Generic Approach to Boost the Sensitivity of Metal Oxide Sensors by Decoupling the Surface Charge Exchange and Resistance Reading Process

As one of the bottleneck parameters for practical applications of metal oxide semiconductor-based gas sensors, sensitivity enhancement has attracted significant attention in the past few decades. In this work, alternative to conventional strategies for designing sensitive surfaces via morphology/defect/heterojunction control (then operating at an optimized isothermal temperature with a maximal response), a facile enhancement approach by decoupling surface charge exchange and resistance reading process (possessing different temperature-dependent behaviors) through pulsed temperature modulation (PTM) is reported. Substantially magnifying electrical responses of a generic metal oxide (e.g., WO₃) micro-electromechanical systems sensor toward diverse analyte molecules are demonstrated. Under the optimal PTM condition, the response toward 10 ppm NO₂ can be boosted from (isothermal) 99.7 to 842.7, and the response toward 100 ppm acetone is increased from (isothermal) 2.7 to 425, which are comparable to or even better than most of the state-of-the-art WO₃-based sensors. In comparison to conventional (isothermal) operation, PTM allows to sequentially manipulate the physisorption/chemisorption of analyte molecules, generation of surface reactive oxygen species, and sensor resistance reading and thus provides additional opportunities in boosting the electrical response of oxide sensors for advanced health and/or environment monitoring in future.

Platelet-rich plasma accelerates skin wound healing by promoting re-epithelialization

BACKGROUND

Autologous platelet-rich plasma (PRP) has been suggested to be effective for wound healing. However, evidence for its use in patients with acute and chronic wounds remains insufficient. The aims of this study were to comprehensively examine the effectiveness, synergy and possible mechanism of PRP-mediated improvement of acute skin wound repair.

METHODS

Full-thickness wounds were made on the back of C57/BL6 mice. PRP or saline solution as a control was administered to the wound area. Wound healing rate, local inflammation, angiogenesis, re-epithelialization and collagen deposition were measured at days 3, 5, 7 and 14 after skin injury. The biological character of epidermal stem cells (ESCs), which reflect the potential for re-epithelialization, was further evaluated in vitro and in vivo.

RESULTS

PRP strongly improved skin wound healing, which was associated with regulation of local inflammation, enhancement of angiogenesis and re-epithelialization. PRP treatment significantly reduced the production of inflammatory cytokines interleukin-17A and interleukin-1β. An increase in the local vessel intensity and enhancement of re-epithelialization were also observed in animals with PRP administration and were associated with enhanced secretion of growth factors such as vascular endothelial growth factor and insulin-like growth factor-1. Moreover, PRP treatment ameliorated the survival and activated the migration and proliferation of primary cultured ESCs, and these effects were accompanied by the differentiation of ESCs into adult cells following the changes of CD49f and keratin 10 and keratin 14.

CONCLUSION

PRP improved skin wound healing by modulating inflammation and increasing angiogenesis and re-epithelialization. However, the underlying regulatory mechanism needs to be investigated in the future. Our data provide a preliminary theoretical foundation for the clinical administration of PRP in wound healing and skin regeneration.

Effects of polymer aging on sorption of 2,2',4,4'-tetrabromodiphenyl ether by polystyrene microplastics

The sorption behavior of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on aged polystyrene (PS) microplastics via seawater soaking, ultraviolet (UV) irradiation, seawater soaking and UV irradiation together was investigated. The effects of environmental factors including salinity, pH, and dissolved organic matter (DOM) on sorption of BDE-47 by the aged PS microplastics were analyzed. The equilibrium sorption capacity of BDE-47 by virgin PS, aged PS with seawater soaking, aged PS with UV irradiation and aged PS with seawater soaking and UV irradiation was 6.16, 4.96, 3.53, and 3.75 ng/g, respectively. The decrease in sorption capacity was related to the increase of surface crystallinity and the appearance of surface oxygen-containing functional groups. The kinetic and isotherm models suggested that aging did not change the sorption mechanism of BDE-47 on PS microplastics. pH had negligible impacts on BDE-47 sorption by virgin and aged PS. Sorption capacity of BDE-47 on aged PS in water with high salinity was lower than that on virgin PS, and DOM has less effect on the sorption of BDE-47 on aged PS.

Electrolyte Membranes with Biomimetic Lithium-Ion Channels

High-performance lithium-ion batteries (LIBs) demand efficient and selective transport of lithium ions. Inspired by ion channels in biology systems, lithium-ion channels are constructed by chemically modifying the nanoporous channels of metal-organic frameworks (MOFs) with negatively charged sulfonate groups. Analogous to the biological ion channels, such pendant anionic moieties repel free anions while allowing efficient transport of cations through the pore channels. Implementing such MOFs as an electrolyte membrane doubly enhances the lithium-ion transference number, alleviates concentration polarization, and affords striking durability of high-rate LIBs. This work demonstrates an ion-selective material design that effectively tunes the ion-transport behavior and could assist with more efficient operation of LIBs.

Resonant-Cantilever-Detected Kinetic/Thermodynamic Parameters for Aptamer-Ligand Binding on a Liquid-Solid Interface

Nucleic acid aptamers have been widely used as recognition elements on various biosensing interfaces, but quantitative kinetic/thermodynamic analysis for revealing the aptamer-ligand binding mechanism, which occurs on a liquid-solid interface, has not been realized due to a lack of usable biophysical tools. Herein we apply a resonant microcantilever sensor to continuously record the frequency shift according to the binding-induced mass change on the liquid-solid interface. The frequency-shift curve is used for tracing the reaction process and is fitted with classic equations to calculate a set of kinetic/thermodynamic parameters, such as rate constants (k_a = 902.95 M^-1 s^-1, k_d = 0.000141 s^-1), equilibrium constants (K_D = 1.55 μM), the Gibbs free energy (ΔG° = -32.57 kJ/mol), and the activation energy (E_a = 38.03 kJ/mol) for the immobilized aptamer and free ATP. This quantitative analysis method is label-free, calibration-free, and highly sensitive. The kinetic/thermodynamic parameter detection method provides new resolution to the in-depth understanding of the ligand-aptamer interaction on the liquid-solid interface for biosensing or lab-on-a-chip applications.

Cantharidin-loaded functional mesoporous titanium peroxide nanoparticles for non-small cell lung cancer targeted chemotherapy combined with high effective photodynamic therapy

BACKGROUND

Although photodynamic therapy (PDT) has emerged as a potential alternative to conventional chemotherapy, the low reactive oxygen species (ROS) yield of the photosensitizer such as TiO2 nanoparticles has limited its application. In addition, it is difficult to achieve effective tumor treatment with a single tumor therapy.

METHODS

We used TiOx nanocomposite (YSA-PEG-TiOX ) instead of TiO2 as a photosensitizer to solve the problem of insufficient ROS generation in PDT. Benefiting from the desired mesoporous structure of TiOx, Cantharidin (CTD), one of the active components of mylabris, is loaded into TiOx for targeted combination of chemotherapy and PDT. The cellular uptake in human non-small cell lung carcinoma cell line (A549) and human normal breast cell line (MCF 10A) was evaluated by confocal microscopy. in vitro cytotoxicity was evaluated using Cell Counting Kit-8 assay. The ROS was detected via a chemical probe DCFH-DA and the photodynamic treatment effect of YSA-PEG-TiOx was further evaluated by a living-dead staining. The cell apoptosis was detected by the flow cytometry.

RESULTS

Our findings showed that the modification of YSA peptide improved the cytotoxicity of YSA-PEG-TiOX /CTD to EphA2 overexpressing A549 non-small cell lung cancer (NSCLC) than non-YSA modified counterparts. In addition, TiOx generated adequate ROS under X-ray irradiation to further kill cancer cells. Flow analysis results also proved the superiority of this combined treatment.

CONCLUSIONS

YSA-PEG-TiOX nanoparticles could significantly increase ROS production under X-ray exposure and provide a new drug delivery nanocarrier for CTD in combination with PDT to achieve effective NSCLC treatment.

Multi-functional anodes boost the transient power and durability of proton exchange membrane fuel cells

Proton exchange membrane fuel cells have been regarded as the most promising candidate for fuel cell vehicles and tools. Their broader adaption, however, has been impeded by cost and lifetime. By integrating a thin layer of tungsten oxide within the anode, which serves as a rapid-response hydrogen reservoir, oxygen scavenger, sensor for power demand, and regulator for hydrogen-disassociation reaction, we herein report proton exchange membrane fuel cells with significantly enhanced power performance for transient operation and low humidified conditions, as well as improved durability against adverse operating conditions. Meanwhile, the enhanced power performance minimizes the use of auxiliary energy-storage systems and reduces costs. Scale fabrication of such devices can be readily achieved based on the current fabrication techniques with negligible extra expense. This work provides proton exchange membrane fuel cells with enhanced power performance, improved durability, prolonged lifetime, and reduced cost for automotive and other applications.

Proton exchange membrane fuel cells often suffer from low lifetimes and high cost. Here, the authors enhance the transient power performance and durability of these fuel cells by integrating a thin layer of tungsten oxide within the anode, which acts as a hydrogen reservoir, oxygen scavenger, and a regulator for the hydrogen-disassociation reaction.

Pentagram-Shaped Ag@Pt Core-Shell Nanostructures as High-Performance Catalysts for Formaldehyde Detection

High-performance HCHO sensors are of great importance in various application fields such as indoor air quality assessments. Herein, bimetallic Ag-Pt nanoparticles are synthesized as high-performance catalysts for ZnO-based gas sensors. Spherical aberration (Cs)-corrected transmission electron microscopy images with atomic resolution clearly indicate that the prepared nanoparticles exhibit a novel Ag@Pt core-shell nanostructure with a pentagram shape. For high-performance HCHO sensor construction, integrated micro-electrodes are first fabricated with the microelectromechanical system (MEMS) technology. Then, the hydrothermal route is used to self-assemble well-aligned ZnO nanowire arrays onto the sensing microregion. After that, the pentagram-shaped Ag@Pt nanoparticles are loaded onto the surface of ZnO nanowires with the inkjet printing technique to form MEMS sensors with Ag@Pt@ZnO as the sensing material. The thoroughly sensing experiments indicate that the Ag@Pt nanoparticles exhibit satisfied catalytic activation to HCHO molecules. The experimental observed detection limit of our sensor to HCHO reaches the parts per billion level. To elucidate the HCHO-sensing mechanism, the online mass spectrum (online MS) is utilized to analyze the components of exhaust gas stream of HCHO flowing through the Ag@Pt@ZnO material. The online MS indicates that with the Ag@Pt catalyst, HCHO molecules are partially oxidized to HCOOH molecules at low temperatures and are completely oxidized to CO₂ molecules at high temperatures.

Preparation of Antimicrobial Hyaluronic Acid/Quaternized Chitosan Hydrogels for the Promotion of Seawater-Immersion Wound Healing

Wound immersion in seawater with high salt, high sodium, and a high abundance of pathogenic bacteria, especially gram-negative bacteria, can cause serious infections and difficulties in wound repair. The present study aimed to prepare a composite hydrogel composed of hyaluronic acid (HA) and quaternized chitosan (QCS) that may promote wound healing of seawater-immersed wounds and prevent bacterial infection. Based on dynamic Schiff base linkage, hydrogel was prepared by mixing oxidized hyaluronic acid (OHA) and hyaluronic acid-hydrazide (HA-ADH) under physiological conditions. With the addition of quaternized chitosan, oxidized hyaluronic acid/hyaluronic acid-hydrazide/quaternized chitosan (OHA/HA-ADH/O-HACC and OHA/HA-ADH/N-HACC) composite hydrogels with good swelling properties and mechanical properties, appropriate water vapor transmission rates (WVTR), and excellent stability were prepared. The biocompatibility of the hydrogels was demonstrated by in vitro fibroblast L929 cell culture study. The results of in vitro and in vivo studies revealed that the prepared antibacterial hydrogels could largely inhibit bacterial growth. The in vivo study further demonstrated that the antibacterial hydrogels exhibited high repair efficiencies in a seawater-immersed wound defect model. In addition, the antibacterial hydrogels decreased pro-inflammatory factors (TNF-α, IL-1β, and IL-6) but enhanced anti-inflammatory factors (TGF-β1) in wound. This work indicates that the prepared antibacterial composite hydrogels have great potential in chronic wound healing applications, such as severe wound cure and treatment of open trauma infections.

cRGDfK-Grafted Small-Size Quercetin Micelles For Enhancing Therapy Efficacy Of Active Ingredient From The Chinese Medicinal Herb

Background

As an active ingredient of Chinese herbal medicine, quercetin (QU) can significantly induce apoptosis of tumor cells and give play to other effect such as decreasing both fibroblast population and collagen in cancer cell nest. However, the antitumor efficacy of quercetin was mostly evaluated at cellular level and rarely developed in vivo by intravenous injection, which may be ascribed to its inferior physicochemical properties including water insolubility, short plasma half-time, and insufficient enrichment in the tumor tissues.

Methods

The DSPE-PEG was used to construct quercetin-loaded micelles, and the integrin ligand cRGDfK was grafted to modify the nanocarrier for enhancing its cancer-specific homing. The MALDI-TOF-MS, DLS, TEM, and UV were orderly operated to characterize guidance molecules and micelles by morphology, size distribution, Zeta potential, and drug encapsulation efficiency. In addition, the surface plasmon resonance study and real-time confocal analysis were employed to demonstrate α_vβ₃ integrin-overexpressing B16 cells-specific binding and uptake. After further pharmacodynamics studies in vitro and in vivo, we also evaluate systemic toxicity about cRGDfK-PM-QU.

Results

The cRGDfK was successfully stitched with DSPE-PEG and modified on the surface of micelles. The ligand modification enhanced the negative charges of the micelles, but it did not induce significant changes in particle size. The quercetin micelles were about 15 nm in size and negatively charged, and had spherical morphology and high drug encapsulation efficiency. In vitro, the cRGDfK-modified micelles (cRGDfK-PM) showed α_vβ₃ integrin-overexpressing B16 cells-specific binding and uptake, and cRGDfK-PM-QU (QU loaded in cRGDfK-PM) induced more significant cell apoptosis and cytotoxic effects against B16 tumor cells than counterpart micelles (PM-QU). In vivo, the cRDGfK modification enhanced enrichment in B16 tumor tissue, improved the therapeutic efficacy of the quercetin-loaded micelles against B16 tumor, and exhibited lower systemic and pulmonary toxicity compared with counterpart micelles in the mouse mode.

Conclusion

Quercetin as a natural product has triggered increasing interest in the antitumor field. In this study, cRGDfK-modified DSPE-PEG micelles significantly optimized quercetin therapeutic efficacy and pulmonary toxicity as well as lowered systemic toxicity.

YAP promotes gastric cancer cell survival and migration/invasion via the ERK/endoplasmic reticulum stress pathway

Yes-associated protein (YAP) has been reported to serve an important role in gastric cancer cell survival and migration. However, the underlying mechanism remains unclear. The aim of present study was to identify the underlying mechanism through which Yap sustains gastric cancer viability and migration. The results of the present study demonstrated that YAP expression was upregulated in gastric cancer MKN-28/74 cells compared with normal gastric GES-1 cells. Functional studies revealed that silencing of YAP inhibited gastric cancer MKN-28/74 cell viability and invasion. Mechanistically, YAP may promote gastric cancer cell survival and migration/invasion by inhibiting the endoplasmic reticulum (ER) stress pathway. In addition, YAP may regulate ER stress by activating the ERK signaling pathway. The results of the present study suggested that YAP may be a tumor promoter in gastric cancer and act through the ERK/ER stress pathway; therefore, YAP may have potential implications for new approaches to gastric cancer therapy.

A TiN Nanorod Array 3D Hierarchical Composite Electrode for Ultrahigh-Power-Density Bromine-Based Flow Batteries

Bromine-based flow batteries are well suited for stationary energy storage due to attractive features of high energy density and low cost. However, the bromine-based flow battery suffers from low power density and large materials consumption due to the relatively high polarization of the Br₂ /Br^- couple on the electrodes. Herein, a self-supporting 3D hierarchical composite electrode based on a TiN nanorod array is designed to improve the activity of the Br₂ /Br^- couple and increase the power density of the bromine-based flow battery. In this design, a carbon felt provides a composite electrode with a 3D electron conductive framework to guarantee high electronic conductivity, while the TiN nanorods possess excellent catalytic activity for the Br₂ /Br^- electrochemical reaction to reduce the electrochemical polarization. Moreover, the 3D micro-nano hierarchical nanorod-array alignment structure contributes to a high electrolyte penetration and a high ion-transfer rate to reduce diffusion polarization. As a result, a zinc-bromine flow battery with the designed composite electrode can be operated at a current density of up to 160 mA cm^-2 , which is the highest current density ever reported. These results exhibit a promising strategy to fabricate electrodes for ultrahigh-power-density bromine-based flow batteries and accelerate the development of bromine-based flow batteries.

CD47-targeted bismuth selenide nanoparticles actualize improved photothermal therapy by increasing macrophage phagocytosis of cancer cells

CD47, a transmembrane protein overexpressed in most tumors, limits macrophage phagocytosis by interacting with macrophage signal-regulated protein α (SIRPα). In this study, we have developed CD47-targeted bismuth selenide nanoparticles (Ab-PEG-Bi₂Se₃) that increase phagocytosis of cancer cells by macrophages to actualize improved photothermal therapy (PTT). The functionalized nanoparticles were constructed by conjugating anti-CD47 antibody (Ab) to PEGylated bismuth selenide nanoparticles (PEG-Bi₂Se₃). The anti-CD47 antibody modified on the nanoparticles enhanced the phagocytic activity of macrophages toward tumor cells by specifically blocking the crosstalk between CD47 and SIRPα. Meanwhile, Ab-PEG-Bi₂Se₃ showed excellent photothermal performance including strong near infrared (NIR) absorbance, high photothermal conversion efficiency and photostability, and exhibited outstanding in vitro PTT effect under NIR laser irradiation. In vivo therapeutic experiments revealed that this CD47-targeted PTT nanoagent, with the assistance of enhanced macrophage phagocytosis, achieved the goal of tumor eradication. Besides, toxicity studies confirmed that Ab-PEG-Bi₂Se₃ had good biocompatibility. In conclusion, Ab-PEG-Bi₂Se₃ may serve as an efficient PTT platform in combination with macrophage-mediated immunotherapy to improve antitumor efficacy.

Interleukin-37 reduces inflammation and impairs phagocytosis of platelets in immune thrombocytopenia (ITP)

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by low platelet count with heterogeneous bleeding manifestations. Severe bleeding in ITP is not completely related with low platelet count. Fcγ receptor (FcγR)-mediated platelet destruction is one of the major mechanisms of ITP. Interleukin-37 (IL-37) is a fundamental natural suppressor of innate immunity and inflammatory responses in several autoimmune diseases. However, the role of IL-37 in the pathogenesis of ITP is unknown. In the present study, we identified that IL-37 expression was elevated in ITP patients, which was correlated with platelet count and the severity of bleeding in ITP, indicating that IL-37 could be a candidate in evaluating disease severity of ITP. In the in vitro study, IL-37 initiated an anti-inflammatory effect on monocytes/macrophages from ITP patients by down-regulating the phosphorylation of MAPK, AKT, and NF-κB signaling pathways. Moreover, IL-37 restored the balance of activating and inhibitory FcγRs and decreased antibody-mediated platelet phagocytosis by monocytes/macrophages. Our findings suggest that IL-37 may be a promising indicator of the disease severity and supplementation of IL-37 may be therapeutically beneficial for ITP patients.

Real-Time Quantification of Cell Internalization Kinetics by Functionalized Bioluminescent Nanoprobes

Cells transport mass dynamically, crossing cell membranes to maintain metabolism and systemic homeostasis, through which biomolecules are also delivered to cells for gene editing, cell reprograming, therapy, and other purposes. Quantifying the translocation kinetics is fundamentally and clinically essential, but remains limited by fluorescence-based technologies, which are semi-quantitative and only provide kinetics information at cellular level or in discrete time. Herein, a real-time method of quantifying cell internalization kinetics is reported using functionalized firefly-luciferase nanocapsules as the probe. This quantitative assay will facilitate the rational design of delivery vectors and enable high-throughput screening of peptides and other functional molecules, constituting an effective tool for broad applications, including drug development and cancer therapy.

Schiff-base reaction induced selective sensing of trace dopamine based on a Pt41Rh59 alloy/ZIF-90 nanocomposite

Zeolitic imidazole frameworks (ZIFs) are a new class of functional porous materials with attractive characters, such as gas storage, selective separation, catalysis, and drug delivery. We report herein using nanoscale ZIF-90 crystals with free aldehyde group of imidazole-2-carboxaldehyde (ICA) ligand for the selective electrochemical detection of dopamine. The averaged adsorption enthalpy ΔH (i.e., isosteric heat) of ZIF-90 to dopamine is estimated as 72 kJ mol^-1 according to grand canonical Monte Carlo (GCMC) simulation. With further modification of a Pt₄₁Rh₅₉ alloy nanocatalyst, the electrochemical sensing performances towards dopamine are improved. The synergetic effect generated by a Pt₄₁Rh₅₉/ZIF-90 nanocomposite endows it a low detection limit of 1 nM and good specificity. The different anti-interference mechanisms to coexisting redox active species and amino analogues are also included in this work. The strategy demonstrated here may be extended to tune metal nodes as well as ligands of ZIFs crystals and further regulating their functionalities for different target molecules identification.

Sorption of polybrominated diphenyl ethers by microplastics

The sorption of polybrominated diphenyl ethers (PBDEs) onto polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyamide (PA) microplastics was analyzed using different kinetic and isotherm models, and under various environmental conditions, including temperature, pH, salinity and dissolved organic matter (DOM). The sorption capacity was in the order of PS > PA > PP > PE, due to the different crystallinity, specific surface area, and surface structure. PS demonstrated the equilibrium sorption capacity, namely, 6.41 ng/g BDE-47, 12.83 ng/g BDE-99, and 14.42 ng/g BDE-153. The second-order kinetic model described the sorption kinetics of PBDEs, and surface sorption was the main mechanism. The sorption of PBDEs by microplastics was a multilayer and physical process. Low temperatures reduced BDE-47 sorption on microplastics, and sorption was a spontaneous and endothermic process. The sorption of BDE-47 was not significantly influenced by pH and salinity. However, DOM exerted a negative effect on the sorption of BDE-47.

Detection of Phenylketonuria Markers Using a ZIF-67 Encapsulated PtPd Alloy Nanoparticle (PtPd@ZIF-67)-Based Disposable Electrochemical Microsensor

Phenylketonuria (PKU) is a common disease in congenital disorder of amino acid metabolism, which can lead to intellectual disability, seizures, behavioral problems, and mental disorders. We report herein a facile method to screen for PKU by the measurements of its metabolites (markers). In this work, a disposable electrochemical microsensor modified with a ZIF (zeolitic imidazolate framework)-based nanocomposite is constructed, in which ZIF-67 crystals are encapsulated with PtPd alloy nanoparticles (NPs) forming the nanocomposite (PtPd@ZIF-67). According to electrochemical measurements, the PtPd@ZIF-67-modified microsensor shows good responses and selectivity to phenylpyruvic acid and phenylacetic acid, while almost no response toward other amino acid analogues is observed. Here, a new sensing mechanism based on the acylation reaction between the imidazole linker in ZIF-67 and carboxyl in PKU markers has been proposed and verified through the Fourier-transform infrared spectroscopy study. Moreover, the encapsulated PtPd NPs elevate the electron transfer capability of the PtPd@ZIF-67-modified microsensor and further improve the electrochemical sensing performance. Finally, we demonstrate that the developed PtPd@ZIF-67-modified microsensor has the possibility to sensing of PKU markers with high response and good specificity and may be extended to exploit the point-of-care rapid PKU screening.

Malignant ureteral obstruction: experience and comparative analysis of metallic versus ordinary polymer ureteral stents

BACKGROUND

To study the outcome and experience of using metallic stents in treating patients with malignant ureteral obstruction (MUO).

METHODS

Seventy-six patients with MUO were assigned to the metallic stent group (MSG) or the ordinary polymer stent group (OPSG) according to the different materials. The success rate of the operation, duration of operation, patency rate serum creatinine values ,postoperative complications and QOL scores were compared between the two groups.

RESULTS

In the OPSG and MSG, the success rates of the operation were 95.5% and 96.9%, respectively, and the durations of the operation were 20.6 ± 2.2 min and 50.9 ± 10.3 min (P < 0.01), respectively. There was no significant difference between the groups in serum creatinine values at 3 days after the operation (P > 0.05); however, the creatinine values at 3 days after the operation decreased significantly compared with those before the operation (P < 0.01). In the OPSG, there was no significant difference in creatinine values between 3 days and 6 months after operation, while the creatinine values 1 year after operation were increased significantly compared to those at 3 days after the operation (P < 0.05). In the MSG, there was no significant difference among creatinine values at different intervals (P > 0.05). The total rate of post-procedural complication was lower in the MSG than that in the OPSG(P < 0.05). There was no significant difference in the QOL score between the two groups before the operation (P > 0.05); however, the QOL scores at 6 months and 1 year after the operation were higher in the MSG than that in the OPSG(P < 0.05). In the MSG, there was no significant difference in the QOL score between preoperation and 6 months after surgery. Similarly, there was also no difference in the QOL score between 6 months after surgery and 1 year after surgery(P > 0.05). On the contrary, the differences of QOL score in the OPSG group were much significant between disparate time intervals (P < 0.05).

CONCLUSIONS

For patients with MUO who require long-term retention of the stent, metallic stents with longer indwelling time are superior to ordinary polymeric stents.

[Effects of human adipose-derived mesenchymal stem cells and platelet-rich plasma on healing of wounds with full-thickness skin defects in mice]

Objective: To investigate the effects of human adipose-derived mesenchymal stem cells (ADSCs) and platelet-rich plasma (PRP) on healing of wounds with full-thickness skin defects in mice. Methods: ADSCs were isolated from the lumbar and abdominal fat donated voluntarily by a healthy woman undergoing liposuction in the Department of Plastic Surgery of Guangzhou General Hospital of Guangzhou Military Area Command, and the cells were cultured and identified. ADSCs of the second passage were used in the following experiments. The venous blood of the volunteer was taken, and PRP was obtained by secondary centrifugation. Thirty-six C57BL/6 mice were divided into simple injury group (n=12), simple ADSCs treatment group (n=12), and ADSCs+ PRP treatment group (n=12) according to the random number table. Each mouse was inflicted with a 1 cm×1 cm wound with full-thickness skin defect on the back. Immediately after injury, the wounds of mice in simple injury group were subcutaneously injected with 1 mL normal saline, the wounds of mice in simple ADSCs treatment group were subcutaneously injected with 1 mL phosphate buffer solution-blended ADSCs suspension (with concentration of 5×10(5) /mL, the same below), and the wounds of mice in ADSCs+ PRP treatment group were subcutaneously injected with 1 mL mixture of PRP and ADSCs (1∶2 volume ratio). Three mice in each group were taken on post injury day (PID) 3, 5, 7, and 14 to observe the gross condition of wound, and the wound healing rate was calculated. On PID 3, 5, and 7, the non-healing wound tissue and 0.5 cm normal skin tissue around the wound margin were taken after gross observation. The inflammation, re-epithelialization, and angiogenesis of tissue were observed by hematoxylin and eosin staining, and the re-epithelialization rate was calculated. The collagen synthesis of tissue was observed by masson staining. Immunohistochemistry was used to observe the expression of macrophages of tissue samples collected on PID 3 and 5. Data were processed with analysis of variance of factorial design and Least-Significant Difference test. Results: (1) On PID 3, the wounds of mice in ADSCs+ PRP treatment group were with granulation tissue regeneration, redness, and swelling, and the wounds of mice in the other two groups were ruddy and with effusion. On PID 5, the wounds of mice in ADSCs+ PRP treatment group had less redness and swelling, which were dry with obvious scab, and wounds of mice in the other two groups were obviously red and swollen. On PID 7, scab formed basically on wounds of mice in the three groups. On PID 14, the wounds of mice in the three groups basically healed, and their crusts were off. On PID 3, 5, 7, and 14, the wound healing rates of mice in ADSCs+ PRP treatment group were obviously higher than those of the other two groups (P<0.05 or P<0.01). On PID 5 and 7, the wound healing rates of mice in simple ADSCs treatment group were obviously higher than those of simple injury group (P<0.01). (2) On PID 3, granulation tissue regeneration of wounds in ADSCs+ PRP treatment group was more than that in the other two groups. On PID 5, inflammatory reaction of wounds of mice was mild in ADSCs+ PRP treatment group, which was severe in the other two groups. On PID 7, the re-epithelialization process of wounds of mice was almost completed in ADSCs+ PRP treatment group, and the number of new vessels was more in ADSCs+ PRP treatment group than in the other two groups. The migration distance of regenerated epithelia around the wound edge in simple injury group and simple ADSCs treatment group was short. On PID 3, 5, and 7, the re-epithelialization rates of wounds of mice in ADSCs+ PRP treatment group were (37.6±4.5)%, (59.1±1.3)%, and (89.2±4.3)%, respectively, significantly higher than (25.7±1.5)%, (34.5±4.4)%, and (50.8±2.7)% in simple injury group and (29.1±0.8)%, (42.6±2.9)%, and (72.9±3.0)% in simple ADSCs treatment group (P<0.01). On PID 5 and 7, the re-epithelialization rates of wounds of mice in simple ADSCs treatment group were significantly higher than those in simple injury group (P<0.05 or P<0.01). (3) On PID 3 and 5, a quite large number of new collagen fibers appeared in granulation tissue of wounds of ADSCs+ PRP treatment group, while the collagen fibers in the other two groups were less. On PID 7, the granulation tissue of mice in ADSCs+ PRP treatment group decreased, and a large number of new collagen fibers appeared. The collagen fibers in wounds tissue of mice in simple ADSCs treatment group increased, while the collagen fibers deposited in wounds tissue of mice in simple injury group was still less. (4) On PID 3 and 5, the numbers of macrophages in wounds tissue of mice in simple ADSCs treatment group were 4.7±0.6 and 5.3±0.6 respectively, obviously lower than 6.3±0.6 and 7.7±0.6 in injury group (P<0.05 or P<0.01); the numbers of macrophages in wounds tissue of mice in ADSCs+ PRP treatment group were 3.0±1.1 and 2.7±0.5, significantly lower than those in the other two groups (P<0.05 or P<0.01). Conclusions: Human PRP and ADSCs are involved in the early inflammation, metaphase of tissue proliferation, and re-epithelialization and shaping process of late stage of wounds with full-thickness skin defects in mice. The combination of ADSCs and PRP may be a comparatively good combination to improve the speed and quality of wound healing.

Problems and Solutions for Platelet-Rich Plasma in Facial Rejuvenation: A Systematic Review

BACKGROUND

In recent years, platelet-rich plasma (PRP) has been widely applied in orthopedics, maxillofacial surgery, burns, and plastic surgery, especially in facial rejuvenation. Research is ongoing into new indications and mechanisms of PRP to promote its wider, safer, and more effective use in the clinic. This article reviews the possible mechanisms of PRP in facial rejuvenation and related research. It is expected that the application of PRP in this field will increase.

METHODS

The use of PRP in facial rejuvenation was screened using inclusion and exclusion criteria. The relevant articles were searched through Pubmed digest database, SCI full-text database, ScienceDirect full-text database, and the CNKI full-text database. The different effects and limitations of PRP were extracted.

RESULTS

A total of 108 articles were obtained, including 18 articles researching PRP in cells, 10 articles on animal research using PRP, 16 articles on the clinical study of PRP, 24 articles involving signs of skin aging, and four articles on the limitations of PRP. The remaining articles were related to the preparation of PRP, the introduction of PRP, and other aspects.

CONCLUSION

Based on in vitro and in vivo research, PRP may play a role in promoting tissue regeneration, oxidative stress and revascularization, which form the theoretical basis for the use of PRP in the clinical treatment of facial rejuvenation.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .