Development of an Interpretable Deep Learning Model for Pathological Tumor Response Assessment After Neoadjuvant Therapy.

BACKGROUND: Neoadjuvant therapy followed by surgery has become the standard of care for locally advanced esophageal squamous cell carcinoma (ESCC) and accurate pathological response assessment is critical to assess the therapeutic efficacy. However, it can be laborious and inconsistency between different observers may occur. Hence, we aim to develop an interpretable deep-learning model for efficient pathological response assessment following neoadjuvant therapy in ESCC. METHODS: This retrospective study analyzed 337 ESCC resection specimens from 2020-2021 at the Pudong-Branch (Cohort 1) and 114 from 2021-2022 at the Puxi-Branch (External Cohort 2) of Fudan University Shanghai Cancer Center. Whole slide images (WSIs) from these two cohorts were generated using different scanning machines to test the ability of the model in handling color variations. Four pathologists independently assessed the pathological response. The senior pathologists annotated tumor beds and residual tumor percentages on WSIs to determine consensus labels. Furthermore, 1850 image patches were randomly extracted from Cohort 1 WSIs and binarily classified for tumor viability. A deep-learning model employing knowledge distillation was developed to automatically classify positive patches for each WSI and estimate the viable residual tumor percentages. Spatial heatmaps were output for model explanations and visualizations. RESULTS: The approach achieved high concordance with pathologist consensus, with an R^2 of 0.8437, a RAcc_0.1 of 0.7586, a RAcc_0.3 of 0.9885, which were comparable to two senior pathologists (R^2 of 0.9202/0.9619, RAcc_0.1 of 8506/0.9425, RAcc_0.3 of 1.000/1.000) and surpassing two junior pathologists (R^2 of 0.5592/0.5474, RAcc_0.1 of 0.5287/0.5287, RAcc_0.3 of 0.9080/0.9310). Visualizations enabled the localization of residual viable tumor to augment microscopic assessment. CONCLUSION: This work illustrates deep learning's potential for assisting pathological response assessment. Spatial heatmaps and patch examples provide intuitive explanations of model predictions, engendering clinical trust and adoption (Code and data will be available at https://github.com/WinnieLaugh/ESCC_Percentage once the paper has been conditionally accepted). Integrating interpretable computational pathology could help enhance the efficiency and consistency of tumor response assessment and empower precise oncology treatment decisions.

The effects of extenders, cryoprotectants and conditions in two-step cooling method on Varicorhinus barbatulus sperm.

In this study, we developed an optimal cryopreservation procedure for Varicorhinus barbatulus sperm. To this end, we optimized (1) the types and dilution ratios of extenders; (2) types and final concentration of cryoprotectants; and (3) freezing conditions, including equilibration time, height above the surface of liquid nitrogen (LN), and the cooling times in the two-step cooling method. The optimum result was obtained when the sperm was diluted at a 1:9 ratio in D-17 with 10% methanol, equilibrated at 4 °C for 10 min, held at 7 cm above LN for 2 min, and finally stored in LN. After storage for 12 h in LN, the sperm was thawed in a water bath at 40 °C for 6s, the post-thaw sperm motility was 66.10 ± 7.12%, while the corresponding rate for fresh sperm was 87.08 ± 2.38%. Using computer-assisted sperm analysis, we found a significant decrease in the motility parameters of post-thaw sperm, especially the parameters related to velocity. To evaluate the effects of cryopreservation on the structural integrity of sperm, transmission electron microscopy and scanning electron microscopy were employed, which showed the defects in frozen sperm, including: abnormal heads, damaged plasma membranes, broken tails, and the disappearance of the mitochondrial internal crest. In addition, we determined the mitochondrial membrane potential to assess the functional integrity of frozen sperm. Our results showed a decrease in the mitochondrial function of frozen sperm. This procedure could be used alongside cryopreservation of V. barbatulus and supports its commercial-scale production and species conservation.

Characterisation, expression and possible functions of prohibitin during spermatogenesis in the silver pomfret Pampus argenteus.

Mitochondria play an important role in spermatogenesis, and some mitochondrial proteins are specifically related to this process. In this study we investigated the cytological characteristics of spermatogenic cells, including mitochondrial dynamics, during spermatogenesis in Pampus argenteus. In addition, we characterised the mitochondria-related protein prohibitin (PHB), which has been reported to play roles in mitochondrial dynamics and animal fertility. The full-length cDNA of the P. argenteus phb gene (Pa-phb) is 1687bp, including a 102-bp 5'-untranslated region (UTR), a 772-bp 3'-UTR and an 813-bp open reading frame encoding 271 amino acids. The predicted P. argenteus PHB protein (Pa-PHB) contains three functional domains (a transmembrane domain, an SPFH domain (the conserved region of stomatins, prohibitins, flotillins and HflK/C) and a coiled-coil domain) and exhibits high similarity with its homologue in other animals. The Pa-phb gene was widely expressed in all tissues examined, especially the liver and heart. We primarily focused on Pa-phb expression during spermatogenesis after observing the cytological features of male germ cells, and found that Pa-phb transcripts were detected throughout the course of development of male germ cells. Notably, we observed colocalised signals of Pa-PHB and mitochondria, which were distributed in the cytoplasm around the nucleus in spermatogonia, spermatocytes and early spermatids, tended to move to one side of the cell in middle spermatids and, finally, were colocalised in the sperm midpiece. These observations indicate that Pa-PHB is primarily localised in mitochondria during spermatogenesis, indicating that it has a role in mitochondria. Based on the results of this and previous studies regarding the essential roles of PHB in mitochondria and spermatogenesis in animals, we propose a functional model for PHB during spermatogenesis, including possible roles in the proliferation of spermatogonia and in the regulation of mitochondrial morphology and function in spermatogenic cells.

Expression and potential functions of KIF3A/3B to promote nuclear reshaping and tail formation during Larimichthys polyactis spermiogenesis.

KIF3A and KIF3B are homologous motor subunits of the Kinesin II protein family. KIF3A, KIF3B, and KAP3 form a heterotrimeric complex and play a significant role in spermatogenesis. Here, we first cloned full-length kif3a/3b cDNAs from Larimichthys polyactis. Lp-kif3a/3b are highly related to their homologs in other animals. The proteins are composed of three domains, an N-terminal head domain, a central stalk domain, and a C-terminus tail domain. Lp-kif3a/3b mRNAs were found to be ubiquitously expressed in the examined tissues, with high expression in the testis. Fluorescence in situ hybridization (FISH) was used to analyze the expression of Lp-kif3a/3b mRNAs during spermiogenesis. The results showed that Lp-kif3a/3b mRNAs had similar expression pattern and were continuously expressed during spermiogenesis. From middle spermatid to mature sperm, Lp-kif3a/3b mRNAs gradually localized to the side of the spermatid where the midpiece and tail form. In addition, we used immunofluorescence (IF) to observe that Lp-KIF3A protein co-localizes with tubulin during spermiogenesis. In early spermatid, Lp-KIF3A protein and microtubule signals were randomly distributed in the cytoplasm. In middle spermatid, however, the protein was detected primarily around the nucleus. In late spermatid, the protein migrated primarily to one side of the nucleus where the tail forms. In mature sperm, Lp-KIF3A and microtubules accumulated in the midpiece. Moreover, Lp-KIF3A co-localized with the mitochondria. In mature sperm, Lp-KIF3A and mitochondria were present in the midpiece. Therefore, Lp-KIF3A/KIF3B may be involved in spermiogenesis in L. polyactis, particularly during nuclear reshaping and tail formation.

Sr-doped nanowire modification of Ca-Si-based coatings for improved osteogenic activities and reduced inflammatory reactions.

Biomedical coatings for orthopedic implants should facilitate osseointegration and mitigate implant-induced inflammatory reactions. In our study, Ca-Si coatings with Sr-containing nanowire-like structures (NW-Sr-CS) were achieved via hydrothermal treatment. In order to identify the effect of nanowire-like topography and Sr dopant on the biological properties of Ca-Si-based coatings, the original Ca-Si coating, Ca-Si coatings modified with nanoplate (NP-CS) and similar nanowire-like structure (NW-CS) were fabricated as the control. Surface morphology, phase composition, surface area, zeta potential and ion release of these coatings were characterized. The in vitro osteogenic activities and immunomodulatory properties were evaluated with bone marrow stromal cells (BMSCs) and RAW 264.7 cells, a mouse macrophage cell line. Compared with the CS and NP-CS coatings, the NW-CS coating possessed a larger surface area and pore volume, beneficial protein adsorption, up-regulated the expression levels of integrin ß1, Vinculin and focal adhesion kinase and promoted cell spreading. Furthermore, the NW-CS coating significantly enhanced the osteogenic differentiation and mineralization as indicated by the up-regulation of ALP activity, mineralized nodule formation and osteoblastogenesis-related gene expression. With the introduction of Sr, the NW-Sr-CS coatings exerted a greater effect on the BMSC proliferation rate, calcium sensitive receptor gene expression as well as PKC and ERK1/2 phosphorylation. In addition, the Sr-doped coatings significantly up-regulated the ratio of OPG/RANKL in the BMSCs. The NW-Sr-CS coatings could modulate the polarization of macrophages towards the wound-healing M2 phenotype, reduce the mRNA expression levels of pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6) and enhance anti-inflammatory cytokines (IL-1ra, IL-10). The Sr-doped nanowire modification may be a valuable approach to enhance osteogenic activities and reduce inflammatory reactions.

Chemical stability and osteogenic activity of plasma-sprayed boron-modified calcium silicate-based coatings.

In recent years, CaSiO3 bio-ceramic coatings have attracted great attention because of their good bioactivity. However, their high degradation rates in physiological environment restrict their practical applications. In this work, boron-modified CaSiO3 ceramic (Ca11Si4B2O22, B-CS) coating was developed on Ti substrates by plasma-spraying technique attempting to obtain enhanced chemical stability and osteogenic activity. The B-CS coating possessed significantly increased chemical stability due to the introduction of boron and consequently the modified crystal structure, while maintaining good bioactivity. Scanning electron microscope and immunofluorescence studies showed that better cellular adhesion and extinctive filopodia-like processes were observed on the B-CS coating. Compared with the pure CaSiO3 (CS) coating, the B-CS coating promoted MC3T3-E1 cells attachment and proliferation. In addition, enhanced collagen I (COL-I) secretion, alkaline phosphatase activity, and extracellular matrix mineralization levels were detected from the B-CS coating. According to RT-PCR results, notable up-regulation expressions of mineralized tissue-related genes, such as runt-related transcription factor 2 (Runx2), bone sialoprotein and osteocalcin, and bone morphogenetic protein 7 (BMP-7) were observed on the B-CS coating compared with the CS coating. The above results suggested that Ca11Si4B2O22 coatings possess excellent osteogenic activity and might be a promising candidate for orthopedic applications.

Plasma sprayed cerium oxide coating inhibits H2O2-induced oxidative stress and supports cell viability.

Oxidative stress is a risk factor in the pathogenesis of osteoporosis, and plays a major role in bone regeneration of osteoporotic patients. Cerium oxide (CeO2) ceramics have the unique ability to protect various types of cells from oxidative damage, making them attractive for biomedical applications. In this study, we developed a plasma sprayed CeO2 coating with a hierarchical topography where ceria nanoparticles were superimposed in the micro-rough coating surface. The protective effects of the CeO2 coating on the response of osteoblasts to H2O2-induced oxidative stress have been demonstrated in terms of cell viability, apoptosis and differentiation. The CeO2 coating reversed the reduced superoxide dismutase activity, decreased reactive oxygen species production and suppressed malondialdehyde formation in H2O2-treated osteoblasts. It indicated that the CeO2 coating can preserve the intracellular antioxidant defense system. The cytocompatibility of the CeO2 coating was further assessed in vitro by cell viability assay and scanning electron microscopy analysis. Taken together, the CeO2 coating could provide an opportunity to be utilized as a potential candidate for bone regeneration under oxidative stress.

Different response of osteoblastic cells to Mg(2+), Zn(2+) and Sr(2+) doped calcium silicate coatings.

Mg(2+), Zn(2+) and Sr(2+) substitution for Ca(2+) in plasma sprayed calcium silicate (Ca-Si) coatings have been reported to impede their degradation in physiological environment and, more importantly, to improve their biological performance. The reason for the improved biological performance is still elusive and, especially, the contribution of the dopant ions is lack of obvious and direct evidence. In this study, we aim to identify the effect of Mg(2+), Zn(2+) and Sr(2+) incorporation on the osteogenic ability of Ca-Si based coatings (Ca2MgSi2O7, Ca2ZnSi2O7 and Sr-CaSiO3) by minimizing the influence of Ca and Si ions release and surface physical properties. Similar surface morphology, crystallinity and roughness were achieved for all samples by optimizing the spray parameters. As expected, Ca and Si ions release from all the coatings showed the comparable concentration with immersing time. The response of MC3T3-E1 cells onto Mg(2+), Zn(2+) and Sr(2+) doped Ca-Si coatings were studied in terms of osteoblastic adhesion, proliferation, differentiation and mineralization. The results showed that the level of cell adhesion and proliferation increased the most on the surface of Mg-modified coating. Gene expressions of early markers of osteoblast differentiation (COL-I and ALP mRNA) were obviously improved on Zn-modified coating. Gene expressions of later markers for osteoblast differentiation (OPN and OC mRNA) and mineralized nodules formation were obviously accelerated on the surface of Sr-modified coating. Since Mg(2+), Zn(2+) and Sr(2+) play a regulatory role in different stages of osteogenesis, it may be possible to utilize this in the development of new coating materials for orthopedic application.

Ferrocene-functionalized polydopamine film timely mediates M1-to-M2 macrophage polarization through adaptive wettability.

Dynamical control of macrophage polarization from M1 (pro-inflammatory) to M2 (anti-inflammatory) at implant surfaces is essential for balancing innate immunity and tissue repair. In this aspect, the design of orthopedic implant that can response to inflammation microenvironment with transformation in surface properties has shown promising in timely driving M1-to-M2 macrophage transition. Considering excessive reactive oxygen species (ROS) contribute to macrophage M1 polarization and progression of inflammation, in this study, ferrocene modified polydopamine (PDA-Fc) films were deposited on plasma sprayed Ti coatings to endow the implants with ROS-responsive and -scavenging abilities. Plasma sprayed Ti (PST) coating and PDA modified PST coating (PST/PDA) served as control. The presence of PDA endowed PST/PDA and PST/PDA-Fc with free-radical scavenging abilities. Moreover, PST/PDA-Fc showed adaptive wettability as evidenced by increased hydrophilicity under H2O2 treatment. With respect to PST/PDA, PST/PDA-Fc exerted greater effects on inducing lipopolysaccharides-induced M1 macrophages to adopt M2-type macrophage phenotype, characterized by higher percentage of CD206-positive cells, increased cell elongation rate and higher expression level of anti-inflammatory cytokine arginase type 1. The results obtained in our study may provide a prospective approach for manipulating an appropriate immune response at implant surfaces.

Deferoxamine-Loaded Chitosan-Based Hydrogel on Bone Implants Showing Enhanced Bond Strength and Pro-Angiogenic Effects.

Angiogenesis is vital for bone fracture healing and plays a significant role in the fate of orthopedic implants. The growth and maintenance of new blood vessels at the fracture site of patients is essential, which promotes the clinical outcome of plasma sprayed Ti (PST) coated orthopedic implants. In order to endow the PST coating with pro-angiogenic effects, deferoxamine-loaded chitosan-based hydrogel was fabricated on the coating surface. Polydopamine-modified chitosan (CS/PDA) hydrogel exhibited enhanced bonding strength to PST coatings as evidenced by scratch test. The deferoxamine-loaded CS/PDA (CS/PDA-DFO) exhibited a sustained drug-release property, and the cumulative concentration of released DFO reached 20.21 µg/mL on day 7. PST-CS/PDA with higher wettability and active group quantity enhanced the viability and adhesion characteristics of human umbilical vein endothelial cells (HUVECs) and upregulated the secretion level of nitric oxide and vascular endothelial growth factor. Moreover, the introduction of DFO in PST-CS/PDA further enhanced the pro-angiogenic effects. Above all, this study offers a novel approach for developing hydrogel coating on orthopedic implants showing enhanced bonding strength and pro-angiogenic effects.

Comparison of deep-learning and radiomics-based machine-learning methods for the identification of chronic obstructive pulmonary disease on low-dose computed tomography images.

Background: Radiomics and artificial intelligence approaches have been developed to predict chronic obstructive pulmonary disease (COPD), but it is still unclear which approach has the best performance. Therefore, we established five prediction models that employed deep-learning (DL) and radiomics-based machine-learning (ML) approaches to identify COPD on low-dose computed tomography (LDCT) images and compared the relative performance of the different models to find the best model for identifying COPD. Methods: This retrospective analysis included 1,024 subjects (169 COPD patients and 855 control subjects) who underwent LDCT scans from August 2018 to July 2021. Five prediction models, including models that employed computed tomography (CT)-based radiomics features, chest CT images, quantitative lung density parameters, and demographic and clinical characteristics, were established to identify COPD by DL or ML approaches. Model 1 used CT-based radiomics features by ML method. Model 2 used a combination of CT-based radiomics features, lung density parameters, and demographic and clinical characteristics by ML method. Model 3 used CT images only by DL method. Model 4 used a combination of CT images, lung density parameters, and demographic and clinical characteristics by DL method. Model 5 used a combination of CT images, CT-based radiomics features, lung density parameters, and demographic and clinical characteristics by DL method. The accuracy, sensitivity, specificity, highest negative predictive values (NPVs), positive predictive values, and areas under the receiver operating characteristic (AUC) curve of the five prediction models were compared to examine their performance. The DeLong test was used to compare the AUCs of the different models. Results: In total, 107 radiomics features were extracted from each subject's CT images, 17 lung density parameters were acquired by quantitative measurement, and 18 selected demographic and clinical characteristics were recorded in this study. Model 2 had the highest AUC [0.73, 95% confidence interval (CI): 0.64-0.82], while model 3 had the lowest AUC (0.65, 95% CI: 0.55-0.75) in the test set. Model 2 also had the highest sensitivity (0.84), the highest accuracy (0.81), and the highest NPV (0.36). In the test set, based on the AUC results, Model 2 significantly outperformed Model 1 (P=0.03). Conclusions: The results showed that the identification ability of models that employ CT-based radiomics features combined with lung density parameters, and demographic and clinical characteristics using ML methods performed better than the chest CT image-based DL methods. ML methods are more suitable and beneficial for COPD identification.

Antibacterial mechanism of plasma sprayed Ca2ZnSi2O7 coating against Escherichia coli.

In our previous work, antibacterial activity of plasma sprayed Ca(2)ZnSi(2)O(7) coating has been demonstrated. However, antibacterial mechanism of Ca(2)ZnSi(2)O(7) coating still remains undefined. In this study, Escherichia coli (E. coli), a kind of Gram-negative bacteria, was chosen to investigate the interactions between the bacterium and Ca(2)ZnSi(2)O(7) coating. Scanning electron microscopy and transmission electron microscopy micrographs exhibited that the morphologies of E. coli on the coating changed with treatment time, from initial slight disturbance to the disruption of cell wall and drastic distortion of bacterial interior where a remarkable material-light region was formed in the center and condensed deoxyribonucleic acid (DNA) molecules were found. Disturbances of cytoplasmic membrane were observed by two-photon confocal microscopy and confirmed by leakage of intracellular potassium ion (K(+)). Results suggest that the destruction of cell wall and the loss of replication ability of DNA molecules are two major reasons causing death of E. coli.

Manganese supplementation of orthopedic implants: a new strategy for enhancing integrin-mediated cellular responses.

Integrin-mediated osteoblast adhesion to adsorbed extracellular ligands on orthopedic implants is crucial for the subsequent osteoblast behaviors and ultimate osseointegration. Considerable research efforts have focused on the development of implant surfaces that promote the adsorption of extracellular ligands, but ignored the fact that integrin binding to ligands requires divalent cations (such as Mn2+). Here, three kinds of Mn-doped nanowire-structured TiO2 coatings with 1.9, 3.9, and 8.8 wt% dopant contents (Mn1-, Mn2-, and Mn3-TiO2) were synthesized on Ti implants to enhance integrin-mediated osteoblastic responses. The Mg-doped and undoped TiO2 nanocoatings served as the control. Mn element was not only successfully incorporated into the TiO2 matrix, but also formed an oxygen-deficient Mn oxide on the nanowire surface. Although the adsorbed fibronectin (Fn) amount on Mn-doped nanocoatings and its unfolded status were slightly attenuated with increasing Mn amount, the interaction between the coating extract and Fn demonstrated a Mn2+-induced unfolding of Fn with the exposure of the RGD motif. Compared to the Mn1-, Mn2- and Mg-doped TiO2 nanocoatings, the Mn3-TiO2 nanocoating significantly upregulated the expression of integrin α5ß1 probably through increasing the ligand-binding affinity of the integrin rather than integrin binding sites in Fn. Consistent with the activation trend of integrin α5ß1, the Mn3-TiO2 nanocoating enhanced cell adhesion with the long stretched structure of actin fibers and extensive formation of vinculin focal adhesion spots and upregulated the levels of alkaline phosphatase and osteocalcin activities. Therefore, Mn supplementation of orthopedic implants may be a promising way to improve osteogenesis at the implant surface.

ZNF804A and schizophrenia susceptibility in Asian populations.

ZNF804A, a recently identified risk gene for schizophrenia, has been extensively investigated and the principle finding for this locus has been the association with SNP rs1344706 in populations of European ancestries. However, in Asian populations, only a few studies have been conducted for rs1344706 and the results were inconsistent. Here, we studied rs1344706 and schizophrenia susceptibility in multiple Asian case-control samples (10 Chinese and 2 Japanese samples; N = 21,062), and the meta-analyses indicated non-significant association of rs1344706 with schizophrenia (P = 0.26), suggesting the same SNP identified in European samples is not predisposing risk in Asians. Further genotyping and association analyses of a set of SNPs spanning the entire genomic region of ZNF804A (520 kb) identified no association except for SNP rs359895 (P = 7.8 x 10(-5) , N = 5,172), a newly reported risk SNP located in the ZNF804A promoter region with functional implications. This suggests that ZNF804A may also contribute to schizophrenia susceptibility in Asians although the risk SNP is different from that in Europeans, and it was supported by the detected up-regulation of ZNF804A mRNA expression in the blood cells of Chinese schizophrenia patients compared with normal controls (P = 0.004). Additionally, the linkage disequilibrium (LD) structure analyses using data from HapMap indicated distinct LD blocks across ZNF804A between Chinese and Europeans, which may explain the different association patterns between them, and also highlight the compounding difficulty of genetic studies of complex diseases like schizophrenia when studying multiple ethnic populations.

Embedding graphs on Grassmann manifold.

Learning efficient graph representation is the key to favorably addressing downstream tasks on graphs, such as node or graph property prediction. Given the non-Euclidean structural property of graphs, preserving the original graph data's similarity relationship in the embedded space needs specific tools and a similarity metric. This paper develops a new graph representation learning scheme, namely Egg, which embeds approximated second-order graph characteristics into a Grassmann manifold. The proposed strategy leverages graph convolutions to learn hidden representations of the corresponding subspace of the graph, which is then mapped to a Grassmann point of a low dimensional manifold through truncated singular value decomposition (SVD). The established graph embedding approximates denoised correlationship of node attributes, as implemented in the form of a symmetric matrix space for Euclidean calculation. The effectiveness of Egg is demonstrated using both clustering and classification tasks at the node level and graph level. It outperforms baseline models on various benchmarks.

Engineering Nanopatterned Structures to Orchestrate Macrophage Phenotype by Cell Shape.

Physical features on the biomaterial surface are known to affect macrophage cell shape and phenotype, providing opportunities for the design of novel "immune-instructive" topographies to modulate foreign body response. The work presented here employed nanopatterned polydimethylsiloxane substrates with well-characterized nanopillars and nanopits to assess RAW264.7 macrophage response to feature size. Macrophages responded to the small nanopillars (SNPLs) substrates (450 nm in diameter with average 300 nm edge-edge spacing), resulting in larger and well-spread cell morphology. Increasing interpillar distance to 800 nm in the large nanopillars (LNPLs) led to macrophages exhibiting morphologies similar to being cultured on the flat control. Macrophages responded to the nanopits (NPTs with 150 nm deep and average 800 nm edge-edge spacing) by a significant increase in cell elongation. Elongation and well-spread cell shape led to expression of anti-inflammatory/pro-healing (M2) phenotypic markers and downregulated expression of inflammatory cytokines. SNPLs and NPTs with high availability of integrin binding region of fibronectin facilitated integrin ß1 expression and thus stored focal adhesion formation. Increased integrin ß1 expression in macrophages on the SNPLs and NTPs was required for activation of the PI3K/Akt pathway, which promoted macrophage cell spreading and negatively regulated NF-κB activation as evidenced by similar globular cell shape and higher level of NF-κB expression after PI3K blockade. These observations suggested that alterations in macrophage cell shape from surface nanotopographies may provide vital cues to orchestrate macrophage phenotype.

Visible-light-responsive reduced graphene oxide/g-C3N4/TiO2 composite nanocoating for photoelectric stimulation of neuronal and osteoblastic differentiation.

Restoration of nerve supply in newly formed bone is critical for bone defect repair. However, nerve regeneration is often overlooked when designing bone repair biomaterials. In this study, employing graphitic carbon nitride (g-C3N4) as a visible-light-driven photocatalyst and reduced graphene oxide (rGO) as a conductive interface, an rGO/g-C3N4/TiO2 (rGO/CN/TO) ternary nanocoating with photoelectric conversion ability was fabricated on a Ti-based orthopedic implant for photoelectric stimulation of both bone and nerve repair. Compared with g-C3N4/TiO2 (CN/TO) and TiO2 nanocoatings, the ternary nanocoating exhibited stronger visible-light absorption as well as higher transient photocurrent density and open circuit potential under blue LED exposure. The improved photo-electrochemical properties of the ternary nanocoating were attributed to the enhanced separation of photogenerated carriers at the heterointerface. For the tested nanocoatings, introducing blue LED light irradiation enhanced MC3T3-E1 osteoblastic differentiation and neurite outgrowth of PC12 cells. Among them, the rGO/CN/TO nanocoating exerted the greatest enhancement. In a coculture system, PC12 cells on the ternary nanocoating released a higher amount of neurotransmitter calcitonin gene-related peptide (CGRP) under light irradiation, which in turn significantly enhanced osteoblastic differentiation. The results may provide a prospective approach for targeting nerve regeneration to stimulate osteogenesis when designing bone repair biomaterials.

Nano-structured titanium coating for improving biological performance.

Nano-structured titanium coating was obtained by alkali treating the vacuum plasma sprayed samples following hot water immersing for 24 h. The influences of the surface microstructure on the biological performance were studied. A canine model was applied for in vivo evaluation of the bone bonding ability of the coatings. The histological examination results demonstrate that new bone was formed more rapidly on the nano-structured coating implants and grew into the porosity than the as-sprayed one. After 4 weeks implantation, the nano-structured implants were found to appose directly to the surrounding bone while large lacunae could still be observed at the interface between the as-sprayed samples and bone. All these results indicate that a nano-structured surface on the porous titanium coating is favorable for bone bonding.

Chemical stability and antimicrobial activity of plasma sprayed bioactive Ca2ZnSi2O7 coating.

Calcium silicate ceramic coatings have received considerable attention in recent years due to their excellent bioactivity and bonding strength. However, their high dissolution rates limit their practical applications. In this study, zinc incorporated calcium silicate based ceramic Ca(2)ZnSi(2)O(7) coating was prepared on Ti-6Al-4V substrate via plasma spraying technology aiming to achieve higher chemical stability and additional antibacterial activity. Chemical stability of the coating was assessed by monitoring mass loss and ion release of the coating after immersion in the Tris-HCl buffer solution and examining pH value variation of the solution. Results showed that the chemical stability of zinc incorporated coating was improved significantly. Antimicrobial activity of the Ca(2)ZnSi(2)O(7) coating was evaluated, and it was found that the coating exhibited 93% antibacterial ratio against Staphylococcus aureus. In addition, in vitro bioactivity and cytocompatibility were confirmed for the Ca(2)ZnSi(2)O(7) coating by simulated body fluid test, MC3T3-E1 cells adhesion investigation and cytotoxicity assay.

Process of cytoplasm elimination during spermiogenesis in Octopus tankahkeei: Polarized development of the spermatid and discarding of the residual body.

The elimination of the spermatid cytoplasm during spermiogenesis enables the sperm to acquire a streamlined architecture, which allows for unhindered swimming. While this process has been well described in vertebrates, it has rarely been reported in invertebrates. In this study, we observed the process of cytoplasm elimination during spermiogenesis in Octopus tankahkeei (Mollusca, Cephalopoda) using light microscopy, transmission electron microscopy, and immunofluorescence. In the early spermatid, the cell is circular, and the nucleus is centrally located. With spermatid development, the cell becomes polarized. The nucleus gradually elongates and moves toward the end of the cell where the tail is forming. As a result, the cytoplasm moves past the nucleus at the anterior region of the future sperm head (the foreside of the acrosome). Following this, during the late stage of spermiogenesis, the cytoplasm condenses and collects on the foreside of the acrosome until finally the residual body is discarded from the top of the sperm head. This represents a distinct directionality for the development of cytoplasmic polarity and discarding of residual body compared with that reported for vertebrates (in which the cytoplasm of the elongating spermatids is polarized toward the caudal region). The fact that the cytoplasm also becomes concentrated suggests that water pumps may be involved in the elimination of water from the cytoplasm before the residual body is discarded. Furthermore, we found that microtubules, forming a manchette-like structure, are involved not only in reshaping of the nucleus but also in the transport of mitochondria and vesicles to the foreside of the acrosome, subsequently allowing them to be discarded with the residual body. This study broadens our understanding of the development of polarization and elimination of cytoplasm from spermatids in animals.