Extracellular matrix stiffness as an energy metabolism regulator drives osteogenic differentiation in mesenchymal stem cells.

The biophysical factors of biomaterials such as their stiffness regulate stem cell differentiation. Energy metabolism has been revealed an essential role in stem cell lineage commitment. However, whether and how extracellular matrix (ECM) stiffness regulates energy metabolism to determine stem cell differentiation is less known. Here, the study reveals that stiff ECM promotes glycolysis, oxidative phosphorylation, and enhances antioxidant defense system during osteogenic differentiation in MSCs. Stiff ECM increases mitochondrial fusion by enhancing mitofusin 1 and 2 expression and inhibiting the dynamin-related protein 1 activity, which contributes to osteogenesis. Yes-associated protein (YAP) impacts glycolysis, glutamine metabolism, mitochondrial dynamics, and mitochondrial biosynthesis to regulate stiffness-mediated osteogenic differentiation. Furthermore, glycolysis in turn regulates YAP activity through the cytoskeletal tension-mediated deformation of nuclei. Overall, our findings suggest that YAP is an important mechanotransducer to integrate ECM mechanical cues and energy metabolic signaling to affect the fate of MSCs. This offers valuable guidance to improve the scaffold design for bone tissue engineering constructs.

Early Predicting Osteogenic Differentiation of Mesenchymal Stem Cells Based on Deep Learning Within One Day.

Osteogenic differentiation of mesenchymal stem cells (MSCs) is proposed to be critical for bone tissue engineering and regenerative medicine. However, the current approach for evaluating osteogenic differentiation mainly involves immunohistochemical staining of specific markers which often can be detected at day 5-7 of osteogenic inducing. Deep learning (DL) is a significant technology for realizing artificial intelligence (AI). Computer vision, a branch of AI, has been proved to achieve high-precision image recognition using convolutional neural networks (CNNs). Our goal was to train CNNs to quantitatively measure the osteogenic differentiation of MSCs. To this end, bright-field images of MSCs during early osteogenic differentiation (day 0, 1, 3, 5, and 7) were captured using a simple optical phase contrast microscope to train CNNs. The results showed that the CNNs could be trained to recognize undifferentiated cells and differentiating cells with an accuracy of 0.961 on the independent test set. In addition, we found that CNNs successfully distinguished differentiated cells at a very early stage (only 1 day). Further analysis showed that overall morphological features of MSCs were the main basis for the CNN classification. In conclusion, MSCs differentiation detection can be achieved early and accurately through simple bright-field images and DL networks, which may also provide a potential and novel method for the field of cell detection in the near future.

Mechanical memory based on chromatin and metabolism remodeling promotes proliferation and smooth muscle differentiation in mesenchymal stem cells.

Stem cells respond and remember mechanical cues from the microenvironment, which modulates their therapeutic effects. Chromatin organization and energy metabolism regulate the stem cell fate induced by mechanical cues. However, the mechanism of mechanical memory is still unclear. This study aimed to investigate the effects of mechanical amplitude, frequency, duration, and stretch cycle on mechanical memory in mesenchymal stem cells. It showed that the amplitude was the dominant parameter to the persistence of cell alignment. F-actin, paxillin, and nuclear deformation are more prone to be remolded than cell alignment. Stretching induces transcriptional memory, resulting in greater transcription upon subsequent reloading. Cell metabolism displays mechanical memory with sustained mitochondrial fusion and increased ATP production. The mechanical memory of chromatin condensation is mediated by histone H3 lysine 27 trimethylation, leading to much higher smooth muscle differentiation efficiency. Interestingly, mechanical memory can be transmitted based on direct cell-cell interaction, and stretched cells can remodel the metabolic homeostasis of static cells. Our results provide insight into the underlying mechanism of mechanical memory and its potential benefits for stem cell therapy.

Osteoinductive Dental Pulp Stem Cell-Derived Extracellular Vesicle-Loaded Multifunctional Hydrogel for Bone Regeneration.

Stem cell-derived extracellular vesicles (EVs) show great potential for promoting bone tissue regeneration. However, normal EVs (Nor-EVs) have a limited ability to direct tissue-specific regeneration. Therefore, it is necessary to optimize the osteogenic capacity of EV-based systems for repairing extensive bone defects. Herein, we show that hydrogels loaded with osteoinductive dental pulp stem cell-derived EVs (Ost-EVs) enhanced bone tissue remodeling, resulting in a 2.23 ± 0.25-fold increase in the expression of bone morphogenetic protein 2 (BMP2) compared to the hydrogel control group. Moreover, Ost-EVs led to a higher expression of alkaline phosphatase (ALP) (1.88 ± 0.16 of Ost-EVs relative to Nor-EVs) and the formation of orange-red calcium nodules (1.38 ± 0.10 of Ost-EVs relative to Nor-EVs) in vitro. RNA sequencing revealed that Ost-EVs showed significantly high miR-1246 expression. An ideal hydrogel implant should also adhere to surrounding moist tissues. In this study, we were drawn to mussel-inspired adhesive modification, where the hydrogel carrier was crafted from hyaluronic acid (HA) and polyethylene glycol derivatives, showcasing impressive tissue adhesion, self-healing capabilities, and the ability to promote bone growth. The modified HA (mHA) hydrogel was also responsive to environmental stimuli, making it an effective carrier for delivering EVs. In an ectopic osteogenesis animal model, the Ost-EV/hydrogel system effectively alleviated inflammation, accelerated revascularization, and promoted tissue mineralization. We further used a rat femoral condyle defect model to evaluate the in situ osteogenic ability of the Ost-EVs/hydrogel system. Collectively, our results suggest that Ost-EVs combined with biomaterial-based hydrogels hold promising potential for treating bone defects.

Predictive value of contrast-enhanced ultrasonography and ultrasound elastography for management of BI-RADS category 4 nonpalpable breast masses.

PURPOSE: The objective of this study was to investigate the independent risk factors and associated predictive values of contrast-enhanced ultrasound (CEUS), shear wave elastography (SWE), and strain elastography (SE) for high-risk lesions (HRL) and malignant tumors (MT) among nonpalpable breast masses classified as BI-RADS category 4 on conventional ultrasound. METHODS: This prospective study involved consecutively admitted patients with breast tumors from January 2018, aiming to explore the management of BI-RADS category 4 breast tumors using CEUS and elastography. We conducted a retrospective review of patient data, focusing on those with a history of a nonpalpable mass as the primary complaint. Pathologic findings after surgical resection served as the gold standard. The CEUS arterial-phase indices were analyzed using contrast agent arrival-time parametric imaging processing mode, while quantitative and qualitative indices were examined on ES images. Independent risk factors were identified through binary logistic regression multifactorial analysis. The predictive efficacy of different modalities was compared using a receiver operating characteristics curve. Subsequently, a nomogram for predicting the risk of HRL/MT was established based on a multifactorial logistic regression model. RESULTS: A total of 146 breast masses from 146 patients were included, comprising 80 benign tumors, 12 HRLs, and 54 MTs based on the final pathology. There was no significant difference in pathologic size between the benign and HRL/MT groups [8.00(6.25,10.00) vs. 9.00(6.00,10.00), P = 0.506]. The diagnostic efficacy of US plus CEUS exceeded that of US plus SWE/SE for BI-RADS 4 nonpalpable masses, with an AUC of 0.954 compared to 0.798/0.741 (P ï¼œ 0.001). Further stratified analysis revealed a more pronounced improvement for reclassification of BI-RADS 4a masses (AUC: 0.943 vs. 0.762/0.675, P ï¼œ 0.001) than BI-RADS 4b (AUC:0.950 vs. 0.885/0.796, P＞0.05) with the assistance of CEUS than SWE/SE. Employing downgrade CEUS strategies resulted in negative predictive values ranging from 95.2 % to 100.0 % for BI-RADS 4a and 4b masses. Conversely, using upgrade nomogram strategies, which included the independent predictive risk factors of irregular enhanced shape, poor defined enhanced margin, earlier enhanced time, increased surrounding vessels, and presence of contrast agent retention, the diagnostic performance achieved an AUC of 0.947 with good calibration. CONCLUSION: After investigating the potential of CEUS and ES in improving risk assessment and diagnostic accuracy for nonpalpable BI-RADS category 4 breast masses, it is evident that CEUS has a more significant impact on enhancing classification compared to ES, particularly for BI-RADS 4a subgroup masses. This finding suggests that CEUS may offer greater benefits in improving risk assessment and diagnostic accuracy for this specific subgroup of breast masses.

Predicting axillary metastasis in breast cancer using lymphatic contrast-enhanced ultrasound-guided fine-needle aspiration of one lymph node.

OBJECTIVES: Fine-needle aspiration (FNA) is a microinvasive method to diagnose lymph nodes. This study aims to determine the capability of lymphatic contrast-enhanced ultrasound (LCEUS)-guided FNA in predicting the axillary metastasis with the target of one lymph node (LN) in patients with breast cancer. METHODS: LCEUS was prospectively performed in 105 patients with breast cancer. The most suspicious LN was targeted based on the characters of LCEUS. FNA was performed in the LN, followed by localization using a guide wire. The detection of lymph cells and/or tumour cells was recognized as a puncture success. Cytologic diagnosis was compared with histologic diagnosis of wire-marked LN for diagnosing accuracy and compared with histologic diagnosis of axillary LNs for predicting accuracy. RESULTS: LCEUS-guided FNA was performed in all 105 female patients who underwent axillary dissection. The puncture success rates were 74.3%, 91.4%, and 97.1% for three sequential groups (P = .010). In diagnosing LN metastasis, the sensitivity, specificity, and accuracy values of LCEUS-guided FNA were 89.7%, 100%, and 95.7%, respectively. In predicting axillary metastasis, the sensitivity, specificity, and accuracy values of LCEUS-guided FNA were 81.4%, 100%, and 91.3%, respectively. CONCLUSIONS: The microinvasive LCEUS-guided FNA of one lymph node can be an accurate method and may help predict axillary metastasis in patients with breast cancer. ADVANCES IN KNOWLEDGE: This study presented that LCEUS combined with FNA would be practical in clinic. The characters of LCEUS could indicate the suspicious LNs and promote the accuracy in predicting axillary metastasis.

Coupling of Perinuclear Actin Cap and Nuclear Mechanics in Regulating Flow-Induced Yap Spatiotemporal Nucleocytoplasmic Transport.

Mechanical forces, including flow shear stress, govern fundamental cellular processes by modulating nucleocytoplasmic transport of transcription factors like Yes-associated Protein (YAP). However, the underlying mechanical mechanism remains elusive. In this study, it is reported that unidirectional flow induces biphasic YAP transport with initial nuclear import, followed by nuclear export as actin cap formation and nuclear stiffening. Conversely, pathological oscillatory flow induces slight actin cap formation, nuclear softening, and sustained YAP nuclear localization. To elucidate the disparately YAP spatiotemporal distribution, a 3D mechanochemical model is developed, which integrates flow sensing, cytoskeleton organization, nucleus mechanotransduction, and YAP transport. The results unveiled that despite the significant localized nuclear stress imposed by the actin cap, its inherent stiffness counteracts the dispersed contractile stress exerted by conventional fibers on the nuclear membrane. Moreover, alterations in nuclear stiffness synergistically regulate nuclear deformation, thereby governing YAP transport. Furthermore, by expanding the single-cell model to a collective vertex framework, it is revealed that the irregularities in actin cap formation within individual cells have the potential to induce topological defects and spatially heterogeneous YAP distribution in the cellular monolayer. This work unveils a unified mechanism of flow-induced nucleocytoplasmic transport, providing a linkage between transcription factor localization and mechanical stimulation.

Frizzled-9 triggers actin polymerization and activates mechano-transducer YAP to rescue simulated microgravity-induced osteoblast dysfunction.

Long-term spaceflight can result in bone loss and osteoblast dysfunction. Frizzled-9 (Fzd9) is a Wnt receptor of the frizzled family that is vital for osteoblast differentiation and bone formation. In the present study, we elucidated whether Fzd9 plays a role in osteoblast dysfunction induced by simulated microgravity (SMG). After 1-7 days of SMG, osteogenic markers such as alkaline phosphatase (ALP), osteopontin (OPN), and Runt-related transcription factor 2 (RUNX2) were decreased, accompanied by a decrease in Fzd9 expression. Furthermore, Fzd9 expression decreased in the rat femur after 3 weeks of hindlimb unloading. In contrast, Fzd9 overexpression counteracted the decrease in ALP, OPN, and RUNX2 induced by SMG in osteoblasts. Moreover, SMG regulated phosphorylated glycogen synthase kinase-3ß (pGSK3ß) and ß-catenin expression or sublocalization. However, Fzd9 overexpression did not affect pGSK3ß and ß-catenin expression or sublocalization induced by SMG. In addition, Fzd9 overexpression regulated protein kinase B also known as Akt and extracellular signal-regulated kinase (ERK) phosphorylation and induced F-actin polymerization to form the actin cap, press the nuclei, and increase nuclear pore size, thereby promoting the nuclear translocation of Yes-associated protein (YAP). Our study findings provide mechanistic insights into the role of Fzd9 in triggering actin polymerization and activating YAP to rescue SMG-induced osteoblast dysfunction and suggest that Fzd9 is a potential target to restore osteoblast function in individuals with bone diseases and after spaceflight.

Comparison of the diagnostic value of contrast-enhanced ultrasound combined with conventional ultrasound versus magnetic resonance imaging in malignant non-mass breast lesions.

OBJECTIVE: To compare the diagnostic value of contrast-enhanced ultrasound (CEUS)+conventional ultrasound vs MRI for malignant non-mass breast lesions (NMLs). METHODS: A total of 109 NMLs detected by conventional ultrasound and examined by both CEUS and MRI were retrospectively analysed. The characteristics of NMLs in CEUS and MRI were noted, and agreement between the two modalities was analysed. Sensitivity, specificity, positive-predictive value (PPV), negative-predictive value (NPV), and area under the curve (AUC) of the two methods for diagnosing malignant NMLs were calculated in the overall sample and subgroups of different sizes(<10 mm, 10-20 mm, >20 mm). RESULTS: A total of 66 NMLs detected by conventional ultrasound showed non-mass enhancement in MRI. Agreement between ultrasound and MRI was 60.6%. Probability of malignancy was higher when there was agreement between the two modalities. In the overall group, the sensitivity, specificity, PPV, and NPV of the two methods were 91.3%, 71.4%, 60%, 93.4% and 100%, 50.4%, 59.7%, 100%, respectively. The diagnostic performance of CEUS+conventional ultrasound was better than that of MRI (AUC: 0.825 vs 0.762, p = 0.043). The specificity of both methods decreased as lesion size increased, but sensitivity did not change. There was no significant difference between the AUCs of the two methods in the size subgroups (p > 0.05). CONCLUSION: The diagnostic performance of CEUS+conventional ultrasound may be better than that of MRI for NMLs detected by conventional ultrasound. However, the specificity of both methods decrease significantly as lesion size increases. ADVANCES IN KNOWLEDGE: This is the first study to compare the diagnostic performance of CEUS+conventional ultrasound vs that of MRI for malignant NMLs detected by conventional ultrasound. While CEUS+conventional ultrasound appears to be superior to MRI, subgroup analysis suggests that diagnostic performance is poorer for larger NMLs.

Value of an expanded range of lesions on contrast-enhanced ultrasound for the diagnosis of hypervascular breast masses.

Background: Breast cancer lesions show an expanded range on contrast-enhanced ultrasound (CEUS). Here, we quantitatively analyze this index to explore its effective cutoff value for distinguishing benign and malignant lesions and the corresponding diagnostic performance and investigate its role in prognostic assessment of malignant lesions. Methods: Consecutive patients who underwent CEUS for breast lesions during the period from September 2017 to June 2019 were included. Original CEUS images were selected, displayed in dual-frame mode, and measured when enhancement of the lesion reached its peak. The longitudinal diameter, transverse diameter, and area of the lesion on the two-dimensional images and the corresponding postenhancement images were measured to calculate six indicators: longitudinal diameter increment, transverse diameter increment, area increment, percent increase in longitudinal diameter, percent increase in transverse diameter, and percent increase in area increment. With postoperative pathology as the gold standard, the cutoff values for distinguishing benign and malignant lesions and the correlations of these indicators with pathological subtypes and pathological grades were evaluated. Results: Malignant lesions showed a more significantly expanded range after enhancement compared to benign lesions, especially in terms of area increase. When the cutoff value of the area increment was set at 0.47 cm2 for distinguishing between benign and malignant lesions, the area under the curve (AUC) was 0.945, and the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 90.1%, 91.5%, 90.9%, 87.2%, and 93.5%, respectively. The pathologically measured maximum diameter of malignant masses correlated with the percent increase in transverse diameter, area increment, and percent increase in area increment. The longitudinal diameter increment in the luminal A group was significantly smaller than that in the human epidermal growth factor receptor 2 (HER2)+ group. The percent increase in transverse diameter was helpful for predicting the pathological grade of malignant masses. When the cutoff value of the percent increase in transverse diameter was set at 10.84% for pathological grading, the AUC was 0.623, and the sensitivity was 90.8%. Conclusions: Indicators related to the expanded lesion range on CEUS are helpful in differential diagnosis of benign and malignant lesions and in prognostic assessment of pathological grades.

The predictive models based on multimodality ultrasonography for the differential diagnosis of thyroid nodules smaller than 10 mm.

OBJECTIVE: The objective of this study was to establish a multimodality ultrasound prediction model based on conventional ultrasound (Con-US), shear wave elastography (SWE), and strain elastography (SE) and contrast-enhanced ultrasound (CEUS) and to explore their diagnostic values for thyroid nodules ≤ 10 mm. METHODS: This retrospective study included 198 thyroid nodules (maximum diameter≤10 mm) in 198 thyroid surgery patients who were examined preoperatively with above-mentioned methods. The pathological findings of the thyroid nodules were used as the gold standard, and there were 72 benign nodules and 126 malignant nodules. The multimodal ultrasound prediction models were developed by logistic regression analysis based on the ultrasound image appearances. The diagnostic efficacy of these prediction models was then compared and internally cross-validated in a fivefold manner. RESULTS: The specific features on CEUS (enhancement boundary, enhancement direction and decreased nodule area) and the parenchyma-to-nodule strain ratio (PNSR) on SE and SWE ratio were included in the prediction model. The Model one combining American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR TI-RADS) score with PNSR and SWE ratio had the highest sensitivity (92.8%), while the Model three combining TI-RADS score with PNSR, SWE ratio and specific CEUS indicators had the highest specificity, accuracy, and AUC (90.2%,91.4%, and 0.958, respectively). CONCLUSION: The multimodality ultrasound predictive models effectively improved the differential diagnosis of thyroid nodules smaller than 10 mm. ADVANCES IN KNOWLEDGE: For the differential diagnosis of thyroid nodules ≤ 10 mm, both ultrasound elastography and CEUS could be effective complements to ACR TI-RADS.

Redox-Responsive Dendrimer Nanogels Enable Ultrasound-Enhanced Chemoimmunotherapy of Pancreatic Cancer via Endoplasmic Reticulum Stress Amplification and Macrophage Polarization.

Developing a multifunctional nanoplatform to achieve efficient theranostics of tumors through multi-pronged strategies remains to be challenging. Here, the design of the intelligent redox-responsive generation 3 (G3) poly(amidoamine) dendrimer nanogels (NGs) loaded with gold nanoparticles (Au NPs) and chemotherapeutic drug toyocamycin (Au/Toy@G3 NGs) for ultrasound-enhanced cancer theranostics is showcased. The constructed hybrid NGs with a size of 193 nm possess good colloidal stability under physiological conditions, and can be dissociated to release Au NPs and Toy in the reductive glutathione-rich tumor microenvironment (TME). The released Toy can promote the apoptosis of cancer cells through endoplasmic reticulum stress amplification and cause immunogenic cell death to maturate dendritic cells. The loaded Au NPs can induce the conversion of tumor-associated macrophages from M2-type to antitumor M1-type to remodulate the immunosuppressive TME. Combined with antibody-mediated immune checkpoint blockade, effective chemoimmunotherapy of a pancreatic tumor mouse model can be realized, and the chemoimmunotherapy effect can be further ultrasound enhanced due to the sonoporation-improved tumor permeability of NGs. The developed Au/Toy@G3 NGs also enable Au-mediated computed tomography imaging of tumors. The constructed responsive dendrimeric NGs tackle tumors through a multi-pronged chemoimmunotherapy strategy targeting both cancer cells and immune cells, which hold a promising potential for clinical translations.

Can pre-operative ultrasound elastography predict aggressive features of solitary papillary thyroid carcinoma?

OBJECTIVE: To investigate whether pre-operative ultrasound elastography (USE) can be used to predict aggressive features of solitary papillary thyroid carcinomas (PTCs). METHODS: Clinical and USE indices were retrospectively analyzed in 487 patients with surgically confirmed solitary PTCs. The patients were grouped per aggressive features on pathologic testing. Univariate and binary logistic regression analyses were performed to explore independent risk factors of aggressive features. RESULTS: Univariate analysis revealed standard deviation (SD) values of the tumor shear-wave velocity (SWV) were associated with capsular invasion (p < 0.05). Further, shear-wave elasticity and SWV ratios correlated with extrathyroidal extension (all p < 0.05). The tumor shear-wave elasticity and SWV SD values were associated with cervical lymph node metastasis (CLNM) (all p < 0.05). Binary logistic regression analysis identified location and capsule contact as independent predictive risk factors for capsular invasion (all p < 0.05); size for extrathyroidal extension (all p < 0.05); and sex, age, margin, and suspected CLNM for CLNM (all p < 0.05). However, pre-operational USE indexes were not independent predictors of aggressive features (all p > 0.05). CONCLUSION: Pre-operative USE indices were not independent risk factors of aggressive features of solitary PTCs. Thus, USE may have a limited value for predicting the aggressive features of PTC. ADVANCES IN KNOWLEDGE: Pre-operative USE indices may have a limited value for predicting the aggressive features of PTC.

Preoperative strain ultrasound elastography can predict occult central cervical lymph node metastasis in papillary thyroid cancer: a single-center retrospective study.

Objective: To determine whether preoperative ultrasound elastography can predict occult central cervical lymph node metastasis (CCLNM) in patients with papillary thyroid cancer. Methods: This retrospective study included 541 papillary thyroid cancer patients with clinically negative lymph nodes prior to surgery between July 2019 and December 2021. Based on whether CCLNM was present on postoperative pathology, patients were categorized as CCLNM (+) or CCLNM (-). Preoperative clinical data, conventional ultrasound features, and ultrasound elastography indices were compared between the groups. Univariate and multivariate logistic regression analysis were performed to identify the independent predictors of occult CCLNM. Results: A total of 36.60% (198/541) patients had confirmed CCLNM, while 63.40% (343/541) did not. Tumor location, bilaterality, multifocality, echogenicity, margin, shape, vascularity, capsule contact, extrathyroidal extension, aspect ratio, and shear wave elasticity parameters were comparable between the groups (all P > 0.05). Univariate analysis showed statistically significant differences between the two groups in age, sex, tumor size, calcification, capsule invasion, and strain rates ratio in strain ultrasound elastography (all P < 0.05). In multivariate logistic regression analysis, the independent predictors of occult CCLNM were age (OR = 0.975, 95% CI = 0.959-0.991, P = 0.002), sex (OR = 1.886, 95% CI = 1.220-2.915, P = 0.004), tumor size (OR = 1.054, 95% CI = 1.014-1.097, P = 0.008), and strain rates ratio (OR = 1.178, 95% CI = 1.065-1.304, P = 0.002). Conclusion: Preoperative strain ultrasound elastography can predict presence of occult CCLNM in papillary thyroid cancer patients and help clinicians select the appropriate treatment strategy.

Ultrasound-enhanced theranostics of orthotopic breast cancer through a multifunctional core-shell tecto dendrimer-based nanomedicine platform.

Design of multifunctional nanoplatforms combined with ultrasound-targeted microbubble destruction (UTMD) technology for enhanced tumor accumulation is feasible to solve the bottleneck of theranostics. Herein, we present the development of zwitterion-modified gadolinium (Gd)-chelated core-shell tecto dendrimers (CSTDs) as a nanomedicine platform (PCSTD-Gd) for enhanced magnetic resonance (MR) imaging-guided chemo-gene therapy of orthotopic breast cancer with the assistance of UTMD. In our design, CSTDs synthesized via supramolecular recognition of ß-cyclodextrin and adamantane were covalently linked with tetraazacyclododecane tetraacetic acid-Gd(III) chelators, modified with 1,3-propane sultone to achieve good protein-resistance property, and used for co-delivery of an microRNA 21 inhibitor (miR 21i) and an anticancer drug doxorubicin (DOX). The overall design is quite advantageous and cooperative. The CSTDs with a greater size than single-generation core dendrimers have amplified the enhanced permeability and retention effect for better passive tumor targeting, with a larger r1 relaxivity for sensitive MR imaging and serum-enhanced gene delivery efficiency due to the better compaction ability as well as the protein resistance ability, and with larger interior space for improved drug loading. Through the unique design and the assistance of UTMD, the obtained PCSTD-Gd/DOX/miR 21i polyplexes enable enhanced MR imaging-guided combined chemo-gene therapy of an orthotopic breast cancer model in vivo.

Nomogram incorporating preoperative clinical and ultrasound indicators to predict aggressiveness of solitary papillary thyroid carcinoma.

Objective: To construct a nomogram based on preoperative clinical and ultrasound indicators to predict aggressiveness of solitary papillary thyroid carcinoma (PTC). Methods: Preoperative clinical and ultrasound data from 709 patients diagnosed with solitary PTC between January 2017 and December 2020 were analyzed retrospectively. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with PTC aggressiveness, and these factors were used to construct a predictive nomogram. The nomogram's performance was evaluated in the primary and validation cohorts. Results: The 709 patients were separated into a primary cohort (n = 424) and a validation cohort (n = 285). Univariate analysis in the primary cohort showed 13 variables to be associated with aggressive PTC. In multivariate logistic regression analysis, the independent predictors of aggressive behavior were age (OR, 2.08; 95% CI, 1.30-3.35), tumor size (OR, 4.0; 95% CI, 2.17-7.37), capsule abutment (OR, 2.53; 95% CI, 1.50-4.26), and suspected cervical lymph nodes metastasis (OR, 2.50; 95% CI, 1.20-5.21). The nomogram incorporating these four predictors showed good discrimination and calibration in both the primary cohort (area under the curve, 0.77; 95% CI, 0.72-0.81; Hosmer-Lemeshow test, P = 0.967 and the validation cohort (area under the curve, 0.72; 95% CI, 0.66-0.78; Hosmer-Lemeshow test, P = 0.251). Conclusion: The proposed nomogram shows good ability to predict PTC aggressiveness and could be useful during treatment decision making. Advances in knowledge: Our nomogram-based on four indicators-provides comprehensive assessment of aggressive behavior of PTC and could be a useful tool in the clinic.

Pulse Capacitive Coupling Electric Field Regulates Cell Migration, Proliferation, Polarization, and Vascularization to Accelerate Wound Healing.

Objectives: Accelerating wound healing using continuous exogenous electrical stimulation is limited due to some serious side effects, including thermal damage. Many previous studies based on direct current contact stimulation may cause chemical burns or blisters, thereby increasing patients suffering. The aim of this study was to develop a safer and more convenient pulse capacitive coupling electrical field (PCCEF) stimulation to accelerate wound healing. Approach: A PCCEF-generating platform was self-designed to facilitate wound healing. The promoting effects and appropriate pulse width were explored by applying PCCEFs (54 mV/mm, 60 Hz) of different pulse widths to various cells involved in wound healing and mouse models for 2 h daily. Results: PCCEFs of ≥10 µs pulse width showed marked promotion of the migration and proliferation of human dermal fibroblasts and HaCaT cells, enhanced the M2-type polarization and YPA/TAZ expression of macrophages, and facilitated the wound healing of mouse models. Comprehensive histological results suggested that PCCEF of 100 µs pulse width exerted the most positive effects. Innovation: A safe and effective PCCEF was developed to promote wound healing, which prevented prolonged stimulation and averted direct contact. Conclusion: PCCEF accelerated wound healing, especially at the optimal 100 µs pulse width, and was expected to be translated to clinical application, helping alleviate patient suffering, while reducing side effects.

Fluid shear stress promotes periodontal ligament cells proliferation via p38-AMOT-YAP.

Periodontal ligament (PDL) cells are a promising tool for periodontal regeneration therapy. Achieving a sufficient number of PDL cells is essential to PDL regeneration. In our study, appropriate flow shear stress (FSS, 1-6 dyn/cm2) promotes the proliferation of PDL cells. FSS remodels cytoskeleton and focal adhesion in a duration-dependent manner. FSS induces PDL cells to form the actin cap within 10 min, flattens the nuclei, and increases the nuclear pore size, which promotes nuclear translocation of Yes-associated protein (YAP). FSS activates p38, which plays a dual function in YAP regulation. p38 regulates the phosphorylation of Akt and cofilin, as well as induced F-actin polymerization to induce YAP activity. In addition, p38 inhibits pLATS and consecutively regulates angiomotin (AMOT) and YAP phosphorylation. AMOT competitively binds to F-actin and YAP to participate in FSS-mediated YAP nuclear translocation and cell proliferation. Taken collectively, our results provide mechanistic insights into the role of p38-AMOT-YAP in FSS-mediated PDL cells proliferation and indicate potential applications in dental regenerative medicine.

Static magnetic field regulates proliferation, migration, and differentiation of human dental pulp stem cells by MAPK pathway.

Magnetic materials are now commonly used in dental clinics. These materials generally produce a static magnetic field (SMF). While it is known that SMF can affect cells' behaviors such as proliferation, migration, and differentiation, the mechanisms underlying these effects are still unclear. Our study investigates the role of the mitogen-activated protein (MAP) kinase pathway in SMF-induced proliferation, migration, osteogenic/odontogenic differentiation, and mineralization in human dental pulp stem cells (DPSCs). Human DPSCs were exposed to SMF of 1 mT and the phosphorylated MAP kinases were detected by Western blot analysis. Three MAP kinases inhibitors were pre-cultured with DPSCs and exposed to SMF for 24 h. Cell viability was analyzed using Cell Counting Kit-8. Cell migration was tested by a wound healing assay. Osteogenic/odontogenic differentiation was detected by ALP staining assay, ALP and DSPP Western blot analysis. Mineralization was studied by alizarin red staining analysis. SMF activated phosphorylation of c-Jun N-terminal kinase (JNK), P38 and extracellular signal-regulated kinase (ERK). The inhibition of JNK, P38, and ERK signaling decreased SMF-induced proliferation and migration. ERK and P38 play more important roles in SMF-induced ALP staining and protein expression. JNK was vital for SMF-induced DSPP expression. JNK, P38, and ERK all involved in SMF-mediated mineralization. Our study demonstrated that the MAPK pathway regulated SMF-induced proliferation, migration, osteogenic/odontogenic differentiation, and mineralization in human DPSCs.

Non-contact electrical stimulation as an effective means to promote wound healing.

Electrical stimulation has been demonstrated to have beneficial effects in skin tissue repair. However, most electrical stimulations are applied with percutaneous electrode, which is prone to causing serious trauma. Using non-contact electrical stimulation (NCES) is expected to reduce the potential risk. In this study, NCES was expediently exerted by a self-designed practical device. Electrode plates of 10-cm spacing with appropriate side lengths of 21 and 30 cm were selected by EF distribution analysis for applying NCES to cells and mice, respectively, and the real EF strengths were measured. The change of loading voltage which had no effect on the regular pattern of EF distribution could be used as a single factor to explore the effect of NCES on wound healing. It was subsequently demonstrated that 53 mV mm-1 NCES facilitated the migration and proliferation of HaCaT cells and HDFs in vitro, and the M2-type polarization of macrophages. Moreover, 54 and 84 mV mm-1 NCESs accelerated the wound healing rate of model mice from the perspective of reducing scarring, enhancing collagen synthesis and increasing angiogenesis in vivo. The promoting role of NCES in wound healing showed the potential to initiate new possibilities for the clinical treatment of skin tissue injuries.