Facile Preparation of Hydrophilic Mesoporous Metal-Organic Framework via Synergistic Etching and Surface Functionalization for Glycopeptides Analysis.

In view of the size and hydrophilicity of glycopeptides, materials having suitable channels (size-exclusion) and strong hydrophilic surface (hydrophilic interaction) are preferred to enrich the glycopeptides in biological samples. Metal-organic frameworks (MOFs) are good candidates. However, their smaller microporous channels and low chemical stability have limited the application. Herein, a facile strategy was established to construct hydrophilic mesoporous MOF via synergistic etching and surface functionalization by using phytic acid (PA). Besides, polyvinylpyrrolidone (PVP) was added during MOF synthesis to enhance the water stability of the MOF. Owing to the expanded hydrophilic mesoporous channels, the PA-modified Ce-MOF effectively and selectively captured 422 glycopeptides from 155 glycoproteins in tryptic digests of human serum (2 µL). The present work sheds light on the easy fabrication of hydrophilic mesoporous materials, and this established material holds unique advantages for glycopeptides analysis in biological samples.

Safe and Efficacious Diphtheria Toxin-Based Treatment for Melanoma: Combination of a Light-On Gene-Expression System and Nanotechnology.

The controversy surrounding the use of diphtheria toxin (DT) as a therapeutic agent against tumor cells arises mainly from its unexpected harmfulness to healthy tissues. We encoded the cytotoxic fragment A of DT (DTA) as an objective gene in the Light-On gene-expression system to construct plasmids pGAVPO (pG) and pU5-DTA (pDTA). Meanwhile, a cRGD-modified ternary complex comprising plasmids, chitosan, and liposome (pG&pDTA@cRGD-CL) was prepared as a nanocarrier to ensure transfection efficiency. Benefiting from spatiotemporal control of this light-switchable transgene system and the superior tumor targeting of the carrier, toxins were designed to be expressed selectively in illuminated lesions. In vitro studies suggested that pG&pDTA@cRGD-CL exerted arrest of the S phase in B16F10 cells upon blue light irradiation and, ultimately, induced the apoptosis and necrosis of tumor cells. Such DTA-based treatment exerted enhanced antitumor activity in mice bearing B16F10 xenografts and displayed prolonged survival time with minimal side effects. Hence, we described novel DTA-based therapy combined with nanotechnology and the Light-On gene-expression system: such treatment could be a promising strategy against melanoma.

Self-Amplified Photodynamic Therapy through the 1 O2 -Mediated Internalization of Photosensitizers from a Ppa-Bearing Block Copolymer.

Nanocarriers are employed to deliver photosensitizers for photodynamic therapy (PDT) through the enhanced penetration and retention effect, but disadvantages including the premature leakage and non-selective release of photosensitizers still exist. Herein, we report a 1 O2 -responsive block copolymer (POEGMA-b-P(MAA-co-VSPpaMA) to enhance PDT via the controllable release of photosensitizers. Once nanoparticles formed by the block copolymer have accumulated in a tumor and have been taken up by cancer cells, pyropheophorbide a (Ppa) could be controllably released by singlet oxygen (1 O2 ) generated by light irradiation, enhancing the photosensitization. This was demonstrated by confocal laser scanning microscopy and in vivo fluorescence imaging. The 1 O2 -responsiveness of POEGMA-b-P(MAA-co-VSPpaMA) block copolymer enabled the realization of self-amplified photodynamic therapy by the regulation of Ppa release using NIR illumination. This may provide a new insight into the design of precise PDT.

Preparation of a hydrophilic interaction liquid chromatography material by sequential electrostatic deposition of layers of polyethyleneimine and hyaluronic acid for enrichment of glycopeptides.

A hydrophilic interaction liquid chromatography (HILIC) material with application in glycoproteomics was obtained by sequential deposition of polyethyleneimine (PEI) and hyaluronic acid (HA) on a negatively charged substrate by means of electrostatic self-assembly. This kind of surface modification endows the material with excellent hydrophilicity and warrants efficient glycopeptides enrichment. The feasibility of this enrichment was verified by using dendritic mesoporous silica nanoparticles (DMSNs) and magnetic graphene oxide (MagG) as negatively charged substrates for PEI and HA adhesion. The two final products (DMSNs@PEI@HA and MagG@PEI@HA) exhibit high enrichment selectivity (molar ratios of IgG and BSA digests = 1:500 and 1:1000), sensitivity (detection limit, 2 fmol/µL), recovery (>90%) and enrichment capacity (300 mg/g). When using DMSNs@PEI@HA, 419 N-glycopeptides derived from 105 glycoproteins were identified. When using MagG@PEI@HA, 376 N-glycopeptides derived from 102 glycoproteins were identified, both from a 2 µL serum sample. This is better than by methods described in previous reports. Graphical abstract Schematic representation of hydrophilic modification of negatively charged nanomaterial substrates by electrostatic self-assembly techniques to obtain hydrophilic interaction liquid chromatography (HILIC) materials for enrichment of N-glycopeptides.

Dendritic Mesoporous Silica Nanoparticles with Abundant Ti4+ for Phosphopeptide Enrichment from Cancer Cells with 96% Specificity.

Selective enrichment and sensitive detection of phosphopeptides are of great significance in many bioapplications. In this work, dendritic mesoporous silica nanoparticles modified with polydopamine and chelated Ti4+ (denoted DMSNs@PDA-Ti4+) were developed to improve the enrichment selectivity of phosphopeptides. The unique central-radial pore structures endowed DMSNs@PDA-Ti4+ with a high surface area (362 m2 g-1), a large pore volume (1.37 cm3 g-1), and a high amount of chelated Ti4+ (75 µg mg-1). Compared with conventional mesoporous silica-based materials with the same functionalization (denoted mSiO2@PDA-Ti4+) and commercial TiO2, DMSNs@PDA-Ti4+ showed better selectivity and a lower detection limit (0.2 fmol/µL). Moreover, 2422 unique phosphopeptides were identified from HeLa cell extracts with a high specificity (>95%) enabled by DMSNs@PDA-Ti4+, better than those in previous reports.

ROS-responsive nano-medicine for navigating autophagy to enhance targeted therapy of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder characterized by immune dysregulation and intestinal inflammation. Rapamycin (Ra), an mTORC1 pathway inhibitor, has shown promise for autophagy induction in IBD therapy but is associated with off-target effects and toxicity. To address these issues, we developed an oral liposome responsive to reactive oxygen species (ROS) using lipids and amphiphilic materials. We combined ketone thiol (TK) for ROS responsive and hyaluronic acid (HA) with high affinity for CD44 receptors to prepare rapamycin-loaded nanoparticle (Ra@TH). Owing to its ROS responsive characteristic, Ra@TH can achieve inflammatory colonic targeting. Additionally, Ra@TH can induce autophagy by inhibiting the mTORC1 pathway, leading to the clearance of damaged organelles, pathogenic microorganisms and oxidative stress products. Simultaneously, it also collaboratively inhibits the NF-κB pathway suppressed by the removal of ROS resulting from TK cleavage, thereby mediating the expression of inflammatory factors. Furthermore, Ra@TH enhances the expression of typical tight junction proteins, synergistically restoring intestinal barrier function. Our research not only expands the understanding of autophagy in IBD treatment but also introduces a promising therapeutic approach for IBD patients.

Preparation and characterization of thermosensitive and folate functionalized Pluronic micelles.

In this study, thermosensitive and folate functionalized poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide)-ploy(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (FA-Pluronic-PNH) copolymer was synthesized. The structure and molecular weight of the copolymer were confirmed by 1H NMR, FT-IR and GPC, respectively. The lower critical solution temperature (LCST) of the copolymer was 39.8 degrees C. By employing doxorubicin (DOX) as a model drug, folate receptor-targeted DOX-loaded micelles were further formed on the copolymer. The blank and DOX-loaded micelles both exhibited nearly spherical shapes and their average diameters were 35 nm and 50 nm, respectively. The in vitro release behaviors of the DOX-loaded micelles were temperature-dependent and the release rate of DOX at 42 degrees C (above LCST) was faster than that at 37 degrees C (below LCST). Furthermore, the cytotoxicity assays of free DOX and DOX-loaded micelles on human cervical cancer cell lines HeLa and human lung cancer cell lines A549 demonstrated that folate increased the cellular uptake of the micelles within targeted cells that vastly over-expressed folate receptors.

Sequential Rocket-Mode Bioactivating Ticagrelor Prodrug Nanoplatform Combining Light-Switchable Diphtherin Transgene System for Breast Cancer Metastasis Inhibition.

The increased risk of breast cancer metastasis is closely linked to the effects of platelets. Our previously light-switchable diphtheria toxin A fragment (DTA) gene system, known as the LightOn system, has demonstrated significant therapeutic potential; it lacks antimetastatic capabilities. In this study, we devised an innovative system by combining cell membrane fusion liposomes (CML) loaded with the light-switchable transgene DTA (pDTA) and a ticagrelor (Tig) prodrug. This innovative system, named the sequential rocket-mode bioactivating drug delivery system (pDTA-Tig@CML), aims to achieve targeted pDTA delivery while concurrently inhibiting platelet activity through the sequential release of Tig triggered by reactive oxygen species with the tumor microenvironment. In vitro investigations have indicated that pDTA-Tig@CML, with its ability to sequentially release Tig and pDTA, effectively suppresses platelet activity, resulting in improved therapeutic outcomes and the mitigation of platelet driven metastasis in breast cancer. Furthermore, pDTA-Tig@CML exhibits enhanced tumor aggregation and successfully restrains tumor growth and metastasis. It also reduces the levels of ADP, ATP, TGF-ß, and P-selectin both in vitro and in vivo, underscoring the advantages of combining the bioactivating Tig prodrug nanoplatform with the LightOn system. Consequently, pDTA-Tig@CML emerges as a promising light-switchable DTA transgene system, offering a novel bioactivating prodrug platform for breast cancer treatment.

Hydrophilic arginine-functionalized mesoporous polydopamine-graphene oxide composites for glycopeptides analysis.

Considering the importance of glycopeptides in the clinical diagnosis of cancer and some serious diseases, the identification of glycopeptides from complex biological samples has attracted considerable attention. Effective pre-enrichment before mass spectrometry analysis plays an important role. In this work, a kind of hydrophilic two-dimensional composites (denoted as GO@MPDA@Arg) based on mesoporous polydopamine-graphene oxide were used to selectively enrich glycopeptides in biological samples. The mesoporous polydopamine (MPDA) layer self-assembled with template Pluronic F127 provided more binding sites to load arginine, and bound arginine enhanced the hydrophilicity of the material. As a result, GO@MPDA@Arg composites exhibited excellent enrichment performance for glycopeptides, containing good selectivity (IgG digests : BSA digests = 1:50, molar ratio), low detection limit for IgG digests (10 fmol µL-1), high loading capacity for IgG digests (200 µg mg-1), and good size exclusion (IgG digests : IgG : BSA = 1:100:100, mass ratio). In addition, mouse brain tissue was selected as the actual biological sample to further study the enrichment effect of GO@MPDA@Arg composites. In three parallel experiments, a total of 401 glycopeptides belonging to 233 glycoproteins were enriched from 200 µg digestion of mouse brain extract. The enrichment results demonstrate that GO@MPDA@Arg composites have application potential for glycopeptides enrichment in protein post-translational modification research.

A novel signal amplification label based on AuPt alloy nanoparticles supported by high-active carbon for the electrochemical detection of circulating tumor DNA.

The detection of circulating tumor DNA (ctDNA) has increasingly received a great deal of attention considering its significance in cancer diagnosis. And the signal amplification plays an important role in the development of sensitive ctDNA biosensors. Herein, the nanocomposites (denoted as HAC-AuPt), integrating from high-active carbon (HAC) and AuPt alloy nanoparticles, were synthesized and subsequently used as a signal amplification label to fabricate a sandwich-type ctDNA electrochemical biosensor. Characterizations demonstrated that HAC presents uniform size distribution and AuPt alloy nanoparticles were successfully loaded on HAC. The current response could be amplified to a great extent by the resultant HAC-AuPt due to its excellent electrochemical property. The nanocomposites were further bounded with DNA signal probes (SPs) via Au-S or Pt-S assembly to form SPs-label. After the capture probes (CPs) were immobilized on the electrode surface, the target DNA (tDNA) and SPs-label were stepwise incubated on the CPs-modified electrode, thus forming a sandwich-type structure. By monitoring the catalytic signal of HAC-AuPt towards the reduction process of H2O2, this biosensor provided a wide linear range of 10-8 mol/L - 10-16 mol/L with a low detection limit of 3.6 × 10-17 mol/L (S/N = 3) for the detection of the tDNA. Furthermore, obvious differences in response signals among different DNAs were observed benefitting from the excellent selectivity of the biosensor. Besides, the long-term stability, reproducibility, and recovery rate were proved to be outstanding. These results indicate that the established biosensor holds a potential application in the clinical diagnosis of ctDNA.

Hydrophilic graphene oxide-dopamine-cationic cellulose composites and their applications in N-Glycopeptides enrichment.

Glycosylation is one of the most important post-translational modifications of proteins, and plays an important role in the structure and function of proteins. However, due to the diversity of glycopeptide forms and their low abundance, it is extraordinarily challenging to capture and separate glycopeptides with high selectivity from complex biological samples with mass spectrometric analysis. Here, we synthesized a new type of hydrophilic composite based on electrostatic interactions, which has been proven to be effective in immobilizing cationic cellulose on graphene oxide-dopamine carriers (expressed as GO-DA-JR), for highly specific enrichment of N-glycopeptides. The introduction of cationic cellulose provides not only a perfect surface charge for the composite but also a greater ability to enrich glycosylated peptides. Thirty-two glycopeptides from human serum immunoglobulin G (IgG) tryptic digests were observed with a greatly improved signal-to-noise ratio (S/N) and also presented high performance in anti-interfering enrichment of glycopeptides from complex samples containing 100-fold bovine serum albumin tryptic digests. In addition, GO-DA-JR has higher sensitivity (1 fmol/µL IgG) and better enrichment capacity (up to 150 mg/g). Moreover, the results of glycopeptide enrichment and glycosylation analysis from human serum also show egood enrichment selectivity from real biological samples. This work exhibits high selectivity, high sensitivity, good stability and operability, indicating its potential for applications of glycopeptides enrichment in post-translational modification proteomics.

Hydrophilic polyphosphoester-conjugated fluorinated chlorin as an entirely biodegradable nano-photosensitizer for reliable and efficient photodynamic therapy.

An entirely biodegradable nano-photosensitizer platform (PPE-FP2) was fabricated by conjugating the photosensitizer TFPC to hydrophilic polyphosphoesters (PPEs) for efficiently liberating photosensitizers at the tumor site. The complete biodegradability of PPE-FP2 avoided residual nanoparticles in vivo after therapy, realizing reliable and effective photodynamic therapy.

In situ formation of fluorescent polydopamine catalyzed by peroxidase-mimicking FeCo-LDH for pyrophosphate ion and pyrophosphatase activity detection.

As pyrophosphate ion (PPi) and pyrophosphatase (PPase) play crucial roles in the pathological process of arthritis, determination of PPi and PPase in biological fluids turns to be of great importance for clinical diagnosis and therapy of arthritic diseases. In this work, we proposed a new fluorescent assay for PPi and PPase activity detection based on the competitive coordination chemistry of Fe3+ between PPi and an in situ formed fluorescent polydopamine (PDA). FeCo layered double hydroxide (FeCo-LDH) was explored as a peroxidase mimic to facilitate the in situ formation of fluorescent PDA from dopamine mediated by low-concentration H2O2 within 30 min; The formed fluorescent PDA could be significantly quenched by Fe3+ through forming a PDA-Fe3+ complex structure; When PPi existed, it coordinated Fe3+ competitively against PDA and inhibited the fluorescence quenching of PDA by Fe3+; When PPi was hydrolyzed under the catalysis of PPase, the Fe3+ ion could quench the fluorescence of the formed PDA again. With these principles, our fluorescent assay was able to detect PPi and PPase activity specifically, providing detection limits down to 54 µM and 0.13 U/L, respectively. Furthermore, accurate determination of PPi and PPase activity in spiked human serum was also demonstrated using the developed assay.

Efficient ovalbumin delivery using a novel multifunctional micellar platform for targeted melanoma immunotherapy.

Cancer immunotherapy is considered to be one of the alternatives to traditional chemotherapy. It's known that foreign antigen, such as ovalbumin (OVA), can label tumor cells, leading to neoantigen recognition by cytotoxic T lymphocytes. Herein, a novel multifunctional micelle coated with PEGylated hyaluronic acid (HA) was prepared through self-assembly and electrostatic interaction. The OVA-loaded micelle with uniform size (132.1 ±â€¯0.2 nm in diameter) exhibited favorable stability and sustained release profiles. The HA-coated micelle could target CD44-overexpressed cells and enhance the cellular uptake of OVA by 11.9 fold compared to free OVA. In vitro studies revealed that the cationic polymer, polyethyleneimine, could facilitate endosomal escape of OVA to label a tumor cell. After treatment with the OVA-loaded micelle, tumor growth in mice was significantly inhibited by 70% compared to the group treated with free OVA. All these results suggest the potential application of the immunotherapeutic micellar platform for melanoma treatment.

A functional drug delivery platform for targeting and imaging cancer cells based on Pluronic F127.

Functional polymeric micelles play an important role in the efficient delivery of therapeutic drugs into tumours. In this study, a functional drug delivery platform with ligands for targeting and fluorescent imaging was designed based on Pluronic F127 (PF127). Using folic acid (FA) and fluorescein isothiocyanate (FITC) to chemically conjugate with PF127, two functional polymers, Pluronic F127-FA (PF127-FA) and Pluronic F127-FITC (PF127-FITC), were synthesized. Solasodine-loaded micelles were then prepared via the thin-film hydration method. By employing A549 and HeLa cells, the results of in vitro cell assays performed using confocal laser scanning microscopy and flow cytometry suggested that the proposed micelles could provide the desired specific targeting and fluorescent imaging functions. In addition, the results of in vitro cytotoxicity experiments showed that the growth inhibition rates of A549 and HeLa cells treated with solasodine-loaded micelles were remarkably higher than those of cells treated with free solasodine. Solasodine-loaded micelles exhibited a more distinct inhibitory effect against HeLa cells than against A549 cells. Thus, an effective drug delivery system for targeting and imaging cancer cells was developed.

Anamperometric superoxide anion radicalbiosensor based on SOD/PtPd-PDARGO modified electrode.

In the present work, a high-performance enzyme-based electrochemical sensor for the detection of superoxide anion radical (O2(●-)) is reported. Firstly, we employed a facile approach to synthesize PtPd nanoparticles (PtPd NPs) on chemically reduced graphene oxide (RGO) coated with polydopamine (PDA). The prepared PtPd-PDARGO composite was well characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectra, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical methods. Then the assembled composite was used as a desired electrochemcial interface for superoxide dismutase (SOD) immobilization. Owing to the PDA layer as well as the synergistic effect of PtPd NPs, the fabricated SOD/PtPd-PDARGO sensor exhibited an outstanding sensitivity of 909.7 µA mM(-1) cm(-2) upon O2(●-) in a linear range from 0.016 mM to 0.24 mM (R(2)=0.992), with a low detection limit of 2 µM (S/N=3) and excellent selectivity, good reproducibility as well as favorable long-term stability.

Three monofunctional copolymers into one multifunctional Micelle: Part 1. Preparation and properties.

In the present work, we propose a new multifunctional micelle, co-self-assembled from different monofunctional copolymers, for tumor targeting and fluorescent and electron spin resonance (ESR) dual detection. Firstly, a poly(D,L-lactic acid)-b-poly(N-isopropyl methacrylamide-co-N-isopropylmaelic acid-co-10-undecenoic acid)-b-poly(N-acryloxysuccinimide) (PLA-PNNUA-PNAS) copolymer, with pH-dependent thermo-responsive properties, was synthesized. The copolymer was synthesized using reversible addition fragmentation chain transfer (RAFT) polymerization method, after which it was further used as a parent copolymer to combine with folic acid (FA), fluorescein isothiocyanate (FITC) and 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO), respectively, resulting into three new monofunctional copolymers. Finally, the multifunctional copolymer micelle was easily then fabricated, through co-self-assembly, using the monofunctional copolymers. The results from in vitro cell assays indicated that the proposed micelle was able to provide desired multifunctional properties, including tumor specific targeting and fluorescent and ESR dual detection. Additionally, the parent copolymer allowed conjugation with other ligands to prepare them for more functional copolymers attachment for future potential applications. More importantly, the multifunctional properties of the copolymer micelles could be rationally tailored, able for given purposes.

A novel lactoferrin-modified ß-cyclodextrin nanocarrier for brain-targeting drug delivery.

The blood-brain barrier (BBB) restricts the transfer and delivery of most drug substances to brain. In this study, a novel nano-drug delivery system for brain-targeting was developed and investigated in vitro and in vivo. Lactoferrin (Lf) was selected as a brain-targeting ligand and conjugated to ß-cyclodextrin (ß-CD) via the heterobifunctional polyethyleneglycol (PEG) linker NHS-PEG-MAL, yielding Lf conjugated ß-cyclodextrin (Lf-CD). UV-vis, FTIR, NMR and transmission electron microscopy (TEM) techniques clearly demonstrated the successful synthesis of Lf-CD nanoparticles with the average diameter of 92.9 ± 16.5 nm. Using near-infrared fluorescent dye IR-775 chloride (IR) as a model compound of poorly water-soluble drugs, IR-loaded Lf-CD nanoparticles (Lf-CD/IR) were successfully prepared with a high entrapment efficiency of 98.1 ± 4.8%. Biodistribution and pharmacokinetics of Lf-CD/IR were evaluated in KM mice after intravenous administration. The results of tissue distribution studies revealed that Lf-CD/IR treatment showed greatly improved BBB transport efficiency. In addition, AUC0-2h of IR in brain after Lf-CD/IR treatment was seven fold higher compared with that of IR treatment without Lf-CD nano-carriers, demonstrating that the introduction of Lf-CD drug-delivery system positively resulted in a higher AUC located in brain tissue. These results provide evidence that Lf-CD nanoparticles could be exploited as a potential brain-targeting drug delivery system for hydrophobic drugs and diagnostic reagents which normally fail to pass through the BBB.

Novel ferrocenyl nitroxide nanoparticles as electron paramagnetic resonance oximetry probes in vitro and in vivo.

AIMS: In this article we report our recent developments in the field of electron paramagnetic resonance oximetry. MATERIALS & METHODS: Novel synthesized ferrocenyl nitroxide radicals (FcN)-1-6 were evaluated to determine their electron paramagnetic resonance oxygen responsiveness and reduction resistance. The 3-ferrocenyl-N-(oxyl-2,2,6,6-tetramethylpiperidin-4-yl) butanamide radical (FcN-6), with outstanding electron paramagnetic resonance oxygen sensitivity, was encapsulated in Pluronic F-127 polymeric nanoparticles. RESULTS: The nanoparticles exhibited good oxygen sensitivity, long-term stability of responsiveness, targeting to lung, liver and tumor, and low toxicity. CONCLUSION: These features make this novel nanoparticle especially valuable for mapping O2 concentrations in the body and monitoring the oxygen level inside tissues.

[Study on the microstructure and ESR dosimetry of tetracycline-stained teeth with SEM observation and ESR measurement].

PURPOSE: To compare the microstructure and ESR dosimetry between tetracycline-stained teeth and normal teeth by means of scanning electron microscopy (SEM) and electron spin resonance (ESR) dosimeter. METHODS: Ten first or second premolars of tetracycline-stained teeth and ten normal teeth extracted for adult orthodontic persons were collected. The enamel on the surface and the dentine on the cross section of both type of teeth were observed with SEM. The ESR signal of teeth components (enamel and dentine) was evaluated by X-band ESR spectroscopy. RESULTS: Compared with normal teeth, the enamel of tetracycline-stained teeth was of porosity and the enamel prisms were irregular. The dentinal tubules and dentinal matrix also showed obvious difference between the two type of teeth. The X-band ESR spectrum of tetracycline-stained teeth was different from normal teeth. CONCLUSION: The microstructure and the native radicals have significant effect on the tetracyclines deposited in the teeth.