Pinctada martensii Hydrolysate Modulates the Brain Neuropeptidome and Proteome in Diabetic (db/db) Mice via the Gut-Brain Axis.

Pinctada martensii hydrolysate (PMH) has been proved to have the effect of ameliorating disorders of glucose and lipid metabolism in db/db mice, but the mechanism of its hyperglycemia effect is still unclear. Bacterial communities in fecal samples from a normal control group, a diabetic control group, and a PMH-treated diabetes mellitus type 2 (T2DM) group were analyzed by 16S gene sequencing. Nano LC-MS/MS was used to analyze mice neuropeptides and proteomes. The 16S rDNA sequencing results showed that PMH modulated the structure and composition of the gut microbiota and improved the structure and composition of Firmicutes and Bacteroidetes at the phylum level and Desulfovibrionaceae and Erysipelatoclostridiaceae at the family level. Furthermore, the expressions of functional proteins of the central nervous system, immune response-related protein, and proteins related to fatty acid oxidation in the brain disrupted by an abnormal diet were recovered by PMH. PMH regulates the brain neuropeptidome and proteome and further regulates blood glucose in diabetic mice through the gut-brain axis. PMH may be used as a prebiotic agent to attenuate T2DM, and target-specific microbial species may have unique therapeutic promise for metabolic diseases.

Carp scales derived double cross-linking hydrogels achieve collagen peptides sustained-released for bone regeneration.

Collagen peptide exhibits a great activity in osteogenic differentiation and wound healing. However, uncontrolled collagen peptide release in bone defects leads to unsatisfactory bone regeneration. In this work, we prepared collagen peptide loaded calcium alginate hydrogel (SA-CP/Ca) derived from Asia carp scales by mixing sodium alginate solution, collagen peptides, calcium carbonate, covalent cross-linking agents N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) in one pot. Physically and chemically double cross-linking realized higher crosslink density, smaller porosity and pore size, and higher energy storage modulus and loss modulus, achieving sustained release of collagen peptides. The release profile is fitted to Keppas-Sahlin model, to find SA-CP/Ca hydrogels are more inclined to release collagen peptides through expansion and degradation. The compatibility and osteogenic ability of SA-CP/Ca are demonstrated in vitro and in vivo.

A strategy for the enrichment and characterization of disulfide bond-contained proteins from Chinese cobra (Naja atra) venom.

A new strategy combined gold-coated magnetic nanocomposites assisted enrichment with mass spectrometry was developed for the characterization of disulfide bond-contained proteins from Chinese cobra (Naja atra) venom. In this work, core-shell nanocomposites were synthesized by the seed-mediated growth method and used for the enrichment of snake venom proteins containing disulfide bonds. A total of 3545 tryptic digested peptides derived from 96 venom proteins in Naja atra venom were identified. The venom proteins comprised 14 toxin families including three-finger toxins, phospholipase A2 , snake venom metalloproteinase, cobra venom factor, and so forth. Extra 16 venom proteins were detected exclusively in the nanocomposites set, among which 11 venom proteins were from the three-finger toxins family. In the present study, the proposed simple and efficient protocol replaced the tedious and laborious technologies commonly used for pre-separating crude snake venom, suggesting widely implementation in low-abundance or trace disulfide bond-contained proteins or peptides characterization.

Synthetic Iowaite Can Effectively Remove Inorganic Arsenic from Marine Extract.

For the removal of arsenic from marine products, iowaite was prepared and investigated to determine the optimal adsorption process of arsenic. Different chemical forms of arsenic (As(III), As(V)) with varying concentrations (0.15, 1.5, 5, 10, 15, and 20 mg/L) under various conditions including pH (3, 5, 7, 9, 11) and contact time (1, 2, 5, 10, 15, 30, 60, 120, 180 min) were exposed to iowaite. Adsorption isotherms and metal ions kinetic modeling onto the adsorbent were determined based on Langmuir, Freundlich, first- and second-order kinetic models. The adsorption onto iowaite varied depending on the conditions. The adsorption rates of standard solution, As(III) and As(V) exceeded 95% under proper conditions, while high complexity was noted with marine samples. As(III) and As(V) from Mactra veneriformis extraction all decreased when exposed to iowaite. The inclusion morphology and interconversion of organic arsenic limit adsorption. Iowaite can be efficiently used for inorganic arsenic removal from wastewater and different marine food products, which maybe other adsorbent or further performance of iowaite needs to be investigated for organic arsenic.

In Situ Imaging of Cellular Reactive Oxygen Species and Caspase-3 Activity Using a Multifunctional Theranostic Probe for Cancer Diagnosis and Therapy.

In this work, a multifunctional theranostic nanoprobe (Au-Ag-HM) was skillfully designed for simultaneous imaging of intracellular reactive oxygen species (ROS) and caspase-3 activity. The Au-Ag-HM was fabricated by coloading of silver nanoparticles (AgNPs) and hematoporphyrin monomethyl ether (HMME) to Au nanoflowers (AuNFs). When Au-Ag-HM was devoured by cancer cells, HepG2 cells were used as the model, and under laser irradiation, the photogenerated intracellular ROS by the photosensitizer HMME would induce the apoptosis of cancer cells. Meanwhile, the intracellular ROS triggered the oxidative etching of AgNPs on Au-Ag-HM, which led to a tremendous localized surface plasmon resonance response and scattering color changes in Au-Ag-HM, allowing in situ dark-field imaging of the ROS level in cancer cells. On the other hand, the ROS-induced activation of cellular caspase-3, which cleaved the C-peptide-containing caspase-3-specific recognition sequence (DEVD) and allowed HMME to release from the nanoprobe, resulted in a significant fluorescence recovery related to caspase-3 activity. Both photogenerated ROS and enhanced caspase-3 activity contributed to the synergistic effect of laser-mediated chemotherapy and photodynamic therapy. Therefore, the as-prepared theranostic probe could be used for simultaneous detection of cellular ROS and caspase-3 activity, distinguishing between tumor cells and normal cells, inducing the apoptosis of cancer cells, and providing a new method for diagnosis and therapy of cancer.

Investigation of Environmental Pollutant-Induced Lung Inflammation and Injury in a 3D Coculture-Based Microfluidic Pulmonary Alveolus System.

The health impact of environmental pollution involving an increase in human diseases has been subject to extensive study in recent decades. The methodology in biomimetic investigation of these pathophysiologic events is still in progress to uncover the gaps in knowledge associated with pollution and its influences on health. Herein, we describe a comprehensive evaluation of environmental pollutant-caused lung inflammation and injury using a microfluidic pulmonary alveolus platform with alveolar-capillary interfaces. We performed a microfluidic three-dimensional coculture with physiological microenvironment simulation at microscale control and demonstrated a reliable reconstruction of tissue layers including alveolar epithelium and microvascular endothelium with typical mechanical, structural, and junctional integrity, as well as viability. On-chip detection and analysis of pulmonary alveolus responses focusing on various inflammatory and injurious dynamics to the respective pollutant stimulations were achieved in the coculture-based microfluidic pulmonary alveolus model, in comparison with common on-chip monoculture and off-chip culture tools. We confirmed the synergistic effects of the epithelial and endothelial interfaces on the stimuli resistance and verified the importance of creating complex tissue microenvironments in vitro to explore pollution-involved human pathology. We believe the microfluidic approach presents great promise in environmental monitoring, drug discovery, and tissue engineering.

Activatable Fluorescence Imaging and Targeted Drug Delivery via Extracellular Vesicle-Like Porous Coordination Polymer Nanoparticles.

Cancer imaging with minimal background signal and targeted intracellular drug delivery are of vital importance in clinical cancer diagnosis and therapy. Herein, we developed a biomimetic nanoprobe for activated fluorescence imaging and targeted drug delivery. pH-responsive porous coordination polymer nanoparticles (PCP NPs) were first synthesized by a codeposition method, anticancer drug doxorubicin (DOX) was then loaded into PCP NPs through physical and electrostatic adsorption (PCP-DOX), and finally the cell membranes extracted from Bel-7402 cancer cells were coated on the DOX-loaded PCP NPs (PCP-DOX-CM). The fluorescence of DOX was quenched due to the fluorescence resonance energy transfer between DOX and PCP NPs. Under acidic environment inside cancer cells, PCP NPs degraded, DOX was released from PCP-DOX-CM, and the fluorescence of DOX was activated, which was very specific for cancers with a high signal-to-noise ratio. Benefited from immune escaping and homologous targeting ability from cancer cell membranes, compared with PCP-CM and PCP-DOX, PCP-DOX-CM significantly enhanced the cellular endocytosis of DOX in Bel-7402 cancer cells and exhibited excellent cancer therapy effect in vitro. Together, our work provides a useful platform for an activated cancer imaging system and personalized cancer treatment.

Theranostic Nanoprobe Mediated Simultaneous Monitoring and Inhibition of P-Glycoprotein Potentiating Multidrug-Resistant Cancer Therapy.

Multidrug resistance is a major cause of failure in the clinical cancer therapy, in which the overexpression of P-glycoprotein (P-gp) plays a crucial role. Herein, we fabricate a theranostic nanoprobe with the function of simultaneous detection and inhibition of P-gp to diagnose and combat multidrug-resistant cancer in vitro and in vivo. For constructing the nanoprobe, elacridar modified quantum dots (QDs-Ela), acting as a gatekeeper, are grafted onto the doxorubicin (DOX) loaded, folic acid (FA) decorated mesoporous silica nanoparticles (MSNs). Upon targeted uptake by multidrug-resistant cancer cells, Bel-7402/ADR are used as a model, the acidic environment results in QDs-Ela removal from the nanoprobe, and subsequent DOX release. The removed QDs-Ela could specifically combine with P-gp in the cancer cell membrane and inhibit their active sites, which prevents the efflux of intracellular DOX and increases the retention of DOX. Another way, the fluorescence intensity of the binding QDs-Ela quantifies the P-gp expression level. Subsequently, in vitro and in vivo experiments both demonstrate the enhanced multidrug-resistant cancer therapy efficacy, i.e., nanoprobe has 10 times better curative effect than free DOX. In addition, due to the conjugation of FA, the nanoprobe exhibits a selective cell targeting ability to Bel-7402/ADR cells. This nanoplatform paves a new avenue for the accurate treatment of multidrug-resistant cancers.

Highly sensitive fluorescent bioassay of 2,3,7,8-tetrachloro-dibenzo-p-dioxin based on abnormal expression of cytochrome P450 1A2 in human cells.

Current in vitro bioassays of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, a major threat carcinogen) are relied on murine cells and fluorescent probe 7-ethoxyresorufin (7-ER), in which TCDD mostly causes abnormal expression of cytochrome P450 1A1 (CYP1A1). However, for human cells, TCDD mainly leads to a distinct abnormal expression of cytochrome P450 1A2 (CYP1A2). The poor response of 7-ER to CYP1A2 limits the traditional bioassay for human cells. Herein, we report a fluorescent probe N-(3-hydroxybutyl)-4-methoxy-1,8-naphthalimide (HBMN) for in vitro bioassay of TCDD with human cells. HBMN had ca. 60 times higher affinity to CYP1A2 than 7-ER. As such, the sensing sensitivity increased by 10 times, and different expression of CYP1A2 by TCDD induction in different human cells was found. Besides, HBMN was also feasible in rapid screening of TCDD concentration by naked eye. It would open a new way to highly sensitive detect TCDD and understand the pathogenesis of TCDD in different human organs.

Determination of Benzopyrene-Induced Lung Inflammatory and Cytotoxic Injury in a Chemical Gradient-Integrated Microfluidic Bronchial Epithelium System.

Environmental pollution is one of the largest sources responsible for human diseases and premature death worldwide. However, the methodological development of a spatiotemporally controllable and high-throughput investigation of the environmental pollution-induced biological injury events is still being explored. In this study, we describe a chemical gradient generator-aided microfluidic cell system for the dynamic study of representative environmental pollutant-induced bronchial epithelium injury in a throughput manner. We demonstrated the stability and reliability of operation-optimized microfluidic system for precise and long-term chemical gradient production. We also performed a microenvironment-controlled microfluidic bronchial epithelium construction with high viability and structure integration. Moreover, on-chip investigation of bronchial epithelium injury by benzopyrene stimulation with various concentrations can be carried out in the single device. The varying bronchial inflammatory and cytotoxic responses were temporally monitored and measured based on the well-established system. The benzopyrene directionally led the bronchial epithelium to present observable cell shrinkage, cytoskeleton disintegration, Caspase-3 activation, overproduction of reactive oxygen species, and various inflammatory cytokine (TNF-α, IL-6, and IL-8) secretion, suggesting its significant inflammatory and cytotoxic effects on respiratory system. We believe the microfluidic advancement has potential applications in the fields of environmental monitoring, tissue engineering, and pharmaceutical development.

Strategy for In Situ Imaging of Cellular Alkaline Phosphatase Activity Using Gold Nanoflower Probe and Localized Surface Plasmon Resonance Technique.

In this work, a simple and ultrasensitive localized surface plasmon resonance (LSPR) method that use Au nanoflowers (AuNFs) as a probe was designed for in situ monitoring of alkaline phosphatase (ALP) activity. The AuNFs were fabricated by hydrogen tetrechloroaurate-induced oxidative disruption of polydopamine-coated Au nanoparticles (AuNPs), and subsequently, growth of Au nanopetals on AuNPs occurred. The as-prepared AuNFs showed a much higher LSPR capability and stronger scattering color change than AuNPs. The strategy for in situ cellular ALP activity detection relied on the deposition of Ag on the AuNFs surface, which changed the morphology of AuNFs and led to a tremendous LSPR response and scattering color change. The deposition of Ag shell on AuNFs was related to ALP activity, where ALP catalyzed the hydrolysis of l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate to form l-ascorbic acid (AA), and then AA reduced Ag+ to Ag and deposited onto AuNFs. With this concept, the ALP activity could be monitored with a detection limit of 0.03 µU L-1. Meanwhile, the ALP activity of single HepG2 cells and HEK 293 cells was tracked with a proposed approach, which indicated the trace expression level of ALP in HEK 293T cell and overexpressed level of ALP in HepG2 cells. After treatment with drugs, the cellular ALP activity of HepG2 cells was decreased with the treating time and dose increasing. Therefore, the proposed strategy could be used for tracking the cellular ALP activity, which paved a new avenue for cell studies and held great potential for discovering novel ALP-based drugs applications.

Ultrasensitive electrochemical detection of poly (ADP-ribose) polymerase-1 via polyaniline deposition.

Recent findings have thrust poly ADP (ADP: adenosine diphosphate)-ribose polymerase-1 (PARP-1) into the limelight as potential chemotherapeutic target because it is closely related to the development of tumor. So, studies on its detection and inhibitors evaluation have attracted more attention. It is interesting that poly (ADP-ribose) (PAR), the catalytic product of PARP-1 in the existence of nicotinamide adenine dinucleotide (NAD+), possess twice charge density of DNA strands. PAR contain 200 units, i.e., about 400bp bases, and multiple branched strands. So, plentiful negative charges on PAR supplied exquisite environment for PANI deposition, which was triggered by horseradish peroxidase (HRP). Because of the unique electrochemical property of PANI, ultrasensitive electrochemical detection of PARP-1 was proposed. Under optimum conditions, DPV intensity linearly increased with the increment of PARP-1 in the range of 0.005-1.0 U. The detection limit was 0.002 U, which was comparable or more sensitive than that obtained from previously reported strategies.

pH-sensitive metal-phenolic network capsules for targeted photodynamic therapy against cancer cells.

Photodynamic therapy (PDT) is an effective and promising method for cancer treatment, which is proposed for more than one century. However, the specific delivery of photosensitizer to target carcinoma cells to reduce the side effect is still a great challenge. This work provides a strategy to deliver photosensitizers to cancer cells by utilizing pH-sensitive polyethylene glycol metal-phenolic network (PEG-MPN) capsules to encapsulate haematoporphyrin monomethyl ether (HMME). With the assistance of folic acid (FA), HMME-doped PEG-MPN capsules (MPN@HMMEs) accumulate in carcinoma cells selectively followed by releasing HMME in the lysosomes because of the physiologically relevant acidic pH environment. From the fluorescent ratiometric sensing and reactive oxygen species (ROS) regionality distribution of MPN@HMMEs, we demonstrated the encapsulated photosensitizers are diffused from lysosomes to cytoplasm. Under irradiation at 638 nm laser, ROS generated from the photosensitizers induced cancer cells undergoing apoptosis while normal cells survive. Therefore, MPN@HMME could be applied as a new strategy for targeted PDT against cancer and PEG-MPN capsules are expected to be general carries for drug delivering.

In Situ Detection and Imaging of Telomerase Activity in Cancer Cell Lines via Disassembly of Plasmonic Core-Satellites Nanostructured Probe.

The label-free localized surface plasmon resonance (LSPR) detection technique has been identified as a powerful means for in situ investigation of biological processes and localized chemical reactions at single particle level with high spatial and temporal resolution. Herein, a core-satellites assembled nanostructure of Au50@Au13 was designed for in situ detection and intracellular imaging of telomerase activity by combining plasmonic resonance Rayleigh scattering spectroscopy with dark-field microscope (DFM). The Au50@Au13 was fabricated by using 50 nm gold nanoparticles (Au50) as core and 13 nm gold nanoparticles (Au13) as satellites, both of them were functionalized with single chain DNA and gathered proximity through the highly specific DNA hybridization with a nicked hairpin DNA (O1) containing a telomerase substrate (TS) primer as linker. In the presence of telomerase, the telomeric repeated sequence of (TTAGGG)n extended at the 3'-end of O1 would hybridized with its complementary sequences at 5'-ends. This led the telomerase extension product of O1 be folded to form a rigid hairpin structure. As a result, the Au50@Au13 was disassembled with the releasing of O1 and Au13-S from Au50-L, which dramatically decreased the plasmon coupling effect. The remarkable LSPR spectral shift was observed accompanied by a detectable color change from orange to green with the increase of telomerase activity at single particle level with a detection limit of 1.3 × 10-13 IU. The ability of Au50@Au13 for in situ imaging intracellular telomerase activity, distinguishing cancer cells from normal cells, in situ monitoring the variation of cellular telomerase activity after treated with drugs were also demonstrated.

Confining a bi-enzyme inside the nanochannels of a porous aluminum oxide membrane for accelerating the enzymatic reactions.

An artificial metabolon with high conversion efficiency was constructed by confining a bi-enzyme into porous aluminum oxide nanochannels, which accelerated enzymatic reactions by minimizing the diffusion loss of intermediate species.