Metallic Nanoparticle-Doped Oxide Semiconductor Film for Bone Tumor Suppression and Bone Regeneration

Bone implants with the photothermal effect are promising for the treatment of bone tumor defects. Noble metal-based photothermal nanoagents are widely studied for their stable photothermal effect, but they are expensive and difficult to directly grow on implant surfaces. In contrast, non-noble metal photothermal nanoagents are economical but unstable. Herein, to develop a stable and economical photothermal film on bone implants, a Ni nanoparticle-doped oxide semiconductor film was grown in situ on Nitinol via the reduction of Ni-Ti-layered double hydroxides. Ni nanoparticles remained stable in the NiTiO₃ structure even when immersed in fluid for 1 month, and thus, the film presented a reliable photothermal effect under near-infrared light irradiation. The film also showed excellent in vitro and in vivo antitumor performance. Moreover, the nanostructure on the film allowed bone differentiation of mouse embryo cells (C3H10T1/2), and the released Ni ions supported the angiogenesis behavior of human vein endothelial cells. Bone implantation experiments further showed the enhancement of osteointegration of the modified Nitinol implant in vivo. This novel multifunctional Nitinol bone implant design offers a promising strategy for the therapy of bone tumor-related defects.

Design of single-phased magnesium alloys with typically high solubility rare earth elements for biomedical applications: Concept and proof

Rare earth elements (REEs) have been long applied in magnesium alloys, among which the mischmetal-containing WE43 alloy has already got the CE mark approval for clinical application. A considerable amount of REEs (7 wt%) is needed in that multi-phased alloy to achieve a good combination of mechanical strength and corrosion resistance. However, the high complex RE addition accompanied with multiple second phases may bring the concern of biological hazards. Single-phased Mg-RE alloys with simpler compositions were proposed to improve the overall performance, i.e., “Simpler alloy, better performance”. The single-phased microstructure can be successfully obtained with typical high-solubility REEs (Ho, Er or Lu) through traditional smelting, casting and extrusion in a wide compositional range. A good corrosion resistance with a macroscopically uniform corrosion mode was guaranteed by the homogeneously single-phased microstructure. The bimodal-grained structure with plenty of sub-grain microstructures allow us to minimize the RE addition to <1 wt%, without losing mechanical properties. The single-phased Mg-RE alloys show comparable mechanical properties to the clinically-proven Mg-based implants. They exhibited similar in-vitro and in-vivo performances (without local or systematic toxicity in SD-rats) compared to a high purity magnesium. In addition, metal elements in our single-phased alloys can be gradually excreted through the urinary system and digestive system, showing no consistent accumulation of RE in main organs, i.e., less burden on organs. The novel concept in this study focuses on the simplification of Mg-RE based alloys for biomedical purpose, and other biodegradable metals with single-phased microstructures are expected to be explored.

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A concept of developing single-phased biodegradable magnesium alloys was proposed.

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Single-phased magnesium alloys with bimodal-grained structures were obtained.

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Good strength and corrosion resistance synergy was achieved in the alloys.

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Significantly reduced rare earth addition is beneficial to the biocompatibility.

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Simpler alloy helps to lower the possible biological risks of Mg related implants.

[Alteration of Wnt3a overexpression and its early monitoring value during hepatocellular carcinogenesis]

Objective: To investigate the dynamic expression pattern of carcinoembryonic Wnt3a and its early monitoring value using a hepatocellular carcinoma model. Methods: Forty-eight Sprague Dawley (SD) rats were fed with pellet feed containing 2-acetylaminofluorene (2-AAF, 0.05%) to induce hepatocarcinogenesis, and control rats were fed a pellet diet. Liver tissue and blood samples were collected every two weeks. Liver tissues were pathologically examined using HE staining and grouped. The gene and Wnt3a mRNA expression were analyzed by genome-wide microarray. The expression and distribution of Wnt3a in liver tissue were analyzed by immunohistochemistry. Wnt3a concentration in liver tissue and serum was quantified by enzyme-linked immunosorbent assay. Statistical methods such as χ² test, Mann-Whitney test and analysis of variance were used to analyze the differences between groups. Results: According to the pathological examination results, the rat livers were divided into four groups: control, hepatocyte degeneration, precancerous lesions and hepatocellular carcinoma. Genome-wide expression profiling analysis and comparison with the control group revealed that 268 and 312 genes were up-regulated and 57 and 201 genes were down-regulated in the precancerous and cancerous group when signal logarithm ratio (SLR) was >8 log₂^cy5/cy3, and these significantly altered genes mainly involved in cell proliferation, signal transduction, tumor metastasis, and apoptosis. The expression of Wnt3a at mRNA level was significantly increased in all stages of cancer induction, including degeneration group (1.15±0.24, q=8.227), precancerous group (1.85±0.18, q=12.361) and cancerous group (2.59±0.55, q=18.082). Compared with the control group (0.25±0.11, F=121.103, P<0.001), the degeneration group, the precancerous group and the liver cancer group were up-regulated by 4.6, 7.4 and 10.4-folds, respectively. Immunohistochemistry showed that compared with the control group, the positive rate of Wnt3a in the degeneration group was 66.7% (12/18, χ²=10.701, P=0.001), and both the precancerous and liver cancer groups were positive (9/9, χ²=17.115, P<0.001). Wnt3a expression was gradually increased in liver and blood samples during the process of carcinogenesis, and the difference between two groups was statistically significant (F=176.711, P<0.001). Wnt3a overexpression was secreted into blood stream via cancerous liver tissue, and there was a linear correlation between Wnt3a levels in blood and liver samples (r=0.732, P<0.001). Conclusions: Wnt3a overexpression is closely related with hepatocellular carcinogenesis, and thus may become a new monitoring marker.

Electronic structure and low-temperature thermoelectric transport of TiCoSb single crystals

Band structure engineering has a strong beneficial impact on thermoelectric performance, where theoretical methods dominate the investigation of electronic structures. Here, we use angle-resolved photoemission spectroscopy (ARPES) to analyze the electronic structure and report on the thermoelectric transport properties of half-Heusler TiCoSb high-quality single crystals. High degeneracy of the valence bands at the L and Γ band maximum points was observed, which provides a band-convergence scenario for the thermoelectric performance of TiCoSb. Previous efforts have shown how crystallographic defects play an important role in TiCoSb transport properties, while the intrinsic properties remain elusive. Using hard X-ray photoelectron spectroscopy (HAXPES), we discard the presence of interstitial defects that could induce in-gap states near the valence band in our crystals. Contrary to polycrystalline reports, intrinsic TiCoSb exhibits p-type transport, albeit defects still affect the carrier concentration. In two initially identical p-type TiCoSb crystal batches, distinct metallic and semiconductive behaviors were found owing to defects not noticeable by elemental analysis. A varying Seebeck effective mass is consistent with the change at the Fermi level within this band convergence picture. This report tackles the direct investigation of the electronic structure of TiCoSb and reveals new insights and the strong impact of point defects on the optimization of thermoelectric properties.

[Clinical follow-up analysis of nusinersen in the disease-modifying treatment of pediatric spinal muscular atrophy]

Objective: To explore the clinical efficacy of disease-modifying drug nusinersen on children with spinal muscular atrophy. Methods: The baseline and longitudinal clinical data of 15 children who were treated with nusinersen in the Children's Hospital, Zhejiang University School of Medicine from October 2019 to October 2021 were retrospectively collected. The general data (gender, age, genotype, and clinical classification, etc.), motor function, nutritional status, scoliosis and respiratory function were analyzed. Wilcoxon rank-sum test was used for comparing multi-system conditions before and after treatment. Results: The age of 15 cases (7 males, 8 females) was 6.8 (2.8, 8.3) years, with 2 cases of type 1, 6 cases of type 2, and 7 cases of type 3 respectively, and the course of disease was 55.0 (21.0, 69.0) months. After 9.0 (9.0, 24.0) months of treatment, the motor function scale evaluations of the Hammersmith neurological examination section 2 (13.0 (7.0, 23.0) vs. 18.0 (10.0, 25.0) scores, Z=-2.67, P=0.018) of 15 children, the Hammersmith functional motor scale expanded (38.0 (18.5, 45.5) vs. 42.0 (23.0, 51.0) scores, Z=-2.38, P=0.018), and the revised upper limb module (27.0 (19.5, 32.0) vs. 33.0 (22.5, 35.5) scores, Z=-2.52, P=0.012) of children with type 2 and 3 had significantly improved. Thirteen patients achieved clinically significant motor function improvement, and 2 of them had kept stable scale scores. Subjective reports also indicated that the muscle strength and daily exercise ability of these children improved after treatment, and no serious adverse reactions were reported. Supplemented by the multi-disciplinary team management, the levels of some indicators such as Cobbs angle of scoliosis and forced vital capacity all had significantly improved (all P<0.05). Conclusions: Nusinersen can improve the motor function of patients with 5q spinal muscular atrophy, which is also proved safe to be used in children. The drug treatment supplemented by the multi-disciplinary team management is helpful to improve the multi-system function of the children with spinal muscular atrophy.

Endothelial cyclin I reduces vulnerability to angiotensin II-induced vascular remodeling and abdominal aortic aneurysm risk

BACKGROUND

Retinoblastoma protein (Rb) supports vasoprotective E2F Transcription Factor 1 (E2f1)/Dihydrofolate Reductase (Dhfr) pathway activity in endothelial cells. Cyclin I (Ccni) promotes Cyclin-Dependent Kinase-5 (Cdk5)-mediated Rb phosphorylation. Therefore, we hypothesized that endothelial Ccni may regulate cardiovascular homeostasis, vessel remodeling, and abdominal aortic aneurysm (AAA) formation.

METHODS

Aortic CCNI mRNA expression was analyzed in the Gene Expression Omnibus (GEO) GSE57691 cohort consisting of AAA patients (n = 39) and healthy controls (n = 10). We employed wild-type (WT) mice and endothelial Ccni knockout (Ccnifl/flTie2-Cre) mice to conduct in vivo and ex vivo experimentation using an Angiotensin (Ang) II hypertension model and a CaCl2 AAA model. Mice were assessed for Rb/E2f1/Dhfr signaling, biopterin (i.e., biopterin [B], dihydrobiopterin [BH2], and tetrahydrobiopterin [BH4]) production, cardiovascular homeostasis, vessel remodeling, and AAA formation.

RESULTS

Aortic CCNI mRNA expression was downregulated in AAA patients. Both Ang II- and CaCl2-induced WT mice showed aortic Ccni upregulation coupled with vasculoprotective upregulation of Rb/E2f1/Dhfr signaling and biopterins. Endothelial Ccni knockout downregulated medial Rb/E2f1/Dhfr signaling and biopterins in Ang II-induced hypertensive mice, which exacerbated eNos uncoupling and H2O2 production. Endothelial Ccni knockout impaired in vivo hemodynamic responses and endothelium-dependent vasodilatation in ex vivo mesenteric arteries in response to Ang II. Endothelial Ccni knockout exacerbated mesenteric artery remodeling and AAA risk in response to Ang II and CaCl2.

CONCLUSIONS

Endothelial Ccni acts as a critical negative regulator of eNos uncoupling-mediated ROS generation and thereby reduces vulnerability to hypertension-induced vascular remodeling and AAA development in mice.

Fluorescence-Reporting-Guided Tumor Acidic Environment-Activated Triple Photodynamic, Chemodynamic, and Chemotherapeutic Reactions for Efficient Hepatocellular Carcinoma Cell Ablation

Tumor acidic environment-activated combination therapy holds great promise to significantly decrease side effects, circumvent multiple drug resistance, and improve therapeutic outcomes for cancer treatment. Herein, Sorafenib/ZnPc(PS)₄@Fe^III-TA nanoparticles (SPFT) are designed with acid-environment turned-on fluorescence to report the activation of triple therapy including photodynamic, chemodynamic, and chemotherapy on hepatocellular carcinoma. The SPFT are composed of SP cores formulated via self-assembly of sorafenib and ZnPc(PS)₄, with high drug loading efficiency, and Fe^III-TA shells containing FeCl₃ and tannic acid. Importantly, the nanoparticles suppress reactive oxygen species (ROS) generation of ZnPc(PS)₄ due to their formation in nanoparticles, while assisting simultaneous uptake of the uploaded drugs in cancer cells. The tumor acidic environment initiates Fe^III-TA decomposition and accelerates a chemodynamic reaction between Fe^II and H₂O₂ to generate toxic ^•OH. Then, the SP core is decomposed to separate ZnPc(PS)₄ and sorafenib, which leads to fluorescence turning-on of ZnPc(PS)₄, expedited photodynamic reactions, and burst release of sorafenib. Notably, SPFT shows low dark cytotoxicity to normal cells but exerts high potency on hepatocellular carcinoma cells under near-infrared light irradiation, which is much more potent than either sorafenib or ZnPc(PS)₄ alone. This research offers a facile nanomedicine design strategy for cancer therapy.

Mg(OH)2 nanosheets on Ti with immunomodulatory function for orthopedic applications

Macrophages play a vital role for guiding the fate of osteogenesis-related cells. It is well known that nano-topography and bioactive ions can direct enhance osteogenic behavior. However, the effects of nanostructure combined with bioactive ions release on macrophage polarization and the following osteogenesis and angiogenesis are rarely reported. Herein, Mg(OH)2 films with nano-sheet structures were constructed on the surface of Ti using hydrothermal treatment. The film presented nano-sheet topography and sustained release of Mg ions. The results of in vitro culture of BMDMs, including PCR, western blot, and flow cytometry suggested that the nano-Mg(OH)2 films were more favorable for macrophages polarizing to tissue healing M2 phenotype. Moreover, air-pouch model confirmed that the nano-Mg(OH)2 film coated Ti would induce milder inflammation and thinner fibrous layer in vivo, compared with untreated Ti. Furthermore, macrophages-conditioned culture mediums were collected from nano-Mg(OH)2 coated Ti group was superior for the osteogenic behaviors of mice bone marrow stem cells and the angiogenic behaviors of human umbilical vein endothelial cells. With harmonious early inflammatory response and subsequently improved osteogenesis and angiogenesis, the nano-Mg(OH)2 coated Ti is promising for orthopedic applications.

Giant anomalous Nernst signal in the antiferromagnet YbMnBi2

A large anomalous Nernst effect (ANE) is crucial for thermoelectric energy conversion applications because the associated unique transverse geometry facilitates module fabrication. Topological ferromagnets with large Berry curvatures show large ANEs; however, they face drawbacks such as strong magnetic disturbances and low mobility due to high magnetization. Herein, we demonstrate that YbMnBi₂, a canted antiferromagnet, has a large ANE conductivity of ~10 A m^-1 K^-1 that surpasses large values observed in other ferromagnets (3-5 A m^-1 K^-1). The canted spin structure of Mn guarantees a non-zero Berry curvature, but generates only a weak magnetization three orders of magnitude lower than that of general ferromagnets. The heavy Bi with a large spin-orbit coupling enables a large ANE and low thermal conductivity, whereas its highly dispersive p_x/y orbitals ensure low resistivity. The high anomalous transverse thermoelectric performance and extremely small magnetization make YbMnBi₂ an excellent candidate for transverse thermoelectrics.

Efficacy and safety of iodine-125 particle implantation for treatment of bone metastatic tumor pain: a retrospective analysis

OBJECTIVE

Patients with advanced tumors often suffer from spinal metastatic tumor pain. The current drugs are less effective and have side effects. The objective was to explore the efficacy of iodine-125 particle implantation in the treatment of bone metastatic tumor pain.

PATIENTS AND METHODS

In a retrospective study, a total of 27 patients with bone metastatic tumors who could not receive surgery or radiotherapy and chemotherapy were analyzed. All patients received conventional treatment, with the visual analog scale (VAS) of >3 points, and the daily onset pain of >3 times. All patients received CT-guided iodine-125 particle implantation to treat local painful lesions. VAS scores were recorded before treatment (T0) and 1 day (T1), 7 days (T2), 30 days (T3), 90 days (T4), and 180 days (T5) after treatment. Kaplan-Meier analytical method was used to calculate the local control rate (LCR) and survival rate (SR).

RESULTS

All patients successfully completed the CT-guided iodine-125 particle implantation. There was no significant difference in VAS scores before and 1 day after surgery. However, compared with pre-operation, the VAS scores decreased at 7, 30, 90, and 180 days after surgery. The postoperative follow-up was 6-38 months, with a median of 16 months; the LCR at 1, 2, and 3 years after the follow-up were 87%, 51%, and 21%, respectively, and the SR was 84%, 43%, and 16%, respectively. Moreover, no serious adverse reactions were observed.

CONCLUSIONS

Iodine-125 particle implantation was effective in the treatment of bone metastatic tumor pain without serious complications, and hence, can be used clinically.

Transmission of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) through infant feeding and early care practices: A systematic review

BACKGROUND

Perinatal practices such as breast-feeding, kangaroo mother care, rooming-in, and delayed cord clamping have varied by institution during the COVID-19 pandemic. The goal of this systematic review was to examine the success of different practices in preventing viral transmission between SARS-CoV-2 positive mothers and their infants.

METHODS

Electronic searches were performed in the Ovid MEDLINE, Ovid Embase, Cochrane Library, EBSCOhost CINAHL Plus, Web of Science, and Scopus databases. Studies involving pregnant or breastfeeding patients who tested positive for SARS-CoV-2 by RT-PCR were included. Infants tested within 48 hours of birth who had two tests before hospital discharge were included. Infants older than one week with a single test were also included.

RESULTS

Twenty eight studies were included. In the aggregated data, among 190 breastfeeding infants, 22 tested positive for SARS-CoV-2 (11.5%), while 4 of 152 (2.63%) among bottle-fed (Fisher's exact test p = 0.0006). The positivity rates for roomed in infants (20/103, 19.4%) were significantly higher than those isolated (5/300, 1.67%) (P < 0.0001). There was no significant difference in positivity rate among infants who received kangaroo care (25%vs 9%, p = 0.2170), or delayed cord clamping (3.62%vs 0.9%, p = 0.1116).

CONCLUSIONS

Lack of robust studies involving large patient population does not allow meaningful conclusions from this systematic review. Aggregated data showed increased positivity rates of SARS-CoV-2 among infants who were breast fed and roomed-in. There were no differences in SARS-CoV-2 positivity rates in infants received skin to skin care or delayed cord clamping.

Biomimetic three-layered membranes comprising (poly)-ε-caprolactone, collagen and mineralized collagen for guided bone regeneration

The distinct structural properties and osteogenic capacity are important aspects to be taken into account when developing guided bone regeneration membranes. Herein, inspired by the structure and function of natural periosteum, we designed and fabricated using electrospinning a fibrous membrane comprising (poly)--ε-caprolactone (PCL), collagen-I (Col) and mineralized Col (MC). The three-layer membranes, having PCL as the outer layer, PCL/Col as the middle layer and PCL/Col/MC in different ratios (5/2.5/2.5 (PCM-1); 3.3/3.3/3.3 (PCM-2); 4/4/4 (PCM-3) (%, w/w/w)) as the inner layer, were produced. The physiochemical properties of the different layers were investigated and a good integration between the layers was observed. The three-layered membranes showed tensile properties in the range of those of natural periosteum. Moreover, the membranes exhibited excellent water absorption capability without changes of the thickness. In vitro experiments showed that the inner layer of the membranes supported attachment, proliferation, ingrowth and osteogenic differentiation of human bone marrow-derived stromal cells. In particular cells cultured on PCM-2 exhibited a significantly higher expression of osteogenesis-related proteins. The three-layered membranes successfully supported new bone formation inside a critical-size cranial defect in rats, with PCM-3 being the most efficient. The membranes developed here are promising candidates for guided bone regeneration applications.

[Abnormal expression of CD44 aggravates liver disease progression in patients with non-alcoholic fatty liver disease accompanied with hepatitis B virus replication]

Objective: To analyze the expression of CD44 in non-alcoholic fatty liver disease (NAFLD) accompanied with hepatitis B virus (HBV) infection and its clinical significance. Methods: Blood sample of hospitalized patients with NAFLD, chronic hepatitis B, cirrhosis, and healthy population (control) was collected. The study was approved by the hospital ethics committee. Serum CD44 level and clinopathological characteristics were analyzed quantitatively by enzyme-linked immunosorbent-assay. Flow cytometry was used to analyze the proportion of CD44(+)T lymphocytes in patients with NAFLD and chronic hepatitis B. NAFLD model was prepared with high-fat diet to verify the abnormal expression of CD44. Results: Compared with the healthy control group, the expression of serum CD44 in the cirrhosis group, chronic hepatitis B group and NAFLD group was increased, and the difference between the groups were statistically significant (P < 0.01). NAFLD patients graded as mild or severe group were equally accompanied by hepatocyte injury, abnormal blood glucose, lipid or CD44. In NAFLD patients accompanied with HBV infection, serum CD44 concentrations were significantly higher in HBsAg, HBeAg and HBV DNA positive group than HBsAg, HBeAg and HBV DNA negative group (P < 0.01). The proportion of CD44(+)T lymphocytes in peripheral blood of NAFLD and chronic hepatitis B group were 78.2% ± 16.3% and 68.5% ± 20.9%, respectively, and both groups (NAFLD and chronic hepatitis B) were significantly higher than the healthy control group (46.5% ± 20.5%) (P < 0.05). The high-fat diet model confirmed that in rat liver tissues the CD44 was overexpressed with fat deposition accompanied with liver cell damage, especially remarkable in liver tissues containing carcinogens. Conclusion: The abnormal expression of CD44 in patients with NAFLD may be related to the malignant transformation of HBV-related liver disease.

A lithium-doped surface inspires immunomodulatory functions for enhanced osteointegration through PI3K/AKT signaling axis regulation

The response of immune systems is crucial to the success of biomedical implants in vivo and in particular, orthopedic implants must possess appropriate immunomodulatory functions to allow sufficient osteointegration. In this work, lithium (Li) is incorporated into titanium (Ti) implants by plasma electrolytic oxidation to realize slow and sustained release of Li ions. In vitro cellular behaviors of mice bone marrow derived macrophages (BMDMs), including gene expression, cytokine secretion, and surface marker analysis suggest that a low dose of Li incorporation could enhance the recruitment of BMDMs, restrict pro-inflammatory polarization (M1 phenotype), and promote anti-inflammatory polarization (M2 phenotype). The in vivo air pouch implantation model is constructed to simulate the microenvironment associated with aseptic loosening and the histology results confirm that a small dose of Li could relieve inflammatory reactions surrounding the implants. Moreover, compared to the Li-free group, the macrophage-conditioned culture medium (MCM) from Li-doped samples is more beneficial for the osteogenic differentiation of the mouse embryo cell line (C3H10T1/2) and angiogenesis of human umbilical vein endothelial cells (HUVECs), which is further confirmed by better osteointegration ability in the bone implantation model of Li-incorporating Ti implants. Furthermore, the molecular mechanism study discloses that osteoimmunomodulatory activity of Li-incorporating Ti implants is achieved by regulating the cascade molecules in the PI3K/AKT signalling pathway. This work reveals that favorable immune-modulated osteogenesis and osseointegration of bone implants can be realized by the incorporation of Li which broadens the strategy to develop the next generation of immunomodulatory biomaterials.

Pure Mg-Al Layered Double Hydroxide Film on Magnesium Alloys for Orthopedic Applications

Mg alloys are promising biodegradable orthopedic implants in the future. However, poor corrosion resistance and biocompatibility limit their wide applications. In this study, a pure Mg-Al layered double hydroxide (Mg-Al LDH) film on AZ31 was prepared through combining hydrofluoric acid pretreatment and hydrothermal treatment. Electrochemical analysis and the immersion test suggested that the as-prepared Mg-Al LDH-coated sample exhibited significantly enhanced corrosion resistance. The in vitro cell culture revealed that the Mg-Al LDH film was favorable for the alkaline phosphatase activity, collagen secretion, and osteogenesis-related gene expression of MC3T3-E1. Furthermore, the LDH-coated sample was beneficial for the migration, vascular endothelial growth factor secretion, and angiogenesis-related gene expression of human umbilical vein endothelial cells. The subcutaneous implantation test demonstrated that the Mg-Al LDH film could protect the substrate from corrosion and induce milder inflammation. The femur implantation demonstrated that the Mg-Al LDH sample showed better bone regeneration and osseointegration than bare AZ31. In summary, the as-prepared pure Mg-Al LDH film is able to enhance the in vitro and in vivo performances of AZ31, indicating a promising application in the orthopedic field.

A pH-response chemotherapy synergistic photothermal therapy for tumor suppression and bone regeneration by mussel-inspired Mg implant

Primary malignant bone tumors can be life-threatening. Surgical resection of tumor plus chemotherapy is the standard clinical treatment. However, postoperative recovery is hindered due to tumor recurrence caused by residual tumor cells and bone defect caused by resection of tumor tissue. Herein, a multifunctional mussel-inspired film was fabricated on Mg alloy, that is, an inner hydrothermal-treated layer, a middle layer of polydopamine, and an outer layer of doxorubicin. The modified Mg alloy showed excellent photothermal effect and thermal/pH-controlled release of doxorubicin. The synergistic effect of chemotherapy and photothermal therapy enabled the modified Mg alloy to kill bone tumor in vitro and inhibit tumor growth in nude mice. Moreover, because of the controlled release of Mg ions and biocompatibility of polydopamine, the modified Mg alloy supported extracellular matrix mineralization, alkaline phosphatase activity, and bone-related gene expression in C3H10T1/2. Bone implantation model in rats verified that the modified Mg showed excellent osteointegration. These findings prove that the use of mussel-inspired multifunction film on Mg alloy offers a promising strategy for the therapy of primary malignant bone tumor.

Demonstration of valley anisotropy utilized to enhance the thermoelectric power factor

Valley anisotropy is a favorable electronic structure feature that could be utilized for good thermoelectric performance. Here, taking advantage of the single anisotropic Fermi pocket in p-type Mg3Sb2, a feasible strategy utilizing the valley anisotropy to enhance the thermoelectric power factor is demonstrated by synergistic studies on both single crystals and textured polycrystalline samples. Compared to the heavy-band direction, a higher carrier mobility by a factor of 3 is observed along the light-band direction, while the Seebeck coefficient remains similar. Together with lower lattice thermal conductivity, an increased room-temperature zT by a factor of 3.6 is found. Moreover, the first-principles calculations of 66 isostructural Zintl phase compounds are conducted and 9 of them are screened out displaying a pz-orbital-dominated valence band, similar to Mg3Sb2. In this work, we experimentally demonstrate that valley anisotropy is an effective strategy for the enhancement of thermoelectric performance in materials with anisotropic Fermi pockets.

Enhanced osteogenesis of titanium with nano-Mg(OH)2 film and a mechanism study via whole genome expression analysis

Titanium (Ti) has been the most widely used orthopedic implant in the past decades. However, their inert surface often leads to insufficient osteointegration of Ti implant. To solve this issue, two bioactive Mg(OH)₂ films were developed on Ti surfaces using hydrothermal treatment (Ti-M1# and Ti-M2#). The Mg(OH)₂ films showed nano-flake structures: sheets on Ti-M1# with a thickness of 14.7 ± 0.7 nm and a length of 131.5 ± 2.9 nm, and on Ti-M2# with a thickness of 13.4 ± 2.2 nm and a length of 56.9 ± 5.6 nm. Both films worked as Mg ions releasing platforms. With the gradual degradation of Mg(OH)₂ films, weakly alkaline microenvironments will be established surrounding the modified implants. Benefiting from the sustained release of Mg ions, nanostructures, and weakly alkaline microenvironments, the as-prepared nano-Mg(OH)₂ coated Ti showed better in vitro and in vivo osteogenesis. Notably, Ti-M2# showed better osteogenesis than Ti-M1#, which can be ascribed to its smaller nanostructure. Moreover, whole genome expression analysis was applied to study the osteogenic mechanism of nano-Mg(OH)₂ films. For both coated samples, most of the genes related to ECM-receptor interaction, focal adhesion, and TGF-β pathways were upregulated, indicating that these signaling pathways were activated, leading to better osteogenesis. Furthermore, cells cultured on Ti-M2# showed markedly upregulated BMP-4 gene expression, suggesting that the nanostructure with Mg ion release ability can better activate BMP-4 related signaling pathways, resulting in better osteogenesis. Nano-Mg(OH)₂ films demonstrated a superior osteogenesis and are promising surface modification strategy for orthopedic applications.

[Value of abnormal expression of Krüppel-like zinc-finger protein transcription factor 5 in the diagnosis and prognosis of liver cancer]

Objective: To explore the value of Krüppel-like factor 5 (KLF5), a family member of the zinc finger protein transcription factor, in the diagnosis and prognostic evaluation of hepatocellular carcinoma (HCC). Methods: Cancerous and non-cancerous tissues were collected from 126 cases after HCC surgery by self-matching method with microarray fabrication. Immunohistochemistry was used to analyze the expression of KLF5, clinicopathological characteristics and prognostic value. The sera of 222 cases with chronic liver disease were collected and their KLF5 levels were quantitatively determined by enzyme-linked immunosorbent assay (ELISA). Simultaneously, 40 normal human sera were used as controls to evaluate the value of abnormal KLF5 in the diagnosis and differentiation of benign and malignant liver diseases. T-test, Z-test and χ (2) test were performed on the data. Results: The positive expression rate of KLF5 in the HCC group was 95.2% (120/126), which was significantly higher than the non-cancerous group 38.9% (49/126; χ (2) = 14.385, P < 0.001). KLF5 expression was significantly correlated with TNM stage (stage I 35%, stage II 40%, stage III 74.4%, stage IV 78.1%), tumor size, alpha fetoprotein (AFP) concentration, portal vein embolism, HBV infection and 5-year survival rate. Univariate/multivariate analysis showed that KLF5 high expression was an independent predictor of HCC prognosis. The serum KLF5 level was significantly higher in HCC patients than liver cirrhosis, chronic hepatitis and normal control group (P < 0.001). With the serum KLF5 > 800 ng/ml and AFP > 25 μg/L as limit, the positive rates for HCC diagnosis were 90.48% and 73.81%, respectively, which were lower than the AFP specificity and false positive rate, and was helpful for the differential diagnosis of benign and malignant liver diseases. Conclusion: The overexpression of KLF5 in liver cancer tissues and blood is closely related to the HCC clinical stage and prognosis. Moreover, KLF5 analysis is helpful for HCC diagnosis and differential diagnosis.

P–212 Mitochondrial DNA content shows a significant association with timing of human embryo development and fertility diagnosis in euploid embryos

Study question

Does mitochondrial DNA content (mtDNA) correlate with clinical parameters and embryo morphokinetics using advanced time-lapse technology?

Summary answer

mtDNA correlated with embryo morphokinetics and the growth trajectory of euploid embryos. Maternal age, anti-mullerian hormone level and fertility diagnosis were significantly associated with mtDNA.

What is known already

With the push towards single embryo transfers, laboratories are working to improve embryo selection. In addition to conventional microscopy, preimplantation genetic testing and time-lapse microscopy have been utilized to aid in embryo selection. More recently, as mtDNA may represent the energy potential of an embryo, some data have supported the use of mtDNA as an additional tool. Limited studies have suggested that a lower amount of mtDNA is associated with higher rates of implantation and improved embryo quality.

Study design, size, duration

This is a retrospective chart review. All embryos that underwent preimplantation genetic testing for aneuploidy (PGT-A) between January to December of 2020 were studied.

Participants/materials, setting, methods

Women undergoing in vitro fertilization (IVF) with intracytoplasmic sperm injection undergoing PGT-A were studied. All patients were from a single academic institution. This study exclusively examined the characteristics of euploid embryos. Mitochondrial DNA content was expressed as a ratio of mtDNA:nDNA (MitoScore). Time-lapse imaging was utilized to evaluate embryo development every 15 minutes in 5–7 focal planes. Chi square test and Spearman correlation analysis were performed with a p-value of &lt; 0.05 considered significant.

Main results and the role of chance

A total of 494 embryos from 52 women who underwent 58 IVF cycles were cultured to blastocyst and 331 embryos were biopsied for PGT-A evaluation. Of these, 132 embryos were diagnosed as euploid. A moderate positive correlation was found between MitoScore and time to morula, time to blast and time to expanded blast (correlation value 0.54, 0.50 and 0.54, respectively; p &lt; 0.001). Consistent with this trend, day 5 blastocysts had a significantly lower MitoScore values than day 6 blastocysts (20.2 v. 29.2; p &lt; 0.001). When examining all biopsied euploid embryos, no significant association was found between MitoScore, blastocyst maturity, trophectoderm or inner cell mass scores.

Our data also demonstrated a positive correlation between MitoScore and maternal age (correlation factor 0.33; p &lt; 0.001). A negative association between MitoScore and serum anti-mullerian hormone levels (correlation factor –0.20; p &lt; 0.021) was also noted. Of particular interest was the significant association between fertility diagnosis and mitochondrial score (p &lt; 0.001).

Even amongst euploid embryos, mtDNA content varied widely, potentially reflecting differences in embryo potential and quality. Additionally, the significant difference in MitoScore between that day 5 and day 6 blastocysts may reflect a fundamental difference in cytoplasmic characteristics and requires further study.

Limitations, reasons for caution

Due to the study cohort of euploid embryos undergoing PGT-A, this study was biased for the selection of high grade embryos. This limited diversity in embryo quality may have masked other potential associations between mitochondrial content and blastocyst quality.

Wider implications of the findings: mtDNA may be additional tool aiding in embryo selection as IVF labs work to improve pregnancy rates while minimizing the risks of transferring multiple embryos. To our knowledge, this is the largest study assessing the relationship of mtDNA content of blastocysts and the timing of embryo development using time-lapse imaging.

Trial registration number

None

P–017 The maintenance of testicular architecture and germ cell in adult testis tissue under organ culture condition based on the gas-liquid interface method

Study question

Can the gas-liquid interface organ culture system that achieved in vitro spermatogenesis in mice also support in vitro spermatogenesis in human adult testis?

Summary answer

Although the progression of spermatogenesis was not observed, germ cells were maintained without the degeneration of the architecture in both fresh and cryopreserved testicular tissues.

What is known already

Although the research on in vitro spermatogenesis have been conducted for 100 years, only the organ culture system using gas-liquid interface method achieved in vitro spermatogenesis in mice. It has not been verified whether this culture system can be applied to other mammals including humans and induce spermatogenesis.

Study design, size, duration

Testicular tissue was obtained from the transgender patients receiving sex reassignment surgery. Testicular specimens were either immediately processed for cultivation or cryopreserved, using a vitrification freezing protocol. Organ culture of testicular fragments was performed in three different media for a maximum period of 3 weeks to evaluate the short-term changes in the cultured tissues (viability, proliferation and maintenance of germ and somatic cells).

Participants/materials, setting, methods

Fresh and cryopreserved-thawed testis fragments (1–2 mm3) were cultured using the organ culture system in alpha-MEM with knock-out serum replacement (K group), alpha-MEM with lipid-rich BSA (A group) and DMEM with FBS (D group). Luteinizing hormone, follicle stimulating hormone and testosterone were supplemented. The number of germ cells (using DDX4), proliferative activity of germ cells (using EdU assay) and intratubular cell apoptosis (by TdT-mediated dUTP Nick End Labeling) were evaluated by immunohistochemical staining weekly.

Main results and the role of chance

The architecture of the seminiferous tubules was maintained until the second week of culture in both the fresh and the cryopreserved culture group. The number of DDX4-positive germ cells per seminiferous tubule in groups D, K, and A was 49 ± 24, 55 ± 21, 50 ± 26 cells/tubule in 1 day, 32 ± 13, 42 ± 7, 36 ± 21 cells/tubule in 1week, respectively. The numbers gradually decreased to 26 ± 8, 24 ± 6 and 27 ± 18 cells/tubule, in 2 weeks, respectively, with no difference among the groups. The number of intratubular EdU-positive cells of groups D, K, and A was 0.2 ± 0.2, 2.8 ± 2.1, 1.1 ± 0.8 cells/tubule at 1 day, 0.1 ± 0.2, 0.5 ± 0.6, 0.3 ± 0.6 cells/tubule at 1 week, respectively. The values were 0.01, 0.05, and 0.03 at 2 weeks. Thus, EdU-positive cells drastically decreased from the first week of culture. The number of DDX4-positive germ cells and the intratubular EdU-positive cells in the cryopreserved culture group was not different from that in the fresh culture group.

Limitations, reasons for caution

Current organ culture systems are incomplete, being unable to induce human in vitro spermatogenesis. Further research is needed to improve culture condition with the aim of producing fertile sperm of infertile adult male patients.

Wider implications of the findings: Our organ culture system could maintain testis structure and germ cells. By using the testis tissues of the transgender patients, which are available with their consent, we will promote the investigation of the culture condition necessary for germ cell proliferation and differentiation.

Trial registration number

Grant-in-Aid for Scientific Research on Innovative Areas 18H05546, Grant-in-Aid for Young Scientists (A) 17H05098 and Takeda Science Foundation