Efficacy and advantage of immunotherapy for melanoma via intramuscular co-expression of plasmid-encoded PD-1 and CTLA-4 scFvs.

Immunotherapy, in the shape of immune checkpoint inhibitors (ICIs), has completely changed the treatment of cancer. However, the increasing expense of treatment and the frequency of immune-related side effects, which are frequently associated with combination antibody therapies and Fc fragment of antibody, have limited the patient's ability to benefit from these treatments. Herein, we presented the therapeutic effects of the plasmid-encoded PD-1 and CTLA-4 scFvs (single-chain variable fragment) for melanoma via an optimized intramuscular gene delivery system. After a single injection, the plasmid-encoded ICI scFv in mouse sera continued to be above 150 ng/mL for 3 weeks and reached peak amounts of 600 ng/mL. Intramuscular delivery of plasmid encoding PD-1 and CTLA-4 scFvs significantly changed the tumor microenvironment, delayed tumor growth, and prolonged survival in melanoma-bearing mice. Furthermore, no significant toxicity was observed, suggesting that this approach could improve the biosafety of ICIs combination therapy. Overall, the expression of ICI scFvs in vivo using intramuscular plasmid delivery could potentially develop into a reliable, affordable, and safe immunotherapy technique, expanding the range of antibody-based gene therapy systems that are available.

Osteosarcoma-targeted Cu and Ce based oxide nanoplatform for NIR II fluorescence/magnetic resonance dual-mode imaging and ros cascade amplification along with immunotherapy.

BACKGROUND: As the lethal bone tumor, osteosarcoma often frequently occurs in children and adolescents with locally destructive and high metastasis. Distinctive kinds of nanoplatform with high therapeutical effect and precise diagnosis for osteosarcoma are urgently required. Multimodal optical imaging and programmed treatment, including synergistic photothermal-chemodynamic therapy (PTT-CDT) elicits immunogenetic cell death (ICD) is a promising strategy that possesses high bio-imaging sensitivity for accurate osteosarcoma delineating as well as appreciable therapeutic efficacy with ignorable side-effects. METHODS AND RESULTS: In this study, mesoporous Cu and Ce based oxide nanoplatform with Arg-Gly-Asp (RGD) anchoring is designed and successfully constructed. After loading with indocyanine green, this nanoplatform can be utilized for precisely targeting and efficaciously ablating against osteosarcoma via PTT boosted CDT and the closely following ICD stimulation both in vitro and in vivo. Besides, it provides off-peak fluorescence bio-imaging in the second window of near-infrared region (NIR II, 1000-1700 nm) and Magnetic resonance signal, serves as the dual-mode contrast agents for osteosarcoma tissue discrimination. CONCLUSION: Tumor targeted Cu&Ce based mesoporous nanoplatform permits efficient osteosarcoma suppression and dual-mode bio-imaging that opens new possibility for effectively diagnosing and inhibiting the clinical malignant osteosarcoma.

Scalable Synthesis of High-Quality Ultrathin Ferroelectric Magnesium Molybdenum Oxide.

The development of ultrathin, stable ferroelectric materials is crucial for advancing high-density, low-power electronic devices. Nonetheless, ultrathin ferroelectric materials are rare due to the critical size effect. Here, a novel ferroelectric material, magnesium molybdenum oxide (Mg2Mo3O8) is presented. High-quality ultrathin Mg2Mo3O8 crystals are synthesized using chemical vapor deposition (CVD). Ultrathin Mg2Mo3O8 has a wide bandgap (≈4.4 eV) and nonlinear optical response. Mg2Mo3O8 crystals of varying thicknesses exhibit out-of-plane ferroelectric properties at room temperature, with ferroelectricity retained even at a 2 nm thickness. The Mg2Mo3O8 exhibits a relatively large remanent polarization ranging from 33 to 52 µC cm- 2, which is tunable by changing its thickness. Notably, Mg2Mo3O8 possesses a high Curie temperature (>980 °C) across various thicknesses. Moreover, the as-grown Mg2Mo3O8 crystals display remarkable stability under harsh environments. This work introduces nolanites-type crystal into ultrathin ferroelectrics. The scalable synthesis of stable ultrathin ferroelectric Mg2Mo3O8 expands the scope of ferroelectric materials and may prosper applications of ferroelectrics.

Soft-tissue reconstruction with pedicled vertical rectus abdominis myocutaneous flap after total or high sacrectomy for giant sacral tumor.

BACKGROUND: The large soft-tissue defect after total or high sacrectomy for giant sacral tumor induces high incidence of wound complications. It remains a huge challenge to reconstruct the soft-tissue defect and achieve the preferred clinical outcome. METHODS: A total of 27 patients undergoing one-stage total or high sacrectomy for giant sacral tumors between 2016 and 2021 in a tertiary university hospital were retrospectively reviewed. Participants were divided into two groups. Thirteen patients underwent a pedicled vertical rectus abdominis myocutaneous (VRAM) flap reconstruction, whereas 14 patients underwent a conventional wound closure. Patient's clinical characteristics, surgical duration, postoperative complications, and outcomes were compared between the two groups. RESULTS: Patients in VRAM and non-VRAM groups were similar in baseline characteristics. The mean tumor size was 12.85 cm (range: 10-17 cm) in VRAM group and 11.79 cm (range: 10-14.5 cm) in non-VRAM group (P = 0.139). The most common giant sacral tumor is chordoma. Patients in VRAM group had a shorter length of drainage (9.85 vs 17.14 days), postoperative time in bed (5.54 vs 17.14 days), and total length of stay (19.46 vs 33.36 days) compared with patients in non-VRAM group. Patients in the VRAM group had less wound infection and debridement than patients in non-VRAM group (15.4% vs 57.1%, P < 0.001). CONCLUSIONS: This study demonstrates the advantages of pedicled VRAM flap reconstruction of large soft-tissue defects after high or total sacrectomy using the anterior-posterior approach. This choice of reconstruction is better than direct wound closure in terms of wound infection, length of drainage, and total length of stay.

Single-cell profiling of the microenvironment in human bone metastatic renal cell carcinoma.

Bone metastasis is of common occurrence in renal cell carcinoma with poor prognosis, but no optimal treatment approach has been established for bone metastatic renal cell carcinoma. To explore the potential therapeutic targets for bone metastatic renal cell carcinoma, we profile single cell transcriptomes of 6 primary renal cell carcinoma and 9 bone metastatic renal cell carcinoma. We also include scRNA-seq data of early-stage renal cell carcinoma, late-stage renal cell carcinoma, normal kidneys and healthy bone marrow samples in the study to better understand the bone metastasis niche. The molecular properties and dynamic changes of major cell lineages in bone metastatic environment of renal cell carcinoma are characterized. Bone metastatic renal cell carcinoma is associated with multifaceted immune deficiency together with cancer-associated fibroblasts, specifically appearance of macrophages exhibiting malignant and pro-angiogenic features. We also reveal the dominance of immune inhibitory T cells in the bone metastatic renal cell carcinoma which can be partially restored by the treatment. Trajectory analysis showes that myeloid-derived suppressor cells are progenitors of macrophages in the bone metastatic renal cell carcinoma while monocytes are their progenitors in primary tumors and healthy bone marrows. Additionally, the infiltration of immune inhibitory CD47+ T cells is observed in bone metastatic tumors, which may be a result of reduced phagocytosis by SIRPA-expressing macrophages in the bone microenvironment. Together, our results provide a systematic view of various cell types in bone metastatic renal cell carcinoma and suggest avenues for therapeutic solutions.

Pressure-Modulated Structural and Magnetic Phase Transitions in Two-Dimensional FeTe: Tetragonal and Hexagonal Polymorphs.

Two-dimensional (2D) Fe chalcogenides with their rich structures and properties are highly desirable for revealing the torturous transition mechanism of Fe chalcogenides and exploring their potential applications in spintronics and nanoelectronics. Hydrostatic pressure can effectively stimulate phase transitions between various ordered states, allowing one to successfully plot a phase diagram for a given material. Herein, the structural evolution and transport characteristics of 2D FeTe were systematically investigated under extreme conditions by comparing two distinct symmetries, i.e., tetragonal (t) and hexagonal (h) FeTe. We found that t-FeTe presented a pressure-induced transition from an antiferromagnetic state to a ferromagnetic state at ∼3 GPa, corresponding to the tetragonal collapse of the layered structure. Contrarily, the ferromagnetic order of h-FeTe was retained up to 15 GPa, which was evidently confirmed by electrical transport and Raman measurements. Furthermore, T-P phase diagrams for t-FeTe and h-FeTe were mapped under delicate critical conditions. Our results can provide a unique platform to elaborate the extraordinary properties of Fe chalcogenides and further develop their applications.

Prediction and related genes of cancer distant metastasis based on deep learning.

Cancer metastasis is one of the main causes of cancer progression and difficulty in treatment. Genes play a key role in the process of cancer metastasis, as they can influence tumor cell invasiveness, migration ability and fitness. At the same time, there is heterogeneity in the organs of cancer metastasis. Breast cancer, prostate cancer, etc. tend to metastasize in the bone. Previous studies have pointed out that the occurrence of metastasis is closely related to which tissue is transferred to and genes. In this paper, we identified genes associated with cancer metastasis to different tissues based on LASSO and Pearson correlation coefficients. In total, we identified 45 genes associated with bone metastases, 89 genes associated with lung metastases, and 86 genes associated with liver metastases. Through the expression of these genes, we propose a CNN-based model to predict the occurrence of metastasis. We call this method MDCNN, which introduces a modulation mechanism that allows the weights of convolution kernels to be adjusted at different positions and feature maps, thereby adaptively changing the convolution operation at different positions. Experiments have proved that MDCNN has achieved satisfactory prediction accuracy in bone metastasis, lung metastasis and liver metastasis, and is better than other 4 methods of the same kind. We performed enrichment analysis and immune infiltration analysis on bone metastasis-related genes, and found multiple pathways and GO terms related to bone metastasis, and found that the abundance of macrophages and monocytes was the highest in patients with bone metastasis.

Phase-Modulated Elastic Properties of 2D Magnetic FeTe: Hexagonal and Tetragonal Polymorphs.

2D layered magnets, such as iron chalcogenides, have emerged these years as a new family of unconventional superconductors and provided the key insights to understand the phonon-electron interaction and pairing mechanism. Their mechanical properties are of strategic importance for the potential applications in spintronics and optoelectronics. However, there is still a lack of efficient approach to tune the elastic modulus despite the extensive studies. Herein, the modulated elastic modulus of 2D magnetic FeTe and its thickness-dependence is reported via phase engineering. The grown 2D FeTe by chemical vapor deposition can present various polymorphs, that is tetragonal FeTe (t-FeTe, antiferromagnetic) and hexagonal FeTe (h-FeTe, ferromagnetic). The measured Young's modulus of t-FeTe by nanoindentation method shows an obvious thickness-dependence, from 290.9 ± 9.2 to 113.0 ± 8.7 GPa when the thicknesses increased from 13.2 to 42.5 nm, respectively. In comparison, the elastic modulus of h-FeTe remains unchanged. These results can shed light on the efficient modulation of mechanical properties of 2D magnetic materials and pave the avenues for their practical applications in nanodevices.

Current state and challenges of emerging biomarkers for immunotherapy in hepatocellular carcinoma (Review).

Hepatocellular carcinoma (HCC) is the most prevalent form of primary liver cancer. According to the American Cancer Society, among patients diagnosed with advanced liver cancer, HCC has the sixth-highest incident rate, resulting in a poor prognosis. Surgery, radiofrequency ablation, transcatheter arterial chemoembolization, radiation, chemotherapy, targeted therapy and immunotherapy are the current treatment options available. Immunotherapy, which has emerged as an innovative treatment strategy over the past decade, is serving a vital role in the treatment of advanced liver cancer. Since only a small number of individuals can benefit from immunotherapy, biomarkers are required to help clinicians identify the target populations for this precision medicine. These biomarkers, such as PD-1/PD-L1, tumor mutational burden and circulating tumor DNA, can be used to investigate interactions between immune checkpoint inhibitors and tumors. The present review summarizes information on the currently available biomarkers used for immunotherapy and the challenges that are present.

Perspectives for immunotherapy of EBV-associated GLELC: A relatively "hot" tumor microenvironment.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric lymphoepithelioma-like carcinoma (EBVaGLELC) represents a small number of gastric cancer (GC), and research on tumor microenvironment (TME) and treatment strategy are still lacking. AIMS: Here, we aim to elucidate the immune features of this rare disease and further help to develop more effective treatment options. MATERIALS & METHODS: A retrospective analysis was conducted between 2019 to 2022 in West China Hospital to reveal the immunological characteristics of EBV-positive GLELC. The difference of immune cell subset and tumor vascular structure between gastric denocarcinoma (GAC) and EBVaGLELC will be pointed out. DISCUSSION: 13 patients with GELEC and 8 patients with GAC were retrospectively studied. The heterogeneity of the immune cell profile was then confirmed through multiplexed immunofluorescence staining (mIF), which revealed a higher proportion of CD3+ T cells, CD8+ T cells, and Treg cells in the EBV-associated GLELC group. Such a distinct TME may provide therapeutic advantages, and patients with this rare subtype of GC could be good candidates for immune checkpoint inhibitors (ICIs). Angiogenesis in EBV-positive GLELC may be less intense than that in gastric adenocarcinoma (GAC), a feature that might decrease their susceptibility to antiangiogenic therapy. Furthermore, we reported a 52-year-old male with advanced EBV-positive GLELC who showed a favorable response to the combined therapy with . A repeat evaluation showed sustained partial response (PR), and the progression-free survival (PFS) was more than 34 months until now. CONCLUSION: Compared with GAC, EBVaGLELC revealed higher T cell infiltration and less intense of angiogenesis. It displays relatively "hot" TME that may provide the rationality to treat with immunotherapy in EBV-related GLELC.

Implant failure and revision strategies after total spondylectomy for spinal tumors.

Background: Although there have been several risk factors reported for implant failure (IF), little consensus exists. Potential applicable measures to protect patients from IF are relatively few. This study aimed to discover new risk factors for IF and explore potential protective measures from IF after total spondylectomy for spinal tumors. Methods: A total of 145 patients undergoing total spondylectomy for thoracic and lumbar spinal tumors between 2010 and 2021 were included from three tertiary university hospitals. Patient demographic and surgical characteristics and follow-up outcomes were collected. Results: During a mean follow-up of 53.77 months (range, 12 to 149 months), 22 of 145 patients (15.17%) developed IF. Patients undergoing thoracolumbar junctional region (T12/L1) resection were more likely to develop IF compared to those undergoing surgery at other vertebral levels (HR = 21.622, 95% CI = 3.567-131.084, P = 0.001). Patients undergoing titanium mesh cage reconstruction were more likely to develop IF compared to patients undergoing expandable titanium cage reconstruction (HR = 8.315, 95% CI = 1.482-46.645, P = 0.016). Patients with bone cement augmentation around the cage were less likely to develop IF compared to those not receiving bone cement augmentation (HR = 0.015, 95% CI = 0.002-0.107, P < 0.001). Of the 22 patients with IF, 14 (63.63%) accepted personalized revision surgery. Conclusion: The use of an expandable cage and the use of bone cement augmentation around the anterior column support cage are protective measures against IF after total spondylectomy.

Diatomite-Templated Synthesis of Single-Atom Cobalt-Doped MoS2 /Carbon Composites to Boost Sodium Storage.

2D transition metal dichalcogenides (TMDCs) and single-atom catalysts (SACs) are promising electrodes for energy conversion/storage because of the layered structure and maximum atom utilization efficiency. However, the integration of such two type materials and the relevant sodium storage applications remain daunting challenges. Here, an ingenious diatomite-templated synthetic strategy is designed to fabricate single-atom cobalt-doped MoS2 /carbon (SA Co-MoS2 /C) composites toward the high-performance sodium storage. Benefiting from the unique hierarchical structure, high electron/sodium-ion conductivity, and abundant active sites, the obtained SA Co-MoS2 /C reveals remarkable specific capacity (≈604.0 mAh g-1 at 0.1 A g-1 ), high rate performance, and outstanding long cyclic stability. Particularly, the sodium-ion full cell composed of SA Co-MoS2 /C anode and Na3 V2 (PO4 )3 cathode demonstrates unexpected stability with the cycle number exceeded 1200. The internal sodium storage mechanism is clarified with the aid of density functional theory calculations and in situ experimental characterizations. This work not only represents a substantial leap in terms of synthesizing SACs on 2D TMDCs but also provides a crucial step toward the practical sodium-ion battery applications.

Characterization of modified rice straw biochar in immobilizing Bacillus subtilis 168 and evaluation on its role as a novel agent for zearalenone-removal delivery.

Microbial remediation of environmental pollutants can be advanced by carrier based cells immobilization. Whereas the effects of microorganisms immobilized on biochar for removal of zearalenone (ZEN) still remain unknown. Herein, this work presented the characterization of rice straw biochar (RSB) around modification in immobilizing Bacillus subtilis 168 and the role in fighting ZEN in vitro. Specifically, 10% of RSB with pH 5 condition were optimal for bearing cells, where majority of cells loaded inside the pore and minority on surface with agglomeration or scattering status. Octadecyl trimethyl ammonium chloride-inclusion RSB showed better performances including over 93% of ZEN detoxification rate (32.48% in free cells), cells preservation, and stability of detoxification in simulated gastrointestinal environment. RSB treated with sulphuric acid made nutrients adsorption generally less than 6.5%. No residues of α-ZEL and α-ZAL were found in ZEN biotransformation process whether by free cells or composites. Mechanism discussion implied that predominant monolayer chemisorption by RSB and subsequent biodegradation by extracellular enzymes from microorganism involved in ZEN-removal process. Collectively, these findings contribute to provide an applying strategy for coordination of biochar and microorganisms as potentially mycotoxin detoxifying agent in agricultural feed bioremediation and environmental decontamination processes.

Bridging Synthesis and Controllable Doping of Monolayer 4 in. Length Transition-Metal Dichalcogenides Single Crystals with High Electron Mobility.

Epitaxial growth and controllable doping of wafer-scale atomically thin semiconductor single crystals are two central tasks to tackle the scaling challenge of transistors. Despite considerable efforts are devoted, addressing such crucial issues simultaneously under 2D confinement is yet to be realized. Here, an ingenious strategy to synthesize record-breaking 4 in. length Fe-doped transition-metal dichalcogenides (TMDCs) single crystals on industry-compatible c-plane sapphire without special miscut angle is designed. Atomically thin transistors with high electron mobility (≈146 cm2 V-1 s-1 ) and remarkable on/off current ratio (≈109 ) are fabricated based on 4 in. length Fe-MoS2 single crystals, due to the ultralow contact resistance (≈489 Ω µm). In-depth characterizations and theoretical calculations reveal that the introduction of Fe significantly decreases the formation energy of parallel steps on sapphire surfaces and contributes to the edge-nucleation of unidirectional alignment TMDCs domains (>99%). This work represents a substantial leap in terms of bridging synthesis and doping of wafer-scale 2D semiconductor single crystals, which should promote the further device downscaling and extension of Moore's law.

Modified Iliac Screw in Lumbopelvic Fixation After Sacral Tumor Resection: A Single-Center Case Series.

BACKGROUND: Traditional iliac screw, S2-alar iliac screw, and modified iliac screw are the 3 common techniques for lumbopelvic fixation. The application of the modified iliac technique in sacral spinal tumors has been rarely reported. OBJECTIVE: To report the feasibility and safety of modified iliac screws after sacral tumor resection and their preliminary clinical outcomes. METHODS: Twenty-seven patients who underwent sacral tumor resection with modified iliac screw fixation between August 2017 and August 2021 at our center were clinically and radiographically evaluated. RESULTS: A total of 59 iliac screws were inserted by freehand according to the anatomic landmarks. The mean operation time was 207 minutes (range, 140-435 minutes). The average estimated blood loss was 1396 mL (300-4200 mL). Computed tomography scans showed that 2 (3.4%) screws penetrated the iliac cortex, indicating a 96.6% implantation accuracy rate. There were no iatrogenic neurovascular or visceral structure complications observed. The mean minimal distances from the screw head to the skin were 24.9 and 25.8 mm on the left and right sides, respectively. The mean minimal distances from the screw head to the horizontal level of the posterior superior iliac spine were 7.9 and 8.3 mm on the left and right sides, respectively. Two patients (7.4%) underwent reoperation for wound infection. At the latest follow-up, no patient had complications of screw head prominence, pseudarthrosis, or instrument failure. CONCLUSION: The modified iliac screw is characterized by its minimal invasiveness and simplicity of placement. It is an ideal alternative for lumbopelvic fixation after sacral tumor resection.

Room-Temperature Magnetoelectric Coupling in Atomically Thin ε-Fe2 O3.

2D multiferroics with magnetoelectric coupling combine the magnetic order and electric polarization in a single phase, providing a cornerstone for constructing high-density information storages and low-energy-consumption spintronic devices. The strong interactions between various order parameters are crucial for realizing such multifunctional applications, nevertheless, this criterion is rarely met in classical 2D materials at room-temperature. Here an ingenious space-confined chemical vapor deposition strategy is designed to synthesize atomically thin non-layered ε-Fe2 O3 single crystals and disclose the room-temperature long-range ferrimagnetic order. Interestingly, the strong ferroelectricity and its switching behavior are unambiguously discovered in atomically thin ε-Fe2 O3 , accompanied with an anomalous thickness-dependent coercive voltage. More significantly, the robust room-temperature magnetoelectric coupling is uncovered by controlling the magnetism with electric field and verifies the multiferroic feature of atomically thin ε-Fe2 O3 . This work not only represents a substantial leap in terms of the controllable synthesis of 2D multiferroics with robust magnetoelectric coupling, but also provides a crucial step toward the practical applications in low-energy-consumption electric-writing/magnetic-reading devices.

Effects of Huhuang Burn Liniment on wound healing and changes in IL-10 and MMP-9 levels in patients with mixed hemorrhoids.

OBJECTIVE: To explore the effects of Huhuang Burn Liniment on wound healing and levels of interleukin-10 (IL-10) and matrix metalloproteinase-9 (MMP-9) in patients with mixed hemorrhoids. METHODS: The clinical data of 113 patients with mixed hemorrhoids admitted to Chongqing Sanxia Central Hospital were retrospectively collected. All patients underwent Milligan-Morgan hemorrhoidectomy, and were divided into two groups according to different postoperative treatments. Group A was treated with 1/5000 potassium permanganate sitz bath after surgery, while group B was treated with Huhuang Burn Liniment. The treatment efficacy, wound healing time, level of pain, exudation, edema, granulation scores, anal function index, levels of IL-10 and MMP-9, quality of life scores, and complications were compared between the two groups. RESULTS: The effective rate of group B (94.74%) was higher than that of group A (60.71%) (P < 0.05). Group B had shorter length of anorectal hyperbaric zone, higher anal canal resting pressure, anal canal diastolic pressure, and anal canal systolic maximum pressure (P < 0.05), lower scores of trauma pain, edema, exudation, and granulation (P < 0.05), higher IL-10 levels, and lower MMP-9 levels (P < 0.05). The complication rate of group B (8.77%) was lower than that in group A (23.21%) (P < 0.05). After treatment, group B had shorter wound healing time and higher quality of life score than group A (P < 0.05). CONCLUSION: The application of Huhuang Burn Liniment in patients with mixed hemorrhoids after surgery could promote wound healing and anal function, reduce trauma pain, exudation and edema, and improve quality of life.

Two-dimensional multiferroic material of metallic p-doped SnSe.

Two-dimensional multiferroic materials have garnered broad interests attributed to their magnetoelectric properties and multifunctional applications. Multiferroic heterostructures have been realized, nevertheless, the direct coupling between ferroelectric and ferromagnetic order in a single material still remains challenging, especially for two-dimensional materials. Here, we develop a physical vapor deposition approach to synthesize two-dimensional p-doped SnSe. The local phase segregation of SnSe2 microdomains and accompanying interfacial charge transfer results in the emergence of degenerate semiconductor and metallic feature in SnSe. Intriguingly, the room-temperature ferrimagnetism has been demonstrated in two-dimensional p-doped SnSe with the Curie temperature approaching to ~337 K. Meanwhile, the ferroelectricity is maintained even under the depolarizing field introduced by SnSe2. The coexistence of ferrimagnetism and ferroelectricity in two-dimensional p-doped SnSe verifies its multiferroic feature. This work presents a significant advance for exploring the magnetoelectric coupling in two-dimensional limit and constructing high-performance logic devices to extend Moore's law.

3D-Printed Patient-Customized Artificial Vertebral Body for Spinal Reconstruction after Total En Bloc Spondylectomy of Complex Multi-Level Spinal Tumors.

Three dimensional (3D)-printing technology facilitates complex spine surgery with unique advantages in artificial vertebral body design and manufacturing. In this study, we aimed to demonstrate how a 3D-printed spinal implant is utilized in the management of multi-level spinal tumors and integrates with comprehensive oncologic treatment. Eight spinal or paraspinal tumor patients requiring spinal reconstruction after total en bloc spondylectomy were selected as candidates for 3D-printed titanium artificial vertebral body implants. All patients underwent surgery on three or more vertebral segments or complex spinal junction segments. The clinical, oncological, and surgical characteristics of patients were collected. Of the eight candidates, seven suffered from pain and/or limb disorder. Six underwent successful 3D-printed spinal implantation, while two failed due to implant mismatching and were converted to conventional reconstruction. Of the six patients undergoing 3D-printed spinal implant surgery: (i) Five had recurrent tumors; (ii) three underwent neoadjuvant therapy; (iii) the median surgery time was 414 min; (iv) the median blood loss was 2150 ml; (v) the median blood transfusion was 2000 ml; (vi) the median length of hospital stay was 9 days; (vii) four patients received adjuvant therapy after surgery; and (viii) all patients experienced no pain, moved freely, and had no local recurrence at a median of 11.5 months post-operative follow-up. Spinal reconstruction with a 3D-printed titanium artificial vertebral body allows for total en bloc resection of complex multi-level spinal tumors. Combined with neoadjuvant and adjuvant therapy, these patients had excellent postoperative outcomes, long-term normal spinal function, and associated low local recurrence probability.

Freehand S2-Alar-Iliac Screw Placement Technique in Lumbosacral Spinal Tumors: A Preliminary Study.

OBJECTIVE: S2-alar-iliac (S2AI) screw technique is widely used in spinal surgery, but it is rarely seen in the field of spinal tumors. The aim of the study is to report the preliminary outcomes of the freehand S2AI screw fixation after lumbosaral tumor resection. METHODS: The records of patients with lumbosacral tumor who underwent S2AI screw fixation between November 2016 to November 2020 at our center were reviewed retrospectively. Outcome measures included operative time, blood loss, complications, accuracy of screws, screw breach, and overall survival. Mean ± standard deviation or range was used to present continuous variables. Kaplan-Meier curve was used to present postoperative survival. RESULTS: A total of 23 patients were identified in this study, including 12 males and 11 females, with an average age of 47.3 ± 14.5 (range,15-73). The mean operation time was 224.6 ± 54.1 (range, 155-370 min). The average estimated blood loss was 1560.9 ± 887.0 (600-4000 ml). A total of 46 S2AI screws were implanted by freehand technique. CT scans showed three (6.5%) screws had penetrated the iliac cortex, indicating 93.5% implantation accuracy rate. No complications of iatrogenic neurovascular or visceral structure were observed. The average follow-up time was 31.6 ± 15.3 months (range, 13-60 months). Two patients' postoperative plain radiography showed lucent zone around the screw. One patient underwent reoperation for wound delayed infection. At the latest follow-up, eight patients had tumor-free survival, 11 had survival with tumor, and four died of disease. CONCLUSION: The freehand S2AI screw technique is reproducible, safe, and reliable in the management of lumbosacral spinal tumors.