Injectable Magnetic Hydrogel Filler for Synergistic Bone Tumor Hyperthermia Chemotherapy.

The therapeutic efficacy of bone tumor treatment is primarily limited by inadequate tumor resection, resulting in recurrence and metastasis, as well as the deep location of tumors. Herein, an injectable doxorubicin (DOX)-loaded magnetic alginate hydrogel (DOX@MAH) was developed to evaluate the efficacy of an alternating magnetic field (AMF)-responsive, chemothermal synergistic therapy for multimodality treatment of bone tumors. The prepared hydrogel exhibits a superior drug-loading capacity and a continuous DOX release. This multifunctionality can be attributed to the combined use of DOX for chemotherapy and iron oxide nanoparticle-containing alginate hydrogels as magnetic hyperthermia agents to generate hyperthermia for tumor elimination without the limit on penetration depth. Moreover, the hydrogel can be formed when in contact with the calcium ions, which are abundant in bone tissues; therefore, this hydrogel could perfectly fit the bone defects caused by the surgical removal of the bone tumor tissue, and the hydrogel could tightly attach the surgical margin of the bone to realize a high efficacy residual tumor tissue elimination treated by chemothermal synergistic therapy. The hydrogel demonstrates excellent hyperthermia performance, as evidenced by in vitro cytotoxicity tests on tumor cells. These tests reveal that the combined therapy based on DOX@MAH under AMF significantly induces cell death compared to single magnetic hyperthermia or chemotherapy. In vivo antitumor effects in tumor-bearing mice demonstrate that DOX@MAH injection at the tumor site effectively inhibits tumor growth and leads to tumor necrosis. This work not only establishes an effective DOX@MAH system as a synergistic chemothermal therapy platform for treating bone tumors but also sheds light on the application of alginate to combine calcium ions of the bone to treat bone defect diseases.

Multi-needle blow-spinning technique for fabricating collagen nanofibrous nerve guidance conduit with scalable productivity and high performance.

Nerve guidance conduits (NGCs) have been widely accepted as a promising strategy for peripheral nerve regeneration. Fabricating ideal NGCs with good biocompatibility, biodegradability, permeability, appropriate mechanical properties (space maintenance, suturing performance, etc.), and oriented topographic cues is still current research focus. From the perspective of translation, the technique stability and scalability are also an important consideration for industrial production. Recently, blow-spinning technique shows great potentials in nanofibrous scaffolds fabrication, possessing high quality, high fiber production rates, low cost, ease of maintenance, and high reliability. In this study, we proposed for the first time the preparation of a novel NGC via blow-spinning technique to obtain optimized performances and high productivity. A new collagen nanofibrous neuro-tube with the bilayered design was developed, incorporating inner oriented and outer random topographical cues. The bilayer structure enhances the mechanical properties of the conduit in dry and wet, displaying good radial support and suturing performance. The porous nature of the blow-spun collagen membrane enables good nutrient delivery and metabolism. The in vitro and in vivo evaluations indicated the bilayer-structure conduit could promoted Schwann cells growth, neurotrophic factors secretion, and axonal regeneration and motor functional recovery in rat.

A multifaceted biomimetic periosteum with a lamellar architecture and osteogenic/angiogenic dual bioactivities.

An artificial periosteum has emerged as an encouraging candidate for bone defect repair. Currently, it remains a great challenge to develop a multifaceted biomimetic periosteum integrating multifunctional features of bioactivities and unique mechanical properties. Here, we successfully fabricated an artificial periosteum (AP) composed of hierarchically assembled Mg-doped mineralized collagen microfibrils with a biomimetically rotated lamellar structure via a "multiscale cascade regulation" strategy combining multiple techniques such as molecular self-assembly, electrospinning, and pressure-driven fusion from molecular to macroscopic levels. The AP has excellent mechanical properties with an ultimate strength and a tensile modulus of 15.9 MPa and 1.1 GPa, respectively. The involvement of Mg-doped nano-hydroxyapatite endowed the AP with good osteogenic and angiogenic activities to promote osteogenic differentiation of bone marrow mesenchymal stem cells and human umbilical vein endothelial cell differentiation into capillary-like structures in vitro. In addition, the results of in vivo evaluations in a rat cranial bone defect model including micro-CT morphology, histological staining, and immunohistochemical analysis showed that Mg-doped mineralized collagen-based AP (MgMC@AP) significantly facilitated cranial bone regeneration and fast vascularization. Our findings suggest that the AP mimicked the composition, lamellar structure, mechanical properties, and biological activities of natural periosteum/lamellae, showing great promise for bone tissue regeneration.

Feasibility Study on the Classification of Persimmon Trees' Components Based on Hyperspectral LiDAR.

Intelligent management of trees is essential for precise production management in orchards. Extracting components' information from individual fruit trees is critical for analyzing and understanding their general growth. This study proposes a method to classify persimmon tree components based on hyperspectral LiDAR data. We extracted nine spectral feature parameters from the colorful point cloud data and performed preliminary classification using random forest, support vector machine, and backpropagation neural network methods. However, the misclassification of edge points with spectral information reduced the accuracy of the classification. To address this, we introduced a reprogramming strategy by fusing spatial constraints with spectral information, which increased the overall classification accuracy by 6.55%. We completed a 3D reconstruction of classification results in spatial coordinates. The proposed method is sensitive to edge points and shows excellent performance for classifying persimmon tree components.

Analysis and Radiometric Calibration for Backscatter Intensity of Hyperspectral LiDAR Caused by Incident Angle Effect.

Hyperspectral LiDAR (HSL) is a new remote sensing detection method with high spatial and spectral information detection ability. In the process of laser scanning, the laser echo intensity is affected by many factors. Therefore, it is necessary to calibrate the backscatter intensity data of HSL. Laser incidence angle is one of the important factors that affect the backscatter intensity of the target. This paper studied the radiometric calibration method of incidence angle effect for HSL. The reflectance of natural surfaces can be simulated as a combination of specular reflection and diffuse reflection. The linear combination of the Lambertian model and Beckmann model provides a comprehensive theory that can be applied to various surface conditions, from glossy to rough surfaces. Therefore, an adaptive threshold radiometric calibration method (Lambertian-Beckmann model) is proposed to solve the problem caused by the incident angle effect. The relationship between backscatter intensity and incident angle of HSL is studied by combining theory with experiments, and the model successfully quantifies the difference between diffuse and specular reflectance coefficients. Compared with the Lambertian model, the proposed model has higher calibration accuracy, and the average improvement rate to the samples in this study was 22.67%. Compared with the results before calibration with the incidence angle of less than 70°, the average improvement rate of the Lambertian-Beckmann model was 62.26%. Moreover, we also found that the green leaves have an obvious specular reflection effect near 650-720 nm, which might be related to the inner microstructure of chlorophyll. The Lambertian-Beckmann model was more helpful to the calibration of leaves in the visible wavelength range. This is a meaningful and a breakthrough exploration for HSL.

Three-Dimensional Printing Guide Template Assisted Percutaneous Vertebroplasty (PVP).

Percutaneous vertebroplasty (PVP) is considered an effective treatment for the back pain caused by osteoporotic vertebral compression fracture. The accuracy of PVP mainly depends on the surgeons' experience and multiple fluoroscopes during a traditional procedure. Puncture related complications were reported all over the world. To make the surgical procedure more precise and decrease the rate of puncture-related complications, our team applied a three-dimensional printing guide template to PVP to modify the traditional procedure. This protocol introduces how to model target vertebrae DICOM imaging data into three-dimensions in the software, how to simulate operation in this 3-D model, and how to use all of the surgical data to reconstruct a patient specific template for application. Using this template, surgeons can identify suitable puncture points accurately to improve the accuracy of the operation. The whole protocol includes: 1) diagnosis of the osteoporotic vertebral compression fracture; 2) acquisition of CT imaging of the target vertebra; 3) simulation of the operation in the software; 4) design and fabrication of the 3-D printing guide template; and 5) application of the template into an operation procedure.