Mitochondria-Targeted Fluorescent Nanoparticles with Large Stokes Shift for Long-Term BioImaging.

Mitochondria (MITO) play a significant role in various physiological processes and are a key organelle associated with different human diseases including cancer, diabetes mellitus, atherosclerosis, Alzheimer's disease, etc. Thus, detecting the activity of MITO in real time is becoming more and more important. Herein, a novel class of amphiphilic aggregation-induced emission (AIE) active probe fluorescence (AC-QC nanoparticles) based on a quinoxalinone scaffold was developed for imaging MITO. AC-QC nanoparticles possess an excellent ability to monitor MITO in real-time. This probe demonstrated the following advantages: (1) lower cytotoxicity; (2) superior photostability; and (3) good performance in long-term imaging in vitro. Each result of these indicates that self-assembled AC-QC nanoparticles can be used as effective and promising MITO-targeted fluorescent probes.

Aptamers Entirely Built from Therapeutic Nucleoside Analogues for Targeted Cancer Therapy.

Owing to the specific and high binding affinity of aptamers to their targets, aptamer-drug conjugates (ApDCs) have emerged as a promising drug delivery system for targeted cancer therapy. However, in a conventional ApDC, the aptamer segment usually just serves as a targeting moiety, and only a limited number of drug molecules are sequentially conjugated to the oligonucleotide, giving a relatively low drug loading capacity. To address this challenge, herein we employ four clinically approved nucleoside analogues, including clofarabine (Clo), ara-guanosine (AraG), gemcitabine (Ge), and floxuridine (FdU), to replace all natural nucleosides in aptamer sequences, generating a series of whole drug-constituted DNA-like oligomers that are termed drugtamers. Similar to their parent aptamers, the obtained drugtamers maintain the targeting capability and can specifically bind to the target receptors overexpressed on the cancer cell surface. With 100% drug loading ratio, active targeting capability, and enzyme-mediated release of active therapeutics, our drugtamers can strongly induce the apoptosis of cancer cells and inhibit the tumor progression, which enables a new potential for a better targeted cancer therapy.

DNA Zipper Mediated Membrane Fusion for Rapid Exosomal MiRNA Detection.

Accurate and reliable detection of exosomal miRNA can serve as a promising method for early diagnosis of disease and evaluation of therapeutic effects. However, current exosomal miRNA detection methods commonly involve exosome enrichment, containing RNA extraction, and qRT-PCR based quantification, which are expensive and time-consuming. Herein, we develop a DNA zipper-mediated membrane fusion approach for rapid exosomal miRNA detection and cancer diagnosis. First, a lipid vesicle probe containing miR21-targeting molecular beacons (MBs) is constructed and further loaded with zipper DNA constructs (ZDCs) on its surface. Meanwhile, complementary zipper DNA constructs (cZDCs) are introduced on the exosome of interest. Upon mixing them together, zipping between ZDC and cZDC induces the membrane fusion of exosomes and vesicle probes, triggering the recognition of exosomal miR21 by contained MBs and fluorescence emission that can be conveniently detected within 30 min. Importantly, with the assistance of flow cytometry, miR21-overexpressed tumor exosomes derived from either cell culture medium or clinical patient serums can be distinguished from exosomes secreted from normal cells. This approach provides a convenient way to accurately detect the exosomal miRNA, which may hold great potential in liquid biopsy for early cancer diagnosis and monitoring the therapeutic effects during the treatments.

Single-Template Molecularly Imprinted Chiral Sensor for Simultaneous Recognition of Alanine and Tyrosine Enantiomers.

Chiral recognition of l-amino acids is of significant importance due to the crucial role of l-amino acids in life sciences and pharmaceutics. In this work, a chiral sensor with capability of probing two chiral amino acids by an attractive single-template molecular imprinting strategy is introduced and used in the simultaneous chiral recognition of d/l-alanine (d/l-Ala) and d/l-tyrosine (d/l-Tyr). The assay relies on the hydrolysis of l-alanyl-l-tyrosine dipeptide doped in silica/polypyrrole (SiO2/PPy) under acidic conditions, resulting in l-Ala and l-Tyr coimprinted chiral sensor. This work opens up a new avenue for simultaneous chiral sensing of two or more chiral amino acids by incorporating only one template, circumventing the shortcomings encountered with multitemplate molecularly imprinted technology.

A Paclitaxel-Based Mucoadhesive Nanogel with Multivalent Interactions for Cervical Cancer Therapy.

Cervical cancer treatment is subject to limited drug access to locally diseased targets and generally resistant to chemotherapy, thus it is essential to develop a local drug delivery system to overcome these problems, premised on guaranteeing drug efficacy. With this goal in mind, a multivalent interactions-based mucoadhesive nanogel for vaginal delivery is proposed. Briefly, the nanogel is constructed with mucoadhesive poly(acrylic acid) as the backbone and multiple inclusions between ß-cyclodextrin and paclitaxel as the crosslinking points. The in vitro experiments demonstrate that nanogel exerts high cytotoxicity to cancer cells, reverses multidrug resistance effectively, and successfully promotes the permeation of drugs. More to the point, as proved in the in vivo experiments, the retention time in the vagina is prolonged and the tumor growth is effectively suppressed by the nanogel without any side effects in the orthotopic cervical cancer model. As mentioned above, this novel mucoadhesive nanogel is believed to be a useful tool toward designing drug delivery systems for cervical cancer treatment.

Coinduction of a Chiral Microenvironment in Polypyrrole by Overoxidation and Camphorsulfonic Acid for Electrochemical Chirality Sensing.

Polypyrrole (PPy) was synthesized by a galvanostatic method using (1 S)-(+)-10-camphorsulfonic acid ((+)-CSA) as the dopant, and the produced PPy was further overoxidized in a solution of (+)-CSA. A chiral microenvironment was successfully formed in the overoxidized PPy (OPPy) as a result of the synergistic effects of overoxidation and (+)-CSA, resulting in a twisted helical architecture of the OPPy chains. The formation of optically active OPPy was confirmed from aspects of its morphology (SEM and AFM) and circular-dichroism (CD) spectra. Finally, an electrochemical chirality sensor was fabricated on the basis of the resultant OPPy, which exhibited excellent biomolecular homochirality in the discrimination of tryptophan (Trp) enantiomers.

Endoplasmic Reticulum-Targeted Fluorescent Nanodot with Large Stokes Shift for Vesicular Transport Monitoring and Long-Term Bioimaging.

Herein, a highly stable aggregation-induced emission (AIE) fluorescent nanodot assembled by an amphiphilic quinoxalinone derivative-peptide conjugate, namely Quino-1-Fmoc-RACR (also termed as Q1-PEP), which exhibits large Stokes shift and an endoplasmic reticulum (ER)-targeting capacity for bioimaging is reported. It is found that the resulting nanodot can effectively enter the ER with high fluorescent emission. As the ER is mainly involved in the transport of synthesized proteins in vesicles to the Golgi or lysosomes, the Q1-PEP nanodot with ER-targeting capacity can be used to monitor vesicular transport inside the cells. Compared to conventional fluorescent dyes with small Stokes shifts, the self-assembled fluorescent nanodot shows superior resistance to photobleaching and aggregation-induced fluorescence quenching, and elimination of the spectra overlap with autofluorescence of biosubstrate owning to their AIE-active and red fluorescence emission characteristics. All these optical properties make the fluorescent nanodot suitable for noninvasive and long-term imaging both in vitro and in vivo.

Light-Trigerred Cellular Epigenetic Molecule Release To Reverse Tumor Multidrug Resistance.

Owing to the high spatial and temporal resolution of light, light-related biotechnologies, for example, optogenetics, has wide ranging applications in neuroscience to control a subject's behavior. Applying light to control tumors' genetic behavior directly was still a challenge so far. Herein, we put forward a strategy of chemical optoepigenomics, in which an epigenetic regulator (vorinostat) and paclitaxel (PTX) were conjugated onto a light-sensitive chemical molecule. The activity of vorinostat could be precisely controlled by the light, which could minimize the off-target effect. After UV irradiation under 350 nm, the photocaged epigenetic regulator (vorinostat) was selectively released from the conjugate in a spatiotemporal manner, inhibiting the activity of histone deacetylase and then reversing the PTX resistance of tumor cells effectively.

The discovery of novel diarylpyri(mi)dine derivatives with high level activity against a wide variety of HIV-1 strains as well as against HIV-2.

By means of structure-based molecular hybridization strategy, a series of novel diarylpyri(mi)dine derivatives targeting the entrance channel of HIV-1 reverse transcriptase (RT) were designed, synthesized and evaluated as potent non-nucleoside reverse transcriptase inhibitors (NNRTIs). Encouragingly, all the tested compounds showed good activities against wild-type (WT) HIV-1 (IIIB) with EC50 in the range of 1.36 nM-29 nM, which is much better than those of nevirapine (NVP, EC50 = 125.42 nM) and azidothymidine (AZT, EC50 = 11.36 nM). Remarkably, these compounds also displayed effective activity against the most of the single and double-mutated HIV-1 strains with low EC50 values, which is comparable to the control drugs. Besides, these compounds were also exhibited favorable enzymatic inhibitory activity. Moreover, preliminary structure-activity relationships (SARs) and molecular modeling study were investigated and discussed in detail. Unexpectedly, four diarylpyrimidines yielded moderate anti-HIV-2 activities. To our knowledge, this is rarely reported that diarylpyrimidine-based NNRTIs have potent activity against both HIV-1 and HIV-2 in cell culture.

Arylazolyl(azinyl)thioacetanilides. Part 20: Discovery of novel purinylthioacetanilides derivatives as potent HIV-1 NNRTIs via a structure-based bioisosterism approach.

By means of structure-based bioisosterism approach, a series of novel purinylthioacetanilide derivatives were designed, synthesized and evaluated as potent HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs). Some of the tested compounds were found to be active against wild-type (WT) HIV-1(IIIB) with EC50 in the range of 0.78-4.46µM. Among them, LAD-8 displayed the most potent anti-HIV activity (EC50=0.78µM, SI=24). In addition, LBD-6 showed moderate activity against L100I mutant (EC50=5.64µM) and double mutant strain RES056 (EC50=22.24µM). Preliminary structure-activity relationships (SARs) were discussed in detail. Molecular modeling study was used to predict the optimal conformation in the NNRTI binding site, which may play a guiding role in further rational optimization.

Enhanced cisplatin chemotherapy sensitivity by self-assembled nanoparticles with Olaparib.

Cisplatin (CDDP) is widely used as one kind of chemotherapy drugs in cancer treatment. It functions by interacting with DNA, leading to the DNA damage and subsequent cellular apoptosis. However, the presence of intracellular PARP1 diminishes the anticancer efficacy of CDDP by repairing DNA strands. Olaparib (OLA), a PARP inhibitor, enhances the accumulation of DNA damage by inhibiting its repair. Therefore, the combination of these two drugs enhances the sensitivity of CDDP chemotherapy, leading to improved therapeutic outcomes. Nevertheless, both drugs suffer from poor water solubility and limited tumor targeting capabilities. To address this challenge, we proposed the self-assembly of two drugs, CDDP and OLA, through hydrogen bonding to form stable and uniform nanoparticles. Self-assembled nanoparticles efficiently target tumor cells and selectively release CDDP and OLA within the acidic tumor microenvironment, capitalizing on their respective mechanisms of action for improved anticancer therapy. In vitro studies demonstrated that the CDDP-OLA NPs are significantly more effective than CDDP/OLA mixture and CDDP at penetrating cancer cells and suppressing their growth. In vivo studies revealed that the nanoparticles specifically accumulated at the tumor site and enhanced the therapeutic efficacy without obvious adverse effects. This approach holds great potential for enhancing the drugs' water solubility, tumor targeting, bioavailability, and synergistic anticancer effects while minimizing its toxic side effects.

Advances in local drug delivery technologies for improved rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by an inflammatory microenvironment and cartilage erosion within the joint cavity. Currently, antirheumatic agents yield significant outcomes in RA treatment. However, their systemic administration is limited by inadequate drug retention in lesion areas and non-specific tissue distribution, reducing efficacy and increasing risks such as infection due to systemic immunosuppression. Development in local drug delivery technologies, such as nanostructure-based and scaffold-assisted delivery platforms, facilitate enhanced drug accumulation at the target site, controlled drug release, extended duration of the drug action, reduced both dosage and administration frequency, and ultimately improve therapeutic outcomes with minimized damage to healthy tissues. In this review, we introduced pathogenesis and clinically used therapeutic agents for RA, comprehensively summarized locally administered nanostructure-based and scaffold-assisted drug delivery systems, aiming at improving the therapeutic efficiency of RA by alleviating the inflammatory response, preventing bone erosion and promoting cartilage regeneration. In addition, the challenges and future prospects of local delivery for clinical translation in RA are discussed.

Nano-formulated delivery of active ingredients from traditional Chinese herbal medicines for cancer immunotherapy.

Cancer immunotherapy has garnered promise in tumor progression, invasion, and metastasis through establishing durable and memorable immunological activity. However, low response rates, adverse side effects, and high costs compromise the additional benefits for patients treated with current chemical and biological agents. Chinese herbal medicines (CHMs) are a potential treasure trove of natural medicines and are gaining momentum in cancer immunomodulation with multi-component, multi-target, and multi-pathway characteristics. The active ingredient extracted from CHMs benefit generalized patients through modulating immune response mechanisms. Additionally, the introduction of nanotechnology has greatly improved the pharmacological qualities of active ingredients through increasing the hydrophilicity, stability, permeability, and targeting characteristics, further enhancing anti-cancer immunity. In this review, we summarize the mechanism of active ingredients for cancer immunomodulation, highlight nano-formulated deliveries of active ingredients for cancer immunotherapy, and provide insights into the future applications in the emerging field of nano-formulated active ingredients of CHMs.

Exercise ameliorates lipid droplet metabolism disorder by the PLIN2-LIPA axis-mediated lipophagy in mouse model of non-alcoholic fatty liver disease.

Excessive hepatic lipid droplets (LDs) accumulation-induced lipid metabolism disorder contributes to the development of non-alcoholic fatty liver disease (NAFLD). Exercise is a promising therapeutic strategy for NAFLD. However, the mechanism by which exercise ameliorates NAFLD through regulating the catabolism of hepatic LDs remains unclear. In the present study, we investigated the effect of perilipin2 (PLIN2)-lysosomal acid lipase (LIPA) axis mediating exercise-triggered lipophagy in a high-fat diet (HFD)-induced NAFLD mouse model. Our results showed that exercise could reduce HFD-induced hepatic LDs accumulation and change the expression of lipolysis-related enzymes. Moreover, exercise upregulated the expression of microtubule associated protein 1 light chain 3 (LC3) and autophagy-related proteins, and downregulated sequestosome 1 (P62) expression and promoted autophagosomes formation. Interestingly, exercise downregulated PLIN2 expression, upregulated LIPA expression, and increased the activity of hepatic LIPA and serum levels of LIPA in the NAFLD mouse model. Further mechanistic studies demonstrated that adenosine monophosphate-activated protein kinase (AMPK) activator-5-Aminoimidazole-4-carboxamide ribonucleoside (AICAr) treatment significantly increased mRNA levels and protein expression of LIPA and LC3II and decreased levels of PLIN2 and P62 in palmitic acid (PA)-treated HepG2 cells. PLIN2 silencing and LIPA overexpression notably increased the mRNA level and protein expression of LC3II and decreased the mRNA level and protein expression of p62, respectively. In summary, our findings reveal novel insights into the effect of exercise on improving lipid droplet metabolism disorder in NAFLD. Enhancing the PLIN2-LIPA axis-mediated lipophagy may be one of the key mechanisms involved in NAFLD alleviation by exercise.

The incidence, risk factors and outcomes of impaired cerebral autoregulation in aortic arch surgery: a single-center, retrospective cohort study.

BACKGROUND: Impairment of cerebral autoregulation (CA) has been observed in patients undergoing cardiopulmonary bypass (CPB), but little is known about its risks and associations with outcomes. The cerebral oximetry index (COx), which is a moving linear correlation coefficient between regional cerebral oxygen saturation (rScO2) and mean blood pressure (MAP), may reflect CA function. When COx approaches 1, it implies that CA is damaged, whereas the CA is functional when the COx value approaches 0. The objective of this study was to analyze the incidence and risks of impaired CA, based on COx assessment, in patients undergoing total aortic arch replacement under systemic moderate hypothermia and circulatory arrest of the lower body (MHCA). We also evaluated the association between impaired CA and patient outcomes. METHODS: One hundred and fifty-four adult patients who underwent total aortic arch replacement with stented elephant trunk implantation under MHCA at our hospital were retrospectively analyzed. Patients were defined as having new-onset impaired CA if pre-CPB COx < 0.3 and post-CPB COx > 0.3. Pre- and intraoperative factors were tested for independent association with impaired CA. Postoperative outcomes were compared between patients with normal and impaired CA. RESULTS: In our 154 patients, 46(29.9%) developed new-onset impaired CA after CPB. Multivariable analysis revealed a prolonged low rScO2 (rScO2 < 55%) independently associated with onset of impaired CA, and receiver operating charactoristic curve showed a cutoff value at 40 min (sensitivity, 89.5%; specificity, 68.0%). Compared with normal CA patients, those with impaired CA showed a significantly higher rates of in-hospital mortality and postoperative complications. CONCLUSIONS: Prolonged low rScO2 (rScO2 < 55%) during aortic arch surgery was closely related to onset of impaired CA. Impaired CA remained associated with the increased rates of postoperative complications and in-hospital mortality. TRIAL REGISTRATION: ChiCTR1800014545 with registered date 20/01/2018.

Photosensitizers with multiple degradation modes for efficient and postoperatively safe photodynamic therapy.

Photodynamic therapy (PDT) is emerging as a powerful tool for cancer treatment due to its unique advantages in terms of noninvasive and spatiotemporal selectivity. However, the residue of photosensitizers (PSs), which usually lead to thorny post-treatment side effects after photodynamic therapy (PDT), is one of bottlenecks for clinical translation. Herein, PSs with multiple degradation modes are developed to solve this issue. Upon 660 nm laser excitation, PSs can produce different types of reactive oxygen species (ROS), in which 1O2 and O2·- could kill the cancer cells, while ·OH could oxide the PSs themselves for photodegradation. After PDT, the residual few number of PSs could be further oxidized by endogenous ROS for biodegradation, and the degradation products could be further excreted by urine. This process therefore solves the slow-metabolism issue of traditional PSs. Among them, SQSe demonstrates the highest killing efficiency with best degradation ability, as confirmed by both in vitro and in vivo results. The postoperative safety of SQSe is further verified by assessment on in vivo artificially induced post-operative side effects.

An aminopeptidase N-based color-convertible fluorescent nano-probe for cancer diagnosis.

Specific cancer diagnosis at an early stage plays a significant role in preventing cancer metastasis and reducing cancer mortality. Thus, exploring specific and sensitive fluorescent probes to realize early cancer diagnosis is an urgent need in clinic. Aminopeptidase N (APN/CD13), overexpressed in numerous malignant tumors, is an important tumor biomarker associated with cancer progression, invasion, and metastasis. In this study, a novel fluorescent molecule APN-SUB, capable of monitoring APN in real time, is encapsulated in a pH-responsive block copolymer (termed APN-SUB nanoprobe) for cancer diagnosis. APN-SUB contains a fluorophore center and a trigger moiety (leucine group), which is covalently conjugated on the fluorophore with an amide bond. The hydrolysis of the amide bond in APN-SUB activated by APN leads to a red shift of maximum fluorescence emission wavelength from 495 nm to 600 nm, realizing dual-color transformation from green to red. Moreover, the APN-SUB nanoprobe with pH-responsiveness is prepared to improve the accumulation and the release rate in the tumor region. It is worth noting that the APN-SUB nanoprobe exhibits good performance for APN imaging, namely, superior limit of detection (0.14 nU mL-1), excellent selectivity and strong photostability. More importantly, the APN-SUB nanoprobe can be successfully employed as a color-convertible fluorescent probe for cancer diagnosis by tracking the activity of APN with high specificity and sensitivity in vivo, demonstrating its potential value for cancer diagnosis.

Supramolecular Cyclic Dinucleotide Nanoparticles for STING-Mediated Cancer Immunotherapy.

Activation of stimulator of interferon genes (STING) can reprogram the immunosuppressive tumor microenvironment (TME) by initiating innate and adaptive immunity. As natural STING agonists, clinical translation of cyclic dinucleotides (CDNs) has been challenged by their short half-life in circulation, poor stability, and low membrane permeability. Herein, we use the natural endogenous small molecules oleic acid and deoxycytidine to construct a ligand for the STING agonist c-di-GMP (CDG), a hydrophobic nucleotide lipid (3',5'-diOA-dC), which can assemble with CDG into stable cyclic dinucleotide nanoparticles (CDG-NPs) through various supramolecular forces driven by molecular recognition. CDG-NPs are homogeneous and stable spherical nanoparticles with an average diameter of 59.0 ± 13.0 nm. Compared with free CDG, CDG-NPs promote the retention and intracellular delivery of CDG in the tumor site, boost STING activation and TME immunogenicity, and potentiate STING-mediated anti-tumor immunity when administered by either intratumoral or systemic routes in melanoma-bearing mice. We propose a flexible supramolecular nanodelivery system for CDG by using endogenous small molecules, which provides a CDN delivery platform for STING-mediated cancer immunotherapy.

Plaque-Targeted Rapamycin Spherical Nucleic Acids for Synergistic Atherosclerosis Treatment.

Atherosclerosis with unstable plaques is the dominant pathological basis of lethal cardio-cerebrovascular diseases, which can cause acute death due to the rupture of plaques. Plaque-targeted drug delivery to achieve promoted treatment remains the main challenge because of the systemic occurrence of atheroma. Herein, a rapamycin (RAP) spherical nucleic acid (SNA) structure, capable of specifically accumulating in plaques for synergistic atherosclerosis treatment is constructed. By designing consecutive phosphorothioate (PS) at 3' terminus of the deoxyribonucleic acid (DNA) strand, multiple hydrophobic RAPs are covalently grafted onto the PS segment to form an amphiphilic drug-grafted DNA (RAP-DNA), which successively self-assembles into micellar SNA (RAP-SNA). Moreover, the phosphodiester-DNA segment constitutes the outer shell of RAP-SNA, enabling further hybridization with functional siRNA (targeting lectin-like oxidized low-density lipoprotein receptor-1, LOX-1) to obtain the drug codelivered SNA (LOX-1/RAP-SNA). With two active ingredients inside, LOX-1/RAP-SNA can not only induce robust autophagy and decrease the evil apoptosis of the pathological macrophages, but also simultaneously prohibit the LOX-1-mediated formation of damageable foam cells, realizing the effect of synergistic therapy. As a result, the LOX-1/RAP-SNA significantly reduces the progression of atheroma and stabilizes the plaques, providing a new strategy for synergistically targeted atherosclerosis treatment.

Journey of Poly(ethylene Glycol) in Living Cells.

As the gold standard for stealth polymer materials, poly(ethylene glycol) (PEG) has been widely used in drug delivery with excellent properties such as low toxicity, reduced immunogenicity, good water solubility, and so forth. However, lack of understanding for the fate of PEG and PEGylated delivery systems at the cellular level has limited the application of PEGylated molecules in diagnosis and therapy. Here, we chose linear PEG 5k as a representative model and focused on the internalization behavior and mechanism, intracellular trafficking, sub-cellular localization, and cellular exocytosis of PEG and PEGylated molecules in living cells. Our investigation showed that PEG could be internalized into cells in 1 h. The internalized PEG was localized to lysosome, cytosol, endoplasmic reticulum (ER) and mitochondria. Importantly, the fate of PEG in cells could be regulated by conjugating different small molecules. PEGylated rhodamine B (PEG-RB) as the positively charged macromolecule was internalized into cells by micropinocytosis and then transported in lysosomes, ER, and mitochondria via vesicles sequentially. In contrast, PEGylated pyropheophorbide-a (PEG-PPa) as the negatively charged macromolecule was internalized into cells and transported to lysosomes ultimately. PEGylation slowed down the exocytosis process of RB and PPa and significantly prolonged their residence time inside the cells. These findings improve the understanding of how PEG and PEGylated molecules interact with the biological system at cellular and sub-cellular levels, which is of significance to rational PEGylation design for drug delivery.