we designed bovine serum albumin (BSA)-bioinspired iron oxide nanoparticles (IONPs) as a nanocarrier to load anticancer drug mitoxantrone (MTX) for enhanced chemotherapy of orthotopic breast cancer. The treatment with IONPs@BSA-MTX complexes increased CD3⁺CD4⁺ and CD3⁺CD8⁺ T lymphocytes more than free MTX. The complexes effectively restored the host immune system and exhibited a better anticancer efficacy than free MTX. It was worth noting that the BSA-inspired IONPs were a satisfactory contrast agent for magnetic resonance imaging of tumors and lymph nodes. Our work provides a novel strategy for enhanced chemotherapy with low levels of immunosuppression in the treatment of breast cancer and other cancers.