Preparation of Liposome Gel by Calcium Cross-Linking Induces the Long-Term Release of DOX to Improve the Antitumor Effect.

Doxorubicin (DOX) is one of the most commonly used anticancer drugs; however, its clinical application is greatly limited due to its toxicity and chemotherapy resistance. The delivery of DOX by liposomes (Lipos) can improve the blood circulation time in vivo and reduce toxic side effects, but the drug's accumulation in the tumor is often insufficient for effective treatment. In this study, we present a calcium cross-linked liposome gel for the encapsulation of DOX, demonstrating its superior long-term release capabilities compared to conventional Lipos. By leveraging this enhanced long-term release, we can enhance drug accumulation within tumors, ultimately leading to improved antitumor efficacy. Lipos were prepared using the thin-film dispersion method in this study. We utilized the ion-responsiveness of glutathione-gelatin (GSH-GG) to form the gel outside the Lipos and named the nanoparticles coated with GSH-GG on the outside of Lipos as Lipos@GSH-GG. The average size of Lipos@GSH-GG was around 342.9 nm, with a negative charge of -25.6 mV. The in vitro experiments revealed that Lipos@GSH-GG exhibited excellent biocompatibility and slower drug release compared to conventional Lipos. Further analysis of cellular uptake and cytotoxicity demonstrated that Lipos@GSH-GG loading DOX (DOX&Lipos@GSH-GG) exhibited superior long-term release effects and lower toxic side effects compared to Lipos loading DOX (DOX&Lipos). Additionally, the findings regarding the long-term release effect in vivo and the tumor accumulation within tumor-bearing mice of Lipos@GSH-GG suggested that, compared to Lipos, it demonstrated superior long-term release capabilities and achieved greater drug accumulation within tumors. In vivo antitumor efficacy experiments showed that DOX&Lipos@GSH-GG demonstrated superior antitumor efficacy to DOX&Lipos. Our study highlights Lipos@GSH-GG as a promising nanocarrier with the potential to enhance efficacy and safety by means of long-term release effects and may offer an alternative approach for effective antitumor therapy in the future.

Combined application of dinitrofluorobenzene and ovalbumin induced AD-like dermatitis with an increase in helper T-cell cytokines and a prolonged Th2 response.

BACKGROUND: The progression of acute-to-chronic atopic dermatitis is accompanied by multiple helper T-cell cytokine responses, but the mechanisms and relative importance of these changes remain unclear. There is no animal model for atopic dermatitis that recapitulates these cytokine responses. OBJECTIVE: We sought to build a novel mouse model for atopic dermatitis (AD) that recapitulates these helper T-cell responses and some dynamic changes in cytokine responses in the progression of AD. METHODS: Female BALB/c mice were subjected to the application of dinitrofluorobenzene (DNFB) and ovalbumin (OVA) to induce AD-like dermatitis. Skin lesions and serum were collected from mice in the acute and chronic phases to detect changes in cytokine responses and other features of AD. RESULTS: Combined application of DNFB and OVA successfully induced AD-like dermatitis and histological changes as well as epidermal barrier dysfunction. In the acute phase of AD-like dermatitis, Th2-associated cytokines were mainly increased in serum and skin lesions. In the chronic phase of AD-like dermatitis, Th2-associated cytokines were still highly expressed, while Th1- and Th17-associated cytokines were also gradually increased. Compared with the acute phase, the JAK-STAT signaling pathway was highly expressed in the chronic phase of AD-like dermatitis. CONCLUSION: The combined application of DNFB and OVA could be used to build a new mouse model for atopic dermatitis. This mouse model recapitulates the helper T-cell responses and some dynamic changes in cytokine responses in the progression of acute-to-chronic in human AD. The JAK-STAT signaling pathway plays a pivotal role in the chronicity of AD.

A Facile Way To Improve the Bioavailability of Nanomedicine Based on the Threshold Theory.

One of the most significant barriers to the clinical transformation of nanomedicines is low drug distribution in solid tumors due to quick clearance of nanomedicine after injection. Studies have revealed that the distribution of nanomedicine in tumor sites can be considerably improved when the number of nanoparticles supplied in a short period surpasses the threshold. Most routinely employed nanomaterials have dose-related safety concerns. To resolve this problem, we use highly biocompatible albumin to construct blank nanoparticles and doxorubicin loading nanoparticles. Under the guidance of the threshold theory, when the quantity of drug loading nanoparticles is constant, the drug delivery effectiveness improves with the addition of blank nanoparticles. This enhanced impact was verified both in vitro and in vivo. The area under the curve of the high dose group (19.5 × 1011) is 2.5 times higher than that of the low dose group (6.5 × 1011). In addition, the drug distribution of the high dose group at the tumor site was also improved by 1.5 times compared with the low dose group. The results of histopathological sections also showed that the administration of excess blank nanoparticles within 24 h has no damage to the animals. This study contributes to the clinical transition of nanomedicine by providing fresh ideas for anticancer nanomedicine research.

Mild Hyperthermia Induced by Hollow Mesoporous Prussian Blue Nanoparticles in Alliance with a Low Concentration of Hydrogen Peroxide Shows Powerful Antibacterial Effect.

The emergence of superbacteria as well as the drug resistance of the current bacteria gives rise to worry regarding a bacterial pandemic and also calls for the development of novel ways to combat the bacteria. Here in this article, we demonstrate that mild hyperthermia induced by hollow mesoporous Prussian blue nanoparticles (HMPBNPs) in alliance with a low concentration of hydrogen peroxide (H2O2) shows a powerful inhibition effect on bacteria. Our results demonstrate that this therapeutic regime could realize almost full growth inhibition of both Gram-positive (Staphylococcus aureus, S. aureus) and -negative bacteria (Escherichia coli, E. coli), as well as potent inhibition/elimination of the S. aureus biofilm. The wound healing results indicate that combination regime of the antibacterial system could be conveniently used for wound disinfection in vivo and could promote wound healing. To our limited knowledge, this is one of the few pioneer works to apply mild hyperthermia for the combat of bacteria, which provides a novel strategy to inspire future studies.

Progress in Intradermal and Transdermal Gene Therapy with Microneedles.

Gene therapy is one of the most widely studied treatments and has the potential to treat a variety of intractable diseases. The skin's limited permeability, as the body's initial protective barrier, drastically inhibits the delivery effect of gene medicine. Given the potential adverse effects and physicochemical features of the medications, improving generic drug penetration into the skin barrier and achieving an effective level of target tissues remains a challenge. Microneedles have made tremendous improvements in aided gene transfer and medication delivery as a unique method. Microneedles offer the advantage of being minimally invasive and painless, as well as the ability to distribute gene medicines straight through the stratum corneum. Microneedles have been used to penetrate skin tissue with various nucleic acids and medicines in recent years, allowing for a wide range of applications in the treatment of skin ailments. This review focuses on skin-related disorders and immunity, and it primarily discusses the progress of microneedle transdermal gene therapy in recent years. It also complements the current major vectors and related microneedle gene therapy applications.

Separation of ofloxacin enantiomers by capillary electrophoresis with fluorescence detection using deoxyribonucleic acid oligonucleotides as chiral selectors.

This study used capillary electrophoresis with fluorescence detection- and a partial-filling mode-based method for chiral separation of ofloxacin. The deoxyribonucleic acid oligonucleotides with different base sequences were studied as potential chiral selectors including deoxyribonucleic acid tetrahedron, G-quadruplex, and G-riched double-strand deoxyribonucleic acid. Under the optimized conditions, all the deoxyribonucleic acid chiral selectors exhibited excellent chiral separation capabilities with a resolution higher than 1.5. The electrophoretic behavior of the ofloxacin enantiomer might result from the intermediate conjugate with different stabilities between chiral selectors and analytes by a combination of the hydrogen bond and spatial recognition structure. Moreover, satisfactory repeatability regarding run-to-run and interday repeatability was obtained, and all the relative standard deviation values of migration times and resolutions were below 4% (n = 6). Conclusively, both spatial structure and arrangement of the G bases potentiated the chiral separation capability of deoxyribonucleic acid for ofloxacin enantiomer. This work offered a stepping stone for enantioseparation using deoxyribonucleic acid as chiral selectors.

Capillary electrophoretic method for Staphylococcus aureus detection by using a novel antimicrobial peptide.

A novel peptide containing antimicrobial sequence and gelatinase cleavage sites was designed for Staphylococcus aureus detection. Since Staphylococcus aureus could secrete gelatinase, the fluorescein labeled peptide GKRWWKWWRRPLGVRGC could be recognized and cleaved. The obtained products were able to be analyzed by capillary electrophoresis with fluorescence detection. To explore the effect of Staphylococcus aureus concentration on enzyme digestion ability of peptide, Staphylococcus aureus with different concentrations were incubated with the peptide. Results indicated that capillary electrophoretic method was efficient for determining Staphylococcus aureus content. Compared with traditional approaches for Staphylococcus aureus detection, capillary electrophoresis possessed higher efficiency, enhanced sensitivity, and low sample consumption. Moreover, the proposed peptide also presented desirable antimicrobial activity. It suggested that the novel antimicrobial peptide used in this research opens a new path of detecting Staphylococcus aureus by capillary electrophoretic method.

How does DNA 'meet' capillary-based microsystems?

DNA possesses various chemical and physical properties which make it important in biological analysis. The opportunity for DNA to 'meet' capillary-based microsystems is rapidly increasing owing to the expanding development of miniaturization. Novel capillary-based methods can provide favourable platforms for DNA-ligand interaction assay, DNA translocation study, DNA separation, DNA aptamer selection, DNA amplification assay, and DNA digestion. Meanwhile, DNA exhibits great potential in the fabrication of new capillary-based biosensors and enzymatic bioreactors. Moreover, DNA has received significant research interest in improving capillary electrophoresis (CE) performance. We focus on highlighting the advantages of combining DNA and capillary-based microsystems. The general trend presented in this review suggests that the 'meeting' has offered a stepping stone for the application of DNA and capillary-based microsystems in the field of analytical chemistry.

Modulation of Aggregation-Caused Quenching to Aggregation-Induced Emission: Finding a Biocompatible Polymeric Theranostics Platform for Cancer Therapy.

Dual intramolecular FRET polymers are synthesized via Suzuki coupling and their luminescence characteristics from aggregation-caused quenching (ACQ) to aggregation-induced emission (AIE) is modulated conveniently by adjusting the charged ratios. The finally obtained AIE polymer is further employed to construct doxorubicin loaded nanoparticles as a promising theranostics platform for cancer therapy.

Resolving quantum dots and peptide assembly and disassembly using bending capillary electrophoresis.

Despite the numerous techniques developed for the studying nanoparticle and peptide interaction nowadays, sensitive and convenient assay in the process of flow, especially to simulate the self-assembly of quantum dots (QDs) and peptide inflow in blood vessels, still remains big challenges. Here, we report a novel assay for studying the self-assembly of QDs and peptide, based on CE using a bending capillary. We demonstrate that the semicircles numbers of the bending capillary affect the self-assembly kinetics of CdSe/ZnS QDs and ATTO-D3 LVPRGSGP9 G2 H6 peptide. Moreover, benefitting from this novel assay, the effect of the position on the self-assembly has also been realized. More importantly, we also demonstrate that this novel assay can be used for studying the stability of the QDs-peptide complex inflow. We believe that our novel assay proposed in this work could be further used as a general strategy for the studying nanoparticle-biomolecule interaction or biomolecule-biomolecule interaction.

A NanoFlare-Based Strategy for In Situ Tumor Margin Demarcation and Neoadjuvant Gene/Photothermal Therapy.

Accurate tumor margin demarcation in situ remains a paramount challenge. Herein, a NanoFlare (also known as spherical-nucleic-acid technology) based strategy is reported for in situ tumor margin delineation by transforming and amplifying the pathophysiological redox signals of tumor microenvironment. The NanoFlare designed (named AuNS-ASON) is based on gold nanostar (AuNS) coated with a dense shell of disulfide bridge-inserted and cyanine dyes-labeled antisense oligonucleotides (ASON) targeting survivin mRNA. The unique anisotropic ASON-spike nanostructure endows the AuNS-ASON with universal cellular internalization of tumor cells, while the disulfide bridge inserted confers response specificity toward redox activation. In vitro experiments demonstrate that the AuNS-ASON can discriminate tumor cells rapidly with activated fluorescence signals (>100-fold) in 2 h, and further achieve synergistic gene/photothermal tumor cells ablation upon near-infrared laser irradiation. Remarkably, in situ tumor margin delineation with high accuracy and outstanding spatial resolution (<100 µm) in mice bearing different tumors is obtained based on the AuNS-ASON, providing intraoperative guidance for tumor resection. Moreover, the AuNS-ASON can enable efficient neoadjuvant gene/photothermal therapy before surgery to reduce tumor extent and increase resectability. The concept of NanoFlare-based microenvironment signal transformation and amplification could be used as a general strategy to guide the design of activatable nanoprobes for cancer theranostics.

Developing a capillary electrophoresis based method for dynamically monitoring enzyme cleavage activity using quantum dots-peptide assembly.

Herein, a novel assay has been developed for monitoring PreScission protease (His-PSP) mediated enzyme cleavage of ATTO 590 labeled peptide substrate (ATTO-LEV). This novel method is based on combining the use of capillary electrophoresis and fluorescence detection (CE-FL) to dynamically monitor the enzyme cleavage activity. A multivalent peptide substrate was first constructed by immobilizing His-tagged ATTO 590 labeled peptide substrate (ATTO-LEVH6) onto the surface of CdSe/ZnS quantum dots (QDs). Once successfully immobilized, the novel multivalent peptide substrate resulted in the Förster resonance energy transfer (FRET) from QDs to ATTO 590. The ATTO-LEVH6-QD assembly was then incubated with His-PSP to study the proteolytic cleavage of surface bound ATTO-LEVH6 by CE-FL. Our data suggests that PreScission-mediated proteolytic cleavage is enzyme concentration- and incubation time-dependent. By combining capillary electrophoresis, QDs and FRET, our study herein not only provides a new method for the detection and dynamically monitoring of PSP enzyme cleavage activity, but also can be extended to the detection of many other enzymes and proteases.

Novel application of fluorescence coupled capillary electrophoresis to resolve the interaction between the G-quadruplex aptamer and thrombin.

The dynamic binding status between the thrombin and its G-quadruplex aptamers and the stability of its interaction partners were probed using our previously established fluorescence-coupled capillary electrophoresis method. A 29-nucleic acid thrombin binding aptamer was chosen as a model to study its binding affinity with the thrombin ligand. First, the effects of the cations on the formation of G-quadruplex from unstructured 29-nucleic acid thrombin binding aptamer were examined. Second, the rapid binding kinetics between the thrombin and 6-carboxyfluorescein labeled G-quadruplex aptamer was measured. Third, the stability of G-quadruplex aptamer-thrombin complex was also examined in the presence of the interfering species. Remarkably, it was found that the complementary strand of 29-nucleic acid thrombin binding aptamer could compete with G-quadruplex aptamer and thus disassociated the G-quadruplex structure into an unstructured aptamer. These data suggest that our in-house established fluorescence-coupled capillary electrophoresis assay could be applied to binding studies of the G-quadruplex aptamers, thrombin, and their ligands, while overcoming the complicated and costly approaches currently available.

In-capillary probing of quantum dots and fluorescent protein self-assembly and displacement using Förster resonance energy transfer.

Herein, a Förster resonance energy transfer system was designed, which consisted of CdSe/ZnS quantum dots donor and mCherry fluorescent protein acceptor. The quantum dots and the mCherry proteins were conjugated to permit Förster resonance energy transfer. Capillary electrophoresis with fluorescence detection was used for the analyses for the described system. The quantum dots and mCherry were sequentially injected into the capillary, while the real-time fluorescence signal of donor and acceptor was simultaneously monitored by two channels with fixed wavelength detectors. An effective separation of complexes from free donor and acceptor was achieved. Results showed quantum dots and hexahistidine tagged mCherry had high affinity and the assembly was affected by His6 -mCherry/quantum dot molar ratio. The kinetics of the self-assembly was calculated using the Hill equation. The microscopic dissociation constant values for out of- and in-capillary assays were 10.49 and 23.39 µM, respectively. The capillary electrophoresis with fluorescence detection that monitored ligands competition assay further delineated the different binding capacities of histidine containing peptide ligands for binding sites on quantum dots. This work demonstrated a novel approach for the improvement of Förster resonance energy transfer for higher efficiency, increased sensitivity, intuitionistic observation, and low sample requirements of the in-capillary probing system.

Investigation of the weak binding of a tetrahistidine-tagged peptide to quantum dots by using capillary electrophoresis with fluorescence detection.

Capillary electrophoresis with fluorescence detection was utilized to probe the self-assembly between cyanine group dye labeled tetrahistidine containing peptide and CdSe/ZnS quantum dots, inside the capillary. Quantum dots and cyanine group dye labeled tetrahistidine containing peptide were injected into the capillary one after the other and allowed to self-assemble. Their self-assembly resulted into a measurable Förster resonance energy transfer signal between quantum dots and cyanine group dye labeled tetrahistidine containing peptide. The Förster resonance energy transfer signal increased upon increasing the cyanine group dye labeled tetrahistidine containing peptide/quantum dot molar ratio and reached a plateau at the 32/1 molar ratio. Additionally, the Förster resonance energy transfer signal was also affected by the increment of the interval time of injection and the sampling time. Online ligand exchange experiments were used to assess, the potential of a monovalent ligand of imidazole and a hexavalent ligand peptide, to displace surface bound cyanine group dye labeled peptide ligands from the quantum dots surface. Under optimal conditions, a linear relationship between the integrated peak areas and hexavalent ligand peptide was obtained at a hexavalent ligand concentration range of 0-0.5 mM. Therefore, the present assay has the potential to be applied in the online ligands detection.

Simultaneous detection of assembly and disassembly of multivalent HA tag and anti-HA antibody in single in-capillary assay.

Herein, we have developed an in-capillary assay for simultaneous detection of the assembly and disassembly of the multivalent HA tag peptide and antibody. HA tag with hexahistidine at C terminus (YPYDVPDYAG4 H6 , termed YPYDH6 ) was conjugated with quantum dots (QDs) by metal-affinity force to form a multivalent HA tag (QD-YPYDH6 ). QD-YPYDH6 and monoclonal anti-HA antibody (anti-HA) were sequentially injected into the capillary. They were mixed and assembled inside the capillary. The reaction products were online discriminated and detected by fluorescence coupled capillary electrophoresis (CE-FL). For the in-capillary assay, the binding efficiency of the multivalent HA tag and antibody on was influenced by the molar ratio and injection time. Such novel assay could even give out the self-assembly kinetic constant of QDs and YPYDH6 as KD of 34.1 µM with n (binding cooperativeness) of 2.2 by Hill equation. More importantly, the simultaneous detection of the assembly and imidazole (Im) induced disassembly of the QD-YPYDH6 -anti-HA complex was achieved in a single in-capillary assay. Our study demonstrated a new method for the online detection of antigen-antibody interactions.

In-capillary detection of fast antibody-peptide binding using fluorescence coupled capillary electrophoresis.

Herein, we report a technique for detecting the fast binding of antibody-peptide inside a capillary. Anti-HA was mixed and interacted with FAM-labeled HA tag (FAM-E4 ) inside the capillary. Fluorescence coupled capillary electrophoresis (CE-FL) was employed to measure and record the binding process. The efficiency of the antibody-peptide binding on in-capillary assays was found to be affected by the molar ratio. Furthermore, the stability of anti-HA-FAM-E4 complex was investigated as well. The results indicated that E4 YPYDVPDYA (E4) or TAMRA-E4 YPYDVPDYA (TAMRA-E4) had the same binding priorities with anti-HA. The addition of excess E4 or TAMRA-E4 could lead to partial dissociation of the complex and take a two-step mechanism including dissociation and association. This method can be applied to detect a wide range of biomolecular interactions.

Online probing quantum dots and engineered enzyme self-assembly in a nanoliter scale.

Nanoparticles provide significantly enhanced binding characteristics. However, fast online probing of the self-assembly process remains hard to achieve in practice. Herein, we report a fluorescence coupled CE method for probing the self-assembly events between quantum dots (QDs) and engineered Jumonji domain-containing protein 6 (Jmjd6) enzyme. QDs and Jmjd6 were sequentially injected into the capillary, where the self-assembly took place in a nanoliter scale. In particular, we showed that the Jmjd6/QD ratio, the interval time, and the injection volume had a great effect on the online self-assembly. The current approach may allow for a better understanding of QDs-enzyme self-assembly and enzymatic activity detection.

A capillary electrophoresis method to explore the self-assembly of a novel polypeptide ligand with quantum dots.

Polyhistidine peptides are effective ligands to coat quantum dots (QDs). It is known that both the number of histidine (His) residues repeats and their structural arrangements in a peptide ligand play important roles in the assembly of the peptide onto CdSe/ZnS QDs. However, due to steric hindrance, a peptide sequence with more than six His residue tandem repeats would hardly coordinate well with Zn(2+) in the QD shell to further enhance the binding affinity. To solve this problem, a His-containing peptide ligand, ATTO 590-E2 G (NH)6 (ATTO-NH), was specifically designed and synthesized for assembly with QDs. With sequential injection of QDs and ATTO-NH into the capillary electrophoresis with fluorescence detection, strong Förster resonance energy transfer phenomenon between the QDs and the ATTO 590 dye was observed, indicating efficient self-assembly of the novel peptide onto the QDs to form ATTO-NH capped QDs inside the capillary. The binding stability of the ligand onto the QD was then systematically investigated by titrating with imidazole, His, and a his-tag containing competitive peptide. It is believed that this new in-capillary assay significantly reduced the sample consumption and the analysis time. By functionalizing QDs with certain metal cation-specific group fused peptide ligand, the QD-based probes could be even extended to the online detection of metal cations for monitoring environment in the future.

Copper-catalyzed intermolecular amidation of 8-methylquinolines with N-fluoroarylsulfonimides via Csp(3)-H activation.

An efficient copper-catalyzed C-H amidation of 8-methylquinolines with N-fluoroarylsulfonimides via Csp(3)-H activation is described. The reaction proceeds with high functional group tolerance, providing a novel approach to valuable quinolin-8-ylmethanamine derivatives in the absence of an additional oxidant.