Boron-Containing Mesoporous Silica Nanoparticles with Effective Delivery and Targeting of Liver Cancer Cells for Boron Neutron Capture Therapy.

Nanocarriers have been researched comprehensively for the development of novel boron-containing agents in boron neutron capture therapy (BNCT). We designed and synthesized a multifunctional mesoporous silica nanoparticle (MSN)-based boron-containing agent. The latter was coated with a lipid bilayer (LB) and decorated with SP94 peptide (SFSIIHTPILPL) on the surface as SP94-LB@BA-MSN. The latter incorporated boric acid (BA) into hydrophobic mesopores, coated with an LB, and modified with SP94 peptide on the LB. SP94-LB@BA-MSN enhanced nano interface tumor-targeting ability but also prevented the premature release of drugs, which is crucial for BNCT because adequate boron content in tumor sites is required. SP94-LB@BA-MSN showed excellent efficacy in the BNCT treatment of HepG-2 cells. In animal studies with tumor-bearing mice, SP94-LB@BA-MSN exhibited a satisfactory accumulation at the tumor site. The boron content reached 40.18 ± 5.41 ppm in the tumor site 4 h after injection, which was 8.12 and 15.51 times higher than those in mice treated with boronated phenylalanine and those treated with BA. For boron, the tumor-to-normal tissue ratio was 4.41 ± 1.13 and the tumor-to-blood ratio was 5.92 ± 0.45. These results indicated that nanoparticles delivered boron to the tumor site effectively while minimizing accumulation in normal tissues. In conclusion, this composite (SP94-LB@BA-MSN) shows great promise as a boron-containing delivery agent for the treatment of hepatocellular carcinoma using BNCT. These findings highlight the potential of MSNs in the field of BNCT.

Boron-Containing MOF Nanoparticles with Stable Metabolism in U87-MG Cells Combining Microdosimetry To Evaluate Relative Biological Effectiveness of Boron Neutron Capture Therapy.

Accurate prediction of the relative biological effectiveness (RBE) of boron neutron capture therapy (BNCT) is challenging. The therapy is different from other radiotherapy; the dynamic distribution of boron-containing compounds in tumor cells affects the therapeutic outcome considerably and hampers accurate measurement of the neutron-absorbed dose. Herein, we used boron-containing metal-organic framework nanoparticles (BMOFs) with high boron content to target U87-MG cells and maintain the concentration of the 10B isotope in cells. The content of boron in the cells could maintain 90% (60 ppm) within 20 min compared with that at the beginning; therefore, the accurate RBE of BNCT can be acquired. The effects of BNCT upon cells after neutron irradiation were observed, and the neutron-absorbed dose was obtained by Monte Carlo simulations. The RBE of BMOFs was 6.78, which was 4.1-fold higher than that of a small-molecule boron-containing agent (boric acid). The energy spectrum of various particles was analyzed by Monte Carlo simulations, and the RBE was verified theoretically. Our results suggested that the use of nanoparticle-based boron carriers in BNCT may have many advantages and that maintaining a stable boron distribution within cells may significantly improve the efficiency of BNCT.

A Bone-Penetrating Precise Controllable Drug Release System Enables Localized Treatment of Osteoporotic Fracture Prevention via Modulating Osteoblast-Osteoclast Communication.

Improving local bone mineral density (BMD) at fracture-prone sites of bone is a clinical concern for osteoporotic fracture prevention. In this study, a featured radial extracorporeal shock wave (rESW) responsive nano-drug delivery system (NDDS) is developed for local treatment. Based on a mechanic simulation, a sequence of hollow zoledronic acid (ZOL)-contained nanoparticles (HZNs) with controllable shell thickness that predicts various mechanical responsive properties is constructed by controlling the deposition time of ZOL and Ca2+ on liposome templates. Attributed to the controllable shell thickness, the fragmentation of HZNs and the release of ZOL and Ca2+ can be precisely controlled with the intervention of rESW. Furthermore, the distinct effect of HZNs with different shell thicknesses on bone metabolism after fragmentation is verified. In vitro co-culture experiments demonstrate that although HZN2 does not have the strongest osteoclasts inhibitory effect, the best pro-osteoblasts mineralization results are achieved via maintaining osteoblast-osteoclast (OB-OC) communication. In vivo, the HZN2 group also shows the strongest local BMD enhancement after rESW intervention and significantly improves bone-related parameters and mechanical properties in the ovariectomy (OVX)-induced osteoporosis (OP) rats. These findings suggest that an adjustable and precise rESW-responsive NDDS can effectively improve local BMD in OP therapy.

3D culture boosting fullerenol nanoparticles to induce calreticulin exposure on MCF-7 cells for enhanced macrophage-mediated cell removal.

Calreticulin (CRT) on the cell surface that acts as an "eat me" signal is vital for macrophage-mediated programmed cell removal. The polyhydroxylated fullerenol nanoparticle (FNP) has appeared as an effective inducer to cause CRT exposure on cancer cell surface, but it failed in treating some cancer cells such as MCF-7 cells based on previous findings. Here, we carried out the 3D culture of MCF-7 cells, and interestingly found that the FNP induced CRT exposure on cells in 3D spheres via re-distributing CRT from endoplasmic reticulum (ER) to cell surface. Phagocytosis experiments in vitro and in vivo illustrated the combination of FNP and anti-CD47 monoclonal antibody (mAb) further enhanced macrophage-mediated phagocytosis to cancer cells. The maximal phagocytic index in vivo was about three times higher than that of the control group. Moreover, in vivo tumorigenesis experiments in mice proved that FNP could regulate the progress of MCF-7 cancer stem-like cells (CSCs). These findings expand the application of FNP in tumor therapy of anti-CD47 mAb and 3D culture can be used as a screening tool for nanomedicine.

Fabricated AIE-Based Probe to Detect the Resistance to Anoikis of Cancer Cells Detached from Tumor Tissue.

(1) Background: Resisting anoikis is a vital and necessary characteristic of malignant cancer cells, but there is no existing quantification method. Herein, a sensitive probe for assessing anoikis resistance of cancer cells detached from the extracellular matrix was developed based on the aggregation-induced emission (AIE) of AIEgens. It has been reported that detached cancer cell endocytose activated integrin clusters, and in the endosome these clusters recruit and activate phosphorylate focal adhesion kinase (pFAK) in the cytoplasm to induce signaling that supports the growth of detached cancer cells. (2) Methods: We established a lost nest cell model of cancer cells and determined their ability to resist anoikis. The colocalization of the activated integrin, pFAK, and endosomes in model cells was observed and calculated. (3) Results: The fluorescence signal intensity of the probe was significantly higher than that of the integrin antibody in the model cells and the fluorescence signal of probe signal was better overlapped with labeled pFAK by fluorescence in endosomes in model cells. (4) Conclusions: We developed a quantitative multi-parametric image analysis program to calculate fluorescent intensity of the probe and antibodies against pFAK and Rab5 in the areas of colocalization. A positive correlation of fluorescence signal intensity between the probe and pFAK on the endosome was observed. Therefore, the probe was used to quantitatively evaluate resisting anoikis of different cancer cell lines under the lost nest condition.

NUCLEAR PORE ANCHOR and EARLY IN SHORT DAYS 4 negatively regulate abscisic acid signaling by inhibiting Snf1-related protein kinase2 activity and stability in Arabidopsis.

Abscisic acid (ABA) is a key regulator of plant responses to abiotic stresses, such as drought. Abscisic acid receptors and coreceptors perceive ABA to activate Snf1-related protein kinase2s (SnRK2s) that phosphorylate downstream effectors, thereby activating ABA signaling and the stress response. As stress responses come with fitness penalties for plants, it is crucial to tightly control SnRK2 kinase activity to restrict ABA signaling. However, how SnRK2 kinases are inactivated remains elusive. Here, we show that NUCLEAR PORE ANCHOR (NUA), a nuclear pore complex (NPC) component, negatively regulates ABA-mediated inhibition of seed germination and post-germination growth, and drought tolerance in Arabidopsis thaliana. The role of NUA in response to ABA depends on SnRK2.2 and SnRK2.3 for seed germination and on SnRK2.6 for drought. NUA does not directly inhibit the phosphorylation of these SnRK2s or affects their abundance. However, the NUA-interacting protein EARLY IN SHORT DAYS 4 (ESD4), a SUMO protease, negatively regulates ABA signaling by directly interacting with and inhibiting SnRK2 phosphorylation and protein levels. More importantly, we demonstrated that SnRK2.6 can be SUMOylated in vitro, and ESD4 inhibits its SUMOylation. Taken together, we identified NUA and ESD4 as SnRK2 kinase inhibitors that block SnRK2 activity, and reveal a mechanism whereby NUA and ESD4 negatively regulate plant responses to ABA and drought stress possibly through SUMOylation-dependent regulation of SnRK2s.

The Dynamic Change of Immune Checkpoints and CD14+ Monocytes in Latent Tuberculosis Infection.

Controlling latent tuberculosis infection (LTBI) is important for preventing tuberculosis (TB). However, the immune regulation of LTBI remains uncertain. Immune checkpoints and CD14+ monocytes are pivotal for immune defense but have been scarcely studied in LTBI. We prospectively enrolled participants with LTBI and controls from January 2017 to December 2019. We measured their CD14+ monocytes and the expression of immune checkpoints, including programmed death-1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and T cell immunoglobulin mucin domain-containing-3 (TIM3) on T lymphocytes in peripheral blood mononuclear cells before and after LTBI treatment. A total of 87 subjects were enrolled, including 29 IGRA-negative healthy controls (HC), 58 in the LTBI group (19 without chronic kidney disease (non-CKD), and 39 with end-stage renal disease (ESRD)). All PD-1, CTLA-4, and TIM3 on lymphocytes and monocytes were higher in the LTBI group than that in the HC group. Total CD14+ monocytes were higher and PD-L2+CD14+ over monocytes were lower in patients with LTBI-non-CKD than that in the HC group. After LTBI treatment, CD14+ monocytes, TIM3+ on CD4+ and monocytes, and CTLA-4 on lymphocytes decreased significantly. Multivariable logistic regression indicated that CD14+ monocytes was an independent factor for LTBI-non-CKD from the HC group, whereas PD-L2+CD14+ monocytes and TIM3+ monocytes were significant for LTBI-ESRD from the HC group. In conclusion, LTBI status was associated with increasing CD14+ monocytes plus low PD-L2 expression. By contrast, increased expression of immune checkpoints over all immune cells might be due to Mycobacterium tuberculosis related immune exhaustion, which decreased after treatment.

The Aggregation Induced Emission Probe of Detecting Enhanced Permeation and Retention Effects is Structured for Evaluating the Applicability of Nanotherapy to Different Tumor Individuals.

Enhanced permeation and retention (EPR) effect, the mechanism by which nanodrugs accumulate in tumors and acquire superior curative effect. The questions of these mechanisms occur because of limited clinical transformation of engineered nanomaterials after 30 years. The difference of EPR limits the therapeutic effect of nanodrugs in the individual patient. Evaluation of the EPR effect in the individual patient will aid in selecting patients who will accumulate higher amounts of nanotherapeutics and show better therapeutic efficacy. Based on varied TIMP1/MMP-9 in serum, an aggregation-induced emission luminogen probe was designed and constructed to detect and evaluate the EPR effect in model mouse. The result showed that the ratio of TIMP1/MMP-9 (in the range 0.2-1.2) and fluorescence intensity of the probe were negative linear correlation and the effects of BSA-rhodamine accumulation in tumor were individualized differences as well as correlated with the relative ratio of TIMP-1/MMP-9 in serum. Our data support the development of these biomarkers probes based on the personalized nanotherapy of tumor.

Genome-wide distribution and functions of the AAE complex in epigenetic regulation in Arabidopsis.

Heterochromatin is widespread in eukaryotic genomes and has diverse impacts depending on its genomic context. Previous studies have shown that a protein complex, the ASI1-AIPP1-EDM2 (AAE) complex, participates in polyadenylation regulation of several intronic heterochromatin-containing genes. However, the genome-wide functions of AAE are still unknown. Here, we show that the ASI1 and EDM2 mostly target the common genomic regions on a genome-wide level and preferentially interacts with genetic heterochromatin. Polyadenylation (poly(A) sequencing reveals that AAE complex has a substantial influence on poly(A) site usage of heterochromatin-containing genes, including not only intronic heterochromatin-containing genes but also the genes showing overlap with heterochromatin. Intriguingly, AAE is also involved in the alternative splicing regulation of a number of heterochromatin-overlapping genes, such as the disease resistance gene RPP4. We provided evidence that genic heterochromatin is indispensable for the recruitment of AAE in polyadenylation and splicing regulation. In addition to conferring RNA processing regulation at genic heterochromatin-containing genes, AAE also targets some transposable elements (TEs) outside of genes (including TEs sandwiched by genes and island TEs) for epigenetic silencing. Our results reveal new functions of AAE in RNA processing and epigenetic silencing, and thus represent important advances in epigenetic regulation.

Correction: Modulated podosome patterning in osteoclasts by fullerenol nanoparticles disturbs the bone resorption for osteoporosis treatment.

Correction for 'Modulated podosome patterning in osteoclasts by fullerenol nanoparticles disturbs the bone resorption for osteoporosis treatment' by Kui Chen et al., Nanoscale, 2020, 12, 9359-9365, DOI: 10.1039/D0NR01625J.

Modulated podosome patterning in osteoclasts by fullerenol nanoparticles disturbs the bone resorption for osteoporosis treatment.

Overactivation and excessive differentiation of osteoclasts (OCs) has been implicated in the course of bone metabolism-related diseases. Although fullerenol nanoparticles (fNPs) have been suggested to inhibit OC differentiation and OC function in our previous work, systemic studies on the effect of fNPs on bone diseases, e.g., osteoporosis (OP), in vivo remain elusive. Herein, it is demonstrated that fNPs significantly suppress the differentiation of OCs that derived from the murine bone marrow monocytes and inhibit the formation of the sealing zone by blocking the formation and patterning of podosomes in OCs spatiotemporally. In vivo, fNPs are supposed to be an efficient inhibitor of the overactivation of OCs in a LPS-induced bone erosion mouse model. The therapeutic effect of fNPs on osteoporosis is also investigated in an ovariectomy-induced osteoporosis rat model. The well-organized trabecular bone, the reduction in the number of TRAP positive cells, the improvement of bone-associated parameters, and the mechanical properties all demonstrate that fNPs, similar to diphosphonates, can be a promising candidate for the effective treatment of osteoporosis.

Intrinsic Biotaxi Solution Based on Blood Cell Membrane Cloaking Enables Fullerenol Thrombolysis In Vivo.

We report the construction of blood cell membrane cloaked mesoporous silica nanoparticles for delivery of nanoparticles [fullerenols (Fols)] with fibrinolysis activity which endows the active Fol with successful thrombolysis effect in vivo. In vitro, Fols present excellent fibrinolysis activity, and the Fol with the best fibrinolysis activity is screened based on the correlation between Fols' structure and their fibrinolysis activity. However, the thrombolytic effect in vivo is not satisfactory. To rectify the unsatisfactory situation and avoid the exogenous stimuli, a natural blood cell membrane cloaking strategy with loading the active Fol is chosen to explore as a novel thrombolysis drug. After cloaking, the therapeutic platform prolongs blood circulation time and enhances the targeting effect. Interestingly, compared with platelet membrane cloaking, red blood cell (RBC) membrane cloaking demonstrates stronger affinity with fibrin and more enrichment at the thrombus site. The Fol with RBC cloaking shows quick and efficient thrombolysis efficacy in vivo with less bleeding risk, more excellent blood compatibility, and better biosafety when compared with the clinical drug urokinase (UK). These findings not only validate the blood cell membrane cloaking strategy as an effective platform for Fol delivery on thrombolysis treatment, but also hold a great promising solution for other active nanoparticle deliveries in vivo.

The High Permeability of Nanocarriers Crossing the Enterocyte Layer by Regulation of the Surface Zonal Pattern.

The intestinal epithelium is a major barrier that limits the absorption of oral drugs. The integrity of the epithelial tissue is a very important factor for preventing intestinal diseases. However, destabilization of the epithelium can promote the transportation of nanocarriers and increase the absorption of oral drugs. In our research, three different gold nanoparticles (GNPs) of the same size but with differing negative surface charge were designed and constructed as a model to determine the surface properties crucial for promoting absorptivity and bioavailability of the nanocarriers. The higher the ratio of surface carboxyl groups on GNPs, the higher capacity to induce transepithelial electrical resistance change and cell monolayer tight junction opening with higher permeability. The half carboxyl and half methyl surfaced GNPs displayed unique zonal surface patterns exhibited the greater ability to pass through intestinal epithelial cell layer but had a relatively small influence on tight junction distribution.

Carboxylated gold nanoparticles inhibit bone erosion by disturbing the acidification of an osteoclast absorption microenvironment.

Hyperactive osteoclasts (OCs) are a fundamental reason for excessive bone resorption and consequent osteoporosis that lead to one-third of the patients sustaining a fracture. OCs, with the help of acidifying vesicles containing vacuolar-type H+-ATPase (V-ATPase), transport cytoplasmic protons into a resorptive pit and create an acidic microenvironment where proteolytic enzymes degrade the bone matrix. Here, we report a previously undescribed application of gold nanoparticles (AuNPs) to inhibit excessive bone resorption by regulating the acidic microenvironment in which OCs resorb bone. Internalized AuNPs, with relatively abundant carboxyl groups, eventually accumulate in the membrane of the intracellular vesicles and interact with the V0 domain of V-ATPase, which prevents it from recruiting the V1 domain. This destroys the acid-secretion function of OCs. The therapeutic effect of AuNPs on bone resorption was assessed in an established lipopolysaccharide-induced bone erosion mouse model. Micro-computed tomography, histology, and tartrate-resistant acid phosphatase staining showed that AuNPs significantly reduced bone erosion. In summary, AuNPs are promising nano-functional materials for repairing bone defects by regulating OC acid secretion.

Epigenetic regulation in plant abiotic stress responses.

In eukaryotic cells, gene expression is greatly influenced by the dynamic chromatin environment. Epigenetic mechanisms, including covalent modifications to DNA and histone tails and the accessibility of chromatin, create various chromatin states for stress-responsive gene expression that is important for adaptation to harsh environmental conditions. Recent studies have revealed that many epigenetic factors participate in abiotic stress responses, and various chromatin modifications are changed when plants are exposed to stressful environments. In this review, we summarize recent progress on the cross-talk between abiotic stress response pathways and epigenetic regulatory pathways in plants. Our review focuses on epigenetic regulation of plant responses to extreme temperatures, drought, salinity, the stress hormone abscisic acid, nutrient limitations and ultraviolet stress, and on epigenetic mechanisms of stress memory.

Microfluidic Analysis for Separating and Measuring the Deformability of Cancer Cell Subpopulations.

Increased deformability and softness endow tumor cells with highly invasive and metastatic capabilities. We exploited these characteristics to fabricate a high-throughput microfluidic device to measure cell deformability and separate cancer cells. Driven by hydrodynamic forces, the cells with better deformability passed through the chip faster, whereas stiffer cells passed through the device over a longer time period. The MDA-MB-231 and MCF-7 cell lines were used to evaluate the device because their metastatic potentials were known. We found that MDA-MB-231 cells, which were softer and exhibited stronger deformability, passed through the device more quickly. HeLa cells were also successfully separated into softer and stiffer subpopulations, whose distinct mechanical properties were confirmed by atomic force microscopy. We also measured the expression of metastasis-associated proteins (epidermal growth factor receptor and integrin ß 1) and found that subpopulations with varied deformabilities had different expression levels. Our results suggested that this high-throughput microfluidic device could be used to screen and evaluate the curative effects of drug and cancer progression by simultaneously testing cell deformability and expression levels of metastasis-associated proteins in separated cell subpopulations.

Small RNA Functions as a Trafficking Effector in Plant Immunity.

Small RNAs represent a class of small but powerful agents that regulate development and abiotic and biotic stress responses during plant adaptation to a constantly challenging environment. Previous findings have revealed the important roles of small RNAs in diverse cellular processes. The recent discovery of bidirectional trafficking of small RNAs between different kingdoms has raised many interesting questions. The subsequent demonstration of exosome-mediated small RNA export provided a possible tool for further investigating how plants use small RNAs as a weapon during the arms race between plant hosts and pathogens. This review will focus on discussing the roles of small RNAs in plant immunity in terms of three aspects: the biogenesis of extracellular small RNAs and the transportation and trafficking small RNA-mediated gene silencing in pathogens.

Exploring the Interaction of Fullerenol with Key Digestive Proteases Using Raman-Based Frequency-Shift Sensing and Molecular Simulation Analysis.

Fullerenol has been demonstrated to be a potential anticancer nanodrug thanks to its excellent antioxidant properties. In this work, surface-enhanced Raman scattering (SERS)-based frequency shift method is employed to explore the interaction between fullerenol and the key digestive proteases (pepsin and trypsin) in the gastrointestinal tract. A dynamic adsorption process of fullerenol on pepsin/trypsin has been monitored by our detection platform. The binding sites of fullerenol to trypsin and pepsin are evidenced by introducing their inhibitors to the detection system, and the binding configurations/modes of fullerenol to pepsin and trypsin are precisely determined through computational simulations. The permeability of fullerenol through intestinal epithelial cells monolayer is also investigated and the results show that it can reach 6% in 6 h and 13% in 48 h, indicating its high oral bioavailability in human body. This work demonstrates the activity of fullerenol in the gastrointestinal tract and provides potential guidance for appropriate oral medicine design with the aid of a molecular docking method.

Au Nanoparticles Attenuate RANKL-Induced Osteoclastogenesis by Suppressing Pre-Osteoclast Fusion.

Osteoclasts are multinucleated terminal cells that originate from a hematopoietic monocyte/macrophage lineage. Excessive osteoclast formation in vivo can lead to bone metabolic diseases such as postmenopausal osteoporosis, multiple myeloma, rheumatoid arthritis, and lytic bone metastases of cancer cells. Au nanoparticles (AuNPs) are inorganic nanoparticles with outstanding biocompatibility. We assessed their effect on osteoclastogenesis and found that pre-osteoclast fusion induced by receptor activator of nuclear factor kappa-B ligand (RANKL) and macrophage colonystimulating factor (M-CSF) was suppressed by AuNPs. Cell migration and actin ring formation were also significantly inhibited. Finally, AuNPs reduced osteoclast bone absorption function. Interestingly, we observed altered fusogenic gene expression in treated pre-osteoclasts. Our results suggest that AuNPs have potential as a therapeutic agent for osteoclast-related bone metabolism diseases.

Highly Dispersed Fullerenols Hamper Osteoclast Ruffled Border Formation by Perturbing Ca2+ Bundles.

Osteoporosis, a common and serious bone disorder affecting aged people and postmenopausal women, is characterized by osteoclast overactivity. One therapeutic strategy is suppressing the bone resorption function of hyperactive osteoclasts, but there is no effective drug in clinical practice so far. Herein, it is demonstrated that fullerenols suppress the bone resorption of osteoclasts by inhibiting ruffled borders (RBs) formation. The RBs formation, which is supported by well-aligned actin bundles (B-actins), is a critical event for osteoclast bone resorption. To facilitate this function, osteoclast RBs dynamics is regulated by variable microenvironments to bundle F-actins, protrude cell membrane, and so on. B-actin perturbation by fullerenols is determined here, offering an opportunity to regulate osteoclast function by destroying RBs. In vivo, the therapeutic effect of fullerenols on overactive osteoclasts is confirmed in a mouse model of lipopolysaccharide-induced bone erosion. Collectively, the findings suggest that fullerenols adhere to F-actin surfaces and inhibit RBs formation in osteoclasts, mainly through hampering Ca2+ from bundling F-actins, and this is likely due to the stereo-hindrance effect caused by adherent fullerenols.