Skeletal muscle regeneration with 3D bioprinted hyaluronate/gelatin hydrogels incorporating MXene nanoparticles

There has been significant progress in the field of three-dimensional (3D) bioprinting technology, leading to active research on creating bioinks capable of producing structurally and functionally tissue-mimetic constructs. Ti3C2Tx MXene nanoparticles (NPs), promising two-dimensional nanomaterials, are being investigated for their potential in muscle regeneration due to their unique physicochemical properties. In this study, we integrated MXene NPs into composite hydrogels made of gelatin methacryloyl (GelMA) and hyaluronic acid methacryloyl (HAMA) to develop bioinks (namely, GHM bioink) that promote myogenesis. The prepared GHM bioinks were found to offer excellent printability with structural integrity, cytocompatibility, and microporosity. Additionally, MXene NPs within the 3D bioprinted constructs encouraged the differentiation of C2C12 cells into skeletal muscle cells without additional support of myogenic agents. Genetic analysis indicated that representative myogenic markers both for early and late myogenesis were significantly up-regulated. Moreover, animal studies demonstrated that GHM bioinks contributed to enhanced regeneration of skeletal muscle while reducing immune responses in mice models with volumetric muscle loss (VML). Our results suggest that the GHM hydrogel can be exploited to craft a range of strategies for the development of a novel bioink to facilitate skeletal muscle regeneration because these MXene-incorporated composite materials have the potential to promote myogenesis.

Regulated Behavior in Living Cells with Highly Aligned Configurations on Nanowrinkled Graphene Oxide Substrates: Deep Learning Based on Interplay of Cellular Contact Guidance

Micro-/nanotopographical cues have emerged as a practical and promising strategy for controlling cell fate and reprogramming, which play a key role as biophysical regulators in diverse cellular processes and behaviors. Extracellular biophysical factors can trigger intracellular physiological signaling via mechanotransduction and promote cellular responses such as cell adhesion, migration, proliferation, gene/protein expression, and differentiation. Here, we engineered a highly ordered nanowrinkled graphene oxide (GO) surface via the mechanical deformation of an ultrathin GO film on an elastomeric substrate to observe specific cellular responses based on surface-mediated topographical cues. The ultrathin GO film on the uniaxially prestrained elastomeric substrate through self-assembly and subsequent compressive force produced GO nanowrinkles with periodic amplitude. To examine the acute cellular behaviors on the GO-based cell interface with nanostructured arrays of wrinkles, we cultured L929 fibroblasts and HT22 hippocampal neuronal cells. As a result, our developed cell-culture substrate obviously provided a directional guidance effect. In addition, based on the observed results, we adapted a deep learning (DL)-based data processing technique to precisely interpret the cell behaviors on the nanowrinkled GO surfaces. According to the learning/transfer learning protocol of the DL network, we detected cell boundaries, elongation, and orientation and quantitatively evaluated cell velocity, traveling distance, displacement, and orientation. The presented experimental results have intriguing implications such that the nanotopographical microenvironment could engineer the living cells' morphological polarization to assemble them into useful tissue chips consisting of multiple cell types.

Highly Aligned Ternary Nanofiber Matrices Loaded with MXene Expedite Regeneration of Volumetric Muscle Loss

Current therapeutic approaches for volumetric muscle loss (VML) face challenges due to limited graft availability and insufficient bioactivities. To overcome these limitations, tissue-engineered scaffolds have emerged as a promising alternative. In this study, we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone) integrated with collagen and Ti3C2Tx MXene nanoparticles (NPs) (PCM matrices), and explored their myogenic potential for skeletal muscle tissue regeneration. The PCM matrices demonstrated favorable physicochemical properties, including structural uniformity, alignment, microporosity, and hydrophilicity. In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts. Moreover, in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury. Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices, leading to elevated intracellular Ca2+ levels in myoblasts through the activation of inducible nitric oxide synthase (iNOS) and serum/glucocorticoid regulated kinase 1 (SGK1), ultimately promoting myogenic differentiation via the mTOR-AKT pathway. Additionally, upregulated iNOS and increased NO- contributed to myoblast proliferation and fiber fusion, thereby facilitating overall myoblast maturation. These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.

Laser-Assisted Structuring of Graphene Films with Biocompatible Liquid Crystal Polymer for Skin/Brain-Interfaced Electrodes

The work presented here introduces a facile strategy for the development of flexible and stretchable electrodes that harness the robust characteristics of carbon nanomaterials through laser processing techniques on a liquid crystal polymer (LCP) film. By utilizing LCP film as a biocompatible electronic substrate, control is demonstrated over the laser irradiation parameters to achieve efficient pattern generation and transfer printing processes, thereby yielding highly conductive laser-induced graphene (LIG) bioelectrodes. To enhance the resolution of the patterned LIG film, shadow masks are employed during laser scanning on the LCP film surface. This approach is compatible with surface-mounted device integration, enabling the circuit writing of LIG/LCP materials in a flexible format. Moreover, kirigami-inspired on-skin bioelectrodes are introduced that exhibit reasonable stretchability, enabling independent connections to healthcare hardware platforms for electrocardiogram (ECG) and electromyography (EMG) measurements. Additionally, a brain-interfaced LIG microelectrode array is proposed that combines mechanically compliant architectures with LCP encapsulation for stimulation and recording purposes, leveraging their advantageous structural features and superior electrochemical properties. This developed approach offers a cost-effective and scalable route for producing patterned arrays of laser-converted graphene as bioelectrodes. These bioelectrodes serve as ideal circuit-enabled flexible substrates with long-term reliability in the ionic environment of the human body.

Mobile Point-of-Care Device Using Molecularly Imprinted Polymer-Based Chemosensors Targeting Interleukin-1β Biomarker

Molecularly imprinted polymers (MIPs) have garnered significant attention as a promising material for engineering specific biological receptors with superior chemical complementarity to target molecules. In this study, we present an electrochemical biosensing platform incorporating MIP films for the selective detection of the interleukin-1β (IL-1β) biomarker, particularly suitable for mobile point-of-care testing (POCT) applications. The IL-1β-imprinted biosensors were composed of poly(eriochrome black T (EBT)), including an interlayer of poly(3,4-ethylene dioxythiophene) and a 4-aminothiophenol monolayer, which were electrochemically polymerized simultaneously with template proteins (i.e., IL-1β) on custom flexible screen-printed carbon electrodes (SPCEs). The architecture of the MIP films was designed to enhance the sensor sensitivity and signal stability. This approach involved a straightforward sequential-electropolymerization process and extraction for leaving behind cavities (i.e., rebinding sites), resulting in the efficient production of MIP-based biosensors capable of molecular recognition for selective IL-1β detection. The electrochemical behaviors were comprehensively investigated using cyclic voltammograms and electrochemical impedance spectroscopy responses to assess the imprinting effect on the MIP films formed on the SPCEs. In line with the current trend in in vitro diagnostic medical devices, our simple and effective MIP-based analytical system integrated with mobile POCT devices offers a promising route to the rapid detection of biomarkers, with particular potential for periodontitis screening.

Spontaneous Osteogenic Differentiation of Human Mesenchymal Stem Cells by Tuna-Bone-Derived Hydroxyapatite Composites with Green Tea Polyphenol-Reduced Graphene Oxide

In recent years, bone tissue engineering (BTE) has made significant progress in promoting the direct and functional connection between bone and graft, including osseointegration and osteoconduction, to facilitate the healing of damaged bone tissues. Herein, we introduce a new, environmentally friendly, and cost-effective method for synthesizing reduced graphene oxide (rGO) and hydroxyapatite (HAp). The method uses epigallocatechin-3-O-gallate (EGCG) as a reducing agent to synthesize rGO (E-rGO), and HAp powder is obtained from Atlantic bluefin tuna (Thunnus thynnus). The physicochemical analysis indicated that the E-rGO/HAp composites had exceptional properties for use as BTE scaffolds, as well as high purity. Moreover, we discovered that E-rGO/HAp composites facilitated not only the proliferation, but also early and late osteogenic differentiation of human mesenchymal stem cells (hMSCs). Our work suggests that E-rGO/HAp composites may play a significant role in promoting the spontaneous osteogenic differentiation of hMSCs, and we envision that E-rGO/HAp composites could serve as promising candidates for BTE scaffolds, stem-cell differentiation stimulators, and implantable device components because of their biocompatible and bioactive properties. Overall, we suggest a new approach for developing cost-effective and environmentally friendly E-rGO/HAp composite materials for BTE application.

Strain-tunable optical microlens arrays with deformable wrinkles for spatially coordinated image projection on a security substrate

As a new concept in materials design, a variety of strategies have been developed to fabricate optical microlens arrays (MLAs) that enable the miniaturization of optical systems on the micro/nanoscale to improve their characteristic performance with unique optical functionality. In this paper, we introduce a cost-effective and facile fabrication process on a large scale up to ~15 inches via sequential lithographic methods to produce thin and deformable hexagonally arranged MLAs consisting of polydimethylsiloxane (PDMS). Simple employment of oxygen plasma treatment on the prestrained MLAs effectively harnessed the spontaneous formation of highly uniform nanowrinkled structures all over the surface of the elastomeric microlenses. With strain-controlled tunability, unexpected optical diffraction patterns were characterized by the interference combination effect of the microlens and deformable nanowrinkles. Consequently, the hierarchically structured MLAs presented here have the potential to produce desirable spatial arrangements, which may provide easily accessible opportunities to realize microlens-based technology by tunable focal lengths for more advanced micro-optical devices and imaging projection elements on unconventional security substrates.

Surface-mediated high antioxidant and anti-inflammatory effects of astaxanthin-loaded ultrathin graphene oxide film that inhibits the overproduction of intracellular reactive oxygen species

Background

Astaxanthin (AST) is known as a powerful antioxidant that affects the removal of active oxygen and inhibits the production of lipid peroxide caused by ultraviolet light. However, it is easily decomposed by heat or light during production and storage because of the unsaturated compound nature with a structural double bond. The activity of AST can be reduced and lose its antioxidant capability. Graphene oxide (GO) is an ultrathin nanomaterial produced by oxidizing layered graphite. The chemical combination of AST with GO can improve the dispersion properties to maintain structural stability and antioxidant activity because of the tightly bonded functionalized GO surface.

Methods

Layered GO films were used as nanocarriers for the AST molecule, which was produced via flow-enabled self-assembly and subsequent controlled solution deposition of RGD peptide and AST molecules. Synthesis of the GO-AST complex was also carried out for the optimized concentration. The characterization of prepared materials was analyzed through transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), atomic force microscope (AFM), and Raman spectroscopy. Antioxidant activity was tested by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2.2-diphenyl-1-picrylhydrazyl (DPPH) assays. The antibacterial effect and antioxidant effects were monitored for the ultrathin GO/RGD/AST Film. Further, reactive oxygen species (ROS) assay was used to evaluate the anti-inflammatory effects on L-929 fibroblasts.

Results

Cotreatment of GO-AST solution demonstrated a high antioxidant combined effect with a high ABTS and DPPH radicals scavenging activity. The GO/RGD/AST film was produced by the self-assembly process exhibited excellent antibacterial effects based on physicochemical damage against E. coli and S. aureus. In addition, the GO/RGD/AST film inhibited H₂O₂-induced intracellular ROS, suppressed the toxicity of lipopolysaccharide (LPS)-induced cells, and restored it, thereby exhibiting strong antioxidant and anti-inflammatory effects.

Conclusion

As GO nanocarrier-assisted AST exerted promising antioxidant and antibacterial reactions, presented a new concept to expand basic research into the field of tissue engineering.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40824-022-00276-4.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Recent Advances of Point-of-Care Devices Integrated with Molecularly Imprinted Polymers-Based Biosensors: From Biomolecule Sensing Design to Intraoral Fluid Testing

Recent developments of point-of-care testing (POCT) and in vitro diagnostic medical devices have provided analytical capabilities and reliable diagnostic results for rapid access at or near the patient's location. Nevertheless, the challenges of reliable diagnosis still remain an important factor in actual clinical trials before on-site medical treatment and making clinical decisions. New classes of POCT devices depict precise diagnostic technologies that can detect biomarkers in biofluids such as sweat, tears, saliva or urine. The introduction of a novel molecularly imprinted polymer (MIP) system as an artificial bioreceptor for the POCT devices could be one of the emerging candidates to improve the analytical performance along with physicochemical stability when used in harsh environments. Here, we review the potential availability of MIP-based biorecognition systems as custom artificial receptors with high selectivity and chemical affinity for specific molecules. Further developments to the progress of advanced MIP technology for biomolecule recognition are introduced. Finally, to improve the POCT-based diagnostic system, we summarized the perspectives for high expandability to MIP-based periodontal diagnosis and the future directions of MIP-based biosensors as a wearable format.

Phenotypic change of mesenchymal stem cells into smooth muscle cells regulated by dynamic cell-surface interactions on patterned arrays of ultrathin graphene oxide substrates

The topographical interface of the extracellular environment has been appreciated as a principal biophysical regulator for modulating cell functions, such as adhesion, migration, proliferation, and differentiation. Despite the existed approaches that use two-dimensional nanomaterials to provide beneficial effects, opportunities evaluating their impact on stem cells remain open to elicit unprecedented cellular responses. Herein, we report an ultrathin cell-culture platform with potential-responsive nanoscale biointerfaces for monitoring mesenchymal stem cells (MSCs). We designed an intriguing nanostructured array through self-assembly of graphene oxide sheets and subsequent lithographical patterning method to produce chemophysically defined regions. MSCs cultured on anisotropic micro/nanoscale patterned substrate were spontaneously organized in a highly ordered configuration mainly due to the cell-repellent interactions. Moreover, the spatially aligned MSCs were spontaneously differentiated into smooth muscle cells upon the specific crosstalk between cells. This work provides a robust strategy for directing stem cells and differentiation, which can be utilized as a potential cell culture platform to understand cell-substrate or cell-cell interactions, further developing tissue repair and stem cell-based therapies.

Rotating Cylinder-Assisted Nanoimprint Lithography for Enhanced Chemisorbable Filtration Complemented by Molecularly Imprinted Polymers

Rotating cylindrical stamp-based nanoimprint technique has many advantages, including the continuous fabrication of intriguing micro/nanostructures and rapid pattern transfer on a large scale. Despite these advantages, the previous nanoimprint lithography has rarely been used for producing sophisticated nanoscale patterns on a non-planar substrate that has many extended applications. Here, the simple integration of nanoimprinting process with a help of a transparent stamp wrapped on the cylindrical roll and UV optical source in the core to enable high-throughput pattern transfer, particularly on a fabric substrate is demonstrated. Moreover, as a functional resin material, this innovative strategy involves a synergistic approach on the synthesis of molecularly imprinted polymer, which are spatially organized free-standing perforated nanostructures such as nano/microscale lines, posts, and holes patterns on various woven or nonwoven blank substrates. The proposed materials can serve as a self-encoded filtration medium for selective separation of formaldehyde molecules. It is envisioned that the combinatorial fabrication process and attractive material paves the way for designing next-generation separation systems in use to capture industrial or household toxic substances.

Role for colorectal teams to support non-colorectal teams to improve clinical outcomes and adherence to ERAS guidelines for segmental colectomy: a cohort study

Background

To identify whether compliance with Enhanced Recovery After Surgery (ERAS) Society recommendations is associated with length of stay (LOS) in a New Zealand hospital for patients undergoing segmental colectomy in mixed acute and elective general surgery wards.

Methods

Consecutive elective colorectal surgeries (n = 770) between October 2012 and February 2019 were audited. Patients with non-segmental colectomies, multi-organ surgeries, LOS > 14 days, and those who died were excluded. Logistic regression was used to determine the relationship between patient demographics, compliance with ERAS guidelines, and suboptimal LOS (> 4 days).

Results

Analysis included 376 patients. Age, surgery prior to 2014, surgical approach, non-colorectal surgical team, operation type, and complications were significantly associated with suboptimal LOS. Non-compliance with ERAS recommendations for laparoscopy [OR 8.9, 95% CI (4.52, 19.67)], removal of indwelling catheters (IDC) [OR 3.14, 95% CI (1.85, 5.51)], use of abdominal drains [OR 4.27, 95% CI (0.99, 18.35)], and removal of PCA [OR 8.71, 95% CI (1.78, 157.27)], were associated with suboptimal LOS (univariable analysis). Multivariable analysis showed that age, surgical team, late removal of IDC, and open approach were independent predictors of suboptimal LOS.

Conclusions

Non-compliance with ERAS guidelines for laparoscopic approach and early removal of IDC was higher among procedures performed by non-colorectal surgery teams, and was also associated with adverse postoperative events and suboptimal LOS. This study demonstrates the importance of the surgical team’s expertise in affecting surgical outcomes, and did not find significant independent associations between most individual ERAS guidelines and suboptimal LOS once adjusting for other factors.

Cutaneous paraneoplastic syndrome associated with anal squamous cell carcinoma: a rare presentation of an uncommon cancer

Paraneoplastic syndromes associated with anal squamous cell carcinoma (scc) are rare. Erythema gyratum repens (egr) is a cutaneous paraneoplastic syndrome with distinctive characteristics. Here, we report the rare case of a 73-year-old woman with a chronic erythematous rash for 11 months associated with intense pruritus. She was treated with prednisone and antihistamines by dermatologists, but did not respond. The patient was subsequently seen in our clinic for unintentional weight loss and anorexia with intermittent nausea and vomiting. During further evaluation with imaging studies, upper endoscopy, and colonoscopy with biopsy, poorly differentiated anal scc was identified. Biopsies of the skin rash were characteristic of egr. She was treated using concurrent chemotherapy with 5-fluorouracil and mitomycin C and pelvic radiation (50.4 Gy in 28 fractions) for anal scc. She tolerated the treatment, and her rash faded, with resolution of the pruritus.

AB0598 THE INCREASING USE OF IMMUNOSUPPRESSANTS IN EARLY SYSTEMIC SCLEROSIS

Background:

Immunosuppression (IS) remains the main treatment for progressing skin involvement, active interstitial lung disease (ILD) and underlying inflammatory joint (IJ) or muscle disease in systemic sclerosis (SSc).

Objectives:

This study investigated the pattern and trends in immunosuppressive agent use in patients with early SSc diagnosed before and after 2007 to determine whether the changes in the preferred type and combination of IS, timing and predictors of administration took place over the past decade.

Methods:

397 SSc patients from Canadian Scleroderma Research Group (CSRG) database (183dcSSc, 214 lcSSc) who had baseline and follow-up visits within 3 years (1.8±0.8) after disease onset were included: 82% females, age at diagnosis 53±13 years, disease duration 1.6±0.8 years. Organ involvement was assessed by modified Rodnan skin score, Medsger Disease Severity Score (DSS) and CSRG definitions using bivariate, chi-squared, ANOVA, and adjusted regression analyses.

Results:

115 dcSSc patients (63%) and 62 lcSSc (29%) received IS, most commonly methotrexate (MTX) (72% dcSSc and 52% lcSSc), followed by mycophenylate mofetil (MMF) and cyclophosphamide (CYC). Within the patients receiving IS, monotherapy prevailed (77% dcSSc and 68% lcSSc); CYC and azathioprine were the preferred choice of IS more frequently in lcSSc compared to dcSSc (p<0.006 and p<0.02, respectively). In dcSSc, IS were predominantly prescribed at years 2 and 3 after the onset of first non-Raynaud’s phenomenon (RP) manifestation, when about half of the patients received IS. The proportion of lcSSc patients receiving IS was significantly lower and distributed more equally through the first three years. After 2007, dcSSc patients received IS more often (74% vs 50%, p=0.001), especially MTX (p=0.02) and MMF (p<0.05), and earlier (peaked at 2 years after disease onset)(Table 1).

Table 1.

Proportion of patients receiving immunosuppressive treatment at each year after disease onset in SSc diagnosed before and after 2007.

Years after the first non-RP symptomlcSScBefore 2007After 2007Total N of pts seen at each year% receiving immune suppressivesTotal N of pts seen at each year% receiving immune suppressivesP-value113154717>0.92242182180.7723491410714>0.9dcSSc1242940430.2862512665650.00013624563540.325

IS administration was associated with male gender, ILD, a-Scl-70 positivity, ACA-negativity and IJ disease in lcSSc, and with ACA-negativity and a higher mRSS in dcSSc. Multivariate logistic regression analysis showed that IS treatment could be predicted by ACA-negativity in lcSSc patients (Exp(B) 0.317, p=0.012) and younger age in dcSSc patients (Exp(B) 0.974, p=0.002).

Conclusion:

Over the past decade, there has been a trend to prescribe IS more often, especially MTX, and earlier in dcSSc patients. MMF has gained favour over CYC. Autoantibody status was the most consistent predictor whether a patient is likely to take IS over the course of the disease.

Disclosure of Interests:

Ryan Park: None declared, Tatiana Nevskaya: None declared, Murray Baron: None declared, Janet Pope Grant/research support from: AbbVie, Bristol-Myers Squibb, Eli Lilly & Company, Merck, Roche, Seattle Genetics, UCB, Consultant of: AbbVie, Actelion, Amgen, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Eicos Sciences, Eli Lilly & Company, Emerald, Gilead Sciences, Inc., Janssen, Merck, Novartis, Pfizer, Roche, Sandoz, Sanofi, UCB, Speakers bureau: UCB

One-Step Laser Patterned Highly Uniform Reduced Graphene Oxide Thin Films for Circuit-Enabled Tattoo and Flexible Humidity Sensor Application

The conversion of graphene oxide (GO) into reduced graphene oxide (rGO) is imperative for the electronic device applications of graphene-based materials. Efficient and cost-effective fabrication of highly uniform GO films and the successive reduction into rGO on a large area is still a cumbersome task through conventional protocols. Improved film casting of GO sheets on a polymeric substrate with quick and green reduction processes has a potential that may establish a path to the practical flexible electronics. Herein, we report a facile deposition process of GO on flexible polymer substrates to create highly uniform thin films over a large area by a flow-enabled self-assembly approach. The self-assembly of GO sheets was successfully performed by dragging the trapped solution of GO in confined geometry, which consisted of an upper stationary blade and a lower moving substrate on a motorized translational stage. The prepared GO thin films could be selectively reduced and facilitated from the simple laser direct writing process for programmable circuit printing with the desired configuration and less sample damage due to the non-contact mode operation without the use of photolithography, toxic chemistry, or high-temperature reduction methods. Furthermore, two different modes of the laser operating system for the reduction of GO films turned out to be valuable for the construction of novel graphene-based high-throughput electrical circuit boards compatible with integrating electronic module chips and flexible humidity sensors.

Abdominoplasty in Prune Belly Syndrome

INTRODUCTION

Many patients with Prune Belly Syndrome (PBS) require abdominoplasty alone or in combination with correction of any urogenital abnormalities. This video presents a simplified technique with which to treat the abdominal flaccidity in PBS.

METHODS

A longitudinal xypho-pubic fusiform figure is drawn on the abdomen, based on the area of skin and subcutaneous tissue to be removed. This is performed with preservation of the musculo-fascial layer and the umbilicus. A lateral elliptical single xypho-pubic line is drawn in the most lax side of the fascia, which is incised along this line. After urinary tract reconstruction and orchidopexy, closure is initiated by suturing the medial edge of the wider fascial flap laterally to the peritoneal side of the contralateral flap. Next, the now outer fascial flap is laid over the inner flap, and a buttonhole is made to expose the umbilicus. The subcutaneous tissue of the inner flap is laterally undermined to gain extra distance for the suture of the outer flap over the inner flap. The subcutaneous tissue and skin are sutured in the midline, incorporating the umbilicus.

RESULTS

In a 30-year period, 43 PBS patients underwent this procedure with good cosmetic and long-term functional results.

CONCLUSION

This abdominoplasty technique is simple and presents good functional and cosmetic results in PBS patients.