Biodegradable, Biocompatible, and Implantable Multifunctional Sensing Platform for Cardiac Monitoring.

Cardiac monitoring after heart surgeries is crucial for health maintenance and detecting postoperative complications early. However, current methods like rigid implants have limitations, as they require performing second complex surgeries for removal, increasing infection and inflammation risks, thus prompting research for improved sensing monitoring technologies. Herein, we introduce a nanosensor platform that is biodegradable, biocompatible, and integrated with multifunctions, suitable for use as implants for cardiac monitoring. The device has two electrochemical biosensors for sensing lactic acid and pH as well as a pressure sensor and a chemiresistor array for detecting volatile organic compounds. Its biocompatibility with myocytes has been tested in vitro, and its biodegradability and sensing function have been proven with ex vivo experiments using a three-dimensional (3D)-printed heart model and 3D-printed cardiac tissue patches. Moreover, an artificial intelligence-based predictive model was designed to fuse sensor data for more precise health assessment, making it a suitable candidate for clinical use. This sensing platform promises impactful applications in the realm of cardiac patient care, laying the foundation for advanced life-saving developments.

Spiral NeuroString: High-Density Soft Bioelectronic Fibers for Multimodal Sensing and Stimulation.

Bioelectronic fibers hold promise for both research and clinical applications due to their compactness, ease of implantation, and ability to incorporate various functionalities such as sensing and stimulation. However, existing devices suffer from bulkiness, rigidity, limited functionality, and low density of active components. These limitations stem from the difficulty to incorporate many components on one-dimensional (1D) fiber devices due to the incompatibility of conventional microfabrication methods (e.g., photolithography) with curved, thin and long fiber structures. Herein, we introduce a fabrication approach, ‶spiral transformation″, to convert two-dimensional (2D) films containing microfabricated devices into 1D soft fibers. This approach allows for the creation of high density multimodal soft bioelectronic fibers, termed Spiral NeuroString (S-NeuroString), while enabling precise control over the longitudinal, angular, and radial positioning and distribution of the functional components. We show the utility of S-NeuroString for motility mapping, serotonin sensing, and tissue stimulation within the dynamic and soft gastrointestinal (GI) system, as well as for single-unit recordings in the brain. The described bioelectronic fibers hold great promises for next-generation multifunctional implantable electronics.

Autonomous alignment and healing in multilayer soft electronics using immiscible dynamic polymers.

Self-healing soft electronic and robotic devices can, like human skin, recover autonomously from damage. While current devices use a single type of dynamic polymer for all functional layers to ensure strong interlayer adhesion, this approach requires manual layer alignment. In this study, we used two dynamic polymers, which have immiscible backbones but identical dynamic bonds, to maintain interlayer adhesion while enabling autonomous realignment during healing. These dynamic polymers exhibit a weakly interpenetrating and adhesive interface, whose width is tunable. When multilayered polymer films are misaligned after damage, these structures autonomously realign during healing to minimize interfacial free energy. We fabricated devices with conductive, dielectric, and magnetic particles that functionally heal after damage, enabling thin-film pressure sensors, magnetically assembled soft robots, and underwater circuit assembly.

Sensors for Volatile Organic Compounds.

This paper provides an overview of recent developments in the field of volatile organic compound (VOC) sensors, which are finding uses in healthcare, safety, environmental monitoring, food and agriculture, oil industry, and other fields. It starts by briefly explaining the basics of VOC sensing and reviewing the currently available and quickly progressing VOC sensing approaches. It then discusses the main trends in materials' design with special attention to nanostructuring and nanohybridization. Emerging sensing materials and strategies are highlighted and their involvement in the different types of sensing technologies is discussed, including optical, electrical, and gravimetric sensors. The review also provides detailed discussions about the main limitations of the field and offers potential solutions. The status of the field and suggestions of promising directions for future development are summarized.

Synthesis, characterization, and humidity-responsiveness of guar gum xanthate and its nanocomposite with copper sulfide covellite.

A novel conjugation of guar gum with xanthate groups via facile aqueous xanthation reaction has been reported. Density of grafted xanthate on guar gum product (GG-X) is as high as 4.4%, thus GG-X is conceivably characterized and confirmed by various spectrometric, electrochemical, thermogravimetric, and microscopic methods. Complexation of GG-X with numerous borderline and soft metal ions (e.g. Fe2+, Co2+, Ni2+, Cu2+, Pb2+, Pt2+ and Cd2+) yields hydrophilic gel-like materials and shows good agreement with hard and soft acid and base (HSAB) theory. This indicates tremendous potential of GG-X in metal ion extraction, removal and hydrogel cross-linking. GG-X is also employed to formulate an aqueous colloidal dispersion of copper sulfide covellite (GG-X/CuS) nanocomposites. GG-X therefore behaves as a surfactant, allowing formation of electronically conductive nanocomposites. XRD indicates apparent beneficial effects of GG-X in the synthesis of CuS with a crystallite size of 15.6 nm. This novel nanocomposite is a promising material for humidity sensing, showing reversible linear responses to relative humidity changes within 10 to 80% range. The interaction between GG-X and water might cause changes in electrical permittivity of GG-X/CuS nanocomposite and/or electrical hopping conductivity between CuS nanoparticles.

Highly Efficient Self-Healing Multifunctional Dressing with Antibacterial Activity for Sutureless Wound Closure and Infected Wound Monitoring.

Wound healing represents a major clinical and public healthcare problem that is frequently challenged by infection risks, detrimental consequences on the surrounding tissues, and difficulties to monitor the healing process. Here we report on a novel self-healing, antibacterial, and multifunctional wound dressing for sutureless wound closure and real-time monitoring of the healing parameters. The self-healing elastomer contains cetyltrimethylammonium bromide (CTAB) and has high mechanical toughness (35 MJ m-3 ), biocompatibility, and outstanding antibacterial activity (bactericidal rate is ≈90% in 12 h), enabling the wound dressing to effectively inhibit bacterial growth and accelerate infected wound healing. In vivo tests based on full-thickness skin incision model shows that the multifunctional wound dressing can help in contracting wound edges and facilitate wound closure and healing, as could be evidenced by notably dense and well-organized collagen deposition. The test provides an evidence that the integrated sensor array within the multifunctional wound dressing can monitor temperature, pH, and glucose level of the wound area in real-time, providing reliable and timely information of the condition of the wound. Ultimately, the reported multifunctional dressing would be of high value in managing the burden associated with wound healing via personalised monitoring and treatment approaches, digital and other people-centred solutions for health care.

Mild radiographic osteoarthritis is associated with increased pain and dissatisfaction following total knee arthroplasty when compared with severe osteoarthritis: a systematic review and meta-analysis.

PURPOSE: The association between severity of radiographic osteoarthritis with patient pain, function, and satisfaction following total knee arthroplasty has been disputed. The discrepancies in current literature prompt us to further examine this association in a systematic review and meta-analysis. METHODS: The OVID-Medline, Embase, and Web of Science databases were searched from their inception up to Mar 2020. The main independent variable was osteoarthritis severity as defined by preoperative radiographs. The outcomes measured were pain, function and satisfaction following total knee arthroplasty. A minimum of three studies assessing the same patient-reported outcome measures were included in the meta-analysis, as well as those separating patients by chronic pain or dissatisfaction. RESULTS: 29 studies were included in this study. Significant heterogeneity was seen between radiographic evaluation and reported outcomes. Patients with only mild radiographic osteoarthritis were more likely to suffer from chronic pain (odds ratio = 2.45, 95% CI = 1.80-3.34, p < 0.001) and dissatisfaction (odds ratio = 2.43, 95% CI = 1.79-3.31, p < 0.001) compared to patients with severe osteoarthritis. A significant association was found between mild radiographic severity and lower total Western Ontario and McMaster Universities Osteoarthritis scores (95% CI = - 0.37-0.06, p = 0.006) as well as Knee Society Scores (CI: - 0.54-0.16, p < 0.001). CONCLUSION: Patients with mild radiographic osteoarthritis are anticipated to gain less from total knee arthroplasty compared to those with severe osteoarthritis. They are also at risk for chronic pain and dissatisfaction and should be consulted about this risk prior to surgery. LEVEL OF EVIDENCE: III.

A Wearable Microneedle-Based Extended Gate Transistor for Real-Time Detection of Sodium in Interstitial Fluids.

Sodium is a prominent prognostic biomarker for assessing health status, such as dysnatremia. As of now, detection and monitoring of sodium levels in the human body is carried out by means of laborious and bulky laboratory equipmentand/or by offline analysis of various body fluids. Herein, an innovative stretchable, skin-conformal and fast-response microneedle extended-gate FET biosensor is reported for real-time detection of sodium in interstitial fluids for minimally invasive health monitoring along with high sensitivity, low limit of detection, excellent biocompatibility, and on-body mechanical stability. The integration of the reported device with a wireless-data transmitter and the Internet-of-Things cloud for real-time monitoring and long-term analysis is reported and discussed. This platform would eventually help bringing unlimited possibilities for effecient medical care and accurate clinical decision-making.

Transanal endoscopic microsurgery under spinal anaesthesia.

BACKGROUND: Transanal endoscopic microsurgery (TEM) is considered the procedure of choice for rectal adenomas non-amendable for endoscopic excision and for early rectal cancer. TEM may gain more importance in patients who are considered unfit for major surgery. The option of spinal anaesthesia may offer many advantages for patients undergoing TEM while maintaining the principles of complete tumour excision. The aim of this study is to report the outcome of patients undergoing TEM under spinal anaesthesia. METHODS: Demographic and clinical data pertaining patients undergoing TEM under spinal anaesthesia between 2004 and 2015 were retrospectively collected. RESULTS: A total of 158 TEM procedures were recorded in the study period. Twenty-three patients (15%) underwent the procedure under spinal anaesthesia and were included in the study; 13 of them were male and ten were female. The mean age of the patients was 69.1 ± 10.6 years. Seventeen (74%) rectal lesions were adenomas, two (9%) were adenocarcinoma and four (17%) had involved margins after polypectomy. The mean tumour size was 2.1 cm (range, 0.5-3). Distance from the anal verge was 7.7 ± 2.2 cm. Seventeen (74%) lesions were in the posterior wall. The operative time was 73 min (range, 46-108) No adverse anaesthesia-related events were recorded, and the post-operative pain was reduced. The median time of hospitalisation was 2 days (range, 1-4). No major complications were noted, and the minor complications were treated conservatively. The surgical margins were free of tumour in all cases. CONCLUSION: TEM under spinal anaesthesia had short duration of surgery, no increase in operative and post-operative complications or hospital length of stay. Avoiding the use of general anaesthesia, in such challenging procedure, may open new opportunities for patients determined to be unfit for general anaesthesia.

Stretchable and Highly Permeable Nanofibrous Sensors for Detecting Complex Human Body Motion.

Wearable strain sensors have been attracting special attention in the detection of human posture and activity, as well as for the assessment of physical rehabilitation and kinematics. However, it is a challenge to fabricate stretchable and comfortable-to-wear permeable strain sensors that can provide highly accurate and continuous motion recording while exerting minimal constraints and maintaining low interference with the body. Herein, covalently grafting nanofibrous polyaniline (PANI) onto stretchable elastomer nanomeshes is reported to obtain a freestanding ultrathin (varying from 300 to 10 000 nm) strain sensor that has high gas permeability (10-33 mg h-1 ). The sensor demonstrates a low weight and can be directly laminated onto the dynamic human skin for long periods of time. The sensor, which produces an intimate connection with solid or living objects, has a stable performance with excellent sustainability, linearity, durability, and low hysteresis. It exibits excellent performance for continuous interrogation of complex movements, mimicking muscle activities, and resembling brain activity. This includes a very precise discrimination of bending and twisting stimuli at different angles (1-180°) and speeds (3-18 rpm) and very low exertion of counter-interference. These results imply the utility of this appraoch for advanced developments of robotic e-skins or e-muscles.

Self-Healing Soft Sensors: From Material Design to Implementation.

The demand for interfacing electronics in everyday life is rapidly accelerating, with an ever-growing number of applications in wearable electronics and electronic skins for robotics, prosthetics, and other purposes. Soft sensors that efficiently detect environmental or biological/physiological stimuli have been extensively studied due to their essential role in creating the necessary interfaces for these applications. Unfortunately, due to their natural softness, these sensors are highly sensitive to structural and mechanical damage. The integration of natural properties, such as self-healing, into these systems should improve their reliability, stability, and long-term performance. Recent studies on self-healing soft sensors for varying chemical and physical parameters are herein reviewed. In addition, contemporary studies on material design, device structure, and fabrication methods for sensing platforms are also discussed. Finally, the main challenges and future perspectives in this field are introduced, while focusing on the most promising examples and directions already reported.

A Multifunctional Electronic Skin Empowered with Damage Mapping and Autonomic Acceleration of Self-Healing in Designated Locations.

Integrating self-healing capabilities into soft electronic devices and sensors is important for increasing their reliability, longevity, and sustainability. Although some advances in self-healing soft electronics have been made, many challenges have been hindering their integration in digital electronics and their use in real-world conditions. Herein, an electronic skin (e-skin) with high sensing performance toward temperature, pressure, and pH levels-both at ambient and/or in underwater conditions is reported. The e-skin is empowered with a novel self-repair capability that consists of an intrinsic mechanism for efficient self-healing of small-scale damages as well as an extrinsic mechanism for damage mapping and on-demand self-healing of big-scale damages in designated locations. The overall design is based on a multilayered structure that integrates a neuron-like nanostructured network for self-monitoring and damage detection and an array of electrical heaters for selective self-repair. This system has significantly enhanced self-healing capabilities; for example, it can decrease the healing time of microscratches from 24 h to 30 s. The electronic platform lays down the foundation for the development of a new subcategory of self-healing devices in which electronic circuit design is used for self-monitoring, healing, and restoring proper device function.

Simultaneous local excision of synchronous rectal polyps by transanal endoscopic microsurgery.

BACKGROUND: The approach to surgical resection of multiple rectal lesions when endoscopic polypectomy is unsuccessful has historically been radical rectal resection with total mesorectal excision. This approach is fraught with high morbidity and mortality. We explored the possibility of performing one transanal endoscopic microsurgery procedure to resect multiple synchronous rectal lesions. MATERIALS AND METHODS: A retrospective analysis of all adult patients undergoing transanal endoscopic microsurgery at a single institution between 2004 and 2015. Clinical, demographic, and pathologic data were analyzed for all patients with synchronous rectal lesions that were excised via one transanal endoscopic microsurgery procedure. RESULTS: Of the 158 patients who underwent transanal endoscopic microsurgery during the study period, 14 (8.8%) had two or more synchronous rectal lesions resected. The mean tumor size was 2.5 cm (range 0.5-3.5). The mean distance from the anal verge for the upper/proximal lesions: 10 ± 2.5 cm, and for the lower/distal lesions: 7 ± 2 cm. Mean operative time was 112 minutes (range 75-170). Median hospitalization time was 3 days (range 2-4). Two patients had urinary retention. No other complications were noted. All the transanal endoscopic microsurgery specimens were with clear margins. CONCLUSION: Transanal endoscopic microsurgery is a safe and feasible procedure for patients with multiple rectal lesions. We demonstrate no increase in surgical time, completeness of specimen resection, no increase in complications or hospital length or stay when compared to patients undergoing transanal endoscopic microsurgery for a single lesion.

Disease Detection with Molecular Biomarkers: From Chemistry of Body Fluids to Nature-Inspired Chemical Sensors.

This article aims to review nature-inspired chemical sensors for enabling fast, relatively inexpensive, and minimally (or non-) invasive diagnostics and follow-up of the health conditions. It can be achieved via monitoring of biomarkers and volatile biomarkers, that are excreted from one or combination of body fluids (breath, sweat, saliva, urine, seminal fluid, nipple aspirate fluid, tears, stool, blood, interstitial fluid, and cerebrospinal fluid). The first part of the review gives an updated compilation of the biomarkers linked with specific sickness and/or sampling origin. The other part of the review provides a didactic examination of the concepts and approaches related to the emerging chemistries, sensing materials, and transduction techniques used for biomarker-based medical evaluations. The strengths and pitfalls of each approach are discussed and criticized. Future perspective with relation to the information and communication era is presented and discussed.

Which patients are less likely to improve after arthroscopic rotator cuff repair?

OBJECTIVE: The aim of this study was to evaluate which specific factors influence the improvement in function and to estimate the time to obtain pain relief following arthroscopic rotator cuff repair. METHODS: A total of 97 patients (57 men and 40 women; mean age: 55.5 ± 9.3 years) who had arthroscopic rotator cuff repair between 2013 and 2016 were included into the study. Multivariable stepwise analysis included preoperative variables (age, gender, body mass index, comorbidities, occupation and participation in sports, Oxford shoulder score at baseline, preceding injury and duration of preoperative symptoms) and arthroscopic findings (size of rotator cuff tear, pathology of the long head of the biceps and cartilage lesions). The change in the Oxford shoulder score at the last follow-up was modeled as a function of the above predictor variables. The time to regain a visual analogue scale (VAS) under two points following surgery was considered the time to regain substantial pain relief. RESULTS: The mean follow-up time was 33.2 ± 14.4 months. Twenty three patients had partial thickness and seventy four had full thickness supraspinatus tears. In third of the patients the tears were defined as large full thickness. At the last follow-up the mean Oxford shoulder score improved from 13.8 ± 4.8 to 42.1 ± 7.2 points (P < 0.001). The mean VAS improved from a preoperative score of 6.7 ± 1.3 points to 1.5 ± 0.6 points postoperatively (P < 0.001) and 80 (83%) patients declared they were satisfied to have had the operation. The mean time interval for substantial pain relief was 4.9 ± 3.6 months. Patients with higher preoperative Oxford shoulder score and larger tear size were correlated with lesser improvement in Oxford shoulder score (R = 0.5, P = 0.001). CONCLUSION: Arthroscopic rotator cuff repair improved pain and function at an average follow-up of three years. A substantial pain relief was regained within five months from surgery. Larger rotator cuff tear size and more favorable preoperative function were predictors of worse postoperative function. LEVEL OF EVIDENCE: Level IV, Therapeutic study.

Time-space-resolved origami hierarchical electronics for ultrasensitive detection of physical and chemical stimuli.

Recent years have witnessed thriving progress of flexible and portable electronics, with very high demand for cost-effective and tailor-made multifunctional devices. Here, we report on an ingenious origami hierarchical sensor array (OHSA) written with a conductive ink. Thanks to origami as a controllable hierarchical framework for loading ink material, we have demonstrated that OHSA possesses unique time-space-resolved, high-discriminative pattern recognition (TSR-HDPR) features, qualifying it as a smart sensing device for simultaneous sensing and distinguishing of complex physical and chemical stimuli, including temperature, relative humidity, light and volatile organic compounds (VOCs). Of special importance, OSHA has shown very high sensitivity in differentiating between structural isomers and chiral enantiomers of VOCs - opening a door for wide variety of unique opportunities in several length scales.

A Freestanding Stretchable and Multifunctional Transistor with Intrinsic Self-Healing Properties of all Device Components.

A flexible and stretchable field-effect transistor (FET) is an essential element in a number of modern electronics. To realize the potential of this device in harsh real-world conditions and to extend its application spectrum, new functionalities are needed to be introduced into the device. Here, solution-processable elements based on carbon nanotubes that empower flexible and stretchable FET with high hole-mobility (µh ≈ 10 cm2 V-1 s-1 ) and relatively low operating voltages (<8 V) and that retain self-healing properties of all FET components are reported. The device has repeatable intrinsic and autonomic self-healing ability, namely without use of any external trigger, enabling the restoration of its electrical and mechanical properties, both after microscale damage or complete cut of the device-for example by a scissor. The device can be repeatedly stretched for >200 cycles of up to 50% strain without a significant loss in its electrical properties. The device is applicable in the form of a ≈3 µm thick freestanding skin tattoo and has multifunctional sensing properties, such as detection of temperature and humidity. With this unprecedented biomimetic transistor, highly sustainable and reliable soft electronic applications can be introduced.

Chemically Modified Polyaniline for the Detection of Volatile Biomarkers of Minimal Sensitivity to Humidity and Bending.

Flexible sensors can be widely used in future wearable devices to monitor people's health states. However, most of the sensors are sensitive to humidity and bending effects, limiting their application in a real-world environment. A new strategy is proposed for obtaining flexible sensors with good tolerance to humidity. By integrating a hydrophobic layer on the surface of doped polyaniline, a flexible sensor that can resist water response with a concentration up to 350 ppm is developed. Good resilience against mechanical bending is also achieved in this flexible sensor. These results may trigger a renaissance in flexible sensor applications for disease diagnosing by wearable devices.

Laparoscopic Total Mesorectal Excision Following Transanal Endoscopic Microsurgery for Rectal Cancer.

BACKGROUND: Patients' selection for transanal endoscopic microsurgery (TEM) depends on diagnostic modalities; however, there are still some limitations in the preoperative diagnosis of rectal lesions, and in some reports, up to third of the adenomas resected by TEM were found to be adenocarcinoma; therefore, salvage radical resection (RR) remains necessary for achieving oncological resection. Salvage RR may encounter some technical problems as the violation of the mesorectum and the scar formation. In this study, we aimed to report the outcome in patients undergoing salvage RR in terms of morbidity and oncological results. MATERIALS AND METHODS: Demographic and clinical data pertaining to patients undergoing RR following TEM between 2004 and 2014 were retrospectively collected. RESULTS: One hundred forty one TEM were performed in the study period, 53 (38%) for malignant rectal lesions. Indication for TEM: 15 (28%) benign adenoma, 25 (47%) early rectal cancer, and 13 (25%) had clinical complete response after neoadjuvant radiochemotherapy. Ten (19%) patients had no residual tumor in TEM specimen, 15 (28%) had T1, and 2 of them underwent salvage low anterior resection (LAR). Ten (19%) had T2, 4 had LAR, and 1 had abdominoperineal resection (APR). Five (9%) had a T3, 3 underwent LAR, and 2 had APR. Among the 13 (25%) after chemo-radiotherapy (CRT), 4 had salvage AR. The time from TEM to RR was 47 days (range32-70). Of 16 salvage surgeries, 8 (50%) were laparoscopic. The median operative time was 210 minutes (range165-360). Five patients had protective ileostomy. Rectal perforation occurred in 2 (12%) patients; both had a posterior location, one after CRT. Two (12%) postoperative small-bowl obstruction and three wound infections occurred. There was no perioperative mortality in any of the patients who underwent RR. The final pathology was no residual disease in 9, T3N1 in 1, T3N0 in 3, T2N1 in 1, and T2N0 in 2 patients. Eight (50%) had adjuvant chemotherapy. CONCLUSION: Laparoscopic total mesorectal excision following TEM seems to be safe, and with no negative impact of the completeness of the resection. The concern of intraoperative specimen perforation is real, and should be dealt with meticulous technique and careful dissection, particularly after CRT.

Controversies in presacral tumors management / Controvérsias no tratamento de tumores pré-sacrais

ABSTRACT Presacral tumors are rare lesions of the retrorectal space that can present diagnostic and therapeutic difficulty because of their anatomic location and the different tissue types and etiology. Although the diagnosis and management of these tumors has evolved in recent years, several points still to be addressed in order to improve perioperative diagnosis and treatment. In the upcoming we will try to highlight some controversial points; the pre-operative biopsies, neoadjuvant therapy, the necessity of surgery and the role of minimally invasive surgeries of presacral tumors.

RESUMO Tumores pré-sacrais são lesões raras do espaço retrorretal que podem trazer dificuldades diagnósticas e terapêuticas por causa de sua localização anatômica e também pelos diferentes tipos de tecidos e etiologia. Embora nos últimos anos o diagnóstico e tratamento desses tumores tenham evoluído, diversos pontos ainda devem ser estudados com vistas à melhora do diagnóstico e tratamento no perioperatório. Mais adiante, tentaremos esclarecer alguns pontos controversos; biópsias pré-operatórias, terapia neoadjuvante, a necessidade de cirurgia e o papel das cirurgias minimamente invasivas para os tumores pré-sacrais.