Role of Gastrointestinal Microbiota from Crucian Carp in Microbial Transformation and Estrogenicity Modification of Novel Plastic Additives.

Ingestion is a major exposure route for hydrophobic organic pollutants in fish, but the microbial transformation and estrogenic modification of the novel plastic additives by the gut microbiota of fish remain obscure. Using an in vitro approach, we provide evidence that structure-related transformation of various plastic additives by the gastric and intestinal (GI) microbiota from crucian carp, with the degradation ratio of bisphenols and triphenyl phosphate faster than those of brominated compounds. The degradation kinetics for these pollutants could be limited by oxygen and cometabolic substrates (i.e., glucose). The fish GI microbiota could utilize the vast majority of carbon sources in a Biolog EcoPlate, suggesting their high metabolic potential and ability to transform various organic compounds. Unique microorganisms associated with transformation of the plastic additives including genera of Citrobacter, Klebsiella, and some unclassified genera in Enterobacteriaceae were identified by combining high-throughput genetic analyses and metagenomic analyses. Through identification of anaerobic transformation products by high-resolution mass spectrometry, alkyl-cleavage was found the common transformation mechanism, and hydrolysis was the major pathway for ester-containing pollutants. After anaerobic incubation, the estrogenic activities of triphenyl phosphate and bisphenols A, F, and AF declined, whereas that of bisphenol AP increased.

Dansyl-labelled cellulose as dual-functional adsorbents for elimination and detection of mercury in aqueous solution via aggregation-induced emission.

Dansyl chloride fluorophore exhibits typical aggregation induced fluorescence emission behavior in acetone/water solution. To realize the integration of detective and adsorptive functions, dansyl chloride is covalently immobilized on cellulose substrate to fabricate an efficient adsorbent for mercury ions in water. The as-prepared material exhibits excellent fluorescence sensing performance exclusively for Hg (II) with the presence of other metal ions. A sensitive and selective fluorescence quenching across the concentration range of 0.1-8.0 mg/L is observed with a detection limit of 8.33 × 10-9 M as a result of the inhibition of aggregation induced emission caused by the coordination between adsorbent and Hg (II). Besides, the adsorption properties for Hg (II) including the influence of initial concentration and contact time are investigated. Langmuir model and pseudo-second-order kinetics are demonstrated to fit well with the adsorption experiment for the uptake of Hg (II) by the functionalized adsorbent, also, intraparticle diffusion kinetic model is proved to aptly describe the Hg (II) removal in aqueous solution. In addition, the recognition mechanism is considered to originate from the Hg (II) triggered structural reversals of naphthalene ring units which are verified by the X-ray photoelectron spectroscopy and density functional theory calculation. Moreover, the synthesis method used in this work also provides a strategy for the sensing application of organic sensor molecules with AIE properties in which the aggregated behavior could be appropriately realized.

Multifunctional Immunoliposomes Enhance the Immunotherapeutic Effects of PD-L1 Antibodies against Melanoma by Reprogramming Immunosuppressive Tumor Microenvironment.

The immunosuppressive tumor microenvironment (TME) can significantly limit the immunotherapeutic effects of the PD-L1 antibody (aPDL1) by inhibiting the infiltration of CD8+ cytotoxic T cells (CTLs) into the tumor tissues. However, how to reprogram the immunosuppressive TME and promote the infiltration of CTLs remains a huge challenge for aPDL1 to achieve the maximum benefits. Herein, the authors design a multifunctional immunoliposome that encapsulates the adrenergic receptor blocker carvedilol (CAR) and connects the "don't eat me" signal antibody (aCD47) and aPDL1 in series via a reactive oxygen species (ROS)-sensitive linker on the surface. In ROS-enriched immunosuppressive TME, the multifunctional immunoliposome (CAR@aCD47/aPDL1-SSL) can first release the outer aCD47 to block the "do not eat me" pathway, promote the phagocytosis of tumor cells by phagocytic cells, and activate CTLs. Then, the aPDL1 on the liposome surface is exposed to block the PD-1/PD-L1 signaling pathway, thereby inducing CTLs to kill tumor cells. CAR encapsulated in CAR@aCD47/aPDL1-SSL can block the adrenergic nerves in the tumor tissues and reduce their densities, thereby inhibiting angiogenesis in the tumor tissues and reprogramming the immunosuppressive TME. According to the results, CAR@aCD47/aPDL1-SSL holds an effective way to reprogram the immunosuppressive TME and significantly enhance immunotherapeutic efficiency of aPDL1 against the primary cancer and metastasis.

Comparison of fundus changes following silicone oil and sterilized air tamponade for macular-on retinal detachment patients.

BACKGROUND: To investigate different tamponade effects of intravitreal silicone oil (SO) and sterilized air on macular vasculature and structure after successful retinal repair for macular-on rhegmatogenous retinal detachment (RRD) patients. METHOD: 21 eyes (21 patients) with macular-on RRD underwent single pars plana vitrectomy following intravitreal SO or sterilized air (Gas) tamponade. Optical Coherence Tomography (OCT) and angiography were used to evaluate retinal layer thickness and flow density (FD) changes throughout the observation period of 12 weeks. Retinal layers were segmented into 7 sets: NFL, GCL + IPL, INL, OPL, ONL + IS, OS+RPE and BRM. Macular perfusion system was segmented into superficial and deep capillary plexus flow density (SCPFD, DCPFD), and choriocapillaries plexus flow density (CCPFD). RESULT: Compared to Gas tamponade, SO tamponade led to more decrease in both superficial and deep retinal blood flow during observation. NFL thickness was found to decrease in both Gas tamponade and SO tamponade eyes. SO tamponade resulted in more pronounced decrease which led to significant intergroup difference. Opposite changing trends were found in GCL + IPL and ONL + IS thicknesses due to different means of tamponade. SO tamponade caused thicknesses of these two segmented layers to decrease, which led to significant intergroup differences. SO tamponade also led to more decrease in INL, OPL thicknesses. No significant intergroup difference of choroidal thickness was observed. CONCLUSION: Compared to gas, silicone oil could have more negative tamponade effects on both fundus vasculature and structure.

Performance and diversity of polyvinyl alcohol-degrading bacteria under aerobic and anaerobic conditions.

OBJECTIVES: To compare the degradation performance and biodiversity of a polyvinyl alcohol-degrading microbial community under aerobic and anaerobic conditions. RESULTS: An anaerobic-aerobic bioreactor was operated to degrade polyvinyl alcohol (PVA) in simulated wastewater. The degradation performance of the bioreactor during sludge cultivation and the microbial communities in each reactor were compared. Both anaerobic and aerobic bioreactors demonstrated high chemical oxygen demand removal efficiencies of 87.5 and 83.6 %, respectively. Results of 16S rDNA sequencing indicated that Proteobacteria dominated in both reactors and that the microbial community structures varied significantly under different operating conditions. Both reactors obviously differed in bacterial diversity from the phyla Planctomycetes, Chlamydiae, Bacteroidetes, and Chloroflexi. Betaproteobacteria and Alphaproteobacteria dominated, respectively, in the anaerobic and aerobic reactors. CONCLUSIONS: The anaerobic-aerobic system is suitable for PVA wastewater treatment, and the microbial genetic analysis may serve as a reference for PVA biodegradation.

Orthogonal Supramolecular Polymer Formation on Highly Oriented Pyrolytic Graphite (HOPG) Surfaces Characterized by Scanning Probe Microscopy.

Formation of an orthogonal supramolecular polymer on a highly oriented pyrolytic graphite (HOPG) surface was demonstrated for the first time by means of scanning probe microscopy (SPM). Atomic force microscopy (AFM) was employed to characterize the variation of both the thickness and the topography of the film formed from (1) monomer 1, (2) monomer 1/Zn(2+), and (3) monomer 1/Zn(2+)/cross-linker 2, respectively. Scanning tunneling microscopy (STM) was used to monitor the self-assembly behavior of monomer 1 itself, as well as 1/Zn(2+) ions binary system on graphite surface, further testifying for the formation of linear polymer via coordination interaction at the single molecule level. These results, given by the strong surface characterization tool of SPM, confirm the formation of the orthogonal polymer on the surface of graphite, which has great significance in regard to fabricating a complex superstructure on surfaces.

Coupling Infusion and Gyration for the Nanoscale Assembly of Functional Polymer Nanofibers Integrated with Genetically Engineered Proteins.

Nanofibers featuring functional nanoassemblies show great promise as enabling constituents for a diverse range of applications in areas such as tissue engineering, sensing, optoelectronics, and nanophotonics due to their controlled organization and architecture. An infusion gyration method is reported that enables the production of nanofibers with inherent biological functions by simply adjusting the flow rate of a polymer solution. Sufficient polymer chain entanglement is obtained at Berry number > 1.6 to make bead-free fibers integrated with gold nanoparticles and proteins, in the diameter range of 117-216 nm. Integration of gold nanoparticles into the nanofiber assembly is followed using a gold-binding peptide tag genetically conjugated to red fluorescence protein (DsRed). Fluorescence microscopy analysis corroborated with Fourier transform infrared spectroscopy (FTIR) data confirms the integration of the engineered red fluorescence protein with the nanofibers. The gold nanoparticle decorated nanofibers having red fluorescence protein as an integral part keep their biological functionality including copper-induced fluorescence quenching of the DsRed protein due to its selective Cu(+2) binding. Thus, coupling the infusion gyration method in this way offers a simple nanoscale assembly approach to integrate a diverse repertoire of protein functionalities into nanofibers to generate biohybrid materials for imaging, sensing, and biomaterial applications.

Human dental pulp stem cell-derived exosomes decorated titanium scaffolds for promoting bone regeneration.

Exosomes, nanoscale extracellular vesicles crucial for intercellular communication, hold great promise as a therapeutic avenue in cell-free tissue regeneration. In this study, we identified and utilized exosomes to adorn anodized titanium scaffolds, inducing osteogenic differentiation in human dental pulp stem cells (hDPSCs). The osteogenesis of hDPSCs was stimulated by exosomes derived from hDPSCs that underwent various periods of osteogenic differentiation. After purification, these exosomes were loaded onto anodized titanium scaffolds. Notably, the scaffolds loaded with exosomes deriving from osteogenic differentiated hDPSCs demonstrated superior bone tissue regeneration compared to those loaded with exosomes deriving from hDPSCs within 10-week. RNA-sequencing analysis shed light on the underlying mechanism, revealing that the osteogenic exosomes carried specific cargo, which is due to upregulated miRNAs (Hsa-miR-29c-5p, Hsa-miR-378a-5p, Hsa-miR-10b-5p and Hsa-miR-9-3p) associated with osteogenesis. And down-regulated anti-osteogenic miRNA (Hsa-miR-31-3p, Hsa-miR-221-3p, Hsa-miR-183-5p and Hsa-miR-503-5p). In conclusion, the identification and utilization of exosomes derived from osteogenic differentiated stem cells offer a novel and promising strategy for achieving cell-free bone regeneration.

Insight into coagulation/flocculation mechanisms on microalgae harvesting by ferric chloride and polyacrylamide in different growth phases.

FeCl3 and polyacrylamide (PAM) had been used to investigate the effect of coagulation, flocculation, and their combination on algae cells and extracellular organic matter (EOM) at different phases. PAM tended to aggregate particle-like substances, while FeCl3 could interact with EOM. The content of EOM kept rising during the algae growth cycle, while OD680 peaked at about 3.0. At stationary phase Ⅰ, the removal efficiencies of UV254, turbidity and OD680 of the suspension conditioned with FeCl3 + PAM reached (88.08 ± 0.89)%, (89.72 ± 0.36)% and (93.99 ± 0.05)%, respectively. Nevertheless, PAM + FeCl3 exhibited the worst efficiency because of the release of EOM caused by the turbulence. The results suggested that algal cells served as a coagulation aid to facilitate floc formation, while excessive EOM deteriorated harvesting performance. The process of FeCl3 + PAM at stationary phase Ⅰ appears to be a promising technology for microalgae harvesting.

Effects of irrigation scheduling on the yield and irrigation water productivity of cucumber in coconut coir culture.

Optimum irrigation scheduling is important for ensuring high yield and water productivity in substrate-cultivated vegetables and is determined based on information such as substrate water content, meteorological parameters, and crop growth. The aim of this study was to determine a precise irrigation schedule for coconut coir culture in a solar greenhouse by comparing the irrigation, evapotranspiration (ET), substrate water content (VWC), as well as the crop growth indices and yield of cucumber, and irrigation water productivity (IWP) under three irrigation schedules: the soil moisture sensor-based method (T-VWC), the accumulated radiation combined with soil moisture sensor-based method (Rn-VWC), and the crop evapotranspiration estimated method using the hourly PM-ETo equation with an improved calculation of Kc (T-ETc). The results showed that the daily irrigation and evapotranspiration amount were the highest under T-VWC treatment, while the lowest under T-ETc treatment. In different meteorological environments, the change in irrigation amount was more consistent with the ET,and the VWC was relatively stable in T-ETc treatment compared with that under T-VWC or Rn-VWC treatments. The plant height, leaves number, leaf area, and stem diameter of T-VWC and Rn-VWC treatments were higher than those of the T-ETc treatments, but there was no significant difference in cucumber yield. Compared with the T-VWC treatment, total irrigation amount under Rn-VWC and T-ETc treatments significantly decreased by 25.75% and 34.04%, respectively ([Formula: see text]). The highest IWP values of 25.07 kg m[Formula: see text] was achieved from T-ETc treatment with significantly increasing by 44.33% compared to the T-VWC treatment (17.37 kg m[Formula: see text]). In summary, the T-ETc treatment allowed more reasonable irrigation management and was appropriate for growing cucumber in coconut coir culture.

Demethylation of lignin with mild conditions and preparation of green adhesives to reduce formaldehyde emissions and health risks.

Demethylated lignin (DL) was prepared in a NaOH/urea solution at room temperature, and the DL solution was directly substituted for phenol to prepare demethylated lignin phenol formaldehyde (DLPF). The 1H NMR results showed that the benzene ring's -OCH3 content dropped from 0.32 mmol/g to 0.18 mmol/g, whereas the functional group content of the phenolic hydroxyl group increased by 176.67 %, increasing the reactivity of DL. The bonding strength of 1.24 MPa and formaldehyde emission of 0.059 mg/m3 met the Chinese national standard with a 60 % replacement of DL with phenol. The volatile organic compound (VOC) emissions of DLPF and PF were simulated, with 25 types of VOCs were found in PF plywood and 14 types found in DLPF plywood. Terpene and aldehyde emissions from DLPF plywood rose, but total VOC emissions were 28.48 % less than those from PF. For carcinogenic risks (CR), both PF and DLPF showed ethylbenzene and naphthalene as carcinogenic VOCs, whereas DLPF had a lower total CR of 6.50 × 10-5. Both plywood had a noncarcinogenic risks of <1, which was within the permissible range to harm humans. In this study, the mild modification conditions of DL benefit its large-scale production, and DLPF effectively reduces the VOCs released from plywood in indoor environments, diminishing the health risks to humans.

A study on the antibacterial property and biocompatibility of ramie fiber.

Ramie fiber (RF) has excellent tensile strength and breathability, making it a promising material for biomedical applications. However, few studies on the antibacterial properties and biocompatibility of RF have been reported. This study aimed to investigate the antibacterial property and biocompatibility of RF with bacteria and fibroblasts. The results showed that the antibacterial activity of RF was better than that of natural cotton fiber (NCF) and close to that of medical cotton fiber (MCF) for bothStaphylococcus aureus(S. aureus) andEscherichia coli(E.coli), and RF was more antibacterial againstS. aureusthanE.coli. The RF, MCF and NCF promoted the proliferation and spread of mouse fibroblast (L929) cells. The results indicated that RF has excellent antibacterial properties and biocompatibility, making it a potential biomaterial for biomedical applications.

Strategy of Stem Cell Transplantation for Bone Regeneration with Functionalized Biomaterials and Vascularized Tissues in Immunocompetent Mice.

The use of human bone marrow mesenchymal stem cells (hBMSCs) to regenerate and repair bone tissue defects is a complex research field of bone tissue engineering; nevertheless, it is a hot topic. One of the biggest problems is the limited survival and osteogenic capacity of the transplanted cells within the host tissue. Even for hBMSCs with their low immunogenicity, the body will still cause a local immune-inflammatory response directed against the allogeneic cells and thereby reduce the activity of the transplanted cells. Even in the case of successful transplantation, the lack of vascularization at the transplantation site makes it difficult for the transplanted cells to exchange nutrients and metabolic wastes that ultimately affects bone regeneration. In this study, we covalently modified alginate with RGD and QK peptides that were injected subcutaneously into immunocompetent mice. Histological analysis, as well as ELISA techniques, proved that this method is able to provide bioactive stem cell transplant beds containing functionalized biomaterials and vascularized surrounding tissues. Inflammation-related factors, such as IL-2, IL-6, TNF-α, and IFN-γ, around the cell graft beds decreased with time and were lowest at the second week. Then, the hBMSCs were injected into the cell transplantation beds intended to form vascularized bonelike tissues that were evaluated by micro-computed tomography (Micro CT), histological, and immunohistochemical analyses. The results showed that the expression of osteogenesis-related proteins RUNX2, COL1A1, and OPN, as well as the expression of angiogenic factor vWF and cartilage-related protein COL2A1 were significantly upregulated in the hBMSC-derived osteogenic tissue. These results suggest that the stem cell transplantation strategy by constructing bioactive cell transplant beds is effective to enhance the bone regeneration capacity of hBMSCs and holds great potential in bone tissue engineering.

Silver(I) metal-organic framework-embedded polylactic acid electrospun fibrous membranes for efficient inhibition of bacteria.

With recent outbreaks of fatal strains of diseases and the emergency of antibiotic resistance, there is a pressing demand to discover bactericidal materials that can effectively reduce or prevent infections by pathogenic bacteria. Herein, silver(I) metal organic frameworks Ag2(HBTC) were embedded into biocompatible polylactic acid (PLA) fibrous membranes through an electrospinning process as an antibiotic-free material for effective bacterial killing. The as-synthesized Ag2(HBTC)/PLA composite membrane showed an inactivation efficiency of more than 99.9% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) at a concentration of 200-250 mg L-1. Mechanistic investigation indicated that the steady release of Ag+ ions and ˙OH generation from the composites contributed to the efficient antibacterial activities through irreversible damage to the bacterial cell membranes. In-depth proteomic analysis demonstrated that Ag2(HBTC)/PLA exerted a biological effect towards bacterial cells through down-regulating functional proteins, thereby destroying the central biochemical pathways of the cellular energy metabolism process, reducing resistance to oxidative damage and inhibiting cell division. In general, this study shows a promising perspective on designing MOF/PLA membranes with broad-spectrum disinfection capability for potential environmental sterilization and public healthcare protection.

A flexible fibrous membrane based on copper(II) metal-organic framework/poly(lactic acid) composites with superior antibacterial performance.

A flexible antibacterial fibrous membrane employing high antibacterial efficiency has great potential in healthcare applications. Herein, a three-dimensional copper(ii) metal-organic framework [Cu2(CA)(H2O)2, Cu-MOF-1] and poly(lactic acid) (PLA) composite fibrous membrane was prepared through a facile electrospinning method. The sphere-like Cu-MOF-1 was rapidly synthesized by a microwave-assisted hydrothermal reaction of Cu(ii) salts with citric acid (H4CA) in the presence of polyvinyl pyrrolidone (PVP). The surface morphology, thermal stability, mechanical properties and hydrophilicity test of the as-prepared Cu-MOF-1/PLA fibrous membrane were studied systematically. Compared with commercial copper nanoparticles (Cu-NPs), citric acid and copper citrate, Cu-MOF-1 showed higher antibacterial properties with the bacteriostatic rates of 97.9% and 99.3% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, when the used dose was 250 µg mL-1. The Cu-MOF-1/PLA fibrous membrane also exhibited outstanding bactericidal activities against E. coli and S. aureus with the antibacterial rates up to 99.3% and 99.8%, respectively. Mechanism investigation indicated that the slowly released Cu2+ ions could destroy the microenvironment of bacteria cells and destroy the integrity and permeability of the cell membrane, leading to enzyme inactivation. Therefore, the as-prepared flexible fibrous membrane will advance progress toward developing a broad spectrum antibacterial textile for healthcare protection related applications.

Titanium carbide/zeolite imidazole framework-8/polylactic acid electrospun membrane for near-infrared regulated photothermal/photodynamic therapy of drug-resistant bacterial infections.

Bacteria induced wound infection has become fatal healthcare issues needed to be resolved urgently. It is of vital importance to develop multifunctional therapeutic platforms to fight against increased bacterial antibiotic resistance. Herein, a titanium carbide (MXene)/zeolite imidazole framework-8 (ZIF-8)/polylactic acid (PLA) composite membrane (MZ-8/PLA) was fabricated through in-situ growth of ZIF-8 on MXene and the subsequent electrospinning process. It indicated MZ-8 can generate singlet oxygen and hyperthermia at photothermal (PTT) convention efficiency of 80.5% with bactericidal rate of more than 99.0%. In addition, MZ-8 showed remarkable antitumor efficiency in vitro and in vivo based on the combined photodynamic/photothermal therapy. Theoretical calculation illustrated MZ-8 could improve the laser activation process by acceleration of intermolecular charge transfer, reducing excitation energy, stabilizing excited states and increasing intersystem crossing rate. After incorporated into electrospun scaffolds, MZ-8/PLA exhibited potent PTT and photodynamic therapy (PDT) properties under 808 nm laser irradiation. The antibacterial rates of MZ-8/PLA were up to 99.9% and 99.8% against Escherichia coli and Methicillin-resistant staphylococcus aureus, respectively. In-vivo experimental results further confirmed that MZ-8/PLA can accelerate bacteria infected wound healing without observable resistance. This work opens a new avenue to design promising platforms for fighting against extremely drug resistant bacterial infection.

Specific complexes derived from extracellular matrix facilitate generation of structural and drug-responsive human salivary gland microtissues through maintenance stem cell homeostasis.

Three-dimensional cultured salivary glands (SGs) microtissues hold great potentials for clinical research. However, most SGs microtissues still lack convincing structure and function due to poor supplementation of factors to maintain stem cell homeostasis. Extracellular matrix (ECM) plays a crucial role in regulating stem cell behavior. Thus, it is necessary to model stem cell microenvironment in vitro by supplementing culture medium with proteins derived from ECM. We prepared specific complexes from human SG ECM (s-Ecx) and analyzed the components of the s-Ecx. Human SG epithelial and mesenchymal cells were used to generate microtissues, and the optimum seeding cell number and ratio of two cell types were determined. Then, the s-Ecx was introduced to the culture medium to assess its effect on stem cell behavior. Multiple specific factors were presented in s-Ecx. s-Ecx promoted maintenance of the stem cell and formation of specific structures resembling that of salivary glands and containing mucins, which suggested stem cell differentiation potential. Moreover, treatment of the microtissues with s-Ecx increased their sensitivity to neurotransmitters. On the basis of the analysis of components, we believed that the presented growth factors are able to interact with stem cell they encountered in vivo, which promote the capacity to maintain stem cell homeostasis. This work provided foundations to study molecular mechanism of stem cell homeostasis in SGs and develop novel therapies for dry mouth through new drug discovery and disease modeling.

Effect of indoor environmental exposure on seminal microbiota and its application in body fluid identification.

Semen is a common body fluid type in forensic sexual assault cases. It is of great significance to effectively identify semen for restoring the crime scene and determining the nature of the case. Nowadays, microbiome-based method shows as a promising tool for forensic body fluid identification. To explore the environmental impact on microbial community of semen and its traceability, 16S rDNA high-throughput sequencing was conducted to ten paired semen samples. Affected by exposure, the diversity of microbial community decreased generally as the genus Staphylococcus exhibited a relatively significant increase. However, the genus Staphylococcus, Corynebacterium, Corynebacterium_1 were observed in almost all 20 samples. Community barplot analysis and heatmap analysis showed composition of the predominant microbe in semen at the phyla and genus level maintained basically, so that it could distinguish from vaginal fluid and saliva regardless of environmental exposure. Based on these results, we believe the application of single microbial marker may limit in semen identification, but the method depending on microbial community might be useful for distinguishing semen even under indoor exposure.

Multifunctional Immunoliposomes Combining Catalase and PD-L1 Antibodies Overcome Tumor Hypoxia and Enhance Immunotherapeutic Effects Against Melanoma.

BACKGROUND: Immune checkpoint blockades (ICBs) are a promising treatment for cancers such as melanoma by blocking important inhibitory pathways that enable tumor cells to evade immune attack. Programmed death ligand 1 monoclonal antibodies (aPDL1s) can be used as an ICB to significantly enhance the effectiveness of tumor immunotherapy by blocking the PD-1/PD-L1 inhibitory pathway. However, the effectiveness of aPDL1s may be limited by low selectivity in vivo and immunosuppressed tumor microenvironment including hypoxia. PURPOSE: To overcome the limitations, we develop a multifunctional immunoliposome, called CAT@aPDL1-SSL, with catalase (CAT) encapsulated inside to overcome tumor hypoxia and aPDL1s modified on the surface to enhance immunotherapeutic effects against melanoma. METHODS: The multifunctional immunoliposomes (CAT@aPDL1-SSLs) are prepared using the film dispersion/post-insertion method. The efficacy of CAT@aPDL1-SSLs is verified by multiple experiments in vivo and in vitro. RESULTS: The results of this study suggest that the multifunctional immunoliposomes preserve and protect the enzyme activity of CAT and ameliorate tumor hypoxia. Moreover, the enhanced cellular uptake of CAT@aPDL1-SSLs in vitro and their in vivo biodistribution suggest that CAT@aPDL1-SSLs have great targeting ability,resulting in improved delivery and accumulation of immunoliposomes in tumor tissue.Finally, by activating and increasing the infiltration of CD8+ T cells at the tumor site, CAT@aPDL1-SSLs inhibit the growth of tumor and prolong survival time of mice,with low systemic toxicity. CONCLUSION: In conclusion, the multifunctional immunoliposomes developed and proposed in this study are a promising candidate for melanoma immunotherapy, and could potentially be combined with other cancer therapies like radiotherapy and chemotherapy to produce positive outcomes.

Sequential stimulation with different concentrations of BMP4 promotes the differentiation of human embryonic stem cells into dental epithelium with potential for tooth formation.

BACKGROUND: Tooth loss caused by caries or injuries has a negative effect on human health; thus, it is important to develop a reliable method of tooth regeneration. Research on tooth regeneration has mainly focused on mouse pluripotent stem cells, mouse embryonic stem cells, and adult stem cells from various sources in mice, whereas little has examined the differentiation of human embryonic stem (hES) cells into dental epithelium (DE) and odontogenic potential in vivo. METHODS: In this study, we induced hES cells to differentiate into dental epithelium using different concentrations of bone morphogenetic protein 4 (BMP4). With 1 pM BMP4, the hES cells differentiated into oral ectoderm (OE). These cells were then stimulated with 30 pM BMP4. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunofluorescence showed the differentiation of OE and DE. The DE generated was mixed with embryonic day 14.5 mouse dental mesenchyme (DM) and transplanted into the renal capsules of nude mice. Thirty days later, the resulting tooth-like structures were examined by micro-computed tomography and hematoxylin and eosin staining. RESULTS: After 4 days of 1 pM BMP4 stimulation, Pitx1-positive OE formed. qRT-PCR and immunofluorescence revealed that induction with 30 pM BMP4 for 2 days caused the OE to differentiate into Pitx2/Dlx2/AMBN-positive DE-like cells. These cells also expressed ß-catenin and p-Smad1/5/8, which are key proteins in the Wnt/ß-catenin and Bmp signaling pathways, respectively. Thirty days after in vivo transplantation, six teeth with enamel and dentin had formed on the kidney. CONCLUSIONS: These results show that hES cells differentiated into DE after sequential stimulation with different concentrations of BMP4, and the DE thus generated showed odontogenic potential.