Frontiers in Bioengineering and Biotechnology最新文献

Introduction: The ability to maintain bone purchase and resist pullout is considered a basic requirement for pedicle screws. However, poor bone density or oversized pilot holes can increase the risk of screw loosening and pullout. Our team developed a novel UHMWPE anchor that attaches to the proximal portion of the pedicle screw to improve engagement with the bone, even in conditions with poor bone quality or large pilot holes.

Methods: Synthetic bone blocks simulating normal bone density (15 PCF) and osteoporotic bone (10 PCF) were used to investigate the pullout strength of anchored pedicle screws and traditional pedicle screws. Five screw constructs were evaluated: (A) 4.0 mm pedicle screw and 3.0 mm pilot hole; (B) 4.0 mm pedicle screw with a 4.0 mm anchor and 3.0 mm pilot hole; (C) 4.0 mm pedicle screw with a 4.0 mm anchor and 3.2 mm pilot hole; (D) 4.0 mm pedicle screw and 3.2 mm pilot hole; (E) 5.0 mm pedicle screw and 3.2 mm pilot hole.

Results: The anchor-based 4.0 mm screw with a 3.0 mm pilot hole (group B) had the highest pullout strength among all groups, both in normal bone and osteoporotic bone. Even when using a larger 3.2 mm pilot hole, the pullout strength of the anchored 4.0 mm screw was within 90% of the values recorded with the 3.0 mm pilot hole. Notably, the average pullout strength of the 4.0 mm pedicle screw with anchor was higher than the 5.0 mm pedicle screw without an anchor in both bone densities.

Conclusion: The results of this study demonstrate that the novel anchor can significantly increase the pullout strength of pedicle screws. The anchor also allows for more flexibility when selecting a screw size, especially when the insertion space is limited.

Neurological development between the ages of 3-11 is crucial to the shaping of infrastructural capabilities like the executive functions that enable the child to achieve academically and socially. Such development can be hindered by neurodevelopmental disorders (NDDs) like attention deficit hyperactivity disorder (ADHD), Dyslexia, and Dysgraphia, which affect 5%-10% of the world population of children. Although the importance of early screening is acknowledged, inadequacies such as access barriers, long waiting time, and excessive cost lead to late detection, even when potential issues are identified. This PRISMA-based systematic review examines the role of technology and serious games that may screen and monitor NDDs in children early. The PubMed and Scopus databases were utilized, and research published between 2013, and February of 2025 was reviewed, where the age interval of the sampled children was between 3 and 11, and extended to 21 in relevant cases. Some of the tools reviewed are eye-tracking systems, machine learning models, mobile applications, and serious games. The quality of studies was assessed by the Mixed Methods Appraisal Tool (MMAT) and the results synthesized narratively. Out of 3,129 records, 37 studies were included according to the inclusion criteria. Findings indicated that although numerous technologies showed promise in recognizing and assisting children with NDDs, the majority had limited capabilities in scalability, longitudinal tracking, and practical application as the following was minimal, and the length of follow-up was low. In summary, the possibilities of using technology to better diagnose and intervene early are promising, although cost, training and implementation frameworks aligned with the NHS are critical barriers.

Background: Vital pulp therapy (VPT) aims to preserve pulp vitality and tooth function. However, materials like calcium hydroxide and mineral trioxide aggregate have limitations in bioactivity, underscoring the need for improved biomaterials. Strontium-doped hydroxyapatite (Sr-HA) and pro-angiogenic agents have emerged as promising strategies to enhance dentin-pulp complex regeneration.

Methods: Hollow hydroxyapatite microspheres with 5%, 10%, and 15% Sr substitution were synthesized, and the optimal concentration was identified through Sr²⁺ release profiling and CCK-8-based cytocompatibility screening. Iloprost was subsequently loaded onto the selected 5% Sr-HA to obtain Ilo@Sr-HA. Human dental pulp stem cells (hDPSCs) were isolated from healthy extracted premolars using the tissue-explant method and identified by flow cytometry and multilineage differentiation assays. The identified cells were used to assess viability, ALP activity, mineralized nodule formation, and odontogenic gene expression. A bilateral rat pulp-exposure model (N = 40; n = 10/group: Blank, Dycal, Sr-HA, Ilo@Sr-HA) was established. Reparative outcomes were quantified using micro-CT and histological scoring at days 7 and 28.

Results: Preliminary screening identified 5% Sr-HA as optimal, with the best ion release and cytocompatibility. Ilo@Sr-HA showed a biphasic release and no cytotoxicity toward hDPSCs. In vitro, Ilo@Sr-HA enhanced hDPSCs proliferation and ALP activity compared with HA and Sr-HA. Mineralized nodule formation increased, with significant DMP1 and DSPP upregulation (P < 0.05). In vivo, Ilo@Sr-HA enhanced reparative dentin formation, with DV/TV reaching 38.91% at 4 weeks vs. 26.53% for Dycal (P < 0.01). Histology confirmed continuous dentin bridges in the Ilo@Sr-HA group, contrasting with incomplete structures in Dycal and Sr-HA. Lower inflammation and better pulp preservation were also observed.

Conclusion: Ilo@Sr-HA combines Sr²⁺ ionic cues with iloprost's pharmacological effects to form a bioactive microenvironment that supports pulp repair and reparative dentinogenesis. Ilo@Sr-HA is a promising material for VPT and dentin-pulp regeneration.

Ultrafine plastic microparticles have been detected in ocular compartments, raising concern about their role in degenerative eye diseases. Nevertheless, significant efforts are required to elucidate the underlying pathophysiological mechanisms that govern their accumulation and persistence. Among the various ocular compartments, the vitreous humor (VH) is particularly susceptible due to its immune privilege and limited clearance capacity. In this conceptual study, we propose turning these physiological constraints into a therapeutic opportunity. We outline potential mechanistic routes through which ultrafine particles infiltrate and accumulate within the VH, contributing to tissue degradation, and simultaneously introduce a novel injectable enzyme-cell therapeutic model designed to mitigate and reverse these effects. The proposed injectable platform employs postmortem-derived VH as a biomimetic vehicle incorporating polyethylene terephthalate (PET)-degrading enzymes (e.g., mPETase) and genetically engineered hyalocytes expressing mono(2-hydroxyethyl) terephthalate hydrolase (MHETase), terephthalic acid dioxygenase (TPADO), and glycol oxidase (GOx). These enzymes collectively catalyze the breakdown of PET into benign metabolites, facilitating localized detoxification, while the VH-based hydrogel scaffold supports the in situ ocular structural reconstitution. Hyalocytes further enhance matrix integration and phagocytic clearance. This work presents a conceptual framework rather than experiential validation, defining a multimodal strategy that may serve as a foundation for future therapies aimed at combating ocular plastic toxicity and informing broader regenerative approaches to microplastic detoxification in immune-privileged tissues.

Background: Inertial measurement units (IMUs) enable portable gait monitoring, yet their accuracy relies on precise event detection. Conventional algorithms using raw signal peaks often fail during running due to speed variations and diverse foot-strike patterns. Therefore, adaptive detection strategies are required for high precision running gait analysis.

Methods: This study proposes MFD-GED (multi-sensor fusion with dynamic gait event detection), a refined method for accurate running gait analysis via a single foot-mounted IMU. To enhance event detection, the framework fuses acceleration- and angular-velocity features and employs a parametric strategy to identify initial contact (IC), terminal contact (TC) and mid-stance (MS), respectively. The algorithm then computes a comprehensive set of gait parameters relevant to running biomechanics assessment. Data were collected from 15 healthy male runners (age: 24.1 ± 1.1 years) performing 10-m running trials. The proposed method was benchmarked against a conventional angular-velocity-based gait-segmentation algorithm (AVGS) and validated using a laboratory reference (LAB) comprising an optical motion-capture and force-plate system. Pearson correlation coefficients (Pearson's r), intraclass correlation coefficients (ICCs), and Bland-Altman analysis were used to assess concurrent validity, while paired t-tests and Cohen's d were employed to evaluate the performance improvement over the AVGS method.

Results: The MFD-GED method demonstrated high concurrent validity against the LAB system (r = 0.743-0.991; ICC = 0.741-0.990). Compared to the AVGS method, systematic bias was reduced for spatial parameters ( $p>0.05$ ), including stride velocity (-0.023 m/s vs. -0.012 m/s) and stride length (0.018 m vs. 0.009 m). For temporal parameters, bias significantly decreased ( $p<0.01$ ; Cohen's d = 1.62-2.20), specifically for contact time (0.057 s vs. 0.001 s) and flight time (-0.063 s vs. -0.003 s). Peak vGRF bias also decreased from -0.310 BW to 0.159 BW ( $p<0.01$ ; Cohen's d = 1.45). Furthermore, error standard deviations were reduced across all metrics.

Conclusion: This study validates an IMU framework improving running gait detection. Through sensor fusion, MFD-GED enables high-fidelity parameter estimation. While lab-validated for healthy young males, findings affirm its potential running for future gait monitoring tasks, aiming to offer a reliable tool for professionals in the field.

This review was intended as a conceptual paper exploring the historical background, general principles, and experimental exploits that have steered meaningful developments in the field of temperature-dependent storage procedures and their impact on the attributes and patency of human vascular tissues assigned for use as grafts in cardiovascular surgery or for research purposes. Attention was focused on advances in the field following a descriptive history of humankind's progress in developing low-temperature methods to conserve and store perishable goods, in understanding cryptobiotic processes and adopting a scientific approach to preservation of biological matter, and in summarizing the pioneering work of Alexis Carrel and others related specifically to the conservation of blood vessels. Further discussed were the principles of low-temperature preservation methods for cells, tissues, and organs, as well as the range of current techniques. The use of particular techniques for the preservation of human vascular tissues, mainly grafts for surgery, was reviewed, emphasizing the extent of their applications, the range of operating conditions (temperature, cryoprotective agents), and the perceived limitations of diverse procedures. It was concluded that many preservation techniques can be employed successfully for storing human blood vessels, however the deep-subzero temperature methods seem to have been the preferred alternative.

Objective: This study investigated lower-limb kinematics and neuromuscular control in individuals with functional ankle instability (FAI) during a standing long jump-landing side-cut tasks, and compared them with Copers (individuals with ankle sprain history but no persistent instability) and healthy controls to reveal synergy reorganization mechanisms underlying FAI and inform rehabilitation strategies.

Methods: Ten participants were included in each group (FAI, Coper, and control). For the jump-landing side-cut task, participants stood 80 cm behind a force plate, jumped forward maximally with both legs, landed on one test leg at the plate center, then immediately side-cut 30° to the opposite side of the test leg (lateral distance ≥80 cm from the plate). Lower-limb kinematics and electromyography were recorded during the task using a synchronized motion capture and EMG system. Muscle synergies were extracted via non-negative matrix factorization (NNMF, 90% variance accounted for as termination criterion) to compare synergy number, activation timing, and muscle contributions among groups.

Results: (1) The FAI group exhibited significantly greater knee and ankle flexion-extension and hip abduction angles compared with the Coper and control groups, while the Coper group showed a larger ankle range of motion than controls (p < 0.05). (2) All three groups demonstrated four common synergy modules. (3) The early synergy (Module 1) activation duration was shorter in the FAI and Coper groups than in controls, whereas the late synergy (Module 4) lasted longer in the FAI group (p < 0.05). (4) Significant differences in muscle weightings were observed among groups across modules (p < 0.05).

Conclusion: Individuals with FAI adopt a protective movement strategy characterized by increased flexion and abduction to enhance stability. Muscle synergy analysis reveals an asymmetric activation pattern with reduced early activation, prolonged late compensation, and a proximal-dominant, delayed distal control pattern. Although the Coper group demonstrates movement characteristics more similar to healthy controls, mild over-flexion and delayed responses remain.

The emergence of allogeneic, universal chimeric antigen receptor (CAR) T cell therapies requires intensified and scalable manufacturing workflows supported by representative scale-down models (SDMs) to enable efficient process development and future large-scale production of off-the-shelf therapies. Here, we present a 7-day CAR-T cell expansion process intensified via perfusion of serum-free medium in a 2 L Univessel® Single-Use stirred-tank bioreactor (STR), consistently achieving 30 × 10⁶ cells/mL, corresponding to 113 ± 7 anti-CD19 CAR-T doses per batch. Parallel runs in 250 mL Ambr® 250 STRs conducted at equivalent volumetric power input (P/V) of ∼8.78 W/m³ demonstrated comparable process performance and final product quality, with univariate and multivariate analyses of cell growth, phenotype, cytotoxicity, and cytokine secretion validating the Ambr® 250 as a predictive SDM for the 2 L process. Integrating capacitance sensing in the 2 L STR enabled robust monitoring of viable cell concentrations in real-time, with strong correlation to offline measurements (R² = 0.98). For downstream processing, the Ksep® 400 was used to automate CAR-T cell harvesting, concentration, and washing at the 2 L scale, achieving >90% product recovery and nine-fold volume reduction without impacting product quality attributes compared to manual methods. This study establishes a scalable CAR-T manufacturing workflow supported by a predictive SDM, providing an efficient platform for process development and scale-up to enable future large-scale production of allogeneic CAR-T cell therapies.

Bone grafting plays a critical role in oral and maxillofacial surgery by restoring structural integrity and function in patients with bone defects resulting from congenital anomalies, trauma, tumor resection, or periodontal disease. To meet clinical needs, various types of bone grafts and substitutes have been utilized, including autografts, allografts, xenografts, and synthetic materials. The success of these materials depends on their ability to support bone regeneration through key biological and mechanical functions. Bone is a hierarchically organized tissue that undergoes continuous remodeling, and effective graft materials must integrate osteogenic cells, osteoinductive signals, osteoconductive scaffolds, mechanical stability, vascularization, and a favorable host environment. While autografts remain the gold standard, limitations such as donor site morbidity and limited availability have led to increased use of alternative materials. Synthetic substitutes offer advantages in customization and availability but often require enhancement to improve biological performance. Recent strategies such as three-dimensional printing, incorporation of growth factors, and nanotechnology-enabled delivery systems are being explored to create next-generation graft materials. This review provides a comprehensive overview of the structural and biological principles underlying bone regeneration, the historical and conceptual evolution of grafting strategies, and the advantages and limitations of current materials used in oral and maxillofacial reconstruction. periodontal disease.