Comparison of the efficacies of TINAVI robot-assisted surgery and conventional open surgery for Levine-Edward type IIA (postreduction) hangman fractures.

The objective was to compare the clinical efficacy of percutaneous pedicle screw internal fixation with the aid of the TINAVI orthopaedic surgery robot with that of traditional open surgery for Levine-Edward type IIA (postreduction) hangman fractures and to evaluate the safety and efficacy of the TINAVI robot-assisted orthopaedic surgery procedure. The clinical data of 60 patients with Levine-Edward type IIA (postreduction) hangman fractures treated surgically from June 2015 to February 2022 were analysed retrospectively. Among these patients, 25 were treated with percutaneous pedicle screw fixation under TINAVI (the robot group), and 35 were treated with pedicle screw implantation assisted by a conventional C-arm X-ray machine (the traditional operation group). The pedicle screw placement grade was evaluated according to the Rampersaud scale. The correct rate of pedicle screw placement was calculated. The invasion of adjacent facet joints, VAS score (Visual Analogue Scale), NDI score (Neck Disability Index), SF-36 score (36-Item Short-Form Health Survey questionnaire), EQ-5D score (EuroQol-5 dimensions questionnaire) and operation-related data were recorded, and patients were followed up. All patients were followed up for an average of 15.0 ± 3.4 months. The accuracy of screw placement in the robot group was higher than that in the traditional operation group, while the rates of intraoperative blood loss and invasion of the facet joint were lower and the incision length and length of hospital stay were shorter. On the 3rd day after the operation, the VAS score in the robot group was significantly higher than that in the traditional operation group, but there was no significant difference in the NDI score. On the 3rd day after the operation, the SF-36 and EQ-5 questionnaire scores of the robot group were better than those of the traditional operation group. No complications occurred in any of the patients. Postoperative cervical X-ray showed that the cervical vertebra was stable, and there was no fracture, angle or displacement. Postoperative CT showed that all fractures healed, and the average healing time was 3.4 months. The treatment of Levine-Edward IIA (postrepositioning) hangman fractures with percutaneous pedicle fixation assisted by the TINAVI orthopaedic surgery robot can significantly improve screw placement accuracy with a low rate of invasion of the adjacent facet joint, a short operation time, a low bleeding rate, and high patient satisfaction. Although there are still many disadvantages, it still has good prospects for application.

High-Strength Cell Sheets and Vigorous Hydrogels from Mesenchymal Stem Cells Derived from Human Embryonic Stem Cells.

Natural cell derivates, including cell sheets (CSs) and matrix gels, have opened new opportunities to probe questions in tissue engineering and regenerative medicine. However, the potential of CSs and hydrogels generated by current protocols is still limited by the challenges of heterogeneity and weak mechanical properties. Here, we developed a 21 day long-term serum-free culture system for human embryonic stem cell (hESC)-derived immunity-and-matrix-regulatory cells (IMRCs). The CSs formed with IMRCs (IMRC-CSs) have a much greater secretion capacity for the extracellular matrix (ECM) and stronger mechanical properties than umbilical cord-derived MSCs, with a ten thousand-fold increase in elastin, a higher elastic modulus of 1500 kPa, a thicker structure of 20.59 µm, and a higher fiber count per square millimeter. The IMRC-CSs could promote corneal chemical injury repair and could be turned into injectable temperature-sensitive hydrogels for uterine adhesion repair via a decellularization process. In summary, we have established a high-strength CS platform using human pluripotent stem cells for the first time, providing a facile and scalable engineering approach for regenerative medicine.

Orthopedic Robot-Assisted Femoral Neck System in the Treatment of Femoral Neck Fracture.

Cannulated screw fixation is the main therapy for femoral neck fractures, especially in young patients. The traditional surgical procedure uses C-arm fluoroscopy to place the screw freehand and requires several guide wire adjustments, which increases the operation time and radiation exposure. Repeated drilling can also cause damage to the blood supply and bone quality of the femoral neck, which can be followed by complications such as screw loosening, nonunion, and femoral head necrosis. In order to make fixation more precise and reduce the incidence of complications, our team applied robot-assisted orthopedic surgery for screw placement using the femoral neck system to modify the traditional procedure. This protocol introduces how to import a patient's X-ray information into the system, how to perform screw path planning in software, and how the robotic arm assists in screw placement. Using this method, the surgeons can place the screw successfully the first time, improve the accuracy of the procedure, and avoid radiation exposure. The whole protocol includes the diagnosis of femoral neck fracture; the collection of intraoperative X-ray images; screw path planning in the software; precise placement of the screw under the assistance of the robotic arm by the surgeon; and verification of the implant placement.

Spine Surgical Robotics: Current Status and Recent Clinical Applications.

With the development of artificial intelligence and the further deepening of medical-engineering integration, spine surgical robot-assisted (RA) technique has made significant progress and its applicability in clinical practice is constantly expanding in recent years. In this review, we have systematically summarized the majority of literature related to spine surgical robots in the past decade, and not only classified robots accordingly, but also summarized the latest research progress in RA technique for screw placement such as cervical, thoracic, and lumbar pedicle screws, cortical bone trajectory screws, cervical lateral mass screws, and S2 sacroiliac screws; guiding targeted puncture and placement of endoscope via the intervertebral foramen; complete resection of spinal tumor tissue; and decompressive laminectomy. In addition, this report also provides a detailed evaluation of RA technique's advantages and disadvantages, and clarifies the accuracy, safety, and practicality of RA technique. We consider that this review can help clinical physicians further understand and familiarize the current clinical application status of spine surgical robots, thereby promoting the continuous improvement and popularization of RA technique, and ultimately benefiting numerous patients.

Bioink derived from human placenta supporting angiogenesis.

Bioprinting is an emerging approach for constructing sophisticated tissue analogues with detailed architectures such as vascular networks, which requires bioink to fulfill the highly printable property and provide a cell-friendly microenvironment mimicking a native extracellular matrix (ECM). Here, we developed a human placental ECM-derived bioink (hp-bioink) meeting the requirements of 3D printing for printability and bioactivity. We first decellularized the human placenta, followed by enzymatic digestion, dialysis, lyophilization, and re-solubilization to convert the extracts into hp-bioink. Then, we demonstrated that 3%-5% of hp-bioink can be printed with self-standing and 1%-2% of hp-bioink can be embedded and printed within suspended hydrogels. Moreover, hp-bioink supports human umbilical vein endothelial cell assemblyin vitroand angiogenesis in micein vivo. Our research enriches the bank of human-derived bioinks, and provides a new opportunity to further accelerate bioprinting research and application.

Two-dimensional fluoroscopy-guided robot-assisted percutaneous endoscopic transforaminal discectomy: a retrospective cohort study.

Percutaneous Endoscopic Transforaminal Discectomy (PETD) has been widely used for minimally invasive treatment of lumbar disc herniation (LDH), and percutaneous disc target puncture has a steep learning curve and high radiation exposure. Proper technology grafting can improve the surgical procedure and clinical outcomes. The changes brought by grafting surgical robots into PETD are worth investigating. A retrospective analysis was performed on the information of patients who received PETD in our hospital from March 2019 to July 2020. A total of 102 of patients who received 2D-guided robot-assisted PETD were included in Group A, and 102 of patients who received C-arm fluoroscopy-guided bare-handed PETD were included in Group B. The number of punctures, number of fluoroscopies, operation duration, intraoperative anxiety score, complications, and visual analogue scale (VAS) score and Oswestry disability index (ODI) before operation, on Day 1 after operation and at the last follow-up visit of the two groups were compared. All 204 patients received successful operations. Group A received 1.20±0.42 punctures, 10.49±2.16 fluoroscopies and 60.69±5.63 minutes of operation, significantly fewer than the 4.84±1.94 punctures, 17.41±3.23 fluoroscopies and 71.19±5.11 minutes of operation of Group B (all P<0.05), and Group A had significantly lower intraoperative anxiety scores and incidence of complications than Group B (both P<0.05). Both groups had comparable VAS and ODI scores on Day 1 after operation and at the last follow-up visit, which were both significantly higher than those before operation (P<0.05). 2D-guided robot-assisted PETD can enable precise planning of the puncture path, make it easier for operators to complete targeted punctures at pathogenic targets, reduce the number of punctures and fluoroscopies, shorten the operation duration to optimize the operation process, and reduce complications and alleviate intraoperative anxiety for better clinical results. Therefore it mayb be a better choice to assist PETD.

3D printed controllable microporous scaffolds support embryonic development in vitro.

Little is known about the complex molecular and cellular events occurring during implantation, which represents a critical step for pregnancy. The conventional 2D culture could not support postimplantation embryos' normal development, and 3D conditions shed light into the "black box". 3D printing technology has been widely used in recapitulating the structure and function of native tissues in vitro. Here, we 3D printed anisotropic microporous scaffolds to culture embryos by manipulating the advancing angle between printed layers, which affected embryo development. The 30° and 60° scaffolds promote embryo development with moderate embryo-scaffold attachments. T-positive cells and FOXA2-positive cells were observed to appear in the posterior region of the embryo and migrated to the anterior region of the embryo on day 7. These findings demonstrate a 3D printed stand that supports embryonic development in vitro and the critical role of 3D architecture for embryo implantation, in which additive manufacturing is a versatile tool.

Reconstruction of functional uterine tissues through recellularizing the decellularized rat uterine scaffolds by MSCs in vivo and in vitro.

Infertile people who suffered from loss of uterine structures and/or functions can be treated through gestational surrogacy or uterus transplantation, which remains challenging due to the ethical and social issues, the lack of donor organs as well as technical and safety risks. One promising solution is to regenerate and reconstruct a bioartificial uterus for transplantation through the engineering of uterine architecture and appropriate cellular constituents. Here, we developed a well-defined system to regenerate a functional rat uterine through recellularization of the decellularized uterine matrix (DUM) patches reseeded with human mesenchymal stem cells (hMSCs). Engraftment of the recellularized DUMs on the partially excised uteri yielded a functional rat uterus with a pregnancy rate and number of fetuses per uterine horn comparable to that of the control group with an intact uterus. Particularly, the recellularized DUMs enhanced the regeneration of traumatic uterine in vivo because of MSC regulation. The established system here will shed light on the treatment of uterine infertility with heterogeneous DUMs/cell resources through tissue engineering in the future.

Effects of Different Biomaterials and Cellular Status on Testicular Cell Self-Organization.

A multicellular organism's development is coupled with cellular self-organization, which is regulated by cell-cell interactions and cell-extracellular matrix (ECM) crosstalk. Testicular cells from different species such as mouse, rat, and porcine can self-organize into seminiferous tubules both in vitro and in vivo, but the understanding of the functional role of the ECM during this process is limited. Here, it is shown that mouse testicular cells encapsulated with the biomaterial Matrigel can self-organize into seminiferous tubules with blood-testis barrier (BTB) formation and Leydig cell differentiation. By varying the encapsulation method, a combination of sodium alginate and collagen is used to promote reorganization of seminiferous tubules, which resemble those in vivo. In addition, the self-organization ability of testicular cells declines with advanced cell age, and those germ cells play a pivotal role in this process. These findings will be helpful to understand the self-organization process of testicular cells and provide insights for the reconstruction of testes.

Sub-Daily Simulation of Mountain Flood Processes Based on the Modified Soil Water Assessment Tool (SWAT) Model.

Floods not only provide a large amount of water resources, but they also cause serious disasters. Although there have been numerous hydrological studies on flood processes, most of these investigations were based on rainfall-type floods in plain areas. Few studies have examined high temporal resolution snowmelt floods in high-altitude mountainous areas. The Soil Water Assessment Tool (SWAT) model is a typical semi-distributed, hydrological model widely used in runoff and water quality simulations. The degree-day factor method used in SWAT utilizes only the average daily temperature as the criterion of snow melting and ignores the influence of accumulated temperature. Therefore, the influence of accumulated temperature on snowmelt was added by increasing the discriminating conditions of rain and snow, making that more suitable for the simulation of snowmelt processes in high-altitude mountainous areas. On the basis of the daily scale, the simulation of the flood process was modeled on an hourly scale. This research compared the results before and after the modification and revealed that the peak error decreased by 77% and the time error was reduced from ±11 h to ±1 h. This study provides an important reference for flood simulation and forecasting in mountainous areas.

Identifying climate change impacts on water resources in Xinjiang, China.

Water resources have an important role in maintaining ecological fuctions and sustaining social and economic development. This is especially true in arid and semi-arid areas, where climate change has a large impact on water resources, such as in Xinjiang, China. Using a combination of precipitation and temperature bias correction methods, we analyzed projected changes in different hydrological components in nine high-alpine catchments distributed in Xinjiang using the Soil and Water Assessment Tool (SWAT). The impacts of elevation, area and aspect of the catchments were analyzed. The results suggested an overall warming and wetting trend for all nine catchments in the near future, with the exception of summer precipitation decreasing in some catchments. The total runoff discharge, evapotranspiration and snow/ice melting will generally increase. Warming temperature plays a more important role in the changes of each hydrological component than increasing precipitation. However, northern Xinjiang was more sensitive to predicted precipitation changes than southern Xinjiang. These results also indicate that the overall increases in water resources are not sustainable, and the impacts of climate change are associated with the elevation, area and slope aspect of the catchments.

Modulating the cellular microenvironment with disulfide-containing nanoparticles as an auxiliary cancer treatment strategy.

Stimuli-responsive drug release nanoparticles are of particular interest due to their enhanced effects and reduced systemic toxicities in the area of cancer therapeutics. The effect of these nanoparticles on the cellular microenvironment has not yet been clearly defined. In this context, redox-responsive nanoparticles were synthesized with disulfide-containing linkages. These nanoparticles depleted the cellular GSH level and modulated the cellular redox microenvironment to more oxidizing conditions. The resulting drug-encapsulated nanoparticles showed improved cytotoxicity, apoptosis, and invasion inhibition of metastatic cancer cells. Moreover, these improvements had a direct correlation with the cellular redox status modulated by nanoparticles. The present study provides a new strategy for designing redox-responsive drug carriers to improve the sensitivity of cells to anticancer drugs and enhance the therapeutic efficacy in metastatic cancer.

Amphiphilic p-sulfonatocalix[4]arene as "drug chaperone" for escorting anticancer drugs.

Supramolecularly constructing multifunctional platform for drug delivery is a challenging task. In this work, we propose a novel supramolecular strategy "drug chaperone", in which macrocyclic amphiphiles directly coassemble with cationic drugs into a multifunctional platform and its surface is further decorated with targeting ligands through host-guest recognition. The coassembling and hierarchical decoration processes were monitored by optical transmittance measurements, and the size and morphology of amphiphilic coassemblies were identified by dynamic light scattering and high-resolution transmission electron microscopy. In cell experiments to validate the drug chaperone strategy, the anticancer activities of free drugs were pronouncedly improved by coassembling with amphiphilic chaperone and further functionalization with targeting ligand.