Customization of Conductive Elastomer Based on PVA/PEI for Stretchable Sensors.

Conductive, stretchable, environmentally-friendly, and strain-sensitive elastomers are attracting immense research interest because of their potential applications in various areas, such as human-machine interfaces, healthcare monitoring, and soft robots. Herein, a binary networked elastomer is reported based on a composite hydrogel of polyvinyl alcohol (PVA) and polyethyleneimine (PEI), which is demonstrated to be ultrastretchable, mechanically robust, biosafe, and antibacterial. The mechanical stretchability and toughness of the hydrogels are optimized by tuning the constituent ratio and water content. The optimal hydrogel (PVA2 PEI1 -75) displays an impressive tensile strain as high as 500% with a corresponding tensile stress of 0.6 MPa. Furthermore, the hydrogel elastomer is utilized to fabricate piezoresistive sensors. The as-made strain sensor displays seductive capability to monitor and distinguish multifarious human motions with high accuracy and sensitivity, like facial expressions and vocal signals. Therefore, the elastomer reported in this study holds great potential for sensing applications in the era of the Internet of Things (IoTs).

GREM1 overexpression inhibits proliferation, migration and angiogenesis of osteosarcoma.

Osteosarcoma is the most common malignancy of bone that occurs in young adults and children, with a five-year survival rate of 60-70%. Metastasis of osteosarcoma maintains an even poorer prognosis. GREM1 plays an important role in regulating organogenesis, body patterning, and tissue differentiation. However, there are limited studies on GREM1 in osteosarcomas. This study was carried out to characterize the expression and function of GREM1 in osteosarcoma cells, thus extending our understanding of osteosarcoma metastasis. GREM1 expression was detected in hBMSC, hFOB1.19, Saos-2, MG63 and U2OS cell lines using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Gain- and loss-of-function approaches were used to assess the biological function of GREM1 in U2OS cells. The effects of GREM1 on U2OS cell proliferation were examined using the CCK-8 and colony formation assay. Migration and invasion ability were confirmed by the wound healing and Transwell assay, respectively. Flow cytometry was used to analyse the effect of GREM1 on the cell cycle and apoptosis. The expression of GREM1 targets was evaluated by qRT-PCR and western blotting. The expression of GREM1 was significantly downregulated in osteosarcoma. GREM1 overexpression inhibited the proliferation, migration and invasion of U2OS cells. GREM1 overexpression suppressed tumour cell-induced endothelial cell migration and invasion ability. The effect of GREM1 may be transduced through regulation of the BMP target transcription factor inhibitor of MMP-2 and -9 as well as Id1. GREM1 overexpression and knockdown regulates the tumorigenesis of osteosarcoma in vivo. In conclusion, GREM1 is downregulated in osteosarcoma cells, and overexpression of GREM1 inhibits the proliferation, migration, invasion and angiogenesis abilities of osteosarcoma cells in vitro and in vivo.

Clinical outcomes of lumbar spinal surgery in patients 80 years or older with lumbar stenosis or spondylolisthesis: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis of all available evidence was performed to assess the safety and efficacy of surgery for lumbar stenosis and spondylolisthesis in patients 80 years or older versus those younger than 80 years. METHODS: A search of the literature was conducted in PubMed/MEDLINE, EMBASE and the Cochrane Collaboration Library. Relevant studies comparing the clinical outcomes of lumbar surgery in octogenarians and younger patients were selected according to the eligibility criteria. The predefined endpoints were extracted and meta-analysed from the identified studies. RESULTS: Data from 16 observational studies including 374,197 patients were included in the final analysis. The pooled data revealed that patients 80 years or older had a significantly higher incidence of overall complication, mortality, readmission and longer length of hospital stay than younger patients. There was a similar improvement in the clinical symptoms (Oswestry Disability Index and pain) of patients in the two groups. No significant differences in overall wound complication, reoperation rate, operative time and intraoperative blood loss were found between the groups. CONCLUSIONS: Our results revealed that the clinical improvement in pain and disability did not significantly differ according to age, although the patients aged 80 years or older had increased incidences of mortality and complication than younger patients. Age alone is not a contraindication for lumbar surgery in very old patients. A careful preoperative evaluation, proper patient selection and appropriate surgical approach are important to achieve successful surgical outcomes. These slides can be retrieved under Electronic Supplementary Material.

Clinical significance of traditional clinical parameters and inflammatory biomarkers for the prognosis of patients with spinal chondrosarcoma: a retrospective study of 150 patients in a single center.

BACKGROUND: To investigate the clinical significance of five inflammatory biomarkers and conventional clinical parameters in prognostic prediction of spinal chondrosarcoma. METHODS: Univariate and multivariate analyses were performed to investigate independent prognostic factors for recurrence and death of patients with spinal chondrosarcoma. Disease-free survival (DFS) and overall survival (OS) were estimated by Kaplan-Meier curve, and differences were analyzed by log-rank test. The optimal cutoff values for NLR, PLR, LMR, and CAR were determined by X-tile program. RESULTS: The optimal cutoff value for NLR, PLR, LMR, AGR, and CAR was 2.7, 200, 3.0, 1.5, and 0.2, respectively. Of the 150 patients included, recurrence was detected in 105 patients, and death occurred in 78 patients. Multivariate analysis indicated that Tomita I-III, total resection, and CAR < 0.2 were significantly associated with longer DFS. Meanwhile, preoperative Frankel score D-E, total resection, and CAR < 0.2 were favorable prognostic factors for OS. Subtype analysis showed that only total resection was an independent prognostic factor for DFS of recurrent spinal chondrosarcoma. CONCLUSION: Total resection could significantly reduce the recurrence rate of spinal chondrosarcoma and improve OS of chondrosarcoma patients. Tomita classification I-III was a favorable factor for DFS, and preoperative Frankel score A-C was an adverse prognostic factor for OS. CAR was the most robust prognostic indicator with a discriminatory ability as compared with other inflammatory indicators. These slides can be retrieved under Electronic Supplementary Material.

Epidemiology of ossification of the spinal ligaments and associated factors in the Chinese population: a cross-sectional study of 2000 consecutive individuals.

BACKGROUND: The epidemiology and cause of ossification of the spinal ligaments (OSL) remains obscure. To date, there is no study that comprehensively evaluates the prevalence, distribution, and concomitance of each type of OSL by CT among general Chinese population. We therefore aimed to comprehensively investigate epidemiological characteristics of OSL using whole spine CT in the Chinese population and examine the factors that correlate with the presence of OSL. METHODS: Ossification of the posterior longitudinal ligament (OPLL), ligamentum flavum (OLF), anterior longitudinal ligament (OALL), nuchal ligament (ONL), and diffuse idiopathic skeletal hyperostosis (DISH) were evaluated from the subjects who underwent PET/CT for the purpose of cancer screening in our hospital. Prevalence, distribution, and concomitance of OSL were reviewed. Logistic regression analysis was performed to identify the risk factors of OSL. RESULTS: A total of 2000 subjects (1335 men and 665 women) were included. The prevalence rate of cervical OPLL (C-OPLL) was 4.1%, thoracic OPLL (T-OPLL) 2.25%, lumbar OPLL (L-OPLL) 0.8%, thoracic OLF (T-OLF) 37.65%, lumbar OLF (L-OLF) 1.45%, ONL 31.5%, DISH 3.85%. The most commonly involved level was C5 for C-OPLL, T1 for T-OPLL, T10 for T-OLF, and T8/9 for OALL. 21% of subjects with C-OPLL had T-OPLL, 44% of C-OPLL had T-OLF, 38% of T-OPLL had C-OPLL, 53% of T-OPLL had T-OLF, 44% of L-OPLL had T-OPLL, and 56% of L-OPLL had T-OLF. The average age of OSL-positive subjects was significantly higher than that of OSL-negative subjects. The results of the multiple regression analysis revealed that males had a strong association with DISH (odds ratio, 3.15; 95% confidence interval, 1.27-7.78; P = 0.013). CONCLUSION: The prevalence of OSL in the Chinese was revealed. Tandem ossification is not uncommon in people with OSL. There is a high incidence of multiple-regional OPLL in the whole spine. Approximately half of the subjects with OPLL coexist with T-OLF. For patients with clinical symptoms induced by OPLL, thorough evaluation of whole spine using CT is recommended.

T-box transcription factor Brachyury in lung cancer cells inhibits macrophage infiltration by suppressing CCL2 and CCL4 chemokines.

Both intra-tumor macrophage and T-box transcription factor Brachyury (T) have been proved to play important roles in tumor progression and metastasis. However, it is still unknown whether T could regulate the infiltration of macrophages. Here, we report that the Brachyury expression in human lung tumors was inversely correlated with the infiltration of macrophages. Brachyury suppressed the capability of human lung cancer cells to attract macrophages. Using PCR array, we found that Brachyury inhibited expression of several chemokines, including CCL2, CCL4, and CXCL10. Accordingly, knockdown of CCL2 and CCL4 in lung cancer cells suppressed macrophage invasion under coculture conditions. Furthermore, we found that Brachyury expression was inversely correlated with CCL2 and CCL4 expression in human lung tumors. Taken together, our findings shed light on the novel role of Brachyury in regulation of macrophage infiltration.

Surgery and survival outcomes of 30 patients with neurological deficit due to clear cell renal cell carcinoma spinal metastases.

PURPOSE: The aim of this study was to provide some useful insights into the clinical and imaging presentations, treatment and prognostic factors in patients with neurological deficit caused by clear cell renal cell carcinoma (CCRCC) spinal metastases for the sake of designing individualized therapeutic plans for such patients. METHODS: A total of 30 patients with neurological deficit due to CCRCC spinal metastases who received surgery in our department were identified during an 8-year period from 2003 to 2012 and used for discussion of treatment options for CCRCC spinal metastases on the basis of literature review and our own experience. RESULTS: Univariate analysis showed that age (≤45 years/>45 years), visceral metastasis, Tomita score (3-5/6-8), Tokuhashi score (4-9/10-12) and radiotherapy were suggested as the potential prognostic factors. However, the multivariate Cox regression model showed that only Tokuhashi score was an independent prognostic factor. CONCLUSIONS: Tokuhashi score 10 or more is a favorable prognostic factor of CCRCC spinal metastasis.

A Novel and Reproducible Classification of Cervical Dumbbell Tumors to Inform Surgical Approach and Reconstruction Techniques.

STUDY DESIGN: A retrospective case series. OBJECTIVE: This study developed a novel classification system based on imaging and anatomy to select optimal surgical approaches and reconstruction strategies to achieve total resection of cervical dumbbell tumors and restore spinal stability. SUMMARY OF BACKGROUND DATA: Total resection is necessary to decrease the recurrence rate of cervical dumbbell tumors. Previous cervical dumbbell tumor classifications are insufficient for determining surgical strategies; therefore, a practical classification is needed. MATERIALS AND METHODS: This study included 295 consecutive patients with cervical dumbbell tumors who underwent total surgical resection. A novel classification of cervical dumbbell tumors was developed based on magnetic resonance imaging and computed tomography. Continuous variables were expressed as mean±SD and were compared using an unpaired two-tailed Student t test. The χ 2 test or the Fisher exact test was used for categorical variables. Kendall's W test assessed three independent raters' inter-rater and intrarater reliabilities on 140 cervical dumbbell tumors. RESULTS: The inter-rater and intrarater consistency coefficient was 0.969 (χ 2 =404.3, P <0.001) and 0.984 (χ 2 =273.7, P <0.001). All patients with type I and II tumors underwent single-posterior surgeries to achieve total resection. Of the patients in this study, 86.1%, 25.9%, 75.9%, and 76.9% underwent posterior surgeries for types IIIa, IIIb, IVa, and V tumors, respectively. All patients with type IVb tumors underwent a combined anterior and posterior approach. Posterior internal fixation was used for all patients in posterior surgery. Anterior reconstruction was applied for patients with type IVb tumors (20/20, 100%) and some with type V tumors (3/13, 23.1%). The mean follow-up duration was 93.6±2.6 months. A recurrence was observed in 19 (6.4%) patients. CONCLUSION: The authors describe a novel classification system that is of practical use for planning the complete resection of cervical dumbbell tumors.

Self-Powered Textile Triboelectric Pulse Sensor for Cardiovascular Monitoring.

Cardiovascular diseases have become a severe threat to human health. Fortunately, most of them can be effectively assessed and prevented through long-term monitoring of cardiovascular signals. Wearable medical sensors play an essential role in monitoring human physiological health, which are heading towards ultra-low power consumption, high sensitivity and stability. Furthermore, a comfortable wearable sensor also needs to be flexible and breathable. Here, a self-powered textile pulse sensor (STPS) based on triboelectric nanogenerator (TENG) is demonstrated for real-time monitoring of the radial artery pulse waveform. STPS can directly convert tiny pressure signals into electrical signals with excellent linearity (R2 = 0.996), low detection limit, and long-term stable performance (5×104 cycles). The flexible textile-based STPS can be conformally attached to the human body for continuously and stably recording physiological mechanical signals, which is expected to be utilized in the personalized cardiovascular pulse monitoring wearable devices in the Internet of Things era.

A new immune signature for survival prediction and immune checkpoint molecules in non-small cell lung cancer.

Background: Immune checkpoint blockade (ICB) therapy has brought remarkable clinical benefits to patients with advanced non-small cell lung carcinoma (NSCLC). However, the prognosis remains largely variable. Methods: The profiles of immune-related genes for patients with NSCLC were extracted from TCGA database, ImmPort dataset, and IMGT/GENE-DB database. Coexpression modules were constructed using WGCNA and 4 modules were identified. The hub genes of the module with the highest correlations with tumor samples were identified. Then integrative bioinformatics analyses were performed to unveil the hub genes participating in tumor progression and cancer-associated immunology of NSCLC. Cox regression and Lasso regression analyses were conducted to screen prognostic signature and to develop a risk model. Results: Functional analysis showed that immune-related hub genes were involved in the migration, activation, response, and cytokine-cytokine receptor interaction of immune cells. Most of the hub genes had a high frequency of gene amplifications. MASP1 and SEMA5A presented the highest mutation rate. The ratio of M2 macrophages and naïve B cells revealed a strong negative association while the ratio of CD8 T cells and activated CD4 memory T cells showed a strong positive association. Resting mast cells predicted superior overall survival. Interactions including protein-protein, lncRNA and transcription factor interactions were analyzed and 9 genes were selected by LASSO regression analysis to construct and verify a prognostic signature. Unsupervised hub genes clustering resulted in 2 distinct NSCLC subgroups. The TIDE score and the drug sensitivity of gemcitabine, cisplatin, docetaxel, erlotinib and paclitaxel were significantly different between the 2 immune-related hub gene subgroups. Conclusions: These findings suggested that our immune-related genes can provide clinical guidance for the diagnosis and prognosis of different immunophenotypes and facilitate the management of immunotherapy in NSCLC.

[Surgical options and clinical outcomes of cervical ossification of the posterior longitudinal ligament].

OBJECTIVE: To discuss the options and clinical outcomes of surgical treatment of cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: From January 2006 to December 2010, 63 patients of cervical OPLL treated surgically by same team were retrospectively analyzed. There were 49 males, 14 females, with a mean age of 56.2 years (from 38 to 76 years). The duration of symptoms ranged from 2 months to 20 years (mean 3.2 years). The ossified ligament was classified via sagittal and coronal images on CT scan. The cervical curvature was measured. Choice of surgical methods was determined according to the type of ossified ligament and cervical curvature. All complications occurred was recorded. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the neurological status. The severity of cervical pain was assessed with visual analogue scale (VAS) method. The results of preoperative, postoperative and follow-up were statistically compared with student t test. RESULTS: The JOA scores of 35 patients performed with anterior approach improved from 9.8 ± 2.3 preoperatively to 11.7 ± 2.1 at final follow-up (t = 3.28, P < 0.05). The VAS sore was significantly decreased at final follow-up compared with preoperative (t = 3.15, P < 0.05). While the JOA scores improved from 10.4 ± 2.7 preoperatively to 12.5 ± 2.3 at final follow-up (t = 3.81, P < 0.05) in 12 patients with laminectomy and from 9.7 ± 2.5 to 11.6 ± 2.6 in 14 patients with laminoplasty (t = 3.56, P < 0.05). The VAS score either in laminectomy or in laminoplasty has not significantly difference between preoperative, 3 month postoperative and final follow-up (P > 0.05). Two patients underwent a combined anterior-posterior approach procedure. Complications in patients included 1 patient of postoperative neurologic deterioration and 2 cases of cerebrospinal fluid leakage in patients with anterior approach, and 2 cases of C(5) nerve palsy in patients with laminectomy. CONCLUSIONS: Surgical options of cervical OPLL should be determined by detailed study of type and range of ossified ligament, as well as the cervical curvature of patients. Good neurological function can be expected in case of appropriate choosing the method for treating the cervical OPLL.

An Artificial Intelligence-Enhanced Blood Pressure Monitor Wristband Based on Piezoelectric Nanogenerator.

Hypertensive patients account for about 16% to 37% of the global population, and about 9.4 million people die each year from hypertension and its complications. Blood pressure is an important indicator for diagnosing hypertension. Currently, blood pressure measurement methods are mainly based on mercury sphygmomanometers in hospitals or electronic sphygmomanometers at home. However, people's blood pressure changes with time, and using only the blood pressure value at the current moment to judge hypertension may cause misdiagnosis. Continuous blood pressure measurement can monitor sudden increases in blood pressure, and can also provide physicians with long-term continuous blood pressure changes as a diagnostic reference. In this article, we design an artificial intelligence-enhanced blood pressure monitoring wristband. The wristband's sensors are based on piezoelectric nanogenerators, with a high signal-to-noise ratio of 29.7 dB. Through the transformer deep learning model, the wristband can predict blood pressure readings, and the loss value is lower than 4 mmHg. By wearing this blood pressure monitoring wristband, we realized three days of continuous blood pressure monitoring of the subjects. The blood pressure monitoring wristband is lightweight, has profound significance for the prevention and treatment of hypertension, and has wide application prospects in medical, military, aerospace and other fields.

Self-Powered Electrical Impulse Chemotherapy for Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is a common oral cancer of the head and neck, which causes tremendous physical and mental pain to people. Traditional chemotherapy usually results in drug resistance and side effects, affecting the therapy process. In this study, a self-powered electrical impulse chemotherapy (EIC) method based on a portable triboelectric nanogenerator (TENG) was established for OSCC therapy. A common chemotherapeutic drug, doxorubicin (DOX), was used in the experiment. The TENG designed with zigzag structure had a small size of 6 cm × 6 cm, which could controllably generate the fixed output of 200 V, 400 V and 600 V. The electrical impulses generated by the TENG increased the cell endocytosis of DOX remarkably. Besides, a simply and ingeniously designed microneedle electrode increased the intensity of electric field (EF) between two adjacent microneedle tips compared with the most used planar interdigital electrode at the same height, which was more suitable for three-dimensional (3D) cells or tissues. Based on the TENG, microneedle electrode and DOX, the self-powered EIC system demonstrated a maximal apoptotic cell ratio of 22.47% and a minimum relative 3D multicellular tumor sphere (MCTS) volume of 160% with the drug dosage of 1 µg mL-1.

A Light-Powered Triboelectric Nanogenerator Based on the Photothermal Marangoni Effect.

The photothermal Marangoni effect enables direct light-to-work conversion, which is significant for realizing the self-propulsion of objects in a noncontact, controllable, and continuous manner. Many promising applications have been demonstrated in micro- and nanomachines, light-driven actuators, cargo transport, and gear transmission. Currently, the related studies about photothermal Marangoni effect-induced self-propulsion, especially rotational motions, remain focused on developing the novel photothermal materials, the structural designs, and the controllable self-propulsion modes. However, extending the related research from the laboratory practice to practical application remains a challenge. Herein, we combined the photothermal Marangoni effect-induced self-propulsion with the triboelectric nanogenerator technology for sunlight intensity determination. Photothermal black silicon, superhydrophobic copper foam with drag-reducing property, and triboelectric polytetrafluoroethylene film were integrated to fabricate a triboelectric nanogenerator. The photothermal-Marangoni-driven triboelectric nanogenerator (PMD-TENG) utilizes the photothermal Marangoni effect-induced self-propulsion to realize the relative motion between the triboelectric layer and the electrode, converting light into electrical signals, with a peak value of 2.35 V. The period of the output electrical signal has an excellent linear relationship with the light intensity. The accessible electrical signal generation strategy proposed here provides a new application for the photothermal Marangoni effect, which could further inspire the practical applications of the self-powered system based on the photothermal Marangoni effect, such as intelligent farming.

Wearable Exoskeleton System for Energy Harvesting and Angle Sensing Based on a Piezoelectric Cantilever Generator Array.

Wearable exoskeletons are developing rapidly due to their superiority in improving human ability and efficiency. The construction of a multifunctional exoskeleton system relies on an efficient continuous energy supply and various high-performance sensors. Here, a magnetic-driven piezoelectric cantilever generator (MPCG) array is designed for energy harvesting and angle sensing of joint motions. Combining theoretical derivation and experimental characterization, it is found that the nonlinear magnetic force acting on the cantilever structure will cause the phenomenon of frequency upconversion, which greatly improves the output of the MPCG. The experiment successfully proves the feasibility of using the MPCG array as an energy-harvesting module to collect energy from human joint motions and power an RH/temp sensor. Furthermore, the MPCG array can also be used to sense the rotation angle and angular velocity. By integrating with a wireless data acquisition and transmission module and supporting software, a wearable joint rehabilitation monitoring and assessment system is built, which can measure the activities of the joint in real time and evaluate the flexion degree. The demonstrated wearable exoskeleton system for joint motion energy harvesting and joint angle sensing is of great value for the construction of a multifunctional exoskeleton system and wearable smart rehabilitation equipment.

Effect of different structures fabricated by additive manufacturing on bone ingrowth.

OBJECTIVE: To study the effects of different structures (solid/hollow) and pore diameters (300/600 µm) on bone ingrowth. METHODS: Porous titanium alloy scaffolds (3.2 * 10.5 mm) were printed using electron beam melting. The implants were divided into either Hollow or Solid Group. The upper half of each implant was printed with a pore diameter of 600 µm while the bottom half was printed with a pore diameter of 300 µm. Visualization of the structural morphology was done using Scanning Electron Microscope (SEM). Cell proliferation was evaluated with the cell counting kit-8 assay and live/dead staining assay. The different lateral femoral condyles of 15 New Zealand rabbits were implanted with different groups of scaffolds. The rabbits were randomly sacrificed at the 4th, 8th, and 12th week postoperatively. Bone mineral density (BMD) and bone volume fraction (BV/TV) evaluation was completed by quantitative Micro-Computed Tomography (Micro-CT). Tissue histology were stained with toluidine blue to observe bone ingrowth under an optical microscope, and the percentage of new bone area were calculated using Image Pro-Plus 6.0. RESULTS: SEM images showed a significant decrease in residual powder in the hollow implant and cell studies showed no obvious cytotoxicity for the Ti6Al4V scaffolds. Micro-CT reconstruction revealed high levels of new bone formation around the scaffolds. The trabeculae around the implants showed a gradual increase with each week, and new bone filled the scaffold pores gradually. BMD, BV/TV, and tissue histology revealed the 300 µm pore diameter is more conducive to bone ingrowth than the 600 µm (p < .05). CONCLUSION: Our study revealed that Ti6Al4V implants with hollow structure could reduce the residual metal powder and implants with 300 µm pore diameter were more effective on bone formation than a 600 µm.

A Self-Powered Optogenetic System for Implantable Blood Glucose Control.

Diabetes treatment and rehabilitation are usually a lifetime process. Optogenetic engineered designer cell-therapy holds great promise in regulating blood glucose homeostasis. However, portable, sustainable, and long-term energy supplementation has previously presented a challenge for the use of optogenetic stimulation in vivo. Herein, we purpose a self-powered optogenetic system (SOS) for implantable blood glucose control. The SOS consists of a biocompatible far-red light (FRL) source, FRL-triggered transgene-expressing cells, a power management unit, and a flexible implantable piezoelectric nanogenerator (i-PENG) to supply long-term energy by converting biomechanical energy into electricity. Our results show that this system can harvest energy from body movement and power the FRL source, which then significantly enhanced production of a short variant of human glucagon-like peptide 1 (shGLP-1) in vitro and in vivo. Indeed, diabetic mice equipped with the SOS showed rapid restoration of blood glucose homeostasis, improved glucose, and insulin tolerance. Our results suggest that the SOS is sufficiently effective in self-powering the modulation of therapeutic outputs to control glucose homeostasis and, furthermore, present a new strategy for providing energy in optogenetic-based cell therapy.

Improved pharmacodynamics of epidermal growth factor via microneedles-based self-powered transcutaneous electrical stimulation.

Epidermal growth factor is an excellent drug for promoting wound healing; however, its conventional administration strategies are associated with pharmacodynamic challenges, such as low transdermal permeability, reduction, and receptor desensitization. Here, we develop a microneedle-based self-powered transcutaneous electrical stimulation system (mn-STESS) by integrating a sliding free-standing triboelectric nanogenerator with a microneedle patch to achieve improved epidermal growth factor pharmacodynamics. We show that the mn-STESS facilitates drug penetration and utilization by using microneedles to pierce the stratum corneum. More importantly, we find that it converts the mechanical energy of finger sliding into electricity and mediates transcutaneous electrical stimulation through microneedles. We demonstrate that the electrical stimulation applied by mn-STESS acts as an "adjuvant" that suppresses the reduction of epidermal growth factor by glutathione and upregulates its receptor expression in keratinocyte cells, successfully compensating for receptor desensitization. Collectively, this work highlights the promise of self-powered electrical adjuvants in improving drug pharmacodynamics, creating combinatorial therapeutic strategies for traditional drugs.

Stretchable graded multichannel self-powered respiratory sensor inspired by shark gill.

Respiratory sensing provides a simple, non-invasive, and efficient way for medical diagnosis and health monitoring, but it relies on sensors that are conformal, accurate, durable, and sustainable working. Here, a stretchable, multichannel respiratory sensor inspired by the structure of shark gill cleft is reported. The bionic shark gill structure can convert transverse elastic deformation into longitudinal elastic deformation during stretching. Combining the optimized bionic shark gill structure with the piezoelectric and the triboelectric effect, the bionic shark gill respiratory sensor (BSG-RS) can produce a graded electrical response to different tensile strains. Based on this feature, BSG-RS can simultaneously monitor the breathing rate and breathing depth of the human body accurately, and realize the effective recognition of the different human body's breathing state under the supporting software. With good stretchability, wearability, accuracy, and long-term stability (50,000 cycles), BSG-RS is expected to be applied as self-powered smart wearables for mobile medical diagnostic analysis in the future.