Novel Stereo-Induction Pattern in Pudovik Addition/Phospha-Brook Rearrangement Towards Chiral Trisubstituted Allenes.

Despite the significance of chiral allene skeletons in catalysis, organic synthesis and medicinal chemistry et al., there is a scarcity of reports on axially chiral allenyl phosphorus compounds. Here, we disclosed an efficient and straightforward cascade reaction between ethynyl ketones and phosphine oxides, resulting in a broad array of trisubstituted allenes incorporating a phosphorus moiety in high yields with excellent stereoselectivities facilitated by peptide-mimic phosphonium salt (PPS) catalysis, Additionally, comprehensive series of mechanistic experiments have been conducted to elucidate that this cascade reaction proceeds via an asymmetric Pudovik addition reaction followed by a subsequent phospha-Brook rearrangement that occurs concomitantly with kinetic resolution, representing a stereospecific rearrangement and protonation process facilitating central-to-axial chirality transfer in a cascade manner. We anticipate that our research will pave the way for a promising exploration of novel stereo-induction pattern in the Pudovik addition/phospha-Brook rearrangement cascade reaction.

Quantitative Pretreatment CT Parameters as Predictors of Tumor Response of Neuroendocrine Tumor Liver Metastasis to Transcatheter Arterial Bland Embolization.

PURPOSE: To assess whether parameters on preprocedural CT can be utilized to predict the response of NETLM to transcatheter arterial bland embolization (TAE). METHODS: We retrospectively reviewed 135 target lesions from 48 NETLM patients who underwent TAE and with complete preprocedural multiphasic CT. Parameters on preprocedural CT including the longest diameter, mean attenuation value in nonenhanced, arterial, and portal-venous phases were collected from each target lesion. Radiological responses were assessed according to RECIST 1.1. The parameters of responder lesions and nonresponder lesions were compared. Arterial enhancement index (AEI) and portal-venous enhancement index (PEI) were calculated. The predictive function of AEI and PEI on tumor response was analyzed by receiver operating characteristic (ROC) curve. RESULTS: A total of 72.6% target lesions had a partial response. For patients, the objective response rate was 72.9%. Mean attenuation values of responder lesions were significantly higher than nonresponder lesions in both arterial and portal-venous phases (105.36 ± 37.24 vs. 76.01 ± 19.19, p < 0.001; 96.61 ± 24.04 vs. 82.12 ± 21.37, p = 0.002). ROC curve showed that both AEI and PEI were effective in predicting tumor response (area under the curve [AUC] 0.757, p < 0.001; AUC 0.655, p = 0.005). CONCLUSION: AEI and PEI, parameters from evaluation of CT pretreatment attenuation of NETLMs, could predict response to TAE treatment.

Proposal and In-Depth Analysis of Emergency Treatment Procedures for Removing Fractured Abutments in Implants With Tapped-In Connections: Case Report.

In implant-supported prostheses, the most frequently reported mechanical complications after implant restoration are loosening or fracture of abutments or screws. Such complications have serious consequences, and removal of fractured abutments or screws is difficult. There are various methods to remove fractured abutment screws in implants with screwed-in connections. However, no approach has been reported to retrieve solid abutments in implants with a locking-taper implant-abutment connection, which are rarely observed in clinical settings. This study presents the case of a 62-year-old male patient with a fractured abutment in an upper-right second premolar implant. Abutment fracture is a common mechanical complication after dental implantation. Parafunctional habits and occlusal overloading may generate excessive occlusal forces, which increase the risk of mechanical complications. This report presents a series of emergency procedures for removing a fractured solid abutment and fabricating a new prosthesis to restore the edentulous area. In this retrospective analysis, the authors deeply consider the whole treatment, through which the deficiencies of the treatment are noted, and corresponding future directions are discussed. This case report presents a convenient approach to removing a solid abutment in a sudden emergency, discusses possible reasons for solid abutment fractures, designs a new rescue kit for easy retrieval of such abutments and summarizes a valid solution for removing fractured solid abutments.

[Research progress on the mechanism of circular RNA involved in stem cell differentiation and its prospect of tissue engineering application].

Circular RNA (circRNA) is a type of single-stranded RNA that binds in a closed loop structure by covalent bond. It is highly expressed and has diverse functions in the eukaryotic transcriptome, and it also has the potential to regulate the process of cell differentiation. Stem cells are important seed cells and common research tools in the field of tissue engineering, which have multi-directional differentiation potential and low immunogenicity. Its clinical application for the treatment of diseases has broad prospects, and the research on their differentiation mechanism has gradually penetrated to the molecular level. A number of studies have shown that circRNA participates in stem cell differentiation and plays a key role through a variety of pathways. This article focuses on the expression changes of circRNA during stem cell differentiation and its research advancement in regulating the differentiation mechanism of various stem cells. The review also prospects its possible role in tissue regeneration and repair, in order to further study the molecular mechanism of circRNA involved in stem cell differentiation and provide ideas for clinical practice of stem cells in biomedical engineering.

Non-thermal plasma reduces periodontitis-induced alveolar bone loss in rats.

Periodontitis, a chronic infectious disease induced by microbial biofilm, is one of the most common diseases worldwide. Scaling and root planning (SRP) has always been recognized as the typical treatment. However, the therapeutic efficiency is often limited due to the intraoperative bleeding and the limitations of instruments. Non-thermal atmospheric plasma (NTP) appears to be a potential tool for periodontitis due to its promising biofilm degradation and decontamination effects. In this study, we investigated the role of NTP, as an adjuvant approach for the treatment of ligature-induced periodontitis in rats. Herein we showed that SRP or SRP-NTP application attenuated the periodontitis-induced alveolar bone loss, reflected by the increased BV/TV value and the decreased CEJ-AB distance, which might be related to the lower detection rate of periodontal pathogen in SRP and SRP-NTP groups. Besides, SRP-NTP rats showed less bone loss and lower CEJ-AB distance than that of SRP group at 30d post treatment, indicating a more comprehensive and long-lasting effect of SRP-NTP. A remarkable decrease of osteoclast number and lower expression of RANKL was also detected in SRP-NTP rats. In addition, expression of inflammatory-related cytokines such as TNF-α and IL-1ß decreased significantly in SRP-NTP group, while IL-10 level increased substantially. These results together illustrated that a combination of SRP and NTP treatment was an effective way to prevent periodontitis progress, which reduced alveolar bone loss and promoted periodontium restoration in ligature-induced periodontitis rats. In conclusion, non-thermal plasma treatment may be considered as a feasible and effective supplementary approach to control periodontitis.

Anatomic Locking Plate for Displaced Intraarticular Calcaneal Fracture: Design and Application.

Calcaneal fracture can lead to long-term disability and have a considerable economic effect. Most calcaneal fractures are intraarticular fractures involving the posterior facet of the subtalar joint. Treating displaced intraarticular calcaneal fractures is complicated because of the lack of an optimal treatment option. Internal fixation typically involves screw-and-plate implants, which can be unfavorable owing to the lack of an anatomic design and the intraoperative bending required for the plate to contour to the irregular surface of the calcaneus. We assessed the outcomes of 30 patients treated using innovative, anatomically designed calcaneal locking plates and the perceived advantages for surgeons. Postoperative computed tomography images of the affected feet were obtained, and the functional performance was recorded. The mean average Böhler angle had increased significantly from 16.8° ± 14.9° to 28.5° ± 9.4° (p < .001). The mean average maximal fracture gap and maximal step-off in the posterior facet of the subtalar joint in the coronal computed tomography images also decreased significantly from 2.8 ± 3.7 mm to 0.8 ± 1.3 mm (p < .01) and from 3.3 ± 2.8 mm to 0.8 ± 1.2 mm (p < .001), respectively. The mean average American Orthopaedic Foot and Ankle Ankle-Hindfoot scale score was 93.9 ± 7.1 at the final follow-up visit. In addition, the surgical time was reduced because bending the plate was not required and the quality of reduction could be assessed easily by examining the gap between the cortex and the plate. The results were promising, revealing that the anatomic locking plate can be used effectively in the treatment of displaced intraarticular calcaneal fractures using simple reduction techniques with a potentially shortened operating time.

Effects of Low-Intensity Pulsed Ultrasound on Implant Osseointegration in Ovariectomized Rats.

OBJECTIVES: To investigate the effect of low-intensity pulsed ultrasound (US) on periimplant bone healing and osseointegration under osteoporotic conditions. METHODS: Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm2, spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0­2, 280 minutes; group 2: weeks 0­4, 560 minutes; group 3: weeks 0­6, 840 minutes; group 4: weeks 0­8, 1120 minutes; group 5: weeks 0­10, 1400 minutes; group 6: weeks 0­12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro­computed tomography; the implantbone interface was assessed histologically; and implant fixation strength was determined by a removal torque test. RESULTS: Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and periimplant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study. CONCLUSIONS: Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action.

Effects of Low-Intensity Pulsed Ultrasound on Implant Osseointegration in Ovariectomized Rats.

OBJECTIVES: To investigate the effect of low-intensity pulsed ultrasound (US) on peri-implant bone healing and osseointegration under osteoporotic conditions. METHODS: Seventy-two 12-week-old female Sprague Dawley rats received bilateral ovariectomies. Twelve weeks later, titanium implants were bilaterally placed in the proximal tibial metaphysis. The right tibia was exposed to low-intensity pulsed US (40 mW/cm2 , spatial and temporal average) for 20 min/d starting the 2nd day after implantation, and the left tibia served as a control without stimulation. The rats were randomly assigned to 6 groups of 12 each according to the US duration (group 1: weeks 0-2, 280 minutes; group 2: weeks 0-4, 560 minutes; group 3: weeks 0-6, 840 minutes; group 4: weeks 0-8, 1120 minutes; group 5: weeks 0-10, 1400 minutes; group 6: weeks 0-12, 1680 minutes). At the end of the 2nd, 4th, 6th, 8th, 10th, and 12th weeks, the rats were euthanized, and bilateral tibias were harvested. Peri-implant bone volume and bone-implant contact were assessed by micro-computed tomography; the implant-bone interface was assessed histologically; and implant fixation strength was determined by a removal torque test. RESULTS: Low-intensity pulsed US increased bone-implant contact at the 4th, 6th, 8th, 10th, and 12th weeks (P = .019, .017, <.001, <.001, and <.001, respectively) and peri-implant bone volume at all times (P = <.001, .002, .012, .007, .005, and .010). Removal torque on the US side was improved at the 6th, 8th, 10th, and 12th weeks (P= .012, <.001, .006, and .009). Ultrasound evoked a favorable bone response in the histologic study. CONCLUSIONS: Low-intensity pulsed US might enhance new bone formation, especially at an early stage, and improve osseointegration in osteoporotic bone as an auxiliary method. However, further studies are needed to elucidate the mechanisms underlying its action.

Change in collateral ligament length and tibiofemoral movement following joint line variation in TKA.

PURPOSE: The primary intent of total knee arthroplasty is the restoration of normal knee kinematics, with ligamentous constraint being a key influential factor. Displacement of the joint line may lead to alterations in ligament attachment sites relative to knee flexion axis and variance of ligamentous constraints on tibiofemoral movement. This study aimed to investigate collaterals strains and tibiofemoral kinematics with different joint line levels. METHODS: A previously validated knee model was employed to analyse the change in length of the collateral ligaments and tibiofemoral motion during knee flexion. The models shifted the joint line by 3 and 5 mm both proximally and distally from the anatomical level. The data were captured from full extension to flexion 135°. RESULTS: The elevated joint line revealed a relative increase in distance between ligament attachments for both collateral ligaments in comparison with the anatomical model. Also, tibiofemoral movement decreased with an elevation in the joint line. Conversely, lowering the joint line led to a significant decrease in distance between ligament attachments, but greater tibiofemoral motion. CONCLUSION: Elevation of the joint line would strengthen the capacity of collateral ligaments for knee motion constraint, whereas a distally shifted joint line might have the advantage of improving tibiofemoral movement by slackening the collaterals. It implies that surgeons can appropriately change the joint line position in accordance with patient's requirement or collateral tensions. A lowered joint line level may improve knee kinematics, whereas joint line elevation could be useful to maintain knee stability. LEVEL OF EVIDENCE: V.

Is the posterior cruciate ligament necessary for medial pivot knee prostheses with regard to postoperative kinematics?

PURPOSE: Excellent clinical and kinematical performance is commonly reported after medial pivot knee arthroplasty. However, there is conflicting evidence as to whether the posterior cruciate ligament should be retained. This study simulated how the posterior cruciate ligament, post-cam mechanism and medial tibial insert morphology may affect postoperative kinematics. METHODS: After the computational intact knee model was validated according to the motion of a normal knee, four TKA models were built based on a medial pivot prosthesis; PS type, modified PS type, CR type with PCL retained and CR type with PCL sacrificed. Anteroposterior translation and axial rotation of femoral condyles on the tibia during 0°-135° knee flexion were analyzed. RESULTS: There was no significant difference in kinematics between the intact knee model and reported data for a normal knee. In all TKA models, normal motion was almost fully restored, except for the CR type with PCL sacrificed. Sacrificing the PCL produced paradoxical anterior femoral translation and tibial external rotation during full flexion. CONCLUSION: Either the posterior cruciate ligament or post-cam mechanism is necessary for medial pivot prostheses to regain normal kinematics after total knee arthroplasty. The morphology of medial tibial insert was also shown to produce a small but noticeable effect on knee kinematics. LEVEL OF EVIDENCE: V.

Biomechanical considerations in the design of high-flexion total knee replacements.

Typically, joint arthroplasty is performed to relieve pain and improve functionality in a diseased or damaged joint. Total knee arthroplasty (TKA) involves replacing the entire knee joint, both femoral and tibial surfaces, with anatomically shaped artificial components in the hope of regaining normal joint function and permitting a full range of knee flexion. In spite of the design of the prosthesis itself, the degree of flexion attainable following TKA depends on a variety of factors, such as the joint's preoperative condition/flexion, muscle strength, and surgical technique. High-flexion knee prostheses have been developed to accommodate movements that require greater flexion than typically achievable with conventional TKA; such high flexion is especially prevalent in Asian cultures. Recently, computational techniques have been widely used for evaluating the functionality of knee prostheses and for improving biomechanical performance. To offer a better understanding of the development and evaluation techniques currently available, this paper aims to review some of the latest trends in the simulation of high-flexion knee prostheses.

METTL3 promotes osteogenic differentiation of human umbilical cord mesenchymal stem cells by up-regulating m6A modification of circCTTN.

BACKGROUND: Human umbilical cord mesenchymal stem cells (hUCMSCs) are promising seed cells in bone tissue engineering. circRNA and N6-methyladenosine (m6A) RNA methylation play important roles in osteogenic differentiation. Here, we investigated the potential relevance of a critical circRNA, hsa_circ_0003376 (circCTTN), and methyltransferase-like 3 (METTL3) in osteogenic differentiation of hUCMSCs. METHODS: Expression of circCTTN after hUCMSC osteogenic induction was detected by qRT-PCR. Three databases (RMBase v2.0, BERMP, and SRAMP) were used to predict m6A sites of circCTTN. RNA was enriched by methylated RNA immunoprecipitation (MeRIP), followed by quantitative real-time polymerase chain reaction to detect m6A level of circCTTN after METTL3 overexpression and osteogenic induction. RNA pull-down, Western blotting, and protein mass spectrometry were performed to investigate the potential mechanisms by which METTL3 promoted m6A modification of circCTTN. Bioinformatic analyses based on database (STRING) search and co-immunoprecipitation were used to analyze the proteins that interacted with METTL3. RESULTS: Overexpression of METTL3 promoted osteogenic differentiation of hUCMSCs and increased m6A level of circCTTN. Two potential m6A modification sites of circCTTN were predicted. No direct interaction between METTL3 and circCTTN was observed. Thirty-one proteins were pulled down by probes specific for circCTTN, including NOP2, and two m6A reading proteins, EIF3A and SND1. Bioinformatics analysis and co-immunoprecipitation showed that METTL3 interacted with EIF3A indirectly through NOP2. CONCLUSIONS: METTL3 promotes the osteogenic differentiation of hUCMSCs by increasing the m6A level of circCTTN. However, METTL3 does not bind directly to circCTTN. METTL3 interacts with circCTTN indirectly through NOP2 and EIF3A.

Novel Nonthermal Atmospheric Plasma Irradiation of Titanium Implants Promotes Osteogenic Effect in Osteoporotic Conditions.

Osteoporosis is a metabolic disease characterized by bone density and trabecular bone loss. Bone loss may affect dental implant osseointegration in patients with osteoporosis. To promote implant osseointegration in osteoporotic patients, we further used a nonthermal atmospheric plasma (NTAP) treatment device previously developed by our research group. After the titanium implant (Ti) is placed into the device, the working gas flow and the electrode switches are turned on, and the treatment is completed in 30 s. Previous studies showed that this NTAP device can remove carbon contamination from the implant surface, increase the hydroxyl groups, and improve its wettability to promote osseointegration in normal conditions. In this study, we demonstrated the tremendous osteogenic enhancement effect of NTAP-Ti in osteoporotic conditions in rats for the first time. Compared to Ti, the proliferative potential of osteoporotic bone marrow mesenchymal stem cells on NTAP-Ti increased by 180% at 1 day (P = 0.004), while their osteogenic differentiation increased by 149% at 14 days (P < 0.001). In addition, the results indicated that NTAP-Ti significantly improved osseointegration in osteoporotic rats in vivo. Compared to the Ti, the bone volume fraction (BV/TV) and trabecular number (Tb.N) values of NTAP-Ti in osteoporotic rats, respectively, increased by 18% (P < 0.001) and 25% (P = 0.007) at 6 weeks and the trabecular separation (Tb.Sp) value decreased by 26% (P = 0.02) at 6 weeks. In conclusion, this study proved a novel NTAP irradiation titanium implant that can significantly promote osseointegration in osteoporotic conditions.

Clinical performance of two onlay designs for molars after root canal treatment.

PURPOSE: To evaluate the clinical performance of two proposed onlay designs. METHODS: Molars with occlusal and/or mesial/distal defects after root canal treatment were classified by design into three groups. Onlays without shoulders were the control group (Group C, n = 50). The designed onlays were Group O (n = 50) and the designed mesio-occlusal/disto-occlusal onlays were Group MO/DO (n = 80). All onlays had an occlusal thickness of approximately 1.5-2.0 mm, and the designed onlays had a shoulder depth and width of approximately 1 mm. In Groups C and O, the box-shaped retention was 1.5 mm in depth. The proximal box was connected with a dovetail retention in Group MO/DO. Patients were examined every 6 months and followed for 36 months. Restorations were evaluated by using the modified United States Public Health Service Criteria. Statistical analysis was performed by using Kaplan-Meier analysis, the chi-square test, and Fisher's exact test. RESULTS: No tooth fracture, debonding, secondary caries, or gingivitis was observed in any group. Groups O and MO/DO had satisfactory survival and success rates, and there was no significant difference in performance characteristics among the three groups (P > 0.05). CONCLUSION: The two proposed onlay designs were effective in protecting molars.

Engineered cell-overexpression of circular RNA hybrid hydrogels promotes healing of calvarial defects.

Craniomaxillofacial bone defects seriously affect the physical and mental health of patients. Bone marrow mesenchymal stem cells (BMSCs) are "gold standard" cells used for bone repair. However, the collection of BMSCs is invasive, and the osteogenic capacity is limited with age. Human umbilical cord mesenchymal stem cells (hUCMSCs) are promising alternative seed cells for bone tissue engineering. Our group previously used high-throughput sequencing technology and bioinformatics methods to detect circ-CTTN (hsa-circ_0003376) molecules, which may play an essential role in the osteogenic differentiation of hUCMSCs. In this study, osteogenic induction in vitro showed that the overexpressing circ-CTTN (OE group) exhibits a more pronounced osteogenic phenotype. The levels of osteogenesis-related genes in the OE group were highly expressed. The gelatin-methacrylate (GelMA) hydrogel possessed excellent biocompatibility and was used to load hUCMSCs. In the rat calvarial defect, the OE group presented a larger bone healing volume and denser bone trabecular distribution than other groups. So far, the overexpression of circ-CTTN could enhance the osteogenic differentiation of hUCMSCs and accelerate bone reconstruction. Our research could provide a new strategy and a strong theoretical basis for promoting hUCMSC clinical application in bone tissue engineering.

Recent Advances in Hydrogel-Based Phototherapy for Tumor Treatment.

Phototherapeutic agent-based phototherapies activated by light have proven to be safe modalities for the treatment of various malignant tumor indications. The two main modalities of phototherapies include photothermal therapy, which causes localized thermal damage to target lesions, and photodynamic therapy, which causes localized chemical damage by generated reactive oxygen species (ROS). Conventional phototherapies suffer a major shortcoming in their clinical application due to their phototoxicity, which primarily arises from the uncontrolled distribution of phototherapeutic agents in vivo. For successful antitumor phototherapy, it is essential to ensure the generation of heat or ROS specifically occurs at the tumor site. To minimize the reverse side effects of phototherapy while improving its therapeutic performance, extensive research has focused on developing hydrogel-based phototherapy for tumor treatment. The utilization of hydrogels as drug carriers allows for the sustained delivery of phototherapeutic agents to tumor sites, thereby limiting their adverse effects. Herein, we summarize the recent advancements in the design of hydrogels for antitumor phototherapy, offer a comprehensive overview of the latest advances in hydrogel-based phototherapy and its combination with other therapeutic modalities for tumor treatment, and discuss the current clinical status of hydrogel-based antitumor phototherapy.

The Potential Value of Probiotics after Dental Implant Placement.

Dental implantation is currently the optimal solution for tooth loss. However, the health and stability of dental implants have emerged as global public health concerns. Dental implant placement, healing of the surgical site, osseointegration, stability of bone tissues, and prevention of peri-implant diseases are challenges faced in achieving the long-term health and stability of implants. These have been ongoing concerns in the field of oral implantation. Probiotics, as beneficial microorganisms, play a significant role in the body by inhibiting pathogens, promoting bone tissue homeostasis, and facilitating tissue regeneration, modulating immune-inflammatory levels. This review explores the potential of probiotics in addressing post-implantation challenges. We summarize the existing research regarding the importance of probiotics in managing dental implant health and advocate for further research into their potential applications.

Lyophilized Platelet-Rich Fibrin Exudate-Loaded Carboxymethyl Chitosan/GelMA Hydrogel for Efficient Bone Defect Repair.

Platelet-rich fibrin (PRF) is an autologous growth factor carrier that promotes bone tissue regeneration, but its effectiveness is restrained by poor storage capabilities, uncontrollable concentration of growth factors, unstable shape, etc. Herein, we developed a photocrosslinkable composite hydrogel by incorporating lyophilized PRF exudate (LPRFe) into the carboxymethyl chitosan methacryloyl (CMCSMA)/gelatin methacryloyl (GelMA) hydrogel to effectively solve the dilemma of PRF. The hydrogel possessed suitable physical properties and sustainable release ability of growth factors in LPRFe. The LPRFe-loaded hydrogel could improve the adhesion, proliferation, migration, and osteogenic differentiation of rat bone mesenchymal stem cells (BMSCs). Furthermore, the animal experiments demonstrated that the hydrogel possessed excellent biocompatibility and biodegradability, and the introduction of LPRFe in the hydrogel can effectively accelerate the bone healing process. Conclusively, the combination of LPRFe with CMCSMA/GelMA hydrogel may be a promising therapeutic approach for bone defects.

Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes.

Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE(2) and NO assay showed that LIPUS could enhance PGE(2) and NO secretion from MLO-Y4 cells at all time points within 24h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE(2) from osteocytes may play a role in this effect.

Promoting the adhesion of human gingival epithelial cells on titanium surface by non-thermal atmospheric plasma irradiation.

OBJECTIVES: This work aimed to study the biological behavior of human gingival epithelial cells (HGECs) irradiated by non-thermal atmospheric plasma (NTAP) on a titanium surface. METHODS: Cultured HGECs (3⁃5 generations) with the best activity were digested and treated for varying times (0, 10, 20, 30, and 60 s) by NTAP and then seeded on the surface of a titanium disc. The HGECs were cultured in oral keratinocyte medium and 1% penicillin/streptomycin solution. The cells were kept in an atmosphere of 5% CO2 at 37 ℃ and incubated for different times (4, 12, 24, and 48 h; n=5). Cell counting kit-8 (CCK-8) was used to detect cell adhesion capacity. Scanning electron microscopy (SEM) was conducted to observe the morphology of cells on titanium plates. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to evaluate the gene expression of adhesion-related molecules, such as Laminin α3, Integrin ß4, and Plectin. RESULTS: The number of adhered cells increased at 0­20 s, whereas that gradually decreased at 20⁃60 s. Therefore, cell culture at the two time points showed that HGECs adhesion reached the maximum when NATP was irradiated for 20 s. Compared with the control group, more cells in the treatment group adhered to the titanium surface at each time point (P<0.05). Cells in the treatment group showed more irregular polygons, more protrusions and pseudopods, and a larger cell diffusion area on the titanium surface than those in the control group. qRT-PCR showed that the expression levels of Laminin α3, Integrin ß4, and Plectin adhesion-related genes on the titanium surface in the treatment group were higher than those in the control group at each culture time point (P<0.05). Western blot showed that the expression levels of Laminin α3, Integrin ß4, and Plectin adhesion-related proteins on the titanium surface were higher in the treatment group than in the control group at 4 and 12 h. CONCLUSIONS: After NTAP treatment, the results showed that 20 s of treatment time could maximize the number of adhered cells on the titanium surface; change the cell adhesion morphology; and significantly upregulate the expression of adhesion-related genes and proteins of Laminin α3, Integrin ß4, and Plectin. Furthermore, it could promote the biological sealing effect of HGECs on the titanium surface.