Skin-inspired, sensory robots for electronic implants.

Drawing inspiration from cohesive integration of skeletal muscles and sensory skins in vertebrate animals, we present a design strategy of soft robots, primarily consisting of an electronic skin (e-skin) and an artificial muscle. These robots integrate multifunctional sensing and on-demand actuation into a biocompatible platform using an in-situ solution-based method. They feature biomimetic designs that enable adaptive motions and stress-free contact with tissues, supported by a battery-free wireless module for untethered operation. Demonstrations range from a robotic cuff for detecting blood pressure, to a robotic gripper for tracking bladder volume, an ingestible robot for pH sensing and on-site drug delivery, and a robotic patch for quantifying cardiac function and delivering electrotherapy, highlighting the application versatilities and potentials of the bio-inspired soft robots. Our designs establish a universal strategy with a broad range of sensing and responsive materials, to form integrated soft robots for medical technology and beyond.

Acellular Dermal Matrix Cover Improves Skin Growth during Tissue Expansion by Affecting Distribution of Mechanical Forces.

BACKGROUND: Biological cover over tissue expander prostheses has been introduced to provide soft-tissue support for tissue expanders during breast reconstruction. However, its impact on mechanically induced skin growth remains unknown. This study investigates the hypothesis that covering the tissue expander with acellular dermal matrix (ADM) affects mechanotransduction without compromising the efficacy of tissue expansion. METHODS: Tissue expansion, with and without use of ADM, was performed on a porcine model. The tissue expanders were inflated twice with 45 mL of saline, and the full-thickness skin biopsy specimens were harvested from expanded and control unexpanded skin 1 week and 8 weeks after the final inflation. Histologic evaluation, immunohistochemistry staining, and gene expression analysis were performed. Skin growth and total deformation were evaluated using isogeometric analysis. RESULTS: The authors' results demonstrate that use of ADM as a biological cover during tissue expansion does not impede mechanotransduction that leads to skin growth and blood vessel formation. Isogeometric analysis revealed similar total deformation and growth of expanded skin with and without a biological cover, confirming that its use does not inhibit mechanically induced skin growth. In addition, the authors found that use of an ADM cover results in more uniform distribution of mechanical forces applied by the tissue expander. CONCLUSIONS: These results suggest that ADM improves mechanically induced skin growth during tissue expansion by facilitating a more uniform distribution of mechanical forces applied by the tissue expander. Therefore, the use of a biological cover has potential to improve outcomes in tissue expansion-based reconstruction.

Effect of icariin on the transformation efficiency of induced pluripotent stem cells into sperm cells in vitro / Estudio de los efectos de icariina en la eficiencia de la transformación de espermatozoides extrovertidos inducidos en cuerpos multicompetentes

Objective: To investigate the effect of icariin on the transformation efficiency of germ cell-like cells from mouse induced pluripotent stem cells into sperm cells in vitro. Methods: Firstly, mouse induced pluripotent stem cells were induced and cultured to transform into germ cell-like cells, and the primordial germ cell-like cells were identified by Western blot and RT-PCR. Then, different concentrations of icariin (0.1μg/mL, 1μg/mL, 10μg/mL and 100μg/mL) were added into the culture medium, and the obtained primitive germ cell-like cells were cultured, Western blot and RT-PCR were used to identify the obtained sperm cells, the transformation efficiency was compared. Results: The primordium germ cell-like cells obtained from mouse induced pluripotent stem cells in vitro specially expressed Oct-4 protein, C-kit protein, Mvh mRNA, Fragilis mRNA and Stella mRNA. The sperm cells were specially expressed VASA, SCP3 and γH2AX proteins. RT-PCR showed that the sperm cells were specially expressed Ddx4, Tp2 and Prm1 mRNA. Compared with the control group, the expression level of VASA protein (1.744±0.283, 2.882±0.373, 6.489±0.460), SCP3 protein (2.250±0.306, 7.058±0.521, 8.654±0.804), γH2AX protein (4.304±0.433, 5.713±0.339, 9.268±0.545), Ddx4 mRNA (1.374±0.145, 2.846±0.194, 4.021±0.154), Tp2 mRNA (1.358±0.130, 3.623±0.326, 5.811±0.390) and Prm1 mRNA (1.326±0.162, 3.487±0.237, 4.666±0.307) in 0.1μg/mL, 1μg/mL, 10μg/mL icariin experimental groups were all lower than that of VASA protein (10.560±0.413), SCP3 protein (13.804±0.642), γH2AX protein (11.874±0.464), Ddx4 mRNA (6.4005±0.361), Tp2 mRNA (7.314±0.256) and Prm1 mRNA (7.334±0.390) in 100μg/mL icariin experimental group. (AU)

Objetivo: Investigar el efecto de icariina en la eficiencia de la conversión in vitro inducida en espermatozoides de cultivos de células germinativas derivadas de la transformación de células madre pluripotentes inducidas de ratón. Métodos: Primero se indujeron y cultivaron células madre pluripotentes inducidas de ratón para transformarlas en células similares a las células germinales, y las células similares a las células germinales primordiales se identificaron mediante Western blot y RT-PCR. A continuación, se añadieron diferentes concentraciones de icariina (0,1μg/mL, 1μg/mL, 10μg/mL and 100μg/mL) al medio de cultivo, y se cultivaron las células primitivas similares a células germinales obtenidas, se utilizaron Western blot y RT-PCR para identificar las células espermáticas obtenidas, y se comparó la eficacia de la transformación. Resultados: Las células germinales primitivas obtenidas in vitro a partir de células madre pluripotentes inducidas de ratón expresaron especialmente la proteína Oct-4, la proteína C-kit, el ARNm de Mvh, el ARNm de Fragilis y el ARNm de Stella. Los espermatozoides expresaban especialmente las proteínas VASA, SCP3 y γH2AX. La RT-PCR mostró que los espermatozoides expresaban especialmente los ARNm Ddx4, Tp2 y Prm1. En comparación con el grupo de control, el nivel de expresión de la proteína VASA (1,744±0,283; 2,882±0,373; 6,489±0,460), la proteína SCP3 (2,250±0,306; 7,058± 0,521; 8,654±0,804), proteína γH2AX (4,304±0,433; 5,713±0,339; 9,268±0,545), ARNm Ddx4 (1,374±0,145; 2,846±0,194; 4,021±0,154), ARNm Tp2 (1,358±0,130; 3,623±0,326; 5,811±0,390) y ARNm Prm1 (1,326±0,162; 3,487±0,237; 4,666±0,307) en grupos experimentales de 0,1μg/mL, 1μg/mL, 10μg/mL de icariina fueron todos más bajos que los de la proteína VASA (10,560±0,413), proteína SCP3 (13,804±0,642), proteína γH2AX (11,874±0,464), ARNm Ddx4 (6,4005±0,361), ARNm Tp2 (7,314±0,256) y ARNm Prm1 (7,334±0,390) en 100μg/mL icariina grupo experimental. (AU)

The determinants of neonatal asphyxia in the tropical province of China: A case-control study.

As the major public health problem among under-5 children in the world, neonatal asphyxia (NA) contributes to 24% of the main causes of neonatal death. The effects of NA is not only limited to death but also has a long-term brain injury with lifelong adverse effects. Therefore, the goal of this study was to identify determinants of NA among newborns in the tropical province of China to guide early interventions and improve the survival and quality of life of these infants. A case control study was conducted at Hainan Women and Children's Medical Center from January 1 to December 31, 2021. A total of 255 newborns (85 cases and 170 controls, 1:2 case to control ratio) were enrolled in the study. A systematic random sampling approach was adopted based on hospital delivery registration. Structured questionnaires were used to collected data. The data was entered into statistical software SPSS version 20.0 for analysis. In the bivariable analysis, variables with P values less than .1 were entered into multivariable logistic regression analysis. At a P value of .05, a statistically significant level was reported. Amniotic fluid stained by meconium/blood (AOR = 3.19, 95% confidence interval [CI]: 1.47-6.95), primiparity, fetal presentation of malpresentation (AOR = 3.89, 95% CI: 1.25-12.09), and low birth weight (AOR = 10.51, 95% CI: 3.02-36.55) were to be significantly associated with NA. This study identified that amniotic fluid stained by meconium/blood, primiparity, low birth weight were determinants of NA. Thus, preventive solutions such as close monitoring of fetus presentation, meliorating the obstetric care setup during antenatal care consultations should be stressed in China.

Effect of icariin on the transformation efficiency of induced pluripotent stem cells into sperm cells in vitro.

OBJECTIVE: To investigate the effect of icariin on the transformation efficiency of germ cell-like cells from mouse induced pluripotent stem cells into sperm cells in vitro. METHODS: Firstly, mouse induced pluripotent stem cells were induced and cultured to transform into germ cell-like cells, and the primordial germ cell-like cells were identified by Western blot and RT-PCR. Then, different concentrations of icariin (0.1µg/mL, 1µg/mL, 10µg/mL and 100µg/mL) were added into the culture medium, and the obtained primitive germ cell-like cells were cultured, Western blot and RT-PCR were used to identify the obtained sperm cells, the transformation efficiency was compared. RESULTS: The primordium germ cell-like cells obtained from mouse induced pluripotent stem cells in vitro specially expressed Oct-4 protein, C-kit protein, Mvh mRNA, Fragilis mRNA and Stella mRNA. The sperm cells were specially expressed VASA, SCP3 and γH2AX proteins. RT-PCR showed that the sperm cells were specially expressed Ddx4, Tp2 and Prm1 mRNA. Compared with the control group, the expression level of VASA protein (1.744±0.283, 2.882±0.373, 6.489±0.460), SCP3 protein (2.250±0.306, 7.058±0.521, 8.654±0.804), γH2AX protein (4.304±0.433, 5.713±0.339, 9.268±0.545), Ddx4 mRNA (1.374±0.145, 2.846±0.194, 4.021±0.154), Tp2 mRNA (1.358±0.130, 3.623±0.326, 5.811±0.390) and Prm1 mRNA (1.326±0.162, 3.487±0.237, 4.666±0.307) in 0.1µg/mL, 1µg/mL, 10µg/mL icariin experimental groups were all lower than that of VASA protein (10.560±0.413), SCP3 protein (13.804±0.642), γH2AX protein (11.874±0.464), Ddx4 mRNA (6.4005±0.361), Tp2 mRNA (7.314±0.256) and Prm1 mRNA (7.334±0.390) in 100µg/mL icariin experimental group. CONCLUSIONS: Icariin can promote the transformation of mouse induced pluripotent stem cells into sperm cells in vitro, and it is concentration-dependent manner in a certain concentration range.

Skin-inspired, sensory robots for electronic implants.

Living organisms with motor and sensor units integrated seamlessly demonstrate effective adaptation to dynamically changing environments. Drawing inspiration from cohesive integration of skeletal muscles and sensory skins in these organisms, we present a design strategy of soft robots, primarily consisting of an electronic skin (e-skin) and an artificial muscle, that naturally couples multifunctional sensing and on-demand actuation in a biocompatible platform. We introduce an in situ solution-based method to create an e-skin layer with diverse sensing materials (e.g., silver nanowires, reduced graphene oxide, MXene, and conductive polymers) incorporated within a polymer matrix (e.g., polyimide), imitating complex skin receptors to perceive various stimuli. Biomimicry designs (e.g., starfish and chiral seedpods) of the robots enable various motions (e.g., bending, expanding, and twisting) on demand and realize good fixation and stress-free contact with tissues. Furthermore, integration of a battery-free wireless module into these robots enables operation and communication without tethering, thus enhancing the safety and biocompatibility as minimally invasive implants. Demonstrations range from a robotic cuff encircling a blood vessel for detecting blood pressure, to a robotic gripper holding onto a bladder for tracking bladder volume, an ingestible robot residing inside stomach for pH sensing and on-site drug delivery, and a robotic patch wrapping onto a beating heart for quantifying cardiac contractility, temperature and applying cardiac pacing, highlighting the application versatilities and potentials of the nature-inspired soft robots. Our designs establish a universal strategy with a broad range of sensing and responsive materials, to form integrated soft robots for medical technology and beyond.

3D morphable systems via deterministic microfolding for vibrational sensing, robotic implants, and reconfigurable telecommunication.

DNA and proteins fold in three dimensions (3D) to enable functions that sustain life. Emulation of such folding schemes for functional materials can unleash enormous potential in advancing a wide range of technologies, especially in robotics, medicine, and telecommunication. Here, we report a microfolding strategy that enables formation of 3D morphable microelectronic systems integrated with various functional materials, including monocrystalline silicon, metallic nanomembranes, and polymers. By predesigning folding hosts and configuring folding pathways, 3D microelectronic systems in freestanding forms can transform across various complex configurations with modulated functionalities. Nearly all transitional states of 3D microelectronic systems achieved via the microfolding assembly can be easily accessed and modulated in situ, offering functional versatility and adaptability. Advanced morphable microelectronic systems including a reconfigurable microantenna for customizable telecommunication, a 3D vibration sensor for hand-tremor monitoring, and a bloomable robot for cardiac mapping demonstrate broad utility of these assembly schemes to realize advanced functionalities.

Multi-Fidelity Gaussian Process Surrogate Modeling of Pediatric Tissue Expansion.

Growth of skin in response to stretch is the basis for tissue expansion (TE), a procedure to gain new skin area for reconstruction of large defects. Unfortunately, complications and suboptimal outcomes persist because TE is planned and executed based on physician's experience and trial and error instead of predictive quantitative tools. Recently, we calibrated computational models of TE to a porcine animal model of tissue expansion, showing that skin growth is proportional to stretch with a characteristic time constant. Here, we use our calibrated model to predict skin growth in cases of pediatric reconstruction. Available from the clinical setting are the expander shapes and inflation protocols. We create low fidelity semi-analytical models and finite element models for each of the clinical cases. To account for uncertainty in the response expected from translating the models from the animal experiments to the pediatric population, we create multifidelity Gaussian process surrogates to propagate uncertainty in the mechanical properties and the biological response. Predictions with uncertainty for the clinical setting are essential to bridge our knowledge from the large animal experiments to guide and improve the treatment of pediatric patients. Future calibration of the model with patient-specific data-such as estimation of mechanical properties and area growth in the operating room-will change the standard for planning and execution of TE protocols.

Bayesian calibration of a computational model of tissue expansion based on a porcine animal model.

Tissue expansion is a technique used clinically to grow skin in situ to correct large defects. Despite its enormous potential, lack of fundamental knowledge of skin adaptation to mechanical cues, and lack of predictive computational models limit the broader adoption and efficacy of tissue expansion. In our previous work, we introduced a finite element model of tissue expansion that predicted key patterns of strain and growth which were then confirmed by our porcine animal model. Here we use the data from a new set of experiments to calibrate the computational model within a Bayesian framework. Four 10×10cm2 patches were tattooed in the dorsal skin of four 12 weeks-old minipigs and a total of six patches underwent successful tissue expander placement and inflation to 60cc for expansion times ranging from 1 h to 7 days. Six patches that did not have expanders implanted served as controls for the analysis. We find that growth can be explained based on the elastic deformation. The predicted area growth rate is k∈[0.02,0.08] [h-1]. Growth is anisotropic and reflects the anisotropic mechanical behavior of porcine dorsal skin. The rostral-caudal axis shows greater deformation than the transverse axis, and the time scale of growth in the rostral-caudal direction is given by rate parameters k1∈[0.04,0.1] [h-1] compared to k2∈[0.01,0.05] [h-1] in the transverse direction. Moreover, the calibration results underscore the high variability in biological systems, and the need to create probabilistic computational models to predict tissue adaptation in realistic settings. STATEMENT OF SIGNIFICANCE: Tissue expansion is a widely used technique in reconstructive surgery because it triggers growth of skin for the correction of large skin lesions and for breast reconstruction after mastectomy. Despite of its potential, complications and undesired outcomes persist due to our incomplete understanding of skin mechanobiology. Here we quantify the deformation and growth fields induced by an expander over 7 days in a porcine animal model and use these data to calibrate a computational model of skin growth using finite element simulations and a Bayesian framework. The calibrated model is a leap forward in our understanding skin growth, we now have quantitative understanding of this process: area growth is anisotropic and it is proportional to stretch with a characteristic rate constant of k∈[0.02,0.08] [h-1].