Extraction of γ-chitosan from insects and fabrication of PVA/γ-chitosan/kaolin nanofiber wound dressings with hemostatic properties.

A nanofiber-based composite nonwoven fabric was fabricated for hemostatic wound dressing, integrating polyvinyl alcohol (PVA), kaolin, and γ-chitosan extracted from three type of insects. The γ-chitosan extracted from Protaetia brevitarsis seulensis exhibited the highest yield at 21.5%, and demonstrated the highest moisture-binding capacity at 535.6%. In the fabrication process of PVA/kaolin/γ-chitosan nonwoven fabrics, an electrospinning technique with needle-less and mobile spinneret was utilized, producing nanofibers with average diameters ranging from 172 to 277 nm. The PVA/kaolin/γ-chitosan nonwoven fabrics demonstrated enhanced biocompatibility, with cell survival rates under certain compositions reaching up to 86.9% (compared to 74.2% for PVA). Furthermore, the optimized fabric compositions reduced blood coagulation time by approximately 2.5-fold compared to PVA alone, highlighting their efficacy in hemostasis. In other words, the produced PVA/kaolin/γ-chitosan nonwoven fabrics offer potential applications as hemostatic wound dressings with excellent biocompatibility and improved hemostatic performance.

Correlation of two different devices for the evaluation of primary implant stability depending on dental implant length and bone density: An in vitro study.

Non-invasive objective implant stability measurements are needed to determine the appropriate timing of prosthetic fitting after implant placement. We compared the early implant stability results obtained using resonance frequency analysis (RFA) and damping capacity analysis (DCA) depending on the implant length and bone density. Total 60, 4.0 mm diameter implants of various lengths (7.3 mm, 10 mm, and 13 mm) were used. In Group I, low-density bone was described using 15 PCF (0.24 g/cm3) polyurethane bone blocks, and in Group II, 30 PCF (0.48 g/cm3) polyurethane bone blocks were used to describe medium density bone. RFA was performed using an Osstell® Beacon+; DCA was performed using Anycheck®. Measurements were repeated five times for each implant. Statistical significance was set at P <0.05. In Group I, bone density and primary implant stability were positively correlated, while implant length and primary implant stability were positively correlated. In Group II, the implant stability quotient (ISQ) and implant stability test (IST) values in did not change significantly above a certain length. Primary implant stability was positively correlated with bone density and improved with increasing implant length at low bone densities. Compared with the Osstell® Beacon+, the simplicity of Anycheck® was easy to use and accessible.

Nanofibrous Material-Reinforced Printable Ink for Enhanced Cell Proliferation and Tissue Regeneration.

The three-dimensional (3D) printing of biomaterials, cells, and bioactive components, including growth factors, has gained interest among researchers in the field of tissue engineering (TE) with the aim of developing many scaffolds to sustain size, shape fidelity, and structure and retain viable cells inside a network. The biocompatible hydrogel employed in 3D printing should be soft enough to accommodate cell survival. At the same time, the gel should be mechanically strong to avoid the leakage of cells into the surrounding medium. Considering these basic criteria, researchers have developed nanocomposite-based printable inks with suitable mechanical and electroconductive properties. These nanomaterials, including carbon family nanomaterials, transition metal dichalcogenides, and polymeric nanoparticles, act as nanofillers and dissipate stress across polymeric networks through their electroactive interactions. Nanofiber-reinforced printable ink is one kind of nanocomposite-based ink that comprises dispersed nanofiber components in a hydrogel matrix. In this current review, we compile various TE applications of nanofiber-reinforced printable ink and describe the 3D-printing parameters, classification, and impact of cross-linkage. Furthermore, we discuss the challenges and future perspectives in this field.

Randomized controlled trial of digital therapeutics for temporomandibular disorder: A pilot study.

OBJECTIVES: Temporomandibular disorder (TMD) is a common condition that affects the temporomandibular joint (TMJ) and the muscles of the jaw, resulting in pain and dysfunction. TMD is affected by both behavioral and psychological factors. Digital therapeutics (DTx) can exert therapeutic effects by controlling behavioral factors through the delivery of appropriate interventions. Here, we report an open-label randomized control trial to evaluate the efficacy of DTx for TMD. METHODS: We recruited 40 participants diagnosed with TMD. Participants were randomly divided into an intervention group (DTx use, n = 20) and a control group (n = 20). The intervention group received the usual treatment process for TMD in addition to the use of the DTx. The control group received the usual treatments only. Patients in both groups were followed up for 3-4 weeks, and outcome data were collected and analyzed. RESULT: The intervention group showed a significant reduction in pain scores as measured by the numerical rating scale (NRS) (p = 0.016). Additionally, the intervention group showed a statistically significant increase in maximal mouth opening compared to the control group (p = 0.0079). However, there were no significant differences in improvement in the Jaw Functional Limitation Scale, Oral Behavior Checklist, and Patient Health Questionnaire-4 between the two groups (p = 0503, = 0.820, and = 0.943, respectively). CONCLUSION: This RCT reveals DTx potential in TMD, showing pain and mouth opening improvements with conventional treatment. But no significant changes were noted in other outcomes. The findings advocate for more extensive, long-term research to solidify DTx's role in TMD management. CLINICAL SIGNIFICANCE: This research underlines DTx potential to improve pain outcomes in TMD therapy, reinforcing its value as a complementary treatment modality.

Enhancing deep learning classification performance of tongue lesions in imbalanced data: mosaic-based soft labeling with curriculum learning.

BACKGROUND: Oral potentially malignant disorders (OPMDs) are associated with an increased risk of cancer of the oral cavity including the tongue. The early detection of oral cavity cancers and OPMDs is critical for reducing cancer-specific morbidity and mortality. Recently, there have been studies to apply the rapidly advancing technology of deep learning for diagnosing oral cavity cancer and OPMDs. However, several challenging issues such as class imbalance must be resolved to effectively train a deep learning model for medical imaging classification tasks. The aim of this study is to evaluate a new technique of artificial intelligence to improve the classification performance in an imbalanced tongue lesion dataset. METHODS: A total of 1,810 tongue images were used for the classification. The class-imbalanced dataset consisted of 372 instances of cancer, 141 instances of OPMDs, and 1,297 instances of noncancerous lesions. The EfficientNet model was used as the feature extraction model for classification. Mosaic data augmentation, soft labeling, and curriculum learning (CL) were employed to improve the classification performance of the convolutional neural network. RESULTS: Utilizing a mosaic-augmented dataset in conjunction with CL, the final model achieved an accuracy rate of 0.9444, surpassing conventional oversampling and weight balancing methods. The relative precision improvement rate for the minority class OPMD was 21.2%, while the relative [Formula: see text] score improvement rate of OPMD was 4.9%. CONCLUSIONS: The present study demonstrates that the integration of mosaic-based soft labeling and curriculum learning improves the classification performance of tongue lesions compared to previous methods, establishing a foundation for future research on effectively learning from imbalanced data.

Recent Advances in Marine Biomaterials Tailored and Primed for the Treatment of Damaged Soft Tissues.

The inherent self-repair abilities of the body often fall short when it comes to addressing injuries in soft tissues like skin, nerves, and cartilage. Tissue engineering and regenerative medicine have concentrated their research efforts on creating natural biomaterials to overcome this intrinsic healing limitation. This comprehensive review delves into the advancement of such biomaterials using substances and components sourced from marine origins. These marine-derived materials offer a sustainable alternative to traditional mammal-derived sources, harnessing their advantageous biological traits including sustainability, scalability, reduced zoonotic disease risks, and fewer religious restrictions. The use of diverse engineering methodologies, ranging from nanoparticle engineering and decellularization to 3D bioprinting and electrospinning, has been employed to fabricate scaffolds based on marine biomaterials. Additionally, this review assesses the most promising aspects in this field while acknowledging existing constraints and outlining necessary future steps for advancement.

Surgical management and final outcomes of chondrosarcoma of the temporomandibular joint: case series and comprehensive literature review.

BACKGROUND: Surgical management for chondrosarcoma of the temporomandibular joint (TMJ) is challenging due to the anatomical location involving the facial nerve and the functional joint. The purpose of this case series was to analyze the largest number of TMJ chondrosarcoma cases reported from a single institution and to review the literature about chondrosarcoma involving the TMJ. METHODS: Ten TMJ chondrosarcoma patients at Seoul National University Dental Hospital were included in this study. Radiographic features, surgical approaches, histopathologic subtypes, and treatment modalities were evaluated. All case reports of TMJ chondrosarcoma published in English from 1954 to 2021 were collected under PRISMA guidelines and comprehensively reviewed. RESULTS: The lesions were surgically resected in all 10 patients with efforts to preserve facial nerve function. Wide excision including margins of normal tissue was performed to ensure adequate resection margins. All TMJs were reconstructed with a metal condyle except one, which was reconstructed with vascularized costal bone. At last follow-up, all patients were still alive, and there had been no recurrence. Among 47 cases (patients from the literature and our cases), recurrence was specified in 43 and occurred in four (9.5%). CONCLUSIONS: For surgical management of TMJ chondrosarcoma, wide excision must consider preservation of the facial nerve. Reconstruction using a metal condyle prosthesis and a vascularized free flap is reliable. A more conservative surgical approach correlates with a favorable prognosis for facial nerve recovery. Nevertheless, wide excision is imperative to prevent tumor recurrence. In cases in which the glenoid fossa is unaffected by the tumor, it is deemed unnecessary to reconstruct the glenoid fossa within an oncological setting.

The Effectiveness of a Novel Air-Barrier Device for Aerosol Reduction in a Dental Environment: Computational Fluid Dynamics Simulation.

The use of equipment such as dental handpieces and ultrasonic tips in the dental environment has potentially heightened the generation and spread of aerosols, which are dispersant particles contaminated by etiological factors. Although numerous types of personal protective equipment have been used to lower contact with contaminants, they generally do not exhibit excellent removal rates and user-friendliness in tandem. To solve this problem, we developed a prototype of an air-barrier device that forms an air curtain as well as performs suction and evaluated the effect of this newly developed device through a simulation study and experiments. The air-barrier device derived the improved design for reducing bioaerosols through the simulation results. The experiments also demonstrated that air-barrier devices are effective in reducing bioaerosols generated at a distance in a dental environment. In conclusion, this study demonstrates that air-barrier devices in dental environments can play an effective role in reducing contaminating particles.

3D printed membranes of polylactic acid and graphene oxide for guided bone regeneration.

We fabricated graphene oxide (GO)-incorporated polylactic acid (PLA) (GO-PLA) films by using three-dimensional (3D) printing to explore their potential benefits as barrier membranes for guided bone regeneration (GBR). Our results showed that the 3D printed GO-PLA films provided highly favorable matrices for preosteoblasts and accelerated new bone formation in rat calvarial bone defect models.

Sinus augmentation with poly(ε)caprolactone-ß tricalcium phosphate scaffolds, mesenchymal stem cells and platelet rich plasma for one-stage dental implantation in minipigs.

PURPOSE: This study evaluated the efficacy of a tube-shaped poly(ε) caprolactone - ß tricalcium phosphate (PCL-TCP) scaffold with the incorporation of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) and platelet-rich plasma (PRP) for bone regeneration in the procedure of single-stage sinus augmentation and dental implantation in minipigs. METHODS: Implants were placed in the bilateral sides of the maxillary sinuses of 5 minipigs and allocated to a PCL-TCP+hUCMSCs+PRP group (n=5), a PCL-TCP+PRP group (n=5), and a PCL-TCP-only group (n=6). After 12 weeks, bone regeneration was evaluated with soft X-rays, micro-computed tomography, fluorescence microscopy, and histomorphometric analysis. RESULTS: Four implants failed (2 each in the PCL-TCP+hUCMSCs+PRP and PCL-TCP+hUCMSC groups). An analysis of the grayscale levels and bone-implant contact ratio showed significantly higher mean values in the PCL-TCP+hUCMSCs+PRP than in the PCL-TCP group (P=0.045 and P=0.016, respectively). In fluoromicroscopic images, new bone formation around the outer surfaces of the scaffolds was observed in the PCL-TCP+hUCMSCs+PRP group, suggesting a tenting effect of the specially designed scaffolds. Bone regeneration at the scaffold-implant interfaces was observed in all 3 groups. CONCLUSIONS: Using a tube-shaped, honeycombed PCL-TCP scaffold with hUCMSCs and PRP may serve to enhance bone formation and dental implants' osseointegration in the procedure of simultaneous sinus lifting and dental implantation.

Biomechanical microenvironmental stimulating effect of pulsed electromagnetic field on the regeneration of crush injured rat sciatic nerve.

This study evaluated the biomechanical microenvironmental stimulating effect of pulsed electromagnetic field (PEMF) on the regeneration of crush-injured rat sciatic nerve, when combined with bone marrow mesenchymal stem cells (BMSCs) and recombinant human nerve growth factor (rhNGF-ß), in the form of an adenoviral vector-mediated NGF. Sprague-Dawley rats were equally distributed into six groups; PBS, BMSC, NGF-Ad + BMSC, PEMF + PBS, PEMF + BMSC and PEMF + NGF-Ad + BMSC. The PBS group received PBS (volume: 10µL/rat), the BMSC group with BMSCs (1 × 106 cell/10 µL/rat) and NGF-Ad group with the rhNGF-ß Ad infected BMSCs (1 × 106 cell/10 µL/rat) immediate after right sciatic nerve crush injury. The PEMF groups were exposed to PEMF of 1mT, 50 Hz, 1 h/day. The rats were observed for 3 weeks. PEMF alone did not showed the positive effect compared with negative control group. The groups transplanted with BMSCs showed higher axonal regeneration compared with the groups without transplantation of the cells whether BMSC was infected with NGF-Ad or not and whether the animals received PEMF. PEMF + NGF-Ad + BMSC group showed the significantly highest number of axons than the other groups. Functionally, all groups showed marked improvement at 3 weeks postoperatively although the difference was not statistically significant among the groups. PEMF showed the positive effect when combined with BMSC and NGF-ad in aspect of number of axons. Therefore, combining the microenvironment stimulation methods of PEMF and conventional methods such as transplantation of stem cells and growth factor could be considered for the regeneration methods in the nerve damage.

Comparison of Implant Surgery Methods of Cortical Tapping and Cortical Widening in Bone of Various Density: A Three-Dimensional Finite Element Study.

PURPOSE: The primary stability of a dental implant is critical for successful osseointegration during immediate loading. The cortical bone should be prepared to achieve enough primary stability, but not overcompressed. In this study, we investigated the stress and strain distribution in the bone around the implant induced by the occlusal force applied during immediate loading at various bone densities by the FEA method to compare cortical tapping and widening surgical techniques. MATERIALS AND METHODS: A three-dimensional geometrical model of a dental implant and bone system was created. Five types of bone density combination (D111, D144, D414, D441 and D444) were designed. Two surgical methods-cortical tapping and cortical widening-were simulated in the model of the implant and bone. An axial load of 100 N and an oblique load of 30 N were applied to the crown. The maximal principal stress and strain were measured for comparative analysis of the two surgical methods. RESULTS: Cortical tapping showed lower maximal stress of bone and maximal strain of bone than cortical widening when dense bone was located around the platform, regardless of the direction of the applied load. CONCLUSIONS: Within the limitations of this FEA study, it can be concluded that cortical tapping is biomechanically more advantageous to the implants under occlusal force during immediate loading, especially when the bone density around the platform is high.

3D bioprinting of human mesenchymal stem cells-laden hydrogels incorporating MXene for spontaneous osteodifferentiation.

Contemporary advances in three-dimensional (3D) bioprinting technologies have enabled the fabrication of tailored live 3D tissue mimetics. Furthermore, the development of advanced bioink materials has been highlighted to accurately reproduce the composition of a native extracellular matrix and mimic the intrinsic properties of laden cells. Recent research has shown that MXene is one of promising nanobiomaterials with osteogenic activity for bone grafts and scaffolds due to its unique atomic structure of three titanium layers between two carbon layers. In this study, the MXene-incorporated gelatin methacryloyl (GelMA) and hyaluronic acid methacryloyl (HAMA) (i.e., GelMA/HAMA-MXene) bioinks were prepared to explore if they have the potential to enable the spontaneous osteodifferentiation of human mesenchymal stem cells (hMSCs) when the hMSCs-laden GelMA/HAMA-MXene bioinks were 3D printed. The physicochemical and rheological characteristics of the GelMA/HAMA-MXene hydrogels were proven to be unprecedentedly favorable supportive matrices suited for the growth and survival of hMSCs. Furthermore, hMSCs were shown to spontaneously differentiate into osteoblasts within GelMA-HAMA/MXene composites to provide favorable microenvironments for osteogenesis. Therefore, our results suggest that the remarkable biofunctional advantages of the MXene-incorporated GelMA/HAMA bioink can be utilized in a wide range of strategies for the development of effective scaffolds in bone tissue regeneration.

State-of-the-art techniques for promoting tissue regeneration: Combination of three-dimensional bioprinting and carbon nanomaterials.

181Biofabrication approaches, such as three-dimensional (3D) bioprinting of hydrogels, have recently garnered increasing attention, especially in the construction of 3D structures that mimic the complexity of tissues and organs with the capacity for cytocompatibility and post-printing cellular development. However, some printed gels show poor stability and maintain less shape fidelity if parameters such as polymer nature, viscosity, shear-thinning behavior, and crosslinking are affected. Therefore, researchers have incorporated various nanomaterials as bioactive fillers into polymeric hydrogels to address these limitations. Carbon-family nanomaterials (CFNs), hydroxyapatites, nanosilicates, and strontium carbonates have been incorporated into printed gels for application in various biomedical fields. In this review, following the compilation of research publications on CFNs-containing printable gels in various tissue engineering applications, we discuss the types of bioprinters, the prerequisites of bioink and biomaterial ink, as well as the progress and challenges of CFNs-containing printable gels in this field.

Electric Control of 2D Van Hove Singularity in Oxide Ultra-Thin Films.

Divergent density of states (DOS) can induce extraordinary phenomena such as significant enhancement of superconductivity and unexpected phase transitions. Moreover, van Hove singularities (VHSs) lead to divergent DOS in 2D systems. Despite recent interest in VHSs, only a few controllable cases have been reported to date. In this work, by utilizing an atomically ultra-thin SrRuO3 film, the electronic structure of a 2D VHS is investigated with angle-resolved photoemission spectroscopy and transport properties are controlled. By applying electric fields with alkali metal deposition and ionic-liquid gating methods, the 2D VHS and the sign of the charge carrier are precisely controlled. Use of a tunable 2D VHS in an atomically flat oxide film could serve as a new strategy to realize infinite DOS near the Fermi level, thereby allowing efficient tuning of electric properties.

Longevity of coal waste for controlling cadmium-contaminated groundwater considering groundwater velocity.

Coal waste composed of naturally occurring minerals is applicable as a reactive medium to permeable reactive barriers due to its reactivity to heavy metals. In this study, we evaluated the longevity of coal waste as PRB media to control heavy metal-contaminated groundwater considering variable groundwater velocity. Breakthrough experiments were conducted using coal waste-filled column by injecting artificial groundwater, 10 mg/L of cadmium solution. The artificial groundwater was fed to the column at different flow rates to mimic a wide range of porewater velocities in the saturated zone. The reaction between cadmium breakthrough curves was analyzed using a two-site nonequilibrium sorption model. The cadmium breakthrough curves showed a significant retardation, which increased with decreasing porewater velocity. The greater the retardation, the longer the longevity of coal waste could be expected. The greater retardation under a slower velocity environment was due to the higher fraction of equilibrium reaction. The nonequilibrium reaction parameters could be functionalized with respect to the porewater velocity. The simulation of contaminant transport using the reaction parameters could be used as a method to evaluate the longevity of the pollution-blocking material in an underground environment.

Deep-UV Transparent Conducting Oxide La-Doped SrSnO3 with a High Figure of Merit.

Perovskite stannate SrSnO3 (SSO) is attracting attention as ultraviolet transparent conducting oxides (UV TCOs) due to its ultrawide band gap and high conductivity. Here, we investigate in detail the thickness-dependent electrical, structural, and optical properties of sequentially strain-relaxed La-doped SrSnO3 (SLSO) epitaxial thin films. We find that the SLSO films grow as an orthorhombic Pnma phase with a - a - c + in the c + direction under the tensile strain. With the strain relaxation, as the films become thicker, vertical grain boundaries are created and the orthorhombic phase becomes reoriented to all three possible orientations. Simultaneously, the conductance starts to deviate from the linear behavior with increasing film thickness. Through the analysis of thickness fringes in optical transmittance, we found that a 120 nm thick nominally 4% La-doped SrSnO3 film has a figure of merit (φTC = 2.65 × 10-3 Ω-1) at λ = 300 nm in the deep-UV region, which is the highest value among the well-known candidates for UV TCOs reported to date.

3D Printing of Skin Equivalents with Hair Follicle Structures and Epidermal-Papillary-Dermal Layers Using Gelatin/Hyaluronic Acid Hydrogels.

Recent advances in three-dimensional (3D) bioprinting technologies have enabled the fabrication of sophisticated live 3D tissue analogs. Despite the existing hydrogel-based bioinks, the development of advanced bioink materials that can accurately reproduce the composition of a native extracellular matrix and mimic the intrinsic properties of laden cells remains challenging. In this study, 3D printed skin equivalents incorporating hair follicle structures and epidermal/papillary dermal layers were fabricated using gelatin methacryloyl/hyaluronic acid methacryloyl (GelMA/HAMA) bioink. The composition of collagen and glycosaminoglycan in native skin was recapitulated by adjusting the combination of GelMA and HAMA. The GelMA/HAMA bioink exhibited excellent viscoelastic and physicochemical properties, 3D printability, cytocompatibility, and functionality to maintain hair-inductive potency while facilitating spontaneous hair pore development. The results indicate that GelMA/HAMA hydrogels are promising candidates as bioinks for the 3D printing of skin equivalents. Furthermore, they may serve as useful models for skin tissue engineering and regeneration.

Detection of volatile sulfur compounds (VSCs) in exhaled breath as a potential diagnostic method for oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma causes a significant proportion of global cancer morbidity and mortality. The aim of this study is to investigate whether the exhaled breath test can be a new, non-invasive, and effective method for diagnosing oral squamous cell carcinoma. METHODS: A comparative analysis of exhaled breath between patients with oral squamous cell carcinoma (OSCC) and healthy controls (HC) was performed with the Twin Breasor II™, a simple gas chromatography system. RESULTS: Both hydrogen sulfide (H2S) and methyl mercaptan (Ch3SH) were significantly higher in the OSCC group than in the HC group. The total sulfur concentration was also higher in the OSCC group, but there was no significant difference in the ratio of Ch3SH to H2S between the two groups. Using logistic regression, we constructed a new variable with an area under the curve (AUC) of 0.740, 68.0% sensitivity, and 72.0% specificity. CONCLUSIONS: Exhaled gas analysis via simple gas chromatography can potentially serve as an accessory non-invasive method for OSCC diagnosis.

Effect of scanning-aid agents on the scanning accuracy in specially designed metallic models: A laboratory study.

The advent of intraoral scanning methods has caused a paradigm shift in dentistry. However, despite their many advantages, intraoral scanners cannot accurately recognize the metallic surfaces of prothesis. Therefore, this experiment was designed to verify the effect of scanning-aid agents on the scanning accuracy using metallic reference models. Three different types of metallic reference models (inlay, onlay, and bridge) were specially designed and produced using a milling machine to simulate intraoral dental restorations. Three experimental groups (application of ScanCure, IP Scan Spray, and VITA Powder Scan Spray) were set up and scanned images (each n = 5) were acquired using the I500® intraoral scanner. The reference datasets were established by a 3D design that reflected the deviations between the measured distances and previously planned distances on the reference models. All acquired experimental datasets were digitally superimposed and compared with the reference datasets. Intragroup comparisons (precision, n = 10) were also performed. The root mean square (RMS) values of trueness in the ScanCure and IP groups were significantly more accurate than those of the VITA group in the inlay and onlay reference models (p < 0.05). Notably, in the bridge reference model, the liquid-type ScanCure group showed the highest accuracy of trueness, with statistical significance (p < 0.05). However, the RMS values of precision were not significantly different among the groups. These findings suggest that liquid-type scanning agents can be effectively used to obtain more accurate scan images of intraoral metallic dental restorations.