Amide proton transfer and apparent diffusion coefficient analysis reveal susceptibility of brain regions to neonatal hypoxic-ischemic encephalopathy.

Purpose: To identify brain regions affected by Hypoxic-Ischemic Encephalopathy (HIE) in neonates using Amide Proton Transfer (APT) imaging and Apparent Diffusion Coefficient (ADC). Materials and methods: Twenty neonates were divided into HIE and control groups. All neonates were undergoing MRI, including APT and DWI. Imaging analysis was performed using SPM12. The independent-samples t-test was used to analyze the difference in APTw values and ADC values between the mild HIE neonates and the control group. The receiver operating characteristic (ROC) curves were established to assess the diagnostic values of APTw and ADC values in different brain regions for HIE. Pearson's correlation analysis was used to analyze the correlation between APTw values and ADC values for each region. Results: APTw values were significantly higher in 26 regions of the HIE group. ADC values were lower in the right anterior temporal lobe and higher in bilateral Subthalamic nucleus in HIE. The APTw values of 22 regions showed very high area under the curve (AUC), whereas the AUC of ADC values in right anterior temporal lobe and right subthalamic nucleus were both 0.802. Notably, the right anterior temporal lobe exhibited significant differences in both APTw and ADC values between the HIE and control groups, additionally, APTw value was significant positive correlated with ADC values in right anterior temporal lobe. Conclusion: APTw and ADC are effective in detecting HIE, with APTw being more sensitive. The right anterior temporal lobe is particularly affected by HIE, with significant changes in APTw and ADC values and a positive correlation between them. This suggests that temporal lobe damage may be critical in the long-term neurological consequences of HIE.

Promising application of pulsed electromagnetic fields on tissue repair and regeneration.

Tissue repair and regeneration is a vital biological process in organisms, which is influenced by various internal mechanisms and microenvironments. Pulsed electromagnetic fields (PEMFs) are becoming a potential medical technology due to its advantages of effectiveness and non-invasiveness. Numerous studies have demonstrated that PEMFs can stimulate stem cell proliferation and differentiation, regulate inflammatory reactions, accelerate wound healing, which is of great significance for tissue regeneration and repair, providing a solid basis for enlarging its clinical application. However, some important issues such as optimal parameter system and potential deep mechanisms remain to be resolved due to PEMFs window effect and biological complexity. Thus, it is of great importance to comprehensively summarizing and analyzing the literature related to the biological effects of PEMFs in tissue regeneration and repair. This review expounded the biological effects of PEMFs on stem cells, inflammation response, wound healing and musculoskeletal disorders in order to improve the application value of PEMFs in medicine. It is believed that with the continuous exploration of biological effects of PEMFs, it will be applied increasingly widely to tissue repair and other diseases.

Regulation of Tendon Stem Cell Behavior by Designed Nanoporous Topography of Microfibers.

Nano scale topography scaffold is more bioactive and biomimetic than smooth fiber topographies. Tendon stem cells (TSCs) play important roles in the tendinogenesis of tendon tissue engineering, but the effects and mechanisms of nano topography on TSC behavior are still unclear. This study determined whether the morphology, proliferation, cytoskeleton, and differentiation of TSCs are affected by topography of scaffold in vitro. The porous PA56 scaffolds were prepared with different concentration ratios of glycerol as the molecular template by electrospinning. Its topological characteristics, hydrophilicity, and degradation properties varied with glycerol proportion and movement rate of the receiving plate. Porous fibers promoted the proliferation of TSCs and the number of TSCs varied with topography. Although there was no significant difference due to the small sample size, the number of pseudopodia and cell polarizability still showed differences among different topographies. The morphology of actin cytoskeleton of TSCs showed difference among cultured on porous fibers, smooth fibers, and in culture media with no fiber, suggesting the orientation growth of cells on porous fiber. Moreover, porous fibers promoted teno-lineage differentiation of TSCs by upregulating tendon-specific gene expression. These findings provide evidence that nano porous topography scaffold promotes TSC proliferation, cytoskeleton orientation, and tenogenic differentiation.

The regulation of tendon stem cell distribution, morphology, and gene expression by the modulus of microfibers.

The mechanical properties of a stem cell culture substrate significantly impact cell adhesion, survival, migration, proliferation, and differentiation in vitro. A major challenge in engineering artificial stem cell substrate is to properly identify the relevant physical features of native stem cell niches, which are likely different for each stem cell type. The behavior of tendon stem cells has potentially significant implications for tendon repair. Here, microfiber scaffolds with various modulus of elasticity are fabricated by near-field electrospinning, and their regulating effects on the in vitro behavior of tendon stem cells (TSCs) are discussed in this study. The number of pseudopodia shows a biphasic relationship with the modulus of scaffold. The proliferation, polarization ratio and alignment degree along the fibers of the TSCs increase with the increase of fiber modulus. TSCs cultured on the scaffold with moderate modulus (1429 MPa) show the upregulation of tendon-specific genes (Col-I, Tnmd, SCX and TNCF). These microfiber scaffolds provide great opportunities to modulate TSCs behavior at the micrometer scales. In conclusion, this study provides an instructive mechanical microenvironment for TSCs behaviors and may lead to the development of desirable engineered artificial stem cell substrate for tendon healing.

dl-Alanine Covalently Bonded Giant Arsenotungstate with Rapid Photochromic and Decent Proton Conduction Properties.

A dl-alanine covalently bonded giant arsenotungstate, namely, Na3Ba11H16[(AsW9O33)6{W2O5(H2O)(dl-Ala)}2{W3O6(H2O)(dl-Ala)}2{W2O5(dl-Ala)}] (1; dl-Ala = dl-alanine), has been synthesized and is composed of six [AsW9O33]9- fragments fused together via two [W2O5(H2O)(dl-Ala)]+ segments, two [W3O6(H2O)(dl-Ala)]5+ segments, and a [W2O5(dl-Ala)]+ segment. This complex represents the first carboxylate-based hybrid polyoxotungstate without the introduction of lanthanide ions. Besides, compound 1 demonstrates not only fast photochromic properties but also interesting proton conductivity properties, with an achieved conductivity of 2.830 × 10-4 S·cm-1 (65 °C, 75% relative humidity).

dl-Serine Covalently Ornamented and Ln3+-Incorporated Arsenotungstates with Fast-Responsive Photochromic and Photoinduced Luminescent Switchable Behaviors.

Three isostructural dl-serine covalently functionalized and multinuclear lanthanide (Ln3+)-embedded arsenotungstates, K2[{As4W44O137(OH)18(H2O)2(dl-Ser)2}{Ln2(H2O)4(dl-Ser)}2{Ln(H2O)7}2]·70H2O (Ln = Sm (1), Eu (2), and Gd (3); dl-Ser = C3H7NO3), were prepared, where the centrosymmetric [{As4W44O137(OH)18(H2O)2(dl-Ser)2}{Ln2(H2O)4(dl-Ser)}2]8- polyanion consists of two {As2W19O59(OH)8(H2O)}6- fragments, integrated with a two-dl-serine-ornamented [W6O23(OH)2(dl-Ser)2{Ln2(H2O)4}2]8- segment. In addition, the photochromic transformation of solid-state compounds 1-3 was observed from colorless to blue after a UV illumination of 4 min, and the decay process lasted as long as ∼20 h in the dark. The coloration kinetic half-life (t1/2) values of compounds 1, 2, and 3 were calculated to be 0.597, 0.920, and 0.723 min, respectively. Furthermore, the luminescent properties and energy migration from arsenotungstates and organic chromophores to Sm3+ and Eu3+ ions in 1 and 2 have been intensively investigated. Further analysis manifests that 1 possesses an effective luminescent switchable behavior, triggered by its fast-responsive photochromism effect.

Electrospun heparin-loaded nano-fiber sutures for the amelioration of achilles tendon rupture regeneration: in vivo evaluation.

Peritendinous blood circulation improvement is a challenge to promote the healing of ruptured tendons in clinical treatment. Although electrospun membranes or scaffolds enable the reduction of complications such as adhesion, however, low efficiency, toxicity issues, the loss of biological activity, and complex electrospinning techniques are all bottlenecks of these systems. Improving the blood supply is crucial for their successful use, which involves promoting the metabolism and nutrient absorption in tendons. Here, a multifunctional, structurally simple strategy involving heparin-loaded sutures (PPH) that are clinically applicable is reported, in the form of electrospun core-shell nanofibers, with the ability to perform sustained release of anticoagulants heparin (verified in our previous publication) for the improvement of the healing of Achilles tendon. The morphology and diameter distribution of the collagen fiber in the PPH group are closely related to the health of the Achilles tendon than those of commercial sutures (CS). The in vivo results of the total collagen content and the expression of collagen type I in the PPH group are more than those of the CS group. After 6 weeks of culture, the tensile strength of the PPH group shows no significant difference compared to the healthy group. The data obtained in this study improves the current understanding on the regeneration of ruptured tendons and presents a promising strategy for clinical treatment.

A study of degradation behaviour and biocompatibility of Zn-Fe alloy prepared by electrodeposition.

Zinc is a biodegradable metal, which exhibits more moderate biodegradability than magnesium and iron, so that it has great application potential in the field of biomedical materials. Alloying of zinc and iron may lead to producing a new type of implant material Zn-Fe alloy, which might be able to meet the requirements for a moderate degradation rate. However, due to the huge difference in the melting point between zinc and iron, the preparation of Zn-Fe alloy is quite challenging and hence rarely reported. In this study, we show that Zn-Fe alloys can be successfully prepared by electrodeposition technology. The microstructures, composition, degradation properties and biocompatibility of the Zn-Fe alloys were systematically studied. The results showed that the content of iron in the alloys ranged from 0 to 8 wt%, depending on the concentration of Fe ions and the current density. In the alloys, the major's phases were η, δ and Г1, and they were mainly affected by the ion concentration in the electrolyte. In the in vitro immersion tests, the Zn-Fe alloy ZF2-1 showed the highest immersion corrosion rate, while ZF3-1 showed the highest electrochemical corrosion rate. Moreover, we found that the corrosion rates of the alloys were significantly higher than that of the pure Fe. In the in vivo experiments, we confirmed that the Zn-Fe alloy possessed good biocompatibility. These results demonstrate that the electrodeposition technology is a good method to prepare Zn-Fe alloys, and the Zn-Fe alloys prepared by this method are potentially promising materials for biomedical applications.

Erratum to "The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity".

[This corrects the article DOI: 10.34133/2020/2640834.].

The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity.

The contact angle, as a vital measured parameter of wettability of material surface, has long been in dispute whether it is affected by gravity. Herein, we measured the advancing and receding contact angles on extremely low contact angle hysteresis surfaces under different gravities (1-8G) and found that both of them decrease with the increase of the gravity. The underlying mechanism is revealed to be the contact angle hysteresis and the deformation of the liquid-vapor interface away from the solid surface caused by gradient distribution of the hydrostatic pressure. The real contact angle is not affected by gravity and cannot measured by an optical method. The measured apparent contact angles are angles of inclination of the liquid-vapor interface away from the solid surface. Furthermore, a new equation is proposed based on the balance of forces acting on the three-phase contact region, which quantitatively reveals the relation of the apparent contact angle with the interfacial tensions and gravity. This finding can provide new horizons for solving the debate on whether gravity affects the contact angle and may be useful for the accurate measurement of the contact angle and the development of a new contact angle measurement system.