Emergent Three-Dimensional Electric Dipole Sinewave in Bulk Perovskite Oxides.

The magnetic and electric dipoles of ferroics play a central role in their fascinating properties. In particular, topological configurations have shown promising potential for use in novel electromechanical and electronic devices. Magnetic configurations from simple collinear to complex topological are well-documented. In contrast, many complex topological features in the electric counterpart remain unexplored. Here, we report the first example of three-dimensional electric dipole sinewave topological structure in a PbZrO3-based bulk perovskite, which presents an interesting triple-hysteresis loop macroscopically. This polar configuration consists of two orthogonal sinewave electric dipole modulations decoded from a polar incommensurate phase by advanced diffraction and atomic-resolution imaging techniques. The resulting topology is unraveled to be the competition between the antiferroelectric and ferroelectric states, stabilized by the modulation of the Pb 6s2 lone pair and the antiferrodistortive effect. These findings further reinforce the similarity of the magnetic and electric topologies.

What Determines the Critical Electric Field of AFE-to-FE in Pb(Zr,Sn,Ti)O3-Based Perovskites?

Electric-field-induced antiferroelectric-ferroelectric (AFE-FE) phase transition is a prominent feature of antiferroelectric (AFE) materials. The critical electric field of this phase transition is crucial for the device performance of AEFs in many applications, but the determining factor of the critical electric field is still unclear. Here, we have established the correlation between the underlying structure and the critical electric field by using in situ synchrotron X-ray diffraction and high-resolution neutron diffraction in Pb(Zr,Sn,Ti)O3-based antiferroelectrics. It is found that the critical electric field is determined by the angle between the average polarization vector in the incommensurate AFE state and the [111]P polarization direction in the rhombohedral FE state. A large polarization rotation angle gives rise to a large critical electric field. Further, density functional theory (DFT) calculations corroborate that the lower energy is required for driving a smaller angle polarization rotation. Our discovery will offer guidance to optimize the performance of AFE materials.

The Optimal Layer for Breast Augmentation in an Autologous Fat Grafting Murine Model.

BACKGROUND: Fat grafting is an effective procedure for breast augmentation, but the variations in this technique result in unpredictable fat retention. Therefore, animal models are needed to simulate the operation and the optimal layer for fat retention. OBJECTIVES: An autologous fat grafting murine model for breast augmentation was built to detect a new layer for fat grafting in the chest. METHODS: The left side of the female rat inguinal fat flap was harvested, dissected into small pieces, and autotransplanted into 3 different layers of the breast. Retention rate and hematoxylin and eosin (H&E) staining were measured at 1, 4, 8 12, and 16 weeks. Immunofluorescence staining was utilized to detect adipocytes and endothelial cells, and immunohistochemistry was conducted to evaluate the expression of integrins ß1 and α6. RESULTS: The volume of fat grafts slightly grew in the intramuscular and submuscular layers at Week 4. Retention rates in the subcutaneous layer and submuscular layer were significantly higher than the intramuscular layer at Week 16. H&E staining showed that oil cysts existed in the subcutaneous layer throughout the 16 weeks. At the terminal time point, well-vascularized mature adipose structures were observed in intramuscular and submuscular layers, with smaller adipocytes in intramuscular layers. Immunohistochemistry analysis showed that integrin ß1 was identically expressed in every adipocyte in all the layers, whereas integrin α6 selectively expressed in bigger adipocytes in the intramuscular layer. The expression intensities of integrin ß1 and α6 were significantly higher in the intramuscular layer than in the subcutaneous and submuscular layers. CONCLUSIONS: The angiogenic and moderate mechanical environment makes the submuscular layer the optimal layer for fat retention.

Macromolecular crowding facilitates rapid fabrication of intact, robust cell sheets.

OBJECTIVES: To develop a rapid and simple method to fabricate intact, robust cell sheets from common cell culture dishes by combination of a macromolecular crowding (MMC) reagent and vitamin C. RESULTS: It was found that 3T3 fibroblasts or human bone marrow mesenchymal stem cells (hBMSCs) and their secreted cell derived extracellular matrices could be easily detached as intact cell sheets under gently pipetting after treated by MMC and vitamin C for 4 days. This method also allowed fabrication of functional multi-layered hepatic cell sheets by culturing 10 × 104 cells/cm2 HepG2 cells on top of confluent 3T3 fibroblast layers. What's more, MMC induced hBMSC cell sheets demonstrated 1.9 times larger area and 1.6 times greater cell number than that of cell sheets harvested from temperature-responsive cell culture dishes. CONCLUSION: MMC based method make it possible to fabricate various types of cell sheets more conveniently, economically, and thus may facilitate wide application of cell sheet technology.

[Long term maintenance of cytochrome P450 activity in a cell sheet-based three-dimensional human hepatic model].

Primary human hepatocytes (PHH) are the gold standard of in vitro human liver model for drug screening. However, a problem of culturing PHH in vitro is the rapid decline of cytochrome P450 (CYP450) activity, which plays an important role in drug metabolism. In this study, thermo-responsive culture dishes were used to explore the conditions for murine embryonic 3T3-J2 fibroblasts to form cell sheet. Based on the cell sheet engineering technology, a three-dimensional (3D) "sandwich" co-culture system of 3T3-J2 cell sheet/PHH/collagen gel was constructed. The tissue structure and protein expression of the model section were observed by hematoxylin eosin staining and immunofluorescence staining respectively. Phenacetin and bupropion were used as substrates to determine the activity of CYP450. The contents of albumin and urea in the system were determined by enzyme linked immunosorbent assay (ELISA). The results showed that the complete 3T3-J2 cell sheet could be obtained when the cell seeding density was 1.5×106 /dish (35 mm dish) and the incubation time at low temperature was 60 min. Through cell sheet stacking, a 3D in vitro liver model was developed. Compared with the two-dimensional (2D) model, in the 3D model, the cell-cell and cell-matrix connections were tighter, the activities of cytochrome P450 CYP1A2 and cytochrome P450 CYP2B6 were significantly increased, and the secretion levels of albumin and urea were increased. These indexes could be maintained stably for 21 d. Therefore, cell sheet stacking is helpful to improve the level of liver function of 3D liver model. This model is expected to be used to predict the metabolism of low-clearance drugs in preclinical, which is of great significance for drug evaluation and other studies.

An Intriguing Polarization Configuration of Mixed Ising- and Néel-Type Model in the Prototype PbZrO3-Based Antiferroelectrics.

Antiferroelectrics are of great academic and technological interest due to their excellent strain and energy storage properties, while the incommensurate modulation-related complex configuration of polarization remains unclear. In this study, an intriguing polarization configuration of mixed Ising- and Néel-type has been established in the prototype PbZrO3-based antiferroelectric materials via the combination of high-resolution synchrotron X-ray and neutron diffraction investigations. Such unusual polarization configuration of antiferroelectrics shows the internal coupling, which mainly contributes from the displacement of the A-site and the distortion of the AO12 and BO6 polyhedra. The electric dipole oscillates in the (001)P plane, and its magnitude and direction show obvious modulation characteristics resulting in a neither antiparallel nor fully compensated polarization configuration, which is completely different from the traditional view of antiferroelectricity. There is an antiferroelectric feature along the [110]P direction, while there is a ferrielectric one along the [1̅10]P direction in which the net polarization can reach 12 µC/cm2. The maximum local polarization can reach 4.3 µC/cm2 in the [110]P direction and 27.6 µC/cm2 in the [1̅10]P direction. This work will be very helpful for the development of antiferroelectric theories and the design of novel energy storage materials.

Outcomes of Right Ventricular Outflow Tract Reconstruction for Children with Persistent Truncus Arteriosus: A 10-Year Single-Center Experience.

The purpose of this report is to assess the mid- and long-term outcomes of right ventricular outflow tract (RVOT) reconstruction for children with persistent truncus arteriosus. Between September 2006 and 2016, 105 patients with persistent truncus arteriosus (PTA) received surgical treatment at Shanghai Children's Medical Center. Direct right ventricle-pulmonary artery anastomosis (pulmonary artery pull-down) was performed in 51 patients; a left auricle or pericardial conduit was inserted between the RVOT and pulmonary artery as a connection in 17 patients; heterograft (bovine jugular vein or Gore-tex) conduits and homograft conduits were used in 30 and 7 cases, respectively, to connect the distal pulmonary and right ventricle outflow tract; and pulmonary valve reconstruction was performed in 38 patients using a Gore-tex monocusp. There were six in-hospital deaths and one delayed death 5 months after operation. After a mean follow-up of 55.8 ± 16.5 months (6-113 months), 19 patients underwent reoperation (3 with pulmonary patch enlargement, 14 with conduit replacement and 2 with aortic valve replacement) 10-89 months after the first operation, with 1 hospital death. The actuarial survival rates were 94.2, 93.3 and 93.3% at 1, 5 and 10 years, respectively. Freedom from reoperation was 98.0, 87.8 and 82.7% at 1, 5 and 10 years, respectively. The follow-up variables included echocardiography, chest radiography, cardiac CT and cardiac function. At the last examination, most of the patients exhibited an improvement of New York Heart Association functional class from III or IV preoperatively to I or II at follow-up. Surgical treatment for PTA has an acceptable survival rate and satisfactory outcomes. Most patients exhibited an improvement in cardiac function during follow-up. Aortic arch deformity, truncal valvular regurgitation and long cardiopulmonary bypass time were regarded as risk factors for hospital mortality. Autologous tissue has a lower reoperation rate and better growth potential than extracardiac conduits. A monocusp valve effectively reduces pulmonary regurgitation in the early postoperative stage.

Single-Stage Correction for Taussig-Bing Anomaly Associated With Aortic Arch Obstruction.

Taussig-Bing anomaly and aortic arch obstruction are two types of complex congenital cardiac malformations. Almost 50% of patients with Taussig-Bing anomaly have aortic arch obstruction. This report assesses the surgical outcomes of single-stage correction in neonates with both defects. Between November 2006 and November 2015, 39 neonates with Taussig-Bing anomaly and aortic arch obstruction (28 patients with coarctation of the aorta and 11 patients with interrupted aortic arch) underwent a one-stage arterial switch operation and aortic reconstruction. There were three in-hospital deaths and one late death (8 months after the surgery). The short-term survival rate was 92.3% (36/39), and the mid-term survival rate was 89.7% (35/39). Follow-up data were available for all patients who survived the operation (range 6-92 months). Echocardiology showed six cases of recoarctation, three cases of left ventricular outflow tract obstruction, three cases of right ventricular outflow tract obstruction, four cases of pulmonary artery stenosis, five cases of aortic regurgitation, and eight cases of pulmonary regurgitation. Eight patients required a reoperation during the follow-up period with no mortality. All survivors remained in good condition (New York Heart association functional class I or II). Single-stage correction of Taussig-Bing anomaly with aortic arch obstruction in neonates had favorable short- and mid-term outcomes in terms of mobility and reoperation rate. The optimal operative procedure should be chosen according to the position of the coronary arteries and the type of aortic anomaly.

Surgical strategies and outcomes of congenital supravalvular aortic stenosis.

BACKGROUND: Various surgical techniques have been introduced to treat supravalvular aortic stenosis (SVAS). However, there is no consensus upon the optimal approach. This study reviewed our institutional experience in the management of SVAS. METHODS: Ninety patients undergoing surgery for SVAS were identified between 2009 and 2016. Based on surgical techniques, patients were divided into three groups: McGoon repair (n = 63), Doty repair (n = 24), and Brom repair (n = 3). Median follow-up was 38.5 months (range, 4 months-7.5 years). Patient status, cumulative event-free survival rate, and risk factors for adverse clinical outcomes were assessed. RESULTS: The early mortality rate was 3.3%. There was one late death and two reinterventions. No differences were observed among three surgical groups. Event-free survival was 98.4% at 3 years and 96.5% at 5 years. Diffuse-type SVAS and a preoperative gradient greater than 60 mmHg were risk factors for adverse cardiac remodeling within 6 months post-surgery. Residual aortic stenosis was associated with male gender, preoperative aortic valve stenosis, and a preoperative peak gradient greater than 90 mmHg. Eleven patients (out of 30) who underwent concomitant pulmonary artery patching had a residual pulmonary gradient greater than 40 mmHg. CONCLUSIONS: Surgical repair of SVAS can be safely achieved using different techniques, with similar midterm mortality and reintervention rates. Higher preoperative gradient is associated with worse clinical results. Issues regarding surgical timing and concomitant pulmonary artery stenosis need to be further addressed.

Guanidinylated bioactive chitosan-based injectable hydrogels with pro-angiogenic and mechanical properties for accelerated wound closure.

Wound healing is a complex process involving the concerted action of many genes and signaling pathways, with angiogenesis being crucial for expediting wound closure. Dressings that possess pro-angiogenic properties are increasingly recognized as attractive candidates for wound care. Drawing inspiration from the active closure of wounds in embryos, we have developed a thermo-responsive hydrogel with mechanoactive properties, combining vascular regeneration and skin wound contraction to accelerate healing. The significant improvement in vascular reconstruction is attributed to the synergistic effect of arginine and deferoxamine (DFO) released from the hydrogels. Additionally, the contraction force of the hydrogel actively promotes skin closure in wounds. Remarkably, groups treated with hydroxybutyl chitosan methacrylate combined with arginine (HBC_m_Arg/DFO) exhibited increased vascularization, and greater wound maturity, leading to enhanced healing. These results highlight the synergistic impact of pro-angiogenic and mechanical properties of the HBC_m_Arg/DFO hydrogel in accelerating wound healing in rats.

A DNA-inspired injectable adhesive hydrogel with dual nitric oxide donors to promote angiogenesis for enhanced wound healing.

Chronic diabetic wounds are a severe complication of diabetes, often leading to high treatment costs and high amputation rates. Numerous studies have revealed that nitric oxide (NO) therapy is a promising option because it favours wound revascularization. Here, base-paired injectable adhesive hydrogels (CAT) were prepared using adenine- and thymine-modified chitosan (CSA and CST). By further introducing S-nitrosoglutathione (GSNO) and binary l-arginine (bArg), we obtained a NO sustained-release hydrogel (CAT/bArg/GSON) that was more suitable for the treatment of chronic wounds. The results showed that the expression of HIF-1α and VEGF was upregulated in the CAT/bArg/GSON group, and improved blood vessel regeneration was observed, indicating an important role of NO. In addition, the research findings revealed that following treatment with the CAT/bArg/GSON hydrogel, the viability of Staphylococcus aureus and Escherichia coli decreased to 14 ± 2 % and 6 ± 1 %, respectively. Moreover, the wound microenvironment was improved, as evidenced by a 60 ± 1 % clearance of DPPH. In particular, histological examination and immunohistochemical staining results showed that wounds treated with CAT/bArg/GSNO exhibited denser neovascularization, faster epithelial tissue regeneration, and thicker collagen deposition. Overall, this study proposes an effective strategy to prepare injectable hydrogel dressings with dual NO donors. The functionality of CAT/bArg/GSON has been thoroughly demonstrated in research on chronic wound vascular regeneration, indicating that CAT/bArg/GSON could be a potential option for promoting chronic wound healing. STATEMENT OF SIGNIFICANCE: This article prepares a chitosan hydrogel utilizing the principle of complementary base pairing, which offers several advantages, including good adhesion, biocompatibility, and flow properties, making it a good material for wound dressings. Loaded GSNO and bArg can steadily release NO and l-arginine through the degradation of the gel. Then, the released l-arginine not only possesses antioxidant properties but can also continue to generate a small amount of NO under the action of NOS. This design achieves a sustained and stable supply of NO at the wound site, maximizing the angiogenesis-promoting and antibacterial effects of NO. More neovascularization and abundant collagen were observed in the regenerated tissues. This study provides an effective repair hydrogel material for diabetic wound.

A unidirectional water-transport antibacterial bilayer nanofibrous dressing based on chitosan for accelerating wound healing.

Excessive accumulation of exudate from wounds often causes infection and hinders skin regeneration. To handle wound exudate quickly and prevent infection, we developed an antibacterial Janus nanofibrous dressing with a unidirectional water-transport function. The dressing consists of a hydrophilic chitosan aerogel (CS-A) as the outer layer and a hydrophobic laurylated chitosan (La-CS) nanofibrous membrane as the inner layer. These dressings achieved excellent liquid absorption performance (2987.8 ±â€¯123.5 %), air and moisture permeability (997.8 ±â€¯23.1 g/m2/day) and mechanical strength (5.1 ±â€¯2.6 MPa). This performance was obtained by adjusting the density of CS-A and the thickness of the La-CS membrane. Moreover, the dressing did not induce significant toxicity to cells and can prevent bacterial aggregation and infection at the wound site. Animal experiments showed that the dressing can shorten the inflammatory phase, enhance blood vessel generation, and accelerate collagen deposition, thus promoting wound healing. Overall, these results suggest that this Janus dressing is a promising material for clinical wound care.

Antibacterial and Osteogenic Dual-Functional Micronano Composite Scaffold Fabricated via Melt Electrowriting and Solution Electrospinning for Bone Tissue Engineering.

The utilization of micronano composite scaffolds has been extensively demonstrated to confer the superior advantages in bone repair compared to single nano- or micron-sized scaffolds. Nevertheless, the enhancement of bioactivities within these composite scaffolds remains challenging. In this study, we propose a novel approach to combine melt electrowriting (MEW) and solution electrospinning (SES) techniques for the fabrication of a composite scaffold incorporating hydroxyapatite (HAP), an osteogenic component, and roxithromycin (ROX), an antibacterial active component. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) confirmed the hierarchical architecture of the nanofiber-microgrid within the scaffold, as well as the successful loading of HAP and ROX. The incorporation of HAP enhanced the water absorption capacity of the composite scaffold, thus promoting cell adhesion and proliferation, as well as osteogenic differentiation. Furthermore, ROX resulted in effective antibacterial capability without any observable cytotoxicity. Finally, the scaffolds were applied to a rat calvarial defect model, and the results demonstrated that the 20% HAP group exhibited superior new bone formation without causing adverse reactions. Therefore, our findings present a promising strategy for designing and fabricating bioactive scaffolds for bone regeneration.

Bioorthogonal targeted cell membrane vesicles/cell-sheet composites reduce postoperative tumor recurrence and scar formation of melanoma.

While surgical resection is the predominant clinical strategy in the treatment of melanoma, postoperative recurrence and undetectable metastasis are both pernicious drawbacks to this otherwise highly successful approach. Furthermore, the deep cavities result from tumor excision can leave long lasting wounds which are slow to heal and often leave visible scars. These unmet needs are addressed in the present work through the use of a multidimensional strategy, and also promotes wound healing and scar reduction. In the first phase, cell membrane-derived nanovesicles (NVs) are engineered to show PD-1 and dibenzocyclooctyne (DBCO). These are capable of reactivating T cells by blocking the PD-1/PD-L1 pathway. In the second phase, azido (N3) labeled mesenchymal stem cells (MSCs) are cultured into cell sheets using tissue engineering, then apply directly to surgical wounds to enhance tissue repair. Owing to the complementary association between DBCO and N3 groups, PD-1 NVs were accumulated at the site of excision. This strategy can inhibit postoperative tumor recurrence and metastasis, whilst also promoting wound healing and reducing scar formation. The results of this study set a precedent for a new and innovative multidimensional therapeutic strategy in the postoperative treatment of melanoma.

Modulation of macrophage polarization by secondary cross-linked hyaluronan-dopamine hydrogels.

The inflammatory response plays a critical role in standard tissue repair processes, wherein active modulation of macrophage polarization is necessary for wound healing. Dopamine, a mussel-inspired bioactive material, is widely involved in wound healing, neural/bone/myocardial regeneration, and more. Recent studies indicated that dopamine-modified biomaterials can potentially alter macrophages polarization towards a pro-healing phenotype, thereby enhancing tissue regeneration. Nevertheless the immunoregulatory activity of dopamine on macrophage polarization remains unclear. This study introduces a novel interpenetrating hydrogel to bridge this research gap. The hydrogel, combining varying concentrations of oxidized dopamine with hyaluronic acid hydrogel, allows precise regulation of mechanical properties, antioxidant bioactivity, and biocompatibility. Surprisingly, both in vivo and in vitro outcomes demonstrated that dopamine concentration modulates macrophage polarization, but not linearly. Lower concentration (2 mg/mL) potentially decrease inflammation and facilitate M2 type macrophage polarization. In contrast, higher concentration (10 mg/mL) exhibited a pro-inflammatory tendency in the late stages of implantation. RNA-seq analysis revealed that lower dopamine concentrations induced the M1/M2 transition of macrophages by modulating the NF-κB signaling pathway. Collectively, this research offers valuable insights into the immunoregulation effects of dopamine-integrated biomaterials in tissue repair and regeneration.

Promoting neurovascularized bone regeneration with a novel 3D printed inorganic-organic magnesium silicate/PLA composite scaffold.

Critical-size bone defect repair presents multiple challenges, such as osteogenesis, vascularization, and neurogenesis. Current biomaterials for bone repair need more consideration for the above functions. Organic-inorganic composites combined with bioactive ions offer significant advantages in bone regeneration. In our work, we prepared an organic-inorganic composite material by blending polylactic acid (PLA) with 3-aminopropyltriethoxysilane (APTES)-modified magnesium silicate (A-M2S) and fabricated it by 3D printing. With the increase of A-M2S proportion, the hydrophilicity and mineralization ability showed an enhanced trend, and the compressive strength and elastic modulus were increased from 15.29 MPa and 94.61 MPa to 44.30 MPa and 435.77 MPa, respectively. Furthermore, A-M2S/PLA scaffolds not only exhibited good cytocompatibility of bone marrow mesenchymal stem cells (BMSCs), human umbilical vein endothelial cells (HUVECs), and Schwann cells (SCs), but also effectively promoted osteogenesis, angiogenesis, and neurogenesis in vitro. After implanting 10% A-M2S/PLA scaffolds in vivo, the scaffolds showed the most effective repair of cranium defects compared to the blank and control group (PLA). Additionally, they promoted the secretion of proteins related to bone regeneration and neurovascular formation. These results provided the basis for expanding the application of A-M2S and PLA in bone tissue engineering and presented a novel concept for neurovascularized bone repair.

Preparation and osteogenesis of a multiple crosslinking silk fibroin/carboxymethyl chitosan/sodium alginate composite scaffold loading with mesoporous silica/poly (lactic acid-glycolic acid) microspheres.

Large bone defect repair is a striking challenge in orthopedics. Currently, inorganic-organic composite scaffolds are considered as a promising approach to these bone regeneration. Silicon ions (Si4+) are bioactive and beneficial to bone regeneration and Si4+-containing inorganic mesoporous silica (MS) can effectively load drugs for bone repair. To better control the release of drug, we prepared biodegradable MS/PLGA (MP) microspheres. MP loaded organic silk fibroin/carboxymethyl chitosan/sodium alginate (MP/SF/CMCS/SA) composite scaffolds were further constructed by genipin and Ca2+ crosslinking. All MP/SF/CMCS/SA scaffolds had good swelling ability, degradation rate and high porosity. The incorporation of 1% MP significantly enhanced the compressive strength of composite scaffolds. Besides, MP loaded scaffold showed a sustained release of Si4+ and Ca2+. Moreover, the release rate of rhodamine (a model drug) of MP/SF/CMCS/SA scaffolds was obviously lower than that of MP. When culturing with rat bone marrow mesenchymal stem cells, scaffolds with 1% MP displayed good proliferation, adhesion and enhanced osteogenic differentiation ability. Based on the results above, the addition of 1% MP in SF/CMCS/SA scaffolds is a prospective way for drug release in bone regeneration and is promising for further in vivo bone repair applications.

Pulmonary Artery Stenosis in Tetralogy of Fallot.

Tetralogy of Fallot (TOF) is the most common cyanotic congenital cardiac defect. The survival rate after primary complete repair is high (98-100%); however, pulmonary artery stenosis (PAS) is not uncommon after TOF repair, and severe PAS aggravates pulmonary regurgitation, resulting in right ventricle dilation, ventricular arrhythmia, and possibly death. PAS in TOF can be congenital due to hypoplasia or coarctation or can be acquired secondary to a surgical procedure. The latter may be caused by an exogenous conduit implant, compression from the adjacent enlarged ascending aorta, or outflow tract dilation after transannular patch repair. PAS can also be caused by the pulmonary artery plasty strategy itself. Here, the intrinsic mechanisms underlying PAS and pulmonary artery plasty techniques and strategies are reviewed to provide guidance for surgeons.

[Research progress of allogeneic abdominal wall transplantation].

Objective: To summarize the research progress of surgical technique and immunosuppressive regimen of abdominal wall vascularized composite allograft transplantation in animals and clinical practice. Methods: The literature on abdominal wall transplantation at home and abroad in recent years was extensively reviewed and analyzed. Results: This review includes animal and clinical studies. In animal studies, partial or total full-thickness abdominal wall transplantation models have been successfully established by researchers. Also, the use of thoracolumbar nerves has been described as an important method for functional reconstruction and prevention of long-term muscle atrophy in allogeneic abdominal wall transplantation. In clinical studies, researchers have utilized four revascularization techniques to perform abdominal wall transplantation, which has a high survival rate and a low incidence of complications. Conclusion: Abdominal wall allotransplantation is a critical reconstructive option for the difficulty closure of complex abdominal wall defects. Realizing the recanalization of the nerve in transplanted abdominal wall to the recipient is very important for the functional recovery of the allograft. The developments of similar research are beneficial for the progress of abdominal wall allotransplantation.

Nrf2-mediated therapeutic effects of dietary flavones in different diseases.

Oxidative stress (OS) is a pathological status that occurs when the body's balance between oxidants and antioxidant defense systems is broken, which can promote the development of many diseases. Nrf2, a redox-sensitive transcription encoded by NFE2L2, is the master regulator of phase II antioxidant enzymes and cytoprotective genes. In this context, Nrf2/ARE signaling can be a compelling target against OS-induced diseases. Recently, natural Nrf2/ARE regulators like dietary flavones have shown therapeutic potential in various acute and chronic diseases such as diabetes, neurodegenerative diseases, ischemia-reperfusion injury, and cancer. In this review, we aim to summarize nrf2-mediated protective effects of flavones in different conditions. Firstly, we retrospected the mechanisms of how flavones regulate the Nrf2/ARE pathway and introduced the mediator role Nrf2 plays in inflammation and apoptosis. Then we review the evidence that flavones modulated Nrf2/ARE pathway to prevent diseases in experimental models. Based on these literature, we found that flavones could regulate Nrf2 expression by mechanisms below: 1) dissociating the binding between Nrf2 and Keap1 via PKC-mediated Nrf2 phosphorylation and P62-mediated Keap1 autophagic degradation; 2) regulating Nrf2 nuclear translocation by various kinases like AMPK, MAPKs, Fyn; 3) decreasing Nrf2 ubiquitination and degradation via activating sirt1 and PI3K/AKT-mediated GSK3 inhibition; and 4) epigenetic alternation of Nrf2 such as demethylation at the promoter region and histone acetylation. In conclusion, flavones targeting Nrf2 can be promising therapeutic agents for various OS-related disorders. However, there is a lack of investigations on human subjects, and new drug delivery systems to improve flavones' treatment efficiency still need to be developed.