Gaussian curvature-driven direction of cell fate toward osteogenesis with triply periodic minimal surface scaffolds.

Leaf photosynthesis, coral mineralization, and trabecular bone growth depend on triply periodic minimal surfaces (TPMSs) with hyperboloidal structure on every surface point with varying Gaussian curvatures. However, translation of this structure into tissue-engineered bone grafts is challenging. This article reports the design and fabrication of high-resolution three-dimensional TPMS scaffolds embodying biomimicking hyperboloidal topography with different Gaussian curvatures, composed of body inherent ß-tricalcium phosphate, by stereolithography-based three-dimensional printing and sintering. The TPMS bone scaffolds show high porosity and interconnectivity. Notably, compared with conventional scaffolds, they can reduce stress concentration, leading to increased mechanical strength. They are also found to support the attachment, proliferation, osteogenic differentiation, and angiogenic paracrine function of human mesenchymal stem cells (hMSCs). Through transcriptomic analysis, we theorize that the hyperboloid structure induces cytoskeleton reorganization of hMSCs, expressing elongated morphology on the convex direction and strengthening the cytoskeletal contraction. The clinical therapeutic efficacy of the TPMS scaffolds assessed by rabbit femur defect and mouse subcutaneous implantation models demonstrate that the TPMS scaffolds augment new bone formation and neovascularization. In comparison with conventional scaffolds, our TPMS scaffolds successfully guide the cell fate toward osteogenesis through cell-level directional curvatures and demonstrate drastic yet quantifiable improvements in bone regeneration.

A single cell RNA sequence atlas of the early Drosophila larval eye.

The Drosophila eye has been an important model to understand principles of differentiation, proliferation, apoptosis and tissue morphogenesis. However, a single cell RNA sequence resource that captures gene expression dynamics from the initiation of differentiation to the specification of different cell types in the larval eye disc is lacking. Here, we report transcriptomic data from 13,000 cells that cover six developmental stages of the larval eye. Our data show cell clusters that correspond to all major cell types present in the eye disc ranging from the initiation of the morphogenetic furrow to the differentiation of each photoreceptor cell type as well as early cone cells. We identify dozens of cell type-specific genes whose function in different aspects of eye development have not been reported. These single cell data will greatly aid research groups studying different aspects of early eye development and will facilitate a deeper understanding of the larval eye as a model system.

Integrative genomic analyses reveal putative cell type-specific targets of the Drosophila ets transcription factor Pointed.

The Ets domain transcription factors direct diverse biological processes throughout all metazoans and are implicated in development as well as in tumor initiation, progression and metastasis. The Drosophila Ets transcription factor Pointed (Pnt) is the downstream effector of the Epidermal growth factor receptor (Egfr) pathway and is required for cell cycle progression, specification, and differentiation of most cell types in the larval eye disc. Despite its critical role in development, very few targets of Pnt have been reported previously. Here, we employed an integrated approach by combining genome-wide single cell and bulk data to identify putative cell type-specific Pnt targets. First, we used chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq) to determine the genome-wide occupancy of Pnt in late larval eye discs. We identified enriched regions that mapped to an average of 6,941 genes, the vast majority of which are novel putative Pnt targets. Next, we integrated ChIP-seq data with two other larval eye single cell genomics datasets (scRNA-seq and snATAC-seq) to reveal 157 putative cell type-specific Pnt targets that may help mediate unique cell type responses upon Egfr-induced differentiation. Finally, our integrated data also predicts cell type-specific functional enhancers that were not reported previously. Together, our study provides a greatly expanded list of putative cell type-specific Pnt targets in the eye and is a resource for future studies that will allow mechanistic insights into complex developmental processes regulated by Egfr signaling.

CD4+ T cells inhibit the generation of CD8+ epidermal-resident memory T cells directed against clinically relevant contact allergens.

BACKGROUND: CD8+ epidermal-resident memory T (TRM ) cells play central roles in local flare-up responses to experimental contact allergens by inducing massive influx of neutrophils to the epidermis upon allergen challenge. Whether similar immunopathogenic mechanisms are involved in the responses to clinically relevant contact allergens is unknown. METHODS: The immune response to cinnamal, ρ-phenylenediamine (PPD) and methylisothiazolinone (MI) was studied in a well-established mouse model for allergic contact dermatitis that includes formation of TRM cells by ELISA, flow cytometry, fluorescence microscopy analyses and cell depletion protocols. RESULTS: We show that the formation of CD4+ and CD8+ epidermal TRM cells and the inflammatory response are highly allergen-dependent. However, the magnitude of the flare-up responses correlated with the number of epidermal CD8+ TRM cells, CXCL1/CXCL2 release and recruitment of neutrophils to the epidermis. Finally, depletion of CD4+ T cells strongly enhanced the number of epidermal CD8+ TRM cells, the flare-up response and the epidermal infiltration of neutrophils for all allergens. CONCLUSION: As the first, this study demonstrates that clinically relevant contact allergens have the ability to generate pathogenic, epidermal CD8+ TRM cells that recruit neutrophils following re-exposure to the allergen, but that this normally is counteracted by the simultaneous induction of anti-inflammatory CD4+ T cells.

The junctional adhesion molecule-like protein (JAML) is important for the inflammatory response during contact hypersensitivity.

BACKGROUND: The junctional adhesion molecule-like protein (JAML) plays important roles in wound healing and activation of epidermal γδ T cells in mice. Whether JAML plays a role in contact hypersensitivity (CHS), the animal model of allergic contact dermatitis (ACD), is not known. METHODS: To examine the role of JAML in CHS, we used various mouse models of CHS in JAML knockout (KO) and wild-type (WT) mice. Furthermore, the expression of the JAML ligand coxsackievirus and adenovirus receptor (CXADR) on keratinocytes was accessed in vitro and in vivo. RESULTS: JAML KO mice had a diminished inflammatory response during both the sensitization and elicitation phase of CHS and had reduced numbers of CD8+ and CD4+ T cells in the epidermis. Furthermore, interferon γ (IFNγ), interleukin 1ß (IL-1ß) and CXCL10 production were significantly reduced in JAML KO mice during the elicitation phase. We found that CD8+ T cells express JAML and that JAML is essential for rapid flare-up responses to contact allergens. Finally, we show that keratinocytes up-regulate the JAML ligand CXADR following exposure to contact allergens. CONCLUSION: Our study is the first to show a central role of JAML in CHS and reveals a potential new target for the treatment of ACD in humans.

CD100 boosts the inflammatory response in the challenge phase of allergic contact dermatitis in mice.

BACKGROUND: Allergic contact dermatitis (ACD) is an inflammatory disease with a complex pathophysiology in which epidermal-resident memory CD8+ T (TRM ) cells play a key role. The mechanisms involved in the activation of CD8+ TRM cells during allergic flare-up responses are not understood. METHODS: The expression of CD100 and its ligand Plexin B2 on CD8+ TRM cells and keratinocytes before and after allergen exposure was determined by flow cytometry and RT-qPCR. The role of CD100 in the inflammatory response during the challenge phase of ACD was determined in a model of ACD in CD100 knockout and wild-type mice. RESULTS: We show that CD8+ TRM cells express CD100 during homeostatic conditions and up-regulate it following re-exposure of allergen-experienced skin to the experimental contact allergen 1-fluoro-2,4-dinitrobenzene (DNFB). Furthermore, Plexin B2 is up-regulated on keratinocytes following exposure to some contact allergens. We show that loss of CD100 results in a reduced inflammatory response to DNFB with impaired production of IFNγ, IL-17A, CXCL1, CXCL2, CXCL5, and IL-1ß and decreased recruitment of neutrophils to the epidermis. CONCLUSION: Our study demonstrates that CD100 is expressed on CD8+ TRM cells and is required for full activation of CD8+ TRM cells and the flare-up response of ACD.

Engineering stem cells to produce exosomes with enhanced bone regeneration effects: an alternative strategy for gene therapy.

BACKGROUND: Exosomes derived from stem cells have been widely studied for promoting regeneration and reconstruction of multiple tissues as "cell-free" therapies. However, the applications of exosomes have been hindered by limited sources and insufficient therapeutic potency. RESULTS: In this study, a stem cell-mediated gene therapy strategy is developed in which mediator mesenchymal stem cells are genetically engineered by bone morphogenetic protein-2 gene to produce exosomes (MSC-BMP2-Exo) with enhanced bone regeneration potency. This effect is attributed to the synergistic effect of the content derived from MSCs and the up-regulated BMP2 gene expression. The MSC-BMP2-Exo also present homing ability to the injured site. The toxic effect of genetical transfection vehicles is borne by mediator MSCs, while the produced exosomes exhibit excellent biocompatibility. In addition, by plasmid tracking, it is interesting to find a portion of plasmid DNA can be encapsulated by exosomes and delivered to recipient cells. CONCLUSIONS: In this strategy, engineered MSCs function as cellular factories, which effectively produce exosomes with designed and enhanced therapeutic effects. The accelerating effect in bone healing and the good biocompatibility suggest the potential clinical application of this strategy.

The recent progress on metal-organic frameworks for phototherapy.

Some infectious or malignant diseases such as cancers are seriously threatening the health of human beings all over the world. The commonly used antibiotic therapy cannot effectively treat these diseases within a short time, and also bring about adverse effects such as drug resistance and immune system damage during long-term systemic treatment. Phototherapy is an emerging antibiotic-free strategy to treat these diseases. Upon light irradiation, phototherapeutic agents can generate cytotoxic reactive oxygen species (ROS) or induce a temperature increase, which leads to the death of targeted cells. These two kinds of killing strategies are referred to as photodynamic therapy (PDT) and photothermal therapy (PTT), respectively. So far, many photo-responsive agents have been developed. Among them, the metal-organic framework (MOF) is becoming one of the most promising photo-responsive materials because its structure and chemical compositions can be easily modulated to achieve specific functions. MOFs can have intrinsic photodynamic or photothermal ability under the rational design of MOF construction, or serve as the carrier of therapeutic agents, owing to its tunable porosity. MOFs also provide feasibility for various combined therapies and targeting methods, which improves the efficiency of phototherapy. In this review, we firstly investigated the principles of phototherapy, and comprehensively summarized recent advances of MOF in PDT, PTT and synergistic therapy, from construction to modification. We expect that our demonstration will shed light on the future development of this field, and bring it one step closer to clinical trials.

2D MOF Periodontitis Photodynamic Ion Therapy.

Traditional surgical intervention and antibiotic treatment are poor and even invalid for chronic diseases including periodontitis induced by diverse oral pathogens, which often causes progressive destruction of tissues, even tooth loss, and systemic diseases. Herein, an ointment comprising atomic-layer Fe2O3-modified two-dimensional porphyrinic metal-organic framework (2D MOF) nanosheets is designed by incorporating a polyethylene glycol matrix. After the atomic layer deposition surface engineering, the enhanced photocatalytic activity of the 2D MOF heterointerface results from lower adsorption energy and more charge transfer amounts due to the synergistic effect of metal-linker bridging units, abundant active sites, and an excellent light-harvesting network. This biocompatible and biodegradable 2D MOF-based heterostructure exhibits broad-spectrum antimicrobial activity (99.87 ± 0.09%, 99.57 ± 0.21%, and 99.03 ± 0.24%) against diverse oral pathogens (Porphyromonas gingivalis, Fusobacterium nucleatum, and Staphylococcus aureus) by the synergistic effect of reactive oxygen species and released ions. This photodynamic ion therapy exhibits a superior therapeutic effect to the reported clinical periodontitis treatment owing to rapid antibacterial activity, alleviative inflammation, and improved angiogenesis.

The role of interleukin-1ß in the immune response to contact allergens.

Interleukin-1ß (IL-1ß) is an important pro-inflammatory cytokine that has an effect on almost every cell lineage in the body. By blocking IL-1ß and investigating the IL-1ß signaling pathway, several studies have demonstrated a central role of IL-1ß in the response to contact allergens. This review summarizes the current literature regarding the basic immunological mechanisms mediated by IL-1ß in the different phases of allergic contact dermatitis (ACD) and highlights potential IL-1ß-targeted treatment options, which in the future may be relevant in the treatment of patients with ACD. This review is based primarily on studies using various mouse models and human in vitro studies, since clinical studies on the effect of IL-1ß in ACD are lacking.

Integrative genomic analysis reveals novel regulatory mechanisms of eyeless during Drosophila eye development.

Eyeless (ey) is one of the most critical transcription factors for initiating the entire eye development in Drosophila. However, the molecular mechanisms through which Ey regulates target genes and pathways have not been characterized at the genomic level. Using ChIP-Seq, we generated an endogenous Ey-binding profile in Drosophila developing eyes. We found that Ey binding occurred more frequently at promoter compared to non-promoter regions. Ey promoter binding was correlated with the active transcription of genes involved in development and transcription regulation. An integrative analysis revealed that Ey directly regulated a broad and highly connected genetic network, including many essential patterning pathways, and known and novel eye genes. Interestingly, we observed that Ey could target multiple components of the same pathway, which might enhance its control of these pathways during eye development. In addition to protein-coding genes, we discovered Ey also targeted non-coding RNAs, which represents a new regulatory mechanism employed by Ey. These findings suggest that Ey could use multiple molecular mechanisms to regulate target gene expression and pathway function, which might enable Ey to exhibit a greater flexibility in controlling different processes during eye development.

Rapid and Superior Bacteria Killing of Carbon Quantum Dots/ZnO Decorated Injectable Folic Acid-Conjugated PDA Hydrogel through Dual-Light Triggered ROS and Membrane Permeability.

One of the most difficult challenges in the biomedical field is bacterial infection, which causes tremendous harm to human health. In this work, an injectable hydrogel is synthesized through rapid assembly of dopamine (DA) and folic acid (FA) cross-linked by transition metal ions (TMIs, i.e., Zn2+ ), which was named as DFT-hydrogel. Both the two carboxyl groups in the FA molecule and catechol in polydopamine (PDA) easily chelates Zn2+ to form metal-ligand coordination, thereby allowing this injectable hydrogel to match the shapes of wounds. In addition, PDA in the hydrogel coated around carbon quantum dot-decorated ZnO (C/ZnO) nanoparticles (NPs) to rapidly generate reactive oxygen species (ROS) and heat under illumination with 660 and 808 nm light, endows this hybrid hydrogel with great antibacterial efficacy against Staphylococcus aureus (S. aureus, typical Gram-positive bacteria) and Escherichia coli (E. coli, typical Gram-negative bacteria). The antibacterial efficacy of the prepared DFT-C/ZnO-hydrogel against S. aureus and E. coli under dual-light irradiation is 99.9%. Importantly, the hydrogels release zinc ions over 12 days, resulting in a sustained antimicrobial effect and promoted fibroblast growth. Thus, this hybrid hydrogel exhibits great potential for the reconstruction of bacteria-infected tissues, especially exposed wounds.

Efficacy of laser treatment for onychomycotic nails: a systematic review and meta-analysis of prospective clinical trials.

Laser therapy for onychomycosis is emerging but its efficacy remains unestablished. To examine current evidence on efficacy of laser treatment of onychomycosis. A systematic review and one-arm meta-analysis, including all prospective clinical trials, identified on PubMed, Cochrane Library, and EMBASE databases. Trials with participants as unit of analysis (UOA), n = 13, were analyzed separately from trials with nails as UOA, n = 7. Summary proportions and 95% confidence intervals (95% CI) were calculated. Outcomes were mycological cure, clinical improvement, or complete cure. Twenty-two prospective trials (four randomized controlled trials and 18 uncontrolled trials) with a total of 755 participants were analyzed. Summary proportions with 95% CI for participants as UOA were mycological cure 70.4%, 95% CI 52.2-83.8%; clinical improvement 67.2%, 95% CI 43.2-84.7%; and complete cure 7.2%, 95% CI 1.9-23.5%. High statistical heterogeneity was detected (mycological cure I2 = 88%, P < 0.01; clinical improvement I2 = 69%, P < 0.01; complete cure I2 = 60%, P = 0.11). The current level of evidence is limited and with high heterogeneity, making it difficult to assess the true efficacy of laser treatment for onychomycosis. Larger randomized controlled trials with well-defined methodology are warranted.

Electrophoretic Deposited Stable Chitosan@MoS2 Coating with Rapid In Situ Bacteria-Killing Ability under Dual-Light Irradiation.

Developing in situ disinfection methods in vivo to avoid drug-resistant bacteria and tissue toxicity is an urgent need. Here, the photodynamic and photothermal properties of the chitosan-assisted MoS2 (CS@MoS2 ) hybrid coating are simultaneously inspired to endow metallic Ti implants with excellent surface self-antibacterial capabilities. This coating, irradiated by only 660 nm visible light (VL) for 10 min, exhibits an antibacterial efficacy of 91.58% and 92.52% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. The corresponding value is 64.67% and 57.44%, respectively, after irradiation by a single 808 nm near infrared light for the same amount of time. However, the combined irradiation using both lights can significantly enhance the efficiency up to 99.84% and 99.65% against E. coli and S. aureus, respectively, which can be ascribed to the synergistic effects of photodynamic and photothermal actions. The former produces single oxygen species under 660 nm VL while the latter induces a rise in temperature of implants, which can inhibit the growth of both E. coli and S. aureus. The introduction of CS can also promote the biocompatibility of implants, which provides a facile, rapid, and safe in situ bacteria-killing method in vivo without needing a second surgery.

In Situ Disinfection through Photoinspired Radical Oxygen Species Storage and Thermal-Triggered Release from Black Phosphorous with Strengthened Chemical Stability.

Photodynamic therapy (PDT) utilizing light-induced reactive oxygen species (ROS) is a promising alternative to combat antibiotic-resistant bacteria and biofilm. However, the photosensitizer (PS)-modified surface only exhibits antibacterial properties in the presence of light. It is known that extended photoirradiation may lead to phototoxicity and tissue hypoxia, which greatly limits PDT efficiency, while ambient pathogens also have the opportunity to attach to biorelevant surfaces in medical facilities without light. Here, an antimicrobial film composed of black phosphorus nanosheets (BPSs) and poly (4-pyridonemethylstyrene) endoperoxide (PPMS-EPO) to control the storage and release of ROS reversibly is introduced. BPS, as a biocompatible PS, can produce high singlet oxygen under the irradiation of visible light of 660 nm, which can be stably stored in PPMS-EPO. The ROS can be gradually thermally released in the dark. In vitro antibacterial studies demonstrate that the PPMS-EPO/BPS film exhibits a rapid disinfection ability with antibacterial rate of 99.3% against Escherichia coli and 99.2% against Staphylococcus aureus after 10 min of irradiation. Even without light, the corresponding antibacterial rate reaches 76.5% and 69.7%, respectively. In addition, incorporating PPMS significantly improves the chemical stability of the BPS.

A randomized double-blinded clinical trial to evaluate the safety and efficacy of a novel superelastic nickel-titanium spinal rod in adolescent idiopathic scoliosis: 5-year follow-up.

PURPOSE: To evaluate the safety and efficacy of a superelastic shape-memory alloy (SNT) rod used in the treatment of adolescent idiopathic scoliosis (AIS). METHODS: AIS Patients with Lenke 1 curves undergoing fusion surgery were randomized (1:1) at the time of surgery to receive either the SNT or a conventional titanium alloy (CTA) rod. Radiographs were obtained preoperatively and postoperatively up to 5 years of follow-up. Parameters assessed included coronal and sagittal Cobb angles, and overall truncal and shoulder balance. Sagittal profiles were subcategorized into Types A (<20°), B (20-40°), and C (>40°). RESULTS: Twenty-four patients with mean age of 15 years were recruited. A total of 87.0% of subjects were followed up till postoperative 5 years, but all patients had minimum 2 years of follow-up. The fulcrum-bending correction index for the SNT group was 113% at postoperative day 4 and 127% at half-year, while the CTA group was 112% at postoperative day 4 and only 106% at half-year. In terms of sagittal profile, the SNT group moved toward type B profile at half-year follow-up with a mean correction of 7.6°, while no significant change was observed in the CTA group (-0.7°). Nickel levels remained normal, and there were no complications. CONCLUSIONS: This is the first randomized clinical trial of a novel SNT rod for treating patients with AIS, noting it to be safe and has potential to gradually correct scoliosis over time. This study serves as a pilot and platform to properly power future large-scale studies to demonstrate efficacy and superiority.

Anti-biofouling function of amorphous nano-Ta2O5 coating for VO2-based intelligent windows.

From environmental and health perspectives, the acquisition of a surface anti-biofouling property holds important significance for the usability of VO2 intelligent windows. Herein, we firstly deposited amorphous Ta2O5 nanoparticles on VO2 film by the magnetron sputtering method. It was found that the amorphous nano-Ta2O5 coating possessed a favorable anti-biofouling capability against Pseudomonas aeruginosa as an environmental microorganism model, behind which lay the mechanism that the amorphous nano-Ta2O5 could interrupt the microbial membrane electron transport chain and significantly elevate the intracellular reactive oxygen species (ROS) level. A plausible relationship was established between the anti-biofouling activity and physicochemical nature of amorphous Ta2O5 nanoparticles from the perspective of defect chemistry. ROS-induced oxidative damage gave rise to microbial viability loss. In addition, the amorphous nano-Ta2O5 coating can endow VO2 with favorable cytocompatibility with human skin fibroblasts. This study may provide new insights into understanding the anti-biofouling and antimicrobial actions of amorphous transition metal oxide nanoparticles, which is conducive to expanding their potential applications in environmental fields.

Unkempt is negatively regulated by mTOR and uncouples neuronal differentiation from growth control.

Neuronal differentiation is exquisitely controlled both spatially and temporally during nervous system development. Defects in the spatiotemporal control of neurogenesis cause incorrect formation of neural networks and lead to neurological disorders such as epilepsy and autism. The mTOR kinase integrates signals from mitogens, nutrients and energy levels to regulate growth, autophagy and metabolism. We previously identified the insulin receptor (InR)/mTOR pathway as a critical regulator of the timing of neuronal differentiation in the Drosophila melanogaster eye. Subsequently, this pathway has been shown to play a conserved role in regulating neurogenesis in vertebrates. However, the factors that mediate the neurogenic role of this pathway are completely unknown. To identify downstream effectors of the InR/mTOR pathway we screened transcriptional targets of mTOR for neuronal differentiation phenotypes in photoreceptor neurons. We identified the conserved gene unkempt (unk), which encodes a zinc finger/RING domain containing protein, as a negative regulator of the timing of photoreceptor differentiation. Loss of unk phenocopies InR/mTOR pathway activation and unk acts downstream of this pathway to regulate neurogenesis. In contrast to InR/mTOR signalling, unk does not regulate growth. unk therefore uncouples the role of the InR/mTOR pathway in neurogenesis from its role in growth control. We also identified the gene headcase (hdc) as a second downstream regulator of the InR/mTOR pathway controlling the timing of neurogenesis. Unk forms a complex with Hdc, and Hdc expression is regulated by unk and InR/mTOR signalling. Co-overexpression of unk and hdc completely suppresses the precocious neuronal differentiation phenotype caused by loss of Tsc1. Thus, Unk and Hdc are the first neurogenic components of the InR/mTOR pathway to be identified. Finally, we show that Unkempt-like is expressed in the developing mouse retina and in neural stem/progenitor cells, suggesting that the role of Unk in neurogenesis may be conserved in mammals.

Silver nanoparticles promote osteogenesis of mesenchymal stem cells and improve bone fracture healing in osteogenesis mechanism mouse model.

The potential use of osteo-conducive biomaterials in the promotion of bone fracture healing has attracted wide attention. This study investigated if silver nanoparticles (AgNps) could promote the proliferation and osteogenesis of mesenchymal stem cells (MSCs), and improve bone fracture healing. We showed that AgNps promoted MSCs' proliferation and osteogenic differentiation in vitro. Using a mouse femoral facture model, AgNps encapsulated in collagen promoted the formation of fracture callus, and induced early closure of the fracture gap. AgNps may promote the formation of the callus and the subsequent end joining of the fracture bone via multiple routes: (i) chemo-attraction of MSCs and fibroblasts to migrate to the fracture site; (ii) induction of the proliferation of MSCs; (iii) induction of osteogenic differentiation of MSCs via induction/activation of TGF-ß/BMP signaling in MSCs. We concluded that AgNps might be beneficial as an adjunct treatment for bone fracture healing clinically. FROM THE CLINICAL EDITOR: Silver nanoparticles are widely used in wound management in the clinical setting. In this article, the authors demonstrated a novel application in that these nanoparticles were efficient in promoting osteoblastic differentiation in both in-vitro and in-vivo studies. The findings may provide a new treatment direction for bone fracture in the future.