Synthetic High-Density Lipoprotein-Based Nanomedicine to Silence SOCS1 in Tumor Microenvironment and Trigger Antitumor Immunity against Glioma

Frontiers in fluorescence imaging: tools for the in situ sensing of disease biomarkers

Fluorescence imaging has been recognized as a powerful tool for the real-time detection and specific imaging of biomarkers within living systems, which is crucial for early diagnosis and treatment evaluation of major diseases. Over the years, significant advancements in this field have been achieved, particularly with the development of novel fluorescent probes and advanced imaging technologies such as NIR-II imaging, super-resolution imaging, and 3D imaging. These technologies have enabled deeper tissue penetration, higher image contrast, and more accurate detection of disease-related biomarkers. Despite these advancements, challenges such as improving probe specificity, enhancing imaging depth and resolution, and optimizing signal-to-noise ratios still remain. The emergence of artificial intelligence (AI) has injected new vitality into the designs and performances of fluorescent probes, offering new tools for more precise disease diagnosis. This review will not only discuss chemical modifications of classic fluorophores and in situ visualization of various biomarkers including metal ions, reactive species, and enzymes, but also share some breakthroughs in AI-driven fluorescence imaging, aiming to provide a comprehensive understanding of these advancements. Future prospects of fluorescence imaging for biomarkers including the potential impact of AI in this rapidly evolving field are also highlighted.

Bright NIR-II emissive cyanine dye-loaded lipoprotein-mimicking nanoparticles for fluorescence imaging-guided and targeted NIR-II photothermal therapy of subcutaneous glioblastoma

Cyanine dye-containing nanoparticles have widely been used in "all-in-one" NIR fluorescence imaging (FI)-guided photothermal therapy (PTT) because of their intrinsically large extinction coefficient and available physical and chemical modulation methods to tune absorption and emission wavelengths. The combination of good brightness and excellent tumor-targeting capacity is the key to realize efficient NIR-II FI-guided PTT. In this study, by covalently decorating NIR-II absorptive cyanine dyes with bulky AIE motify, we demonstrate how steric hindrance suppresses π-π stacking-induced fluorescence quenching and contributes to the good brightness of NIR-II FI of subcutaneous glioblastoma. The resulting cyanine dye (C12-TPAE) is 5 times brighter than the original cyanine dye in the formulated liposomal nanoparticles and C12-TPAE-AL has a high photothermal conversion efficiency of 62.4%, with good colloidal and light stability. Importantly, the ApoE peptide is absorbed on the liposomal surface, yielding lipoprotein-mimicking nanoparticles, which achieve active targeting of glioblastoma and efficient FI-guided PTT without tumor recurrence without any side effects on normal organs (heart, kidneys, liver, spleen, or lung). This research highlights a facile design route for bright NIR-II emissive and NIR-II photothermal cyanine dyes and indicates that cyanine dye-containing biomimetic theranostic nanoplatforms are promising candidates for future precision therapy.

Facile Alkyne Assembly-Enabled Functional Au Nanosheets for Photoacoustic Imaging-Guided Photothermal/Gene Therapy of Orthotopic Glioblastoma

Treatment of glioblastoma (GBM) remains challenging due to the presence of blood-brain barrier (BBB) and tumor heterogeneity. Herein, Au nanosheets (AuNSs) functionalized with RGD peptides and small interfering RNA (siRNA), referred to as AuNSs-RGD-C≡C-siRNA (ARCR), are prepared to achieve multimodal therapy for GBM. The AuNSs with a large modifiable surface area, intriguing photothermal conversion efficiency (50.26%), and remarkable photothermal stability (44 cycles over 7 h) are created using a well-designed amphiphilic surfactant. Furthermore, alkynyl groups are assembled onto the Au surface within 1 min, enabling strong covalent binding of siRNA to AuNSs and thereby avoiding the interference from biological thiols. Owing to the lipophilicity of the surfactant and the targeting property of RGD, ARCR effectively passes through the BBB and accumulates in GBM tumor regions, allowing near-infrared photoacoustic imaging-guided photothermal/gene therapy. This work proposes a facile strategy to construct theranostic Au-based materials, highlighting the potential of multifunctional nanoagents for GBM therapy.

Stimuli-Responsive Polymeric Nanocarriers Accelerate On-Demand Drug Release to Combat Glioblastoma

Glioblastoma multiforme (GBM) is a highly malignant brain tumor with a poor prognosis and limited treatment options. Drug delivery by stimuli-responsive nanocarriers holds great promise for improving the treatment modalities of GBM. At the beginning of the review, we highlighted the stimuli-active polymeric nanocarriers carrying therapies that potentially boost anti-GBM responses by employing endogenous (pH, redox, hypoxia, enzyme) or exogenous stimuli (light, ultrasonic, magnetic, temperature, radiation) as triggers for controlled drug release mainly via hydrophobic/hydrophilic transition, degradability, ionizability, etc. Modifying these nanocarriers with target ligands further enhanced their capacity to traverse the blood-brain barrier (BBB) and preferentially accumulate in glioma cells. These unique features potentially lead to more effective brain cancer treatment with minimal adverse reactions and superior therapeutic outcomes. Finally, the review summarizes the existing difficulties and future prospects in stimuli-responsive nanocarriers for treating GBM. Overall, this review offers theoretical guidelines for developing intelligent and versatile stimuli-responsive nanocarriers to facilitate precise drug delivery and treatment of GBM in clinical settings.

Personalized Nanovaccines Enhance Lymph Node Accumulation and Reprogram the Tumor Microenvironment for Improved Photodynamic Immunotherapy

Tumor immunotherapy has emerged as an efficacious therapeutic approach that mobilizes the patient's immune system to achieve durable tumor suppression. Here, we design a photodynamic therapy-motivated nanovaccine (Dex-HDL/ALA-Fe3O4) co-delivering 5-aminolevulinic acid and Fe3O4 nanozyme that demonstrate a long-term durable immunotherapy strategy. After vaccination, the nanovaccine exhibits obvious tumor site accumulation, lymph node homing, and specific and memory antitumor immunity evocation. Upon laser irradiation, Dex-HDL/ALA-Fe3O4 effectively generates reactive oxygen species at the tumor site not only to induce the immunogenic cell death-cascade but also to trigger the on-demand release of full types of tumor antigens. Intriguingly, Fe3O4 nanozyme-catalyzed hydrogen peroxide generated oxygen for alleviating tumor hypoxia and modifying the inhibitory tumor microenvironment, thereby exhibiting remarkable potential as a sensitizer. The intravenous administration of nanovaccines in diverse preclinical cancer models has demonstrated remarkable tumor regression and inhibition of postoperative tumor recurrence and metastasis, thereby enabling personalized treatment strategies against highly heterogeneous tumors.

Lipid-based nanoparticles to address the limitations of GBM therapy by overcoming the blood-brain barrier, targeting glioblastoma stem cells, and counteracting the immunosuppressive tumor microenvironment

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor, characterized by high heterogeneity, strong invasiveness, poor prognosis, and a low survival rate. A broad range of nanoparticles have been recently developed as drug delivery systems for GBM therapy owing to their inherent size effect and ability to cross the blood-brain barrier (BBB). Lipid-based nanoparticles (LBNPs), such as liposomes, solid lipid NPs (SLNs), and nano-structured lipid carriers (NLCs), have emerged as the most promising drug delivery system for the treatment of GBM because of their unique size, surface modification possibilities, and proven bio-safety. In this review, the main challenges of the current clinical treatment of GBM and the strategies on how novel LBNPs overcome them were explored. The application and progress of LBNP-based drug delivery systems in GBM chemotherapy, immunotherapy, and gene therapy in recent years were systematically reviewed, and the prospect of LBNPs for GBM treatment was discussed.