Ultrasound-controlled DOX-SiO2 nanocomposites enhance the antitumour efficacy and attenuate the toxicity of doxorubicin

Development of Uveal Melanoma-Specific Aptamer for Potential Biomarker Discovery and Targeted Drug Delivery

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. However, challenges in early diagnosis, high risk of liver metastasis, and lack of effective targeted therapy lead to poor prognosis and high mortality of UM. Therefore, generating an effective molecular tool for UM diagnosis and targeted treatment is of great significance. In this study, a UM-specific DNA aptamer, PZ-1, was successfully developed, which could specifically distinguish molecular differences between UM cells and noncancerous cells with nanomolar-range affinity and presented excellent recognition ability for UM in vivo and clinical UM tissues. Subsequently, the binding target of PZ-1 on UM cells was identified as JUP (junction plakoglobin) protein, which held great potential as a biomarker and therapeutic target for UM. Meanwhile, the strong stability and internalization capacity of PZ-1 were also determined, and a UM-specific aptamer-guided "nanoship" was engineered to load and selectively release doxorubicin (Dox) to targeted UM cells, with lower toxicity to nontumor cells. Taken together, the UM-specific aptamer PZ-1 could serve as a molecular tool to discover the potential biomarker for UM and to achieve the targeted therapy of UM.

Ultrasound nanotheranostics: Toward precision medicine

Ultrasound (US) is a mechanical wave that can penetrate biological tissues and trigger complex bioeffects. The mechanisms of US in different diagnosis and treatment are different, and the functional application of commercial US is also expanding. In particular, recent developments in nanotechnology have led to a wider use of US in precision medicine. In this review, we focus on US in combination with versatile micro and nanoparticles (NPs)/nanovesicles for tumor theranostics. We first introduce US-assisted drug delivery as a stimulus-responsive approach that spatiotemporally regulates the deposit of nanomedicines in target tissues. Multiple functionalized NPs and their US-regulated drug-release curves are analyzed in detail. Moreover, as a typical representative of US therapy, sonodynamic antitumor strategy is attracting researchers' attention. The collaborative efficiency and mechanisms of US and various nano-sensitizers such as nano-porphyrins and organic/inorganic nanosized sensitizers are outlined in this paper. A series of physicochemical processes during ultrasonic cavitation and NPs activation are also discussed. Finally, the new applications of US and diagnostic NPs in tumor-monitoring and image-guided combined therapy are summarized. Diagnostic NPs contain substances with imaging properties that enhance US contrast and photoacoustic imaging. The development of such high-resolution, low-background US-based imaging methods has contributed to modern precision medicine. It is expected that the integration of non-invasive US and nanotechnology will lead to significant breakthroughs in future clinical applications.

Ultrasound and laser-promoted dual-gas nano-generator for combined photothermal and immune tumor therapy

The combination of photothermal therapy (PTT) and immune tumor therapy has emerged as a promising avenue for cancer treatment. However, the insufficient immune response caused by inefficient immunogenic cell death (ICD) inducers and thermal resistance, immunosuppression, and immune escape resulting from the hypoxic microenvironment of solid tumors severely limit its efficacy. Herein, we report an ultrasound and laser-promoted dual-gas nano-generator (calcium carbonate-polydopamine-manganese oxide nanoparticles, CPM NPs) for enhanced photothermal/immune tumor therapy through reprogramming tumor hypoxic microenvironment. In this system, CPM NPs undergo reactive decomposition in a moderately acidic tumor, resulting in the generation of calcium, manganese ions, carbon dioxide (CO₂), and oxygen (O₂). Calcium and manganese ions act as adjuvants that trigger an immune response. The cancer cell membrane rupture caused by sudden burst of bubbles (CO₂ and O₂) under ultrasound stimulation and the photothermal properties of PDA also contributed to the ICD effect. The generation of O₂ alleviates tumor hypoxia and thus reduces hypoxia-induced heat resistance and immunosuppressive effects, thereby improving the therapeutic efficacy of combination PTT and immune therapy. The present study provides a novel approach for the fabrication of a safe and effective tumor treatment platform for future clinical applications.

Poly(methacrylate citric acid) as a Dual Functional Carrier for Tumor Therapy

Owing to its pH-sensitive property and chelating Cu²⁺ effect, poly(methacrylate citric acid) (PCA) can be utilized as a dual functional nanocarrier to construct a nanodelivery system. Negatively charged carboxyl groups can interact with positively charged antineoplastic drugs through electrostatic interaction to form stable drug nanoparticles (NPs). Through drug experimental screening, doxorubicin (DOX) was selected as the model drug, PCA/DOX NPs with a diameter of 84 nm were prepared, and the drug-loading content was 68.3%. PCA/DOX NPs maintained good stability and a sustained release profile. Cell experiments presented that PCA/DOX NPs could inhibit effectively the growth of 4T1 cells; the IC₅₀ value was decreased by approximately 15-fold after incubation for 72 h. The cytotoxicity toward H9C2 was decreased significantly. Moreover, based on its ability to efficiently adsorb copper ions, PCA showed good vascular growth inhibition effect in vitro. Furthermore, animal experiments showed that PCA/DOX NPs presented stronger anticancer effects than DOX; the tumor inhibition rate was increased by 1.5-fold. Myocardial toxicity experiments also confirmed that PCA reduced the cardiotoxicity of DOX. In summary, PCA/DOX NPs show good antitumor efficacy and low toxicity, and have good potential for clinical application.

Dual-Targeted Fe₃O₄@MnO₂ Nanoflowers for Magnetic Resonance Imaging-Guided Photothermal-Enhanced Chemodynamic/Chemotherapy for Tumor

The construction of high-efficiency tumor theranostic platform will be of great interest in the treatment of cancer patients; however, significant challenges are associated with developing such a platform. In this study, we developed high-efficiency nanotheranostic agent based on ferroferric oxide, manganese dioxide, hyaluronic acid and doxorubicin (FMDH-D NPs) for dual targeting and imaging guided synergetic photothermal-enhanced chemodynamic/chemotherapy for cancer, which improved the specific uptake of drugs at tumor site by the dual action of CD44 ligand hyaluronic acid and magnetic nanoparticles guided by magnetic force. Under the acidic microenvironment of cancer cells, FMDH-D could be decomposed into Mn²⁺ and Fe²⁺ to generate •OH radicals by triggering a Fenton-like reaction and responsively releasing doxorubicin to kill cancer cells. Meanwhile, alleviating tumor hypoxia improved the efficacy of chemotherapy in tumors. The photothermal properties of FMDH generated high temperatures, which further accelerated the generation of reactive oxygen species, and enhanced effects of chemodynamic therapy. Furthermore, FMDH-D NPs proved to be excellent T₁/T₂-weighted magnetic resonance imaging contrast agents for monitoring the tumor location. These results confirmed the considerable potential of FMDH-D NPs in a highly efficient synergistic therapy platform for cancer treatment.

Accurately Controlled Delivery of Temozolomide by Biocompatible UiO-66-NH2 Through Ultrasound to Enhance the Antitumor Efficacy and Attenuate the Toxicity for Treatment of Malignant Glioma

Background

Glioma is the most common and malignant primary brain tumour in adults and has a dismal prognosis. Temozolomide (TMZ) is the only clinical first-line chemotherapy drug for malignant glioma up to present. Due to poor aqueous solubility and toxic effects, TMZ is still inefficient and limited for clinical glioma treatment.

Methods

UiO-66-NH₂ nanoparticle is a zirconium-based framework, constructed by Zr and 2-amino-1,4-benzenedicarboxylic acid (BDC-NH₂) with octahedral microporous structure, which can be decomposed by the body into an ionic form to discharge. We prepared the nanoscale metal-organic framework (MOF) of UiO-66-NH₂ to load TMZ for therapy of malignant glioma, TMZ is released from UiO-66-NH₂ through a porous structure. The ultrasound accelerates its porous percolation and promotes the rapid dissolution of TMZ through low-frequency oscillations and cavitation effect. The biological safety and antitumor efficacy were evaluated both in vitro and in vivo.

Results

The prepared TMZ@MOF exhibited excellent biocompatibility and biosafety due to minimal drug leakage without ultrasound intervention. We further used the flank model of glioblastoma to verify the in vivo therapeutic effect. TMZ@UiO-66-NH₂ nanocomposites could be well delivered to the tumour tissue, which led to local enrichment of the TMZ concentration. Furthermore, TMZ@UiO-66-NH₂ nanocomposites under ultrasound demonstrated much more efficient inhibition for tumor growth than TMZ@UiO-66-NH₂ nanocomposites and TMZ alone. Meanwhile, the bone marrow suppression side effects of TMZ were significantly reduced by TMZ@UiO-66-NH₂ nanocomposites.

Conclusion

In this work, TMZ@UiO-66-NH₂ nanocomposites with ultrasound mediation could effectively improve the killing effect of malignant glioma and decrease TMZ-induced toxicity in normal tissues, demonstrating great potential for the delivery of TMZ in the clinical treatment of malignant gliomas.

Frontiers in the treatment of glioblastoma: Past, present and emerging

Glioblastoma (GBM) is one of the most aggressive cancers of the brain. Despite extensive research over the last several decades, the survival rates for GBM have not improved and prognosis remains poor. To date, only a few therapies are approved for the treatment of GBM with the main reasons being: 1) significant tumour heterogeneity which promotes the selection of resistant subpopulations 2) GBM induced immunosuppression and 3) fortified location of the tumour in the brain which hinders the delivery of therapeutics. Existing therapies for GBM such as radiotherapy, surgery and chemotherapy have been unable to reach the clinical efficacy necessary to prolong patient survival more than a few months. This comprehensive review evaluates the current and emerging therapies including those in clinical trials that may potentially improve both targeted delivery of therapeutics directly to the tumour site and the development of agents that may specifically target GBM. Particular focus has also been given to emerging delivery technologies such as focused ultrasound, cellular delivery systems nanomedicines and immunotherapy. Finally, we discuss the importance of developing novel materials for improved delivery efficacy of nanoparticles and therapeutics to reduce the suffering of GBM patients.

A novel role of kallikrein-related peptidase 8 in the pathogenesis of diabetic cardiac fibrosis

Rationale: Among all the diabetic complications, diabetic cardiomyopathy, which is characterized by myocyte loss and myocardial fibrosis, is the leading cause of mortality and morbidity in diabetic patients. Tissue kallikrein-related peptidases (KLKs) are secreted serine proteases, that have distinct and overlapping roles in the pathogenesis of cardiovascular diseases. However, whether KLKs are involved in the development of diabetic cardiomyopathy remains unknown.The present study aimed to determine the role of a specific KLK in the initiation of endothelial-to-mesenchymal transition (EndMT) during the pathogenesis of diabetic cardiomyopathy.

Methods and Results-By screening gene expression profiles of KLKs, it was found that KLK8 was highly induced in the myocardium of mice with streptozotocin-induced diabetes. KLK8 deficiency attenuated diabetic cardiac fibrosis, and rescued the impaired cardiac function in diabetic mice. Small interfering RNA (siRNA)-mediated KLK8 knockdown significantly attenuated high glucose-induced endothelial damage and EndMT in human coronary artery endothelial cells (HCAECs). Diabetes-induced endothelial injury and cardiac EndMT were significantly alleviated in KLK8-deficient mice. In addition, transgenic overexpression of KLK8 led to interstitial and perivascular cardiac fibrosis, endothelial injury and EndMT in the heart. Adenovirus-mediated overexpression of KLK8 (Ad-KLK8) resulted in increases in endothelial cell damage, permeability and transforming growth factor (TGF)-β1 release in HCAECs. KLK8 overexpression also induced EndMT in HCAECs, which was alleviated by a TGF-β1-neutralizing antibody. A specificity protein-1 (Sp-1) consensus site was identified in the human KLK8 promoter and was found to mediate the high glucose-induced KLK8 expression. Mechanistically, it was identified that the vascular endothelial (VE)-cadherin/plakoglobin complex may associate with KLK8 in HCAECs. KLK8 cleaved the VE-cadherin extracellular domain, thus promoting plakoglobin nuclear translocation. Plakoglobin was required for KLK8-induced EndMT by cooperating with p53. KLK8 overexpression led to plakoglobin-dependent association of p53 with hypoxia inducible factor (HIF)-1α, which further enhanced the transactivation effect of HIF-1α on the TGF-β1 promoter. KLK8 also induced the binding of p53 with Smad3, subsequently promoting pro-EndMT reprogramming via the TGF-β1/Smad signaling pathway in HCAECs. The in vitro and in vivo findings further demonstrated that high glucose may promote plakoglobin-dependent cooperation of p53 with HIF-1α and Smad3, subsequently increasing the expression of TGF-β1 and the pro-EndMT target genes of the TGF-β1/Smad signaling pathway in a KLK8-dependent manner.

Conclusions: The present findings uncovered a novel pro-EndMT mechanism during the pathogenesis of diabetic cardiac fibrosis via the upregulation of KLK8, and may contribute to the development of future KLK8-based therapeutic strategies for diabetic cardiomyopathy.

Robust fluorescent amphiphilic polymer micelle for drug carrier application

The prepared micelles DPOA possessed good biocompatibility, robust stability, and high fluorescent property. The introduction of fluorescent dye made the amphiphilic copolymer obtain the ability of bioimaging to monitor the transport of drug carriers.

Novel Span-PEG Multifunctional Ultrasound Contrast Agent Based on CNTs as a Magnetic Targeting Factor and a Drug Carrier

Based on the targeting of ferroferric oxide (Fe3O4) and the drug-loading property of carbon nanotubes (CNTs), a novel Span-PEG-composited Fe3O4-CNTs-DOX multifunctional ultrasound contrast agent was designed and applied to tumor lesions. In situ liquid phase synthesis was employed to prepare the Fe3O4-CNTs magnetic targeting complex, and the physical method was used to obtain the Fe3O4-CNTs-DOX complex by loading doxorubicin (DOX) onto Fe3O4-CNTs. The targeted drug-loading complex Fe3O4-CNTs-DOX was combined with the membrane material of Span-PEG by the acoustic vibration cavitation method. The maximum tolerance for Span-PEG-composited Fe3O4-CNTs-DOX microbubbles was 450 times higher, which has good safety. The loading rate of DOX in the obtained composite microbubbles was 17.02%. The proliferation inhibition rate of Span-PEG-composited Fe3O4-CNTs-DOX microbubbles on liver cancer SMMC-7721 cells reached 48.3%. Span-PEG-composited Fe3O4-CNTs-DOX microbubbles could significantly enhance ultrasonic imaging and enrich at a specific location under an external magnetic field, and the extended imaging time could ensure the effective observation and diagnosis of lesions.

Core-Shell Structure Design of Hollow Mesoporous Silica Nanospheres Based on Thermo-Sensitive PNIPAM and pH-Responsive Catechol-Fe3+ Complex

A kind of core-shell hybrid nanoparticle comprised of a hollow mesoporous silica nanoparticles (HMS) core and a copolymer shell bearing N-(3,4-dihydroxyphenethyl) methacrylamide (DMA) and N-isopropylacrylamide (NIPAM) as responsive moieties was prepared. Moreover, the factors that could impact the surface morphology and hierarchical porous structure were discussed. In the presence of Fe3+, catechol-Fe3+ complexes were formed to achieve pH-responsive polymer shell, combining with thermal-sensitiveness of poly(N-isopropylacrylamide). Doxorubicin (DOX) was applied as a model drug and the behaviors of its loading/release behaviors were investigated to prove the idea. The results exhibited a significant drug loading capacity of 8.6% and embed efficiency of 94.6% under 1 mg ml-1 DOX/PBS solution. In fact, the loading capacity of drug can be easily improved to as high as 28.0% by increasing the DOX concentration. The vitro cytotoxicity assay also indicated that the as-prepared nanoparticles have no significant cytotoxicity on RAW 264.7 cells. The in vitro experiment showed that the cumulative release of DOX was obviously dependent on the temperature and pH values. This pH/temperature-sensitive hollow mesoporous silica nanosphere is expected to have potential applications in controlled drug release.