A study on the morphology of iliac crest based on the objectives of jaw bone defect reconstruction.

OBJECTIVES: to understand the morphological characteristics of iliac crest and provide advice and assistance for jaw bone reconstruction with iliac bone flap by evaluating the thickness and curvature of iliac crest. MATERIALS AND METHODS: 100 patients who had taken Spiral CT of the Abdominal region before surgeries between 2020 and 2022 were included in this study. 3D reconstruction images of the iliac bones were created. 5 vertical planes perpendicular to the iliac crest were made every 2 cm along the centerline of the iliac crest (VP2 ~ VP10). On these vertical planes, 4 perpendicular lines were made every 1 cm along the long axis of the iliac crest (D1 ~ D4). The thicknesses at these sites, horizontal angle (HA) of iliac crest and the distance between inflection point and the central point of anterior superior iliac spine (DIA) were measured. RESULTS: The thickness of iliac bone decreased significantly from D1 ~ D4 on VP6 ~ VP10 and from VP2 ~ VP10 on D3 and D4 level (P<0.05). HA of iliac crests was 149.13 ± 6.92°, and DIA was 7.36 ± 1.01 cm. Iliac bone thickness, HA and DIA had very weak or weak correlation with patient's age, height and weight. CONCLUSIONS: The average thicknesses of iliac crest were decreased approximately from front to back, from top to bottom. The thickness and curvature of the iliac crest were difficult to predict by age, height and weight. CLINICAL RELEVANCE: Virtual surgical planning is recommended before jaw bone reconstruction surgery with iliac bone flap, and iliac crest process towards alveolar process might be a better choice.

Clinical applications and outcomes of the surgical tooth extrusion technique: A bibliometric analysis from 1982 to 2023.

STATEMENT OF PROBLEM: The surgical extrusion technique has been advocated for severely damaged teeth as well as for intruded and unerupted teeth. However, a quantitative literature analysis is lacking. PURPOSE: The purpose of this bibliometric analysis was to provide a comprehensive overview of surgical extrusion, assess the applications and outcomes, and evaluate topics for future research. MATERIAL AND METHODS: An electronic search was conducted in leading databases in April 2023. Human studies with surgical tooth extrusion or synonyms in titles or abstracts were included. A bibliographic analysis, co-occurrence analysis, and coupling of publications were performed. The analysis of variance was used to assess the characteristics of the subgroups based on indications. The survival rate was evaluated by using the Kaplan-Meier method in the R software program (α=.05). RESULTS: Fifty-one studies from 1982 to 2023 were included. The Journal of Dental Traumatology and the Journal of Prosthetic Dentistry combined published approximately one-third of the papers and acquired the most citations. The burst detection of keywords revealed 4 popular research topics: the Benex extraction system, chlorhexidine for infection control, rigid or semi-rigid splints to decrease the risk of complications, and novel restorative materials to improve esthetics. An overall survival rate of 96.36% was reported among 316 participants with 330 extruded teeth. No significant differences were found in study types, geographic distribution, year of publication, or citation counts among the 4 subgroups (surgical extrusion for subgingival fractures, extensive caries, intruded teeth, and unerupted teeth). A significant difference was observed among the Kaplan-Meier curves of the 4 subgroups (P=.030). CONCLUSIONS: Surgical extrusion may be used to save otherwise nonrestorable teeth, and the procedure has shown promising survival rates when teeth are properly selected and the procedure is well executed. Subgingival fractures and extensive caries near bone level are the predominant indications, as well as intruded and unerupted teeth. Surgical extrusion is a reliable treatment option to facilitate tooth restoration for severely damaged teeth, especially for maxillary anterior teeth.

Morphometric Variations and Growth Analysis of the Side Face Profiles of Chinese Children.

OBJECTIVE: We aim to use geometric morphometric methods to analyze the contours of the side face profile and its variations in 116 children in Hunan province, China, in order to reveal common morphological features and growth of the side face profiles of Chinese children. DESIGN: We photographed the side faces with consistent standardized procedures. Thirty-seven landmarks were recorded, which comprehensively reflected the facial sagittal plane. The collection of coordinate data regarding landmarks was conducted by tpsDig software. Other analyses, such as average shape analysis, principal component analysis, variations analysis, and allometric analysis, were conducted using tpsRelw and tpsRegr. RESULT: Based on the 37 landmarks, principal component analysis was used on the profiles of boys and girls. The result shows that PC1 and PC2 account for 35.46% and 27.44% of the side face contour variations, respectively. There is no significant difference in the side profiles of boys and girls. Overlapping distributions between the boys and girls occurred. A significant difference occurs when principal component analysis was used on the side profiles of children and adults. CONCLUSIONS: There is a significant difference in the side face profiles between adult males and females. Adult males have a higher brow (the 8th landmark) than females, and adult females have a more curved forehead. However, the side face profiles of boys and girls around 10 years of age are generally similar, which suggests that the significant difference in side face profiles between adult males and females may be formed after the age of 10. This study is of great significance for both orthodontists and pediatricians to use different norms for kids and adults and different norms for males and females for each of those age groups.

Low-dose and same day use of polyethylene glycol improves image of video capsule endoscopy: A multi-center randomized clinical trial.

BACKGROUND AND AIM: Clear visualization of the small bowel is a requirement for satisfactory video capsule endoscopy (VCE). The aim of this study was to identify the optimal dose and timing of polyethylene glycol (PEG) for small bowel preparation before VCE. METHODS: A total of 410 patients were enrolled in this prospective randomized trial. All patients fasted for 12 h and ingested 320 mg simethicone 30 min before swallowing the capsule. Patients were randomized into five groups: Group A (no PEG), Group B (1-L PEG, 12 h before VCE), Group C (2-L PEG, 12 h before VCE), Group D (1-L PEG, 4 h before VCE), and Group E (2-L PEG, 4 h before VCE). The primary endpoint was small bowel visualization quality (SBVQ), and the secondary endpoints were patient acceptability and diagnosis rate of VCE. RESULTS: Excellent SBVQ was achieved in 27 (32.5%) of Group A, 38 (46.3%) of Group B, 40 (48.2%) of Group C, 55 (66.3%) of Group D, and 43 (54.4%) of Group E. The percentage of excellent SBVQ in Group D was significantly more than in Group A (66.3% vs 32.5%, P < 0.001), and diagnostic rate in the distal segment was higher (28.9% vs 10.8%, P = 0.0035). Patient acceptance of 1-L PEG was better than of 2-L PEG (P < 0.005). CONCLUSION: Small bowel cleansing with 1-L PEG given 4 h before VCE was the optimal preparation for visualization of the bowel and patient acceptance (ClinicalTrials.gov, ID: NCT02486536).

The role of Rho-GEF Trio in regulating tooth root development through the p38 MAPK pathway.

Trio, the Rho guanine nucleotide exchange factor (Rho-GEF), plays diverse roles in cell migration, cell axon guidance and cytoskeleton reorganization. Conserved during evolution, Trio encodes two guanine nucleotide exchange factor domains (GEFs) and activates small GTPases. The Rho-family small GTPases RhoA and Rac1, which are target molecules of Trio, have been described to engage in craniofacial development and tooth formation. However, the exact role of Trio in tooth development remains elusive. In this study, we generated Wnt1-cre;Triofl/fl mice to address the potential function of Trio in tooth development. Wnt1-cre;Triofl/fl mice showed short root deformity as well as decreased expression of odontogenic makers such as RUNX2, OSX, OCN, and OPN. In vitro, Trio was silenced in human stem cells of dental papilla (SCAPs). Compared with the control group, the proliferation and migration ability in the experimental group was disrupted. After knocking down Trio in SCAPs, the cells showed phenotypes of poor odontogenic differentiation and weak mineralized nodules. To study the underlying mechanism, we investigated the p38 MAPK pathway and found that loss of Trio blocked the cascade transduction of p38 MAPK signaling. In conclusion, we identified Trio as a novel coordinator in regulating root development and clarified its relevant molecular events.

LL-37 inhibits LPS-induced inflammation and stimulates the osteogenic differentiation of BMSCs via P2X7 receptor and MAPK signaling pathway.

Oral diseases, such as periapical periodontitis and periodontitis, are characterized by inflammation-induced bone loss. LL-37, a human antimicrobial peptide (AMP), has multiple biological functions and the potential to promote osteogenesis. Therefore, this study aimed to investigate the regulatory effects of LL-37 within normal and inflammatory microenvironments. The roles of P2X7 receptor (P2X7R) and mitogen-activated protein kinase (MAPK) signaling pathway were also demonstrated. The results showed that LL-37 promoted bone marrow stromal cell (BMSC) proliferation, migration and osteogenic differentiation. LL-37 inhibited the expression of the inflammatory cytokines interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and receptor activator of nuclear factor kappa-B ligand (RANKL) at both protein and gene levels, and attenuated the lipopolysaccharide (LPS)-induced inhibition of osteogenesis. Immunofluorescence (IF) confirmed P2X7R expression in BMSCs. BBG, a P2X7R antagonist, significantly attenuated LL-37-promoted osteogenesis. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH2-terminal kinase (JNK) increased after LL-37 stimulation, which did not affect p38 phosphorylation. The effects of LL-37 on osteogenesis-related gene expression were markedly attenuated by selective inhibitors of ERK1/2 and JNK. Furthermore, a mouse model of LPS-stimulated calvarial osteolysis was established, and results showed that LL-37 markedly inhibited osteoclastic bone resorption. In conclusion, we speculate that LL-37 inhibits inflammation and promotes BMSC osteogenesis via P2X7R and MAPK signaling pathway.

Gold nanoparticles in injectable calcium phosphate cement enhance osteogenic differentiation of human dental pulp stem cells.

In this study, a novel calcium phosphate cement containing gold nanoparticles (GNP-CPC) was developed. Its osteogenic induction ability on human dental pulp stem cells (hDPSCs) was investigated for the first time. The incorporation of GNPs improved hDPSCs behavior on CPC, including better cell adhesion (about 2-fold increase in cell spreading) and proliferation, and enhanced osteogenic differentiation (about 2-3-fold increase at 14 days). GNPs endow CPC with micro-nano-structure, thus improving surface properties for cell adhesion and subsequent behaviors. In addition, GNPs released from GNP-CPC were internalized by hDPSCs, as verified by transmission electron microscopy (TEM), thus enhancing cell functions. The culture media containing GNPs enhanced the cellular activities of hDPSCs. This result was consistent with and supported the osteogenic induction results of GNP-CPC. In conclusion, GNP-CPC significantly enhanced the osteogenic functions of hDPSCs. GNPs are promising to modify CPC with nanotopography and work as bioactive additives thus enhance bone regeneration.

Intrafibrillar mineralization of polyacrylic acid-bound collagen fibrils using a two-dimensional collagen model and Portland cement-based resins.

The biomimetic remineralization of apatite-depleted dentin is a potential method for enhancing the durability of resin-dentin bonding. To advance this strategy from its initial proof-of-concept design, we sought to investigate the characteristics of polyacrylic acid (PAA) adsorption to desorption from type I collagen and to test the mineralization ability of PAA-bound collagen. Portland cement and ß-tricalcium phosphate (ß-TCP) were homogenized with a hydrophilic resin blend to produce experimental resins. The collagen fibrils reconstituted on nickel (Ni) grids were mineralized using different methods: (i) group I consisted of collagen treated with Portland cement-based resin in simulated body fluid (SBF); (ii) group II consisted of PAA-bound collagen treated with Portland cement-based resin in SBF; and (iii) group III consisted of PAA-bound collagen treated with ß-TCP-doped Portland cement-based resin in deionized water. Intrafibrillar mineralization was evaluated using transmission electron microscopy. We found that a carbonyl-associated peak at pH 3.0 increased as adsorption time increased, whereas a hydrogen bond-associated peak increased as desorption time increased. The experimental resins maintained an alkaline pH and the continuous release of calcium ions. Apatite was detected within PAA-bound collagen in groups II and III. Our results suggest that PAA-bound type I collagen fibrils can be mineralized using Portland cement-based resins.

Surgical Reconstruction of Maxillary and Mandibular Defects Using a Printed Titanium Mesh.

PURPOSE: To reconstruct maxillary and mandibular defects with printed titanium mesh using computer-assisted surgery (CAS) for the achievement of structural, esthetic, and functional goals. PATIENTS AND METHODS: The authors designed and implemented this prospective study of patients with maxillary or mandibular defects who underwent reconstruction with printed titanium mesh using CAS. After surgery, the preoperative design and postoperative outcome were evaluated using Geomagic Studio software. RESULTS: The sample was comprised of 2 patients with maxillary defects and 2 with mandibular defects. A satisfactory contour was achieved in all patients. The rate of concordance between the preoperative design and the postoperative outcome was higher than 81 and 94% within 3 mm for the mandibular and maxillary reconstructions, respectively. CONCLUSION: The results of this study suggest that complicated maxillary and mandibular defects can be satisfactorily reconstructed with customized printed titanium meshes using CAS.

Surface demineralized freeze-dried bone allograft followed by reimplantation in a failed mandibular dental implant.

The removal of a failed implant with high torque causes significant damage to the surrounding tissue, compromising bone regeneration and subsequent osseointegration in the defect area. Here, we report a case of carrier screw fracture followed by immediate implant removal, bone grafting and delayed reimplantation. A dental implant with a fractured central carrier screw was removed using the bur-forceps technique. The resulting three-wall bone defect was filled with granular surface demineralized freeze-dried bone allograft (SD-FDBA). Cone-beam computerized tomography was performed at 1 week, 6 months and 15 months postoperatively and standardized for quantitative evaluation. The alveolar bone width and height at 15 months post-surgery were about 91% of the original values, with a slightly lower bone density, calculated using the gray value ratio. The graft site was reopened and was found to be completely healed with dense and vascularized bone along with some residual bone graft. Reimplantation followed by restoration was performed 8 months later. The quality of regenerated bone following SD-FDBA grafting was adequate for osseointegration and long-term implant success. The excellent osteogenic properties of SD-FDBA are attributed to its human origin, cortical bone-like structure, partly demineralized surfaces and bone morphogenetic protein-2-containing nature. Further investigation with more cases and longer follow-up was required to confirm the final clinical effect.

Breaking the radiation damage limit with Cryo-SAXS.

Small angle x-ray scattering (SAXS) is a versatile and widely used technique for obtaining low-resolution structures of macromolecules and complexes. SAXS experiments measure molecules in solution, without the need for labeling or crystallization. However, radiation damage currently limits the application of SAXS to molecules that can be produced in microgram quantities; for typical proteins, 10-20 µL of solution at 1 mg/mL is required to accumulate adequate signal before irreversible x-ray damage is observed. Here, we show that cryocooled proteins and nucleic acids can withstand doses at least two orders of magnitude larger than room temperature samples. We demonstrate accurate T = 100 K particle envelope reconstructions from sample volumes as small as 15 nL, a factor of 1000 smaller than in current practice. Cryo-SAXS will thus enable structure determination of difficult-to-express proteins and biologically important, highly radiation-sensitive proteins including light-activated switches and metalloenzymes.

Proteomic and single-cell analysis shed new light on the anti-inflammatory role of interferonß in chronic periodontitis.

Periodontitis, a condition that results in periodontal attachment loss and alveolar bone resorption, contributes to the global burden of oral disease. The underlying mechanism of periodontitis involves the dysbiosis and dyshomeostasis between host and oral microbes, among which the macrophage is one of the major innate immune cell players, producing interferon ß (IFNß) in response to bacterial infection. The objective of this research was to examine the interaction of macrophages with periodontitis and the role and mechanism of IFNß on macrophages. IFNß has been shown to have the potential to induce the differentiation of M1 to M2 macrophages, which are stimulated by low levels of lipopolysaccharide (LPS). Additionally, IFNß has been demonstrated to promote the production of ISG15 by macrophages, which leads to the inhibition of the innate immune response. Moreover, our investigation revealed that IFNß has the potential to augment the secretion of ISG15 and its downstream cytokine, IL10, in LPS-stimulated macrophages. Single-cell analysis was conducted on the gingival tissues of patients with periodontitis, which revealed a higher proportion of macrophages in the periodontitis-diseased tissue and increased expression of IFNß, ISG15, and IL10. Gene Set Enrichment Analysis indicated that bacterial infection was associated with upregulation of IFNß, ISG15, and IL10. Notably, only IL10 has been linked to immunosuppression, indicating that the IFNß-ISG15-IL10 axis might promote an anti-inflammatory response in periodontitis through IL10 expression. It is also found that macrophage phenotype transitions in periodontitis involve the release of higher levels of IFNß, ISG15, and IL10 by the anti-inflammatory M2 macrophage phenotype compared to the pro-inflammatory M1 phenotype and myeloid-derived suppressor cells (MDSCs). This implies that the IFNß-induced production of IL10 might be linked to the M2 macrophage phenotype. Furthermore, cell communication analysis demonstrated that IL10 can promote fibroblast proliferation in periodontal tissues via STAT3 signaling.

CREB1 alleviates the apoptosis and potentiates the osteogenic differentiation of zoledronic acid-treated human periodontal ligament stem cells via up-regulating VEGF.

Periodontitis represents a severe inflammatory illness in tooth supporting tissue. It has been supported that cAMP response element binding protein 1 (CREB1), a common transcription factor, extensively participates in osteogenic differentiation. Here, the current study was to look into the impacts of CREB1 on the process of periodontitis and its possible action mechanism. After human periodontal ligament stem cells (PDLSCs) were challenged with zoledronic acid (ZA), CREB1 expression was examined with RT-qPCR and western blotting. CCK-8 assay appraised cell activity. Following CREB1 elevation or/and vascular endothelial growth factor (VEGF) silencing in ZA-treated PDLSCs, CCK-8 and TUNEL assays separately estimated cell viability and apoptosis. Western blotting tested the expression of apoptosis- and osteogenic differentiation-associated proteins. ALP staining measured PDLSCs osteogenic ability and ARS staining estimated mineralized nodule formation. JASPAR predicted the potential binding of CREB1 with VEGF promoter, which was then testified by ChIP and luciferase reporter assays. RT-qPCR and western blotting tested VEGF expression. CREB1 expression was declined in ZA-exposed PDLSCs and CREB1 elevation exacerbated the viability and osteogenic differentiation while obstructed the apoptosis of PDLSCs. Additionally, CREB1 bond to VEGF promoter and transcriptionally activated VEGF expression. Further, VEGF absence partially stimulated the apoptosis while suppressed the osteogenic differentiation of CREB1-overexpressing PDLSCs treated by ZA. To be concluded, CREB1 might activate VEGF transcription to obstruct the apoptosis while contribute to the osteogenic differentiation of ZA-treated PDLSCs.

Interaction among protein, daidzein and surfactants in the WPI-based daidzein self-microemulsifying delivery system.

The self-microemulsifying delivery system was fabricated by whey protein isolate (WPI), daidzein (Dai) and surfactants, the interaction of WPI, Dai and D-α-Tocopherol polyethylene glycol succinate (TPGS) was hereby studied in the absence or presence of Tween 20. The increase of surfactant concentration led to the decrease of the modulus and changes of protein interfacial conformation, which allowed the formation of a strong intermolecular network. The environment and structure of WPI and daidzein could be changed by TPGS, and the addition of Tween 20 could further enhance the interaction between the components by changing TPGS structure. With the increase of surfactants and oil phase, Ksv and Ka values of WPI-Dai increased first and then decreased. Therefore, the interaction between the components was also dependent on the WPI-surfactant ration. These findings provide a potential strategy for designing microemulsion food system based on the understanding of the interactions among individual composition of microemulsions.

Morphometric variations and growth of the profile of the face in Chinese boys aged 4-15 years.

Much research has been conducted on the morphological growth and development of Chinese children. However, very few facial measurements have been documented, especially of the sagittal plane of the face. Morphometric variations and growth of the sagittal plane of the face in children were analyzed using geometric morphometric method in this study. The studied sample consisted of 108 boys (4-15 years) from Huzhu County in Qinghai Province of China, which were divided into three groups: 4-6 years old, 7-11 years old and 12-15 years old. It was revealed that the landmark-groups of nose area were relatively long, indicating large variation in the direction of the nasal protuberance, which possibly reflected the vigorous growth of the children's nose. There were larger landmark-groups' variability ranges in children aged 7-11 years, which may be related to the rapid growth in this period. The average morphology of the sagittal plane of the face changed a lot with age, which was showed in the comparison of the averaged graph of three groups: (1) the proportion of the forehead to entire face became smaller; (2) the 7th landmark extruded more noticeably; (3) the nose became protruding; (4) the position of the mouth was relatively getting more upward, and the angle formed between the upper lip and the lower lip increased, and the lower lip moved forward; (5) the chin protuberated. Principal Component Analysis (PCA) revealed significant differences in the main distribution areas between age group 4-6 years and 12-15 years, even though there was a lot of overlap in the three age groups. Allometric analysis showed that the sagittal plane of the face aged 4-6 years and 7-11 years changed in the following way as the size increased: the forehead became vertical and the upper lip turned to be smaller. Additionally, as the size increased in age group 12-15 years, the most prominent landmark of the forehead became more conspicuous, and the bridge of the nose got more upturned. These may reflect the common morphological features and growing development of the facial sagittal plane of Chinese children.

Comparative study on two colonic bowel preparations for patients with chronic constipation.

OBJECTIVE: To determine the efficacy, tolerance, and safety of oral sodium phosphate compared with polyethylene glycol in patients with chronic constipation. MATERIAL AND METHODS: From May 2007 to October 2007, 100 patients with chronic constipation were prospectively randomized into two groups for colonoscopy. Group A (n=49) received sodium phosphate before colonoscopy, while Group B (n=51) received polyethylene glycol. During the same period, another 50 patients in Group C with normal defecation function were enrolled and received the polyethylene glycol preparation. Patients with intestinal stenosis found by colonoscopy were excluded. The quality of preparation was assessed by the endoscopist, who was blinded to the types of bowel preparation. Laboratory examinations including hematocrit, serum phosphorous, serum calcium, blood urea nitrogen, and serum creatinine were carried out in Groups A and B before and after preparation. A questionnaire was used to assess adverse effects and patients' tolerance to the bowel preparation. RESULTS: Two patients in Group A with a diagnosis of malignant tumor detected by colonoscopy were excluded. The baseline parameters, including weight, age, gender, endoscopic diagnosis, or constipation status, were homogeneously distributed in the three groups. It was shown that the quality of preparation in Group B was poorer than that in Group C (p<0.05). Compared with Group B, Group A showed better quality of preparation, a smaller amount of intestinal air bubble, and a higher number of defecations after taking the medicine (p<0.05 for all). There were no significant differences in acceptance of the two preparations and the prevalence of adverse effects. Transient hyperphosphatasemia was noted in four patients in Group A, but neither clinical symptoms nor hypocalcemia was observed. CONCLUSIONS: Based on our preliminary study, in the preparation of patients with chronic constipation for colonoscopy, sodium phosphate is just as well tolerated and safe as a standard polyethylene glycol preparation and might provide a better quality of bowel preparation.

Biocompatibility and osteogenic activity of guided bone regeneration membrane based on chitosan-coated magnesium alloy.

Ideally, a guided bone regeneration membrane (GBRM) should possess high strength, as for titanium membranes, along with excellent biocompatibility and osteoconductivity, as for natural absorbable collagen membranes. Besides titanium, magnesium (Mg) is another metal widely used in the biomedical field, which also exhibits biodegradability. In this study, a composite chitosan­magnesium (CS-Mg) membrane was fabricated by dip-coating Mg alloy into chitosan solution. In vitro and in vivo tests were performed to investigate whether this membrane could be used as biodegradable GBRM, and the test results were compared with those obtained for a commercial GBRM (Heal-All). The microstructure was analyzed by scanning electron microscopy-electron dispersive spectroscopy. The degradation behavior was investigated by immersing the membranes into Dulbecco's modified Eagle medium (DMEM). The in vitro biocompatibility was evaluated by cell adhesion, cytotoxicity and alkaline phosphatase (ALP) assays using MG63 cells. The cytotoxicity and ALP assays were performed with diluted extracts of Mg, CS-Mg and Heal-All. The results show that CS-Mg has a suitable degradation rate, as well as similar cell adhesion and cytocompatibility to Heal-All. However, the 10% CS-Mg extracts exhibited higher ALP activity at 3 and 5 days (p < 0.05) compared with the medium control and the Heal-All extracts, but no differences with 10% Mg extracts (p > 0.05). Rabbit calvarial defects were used for testing the osteogenic activity in vivo. Three groups of samples were examined: CS-Mg, Heal-All, and a blank control. Higher amounts of new bone were formed for the CS-Mg and Heal-All groups (p < 0.05) compared with the blank control, whereas no significant differences between the CS-Mg and Heal-All groups were observed (p > 0.1). In conclusion, the CS-Mg membrane shows great potential for application as a biodegradable metallic GBRM with excellent osteogenic activity.

Iron oxide nanoparticle-calcium phosphate cement enhanced the osteogenic activities of stem cells through WNT/ß-catenin signaling.

Calcium phosphate cement (CPC), functionalized with iron oxide nanoparticles (IONP), is of great promise to promote osteoinduction and new bone formation. In this work, the IONP powder was added into the CPC powder to fabricate CPC + IONP scaffolds and the effects of the novel composite on bone matrix formation and osteogenesis of human dental pulp stem cells (hDPSCs) were explored. A series of CPC + IONP magnetic scaffolds with different IONP contents (1%, 3% and 6%) were fabricated using 5% chitosan solution as the cement liquid. Western blotting and RT-PCR were used to analyze the signaling pathway. The IONP incorporation substantially enhanced the performance of CPC + IONP, with increases in both mechanical strength and cellular activities. The IONP addition greatly promoted the osteogenesis of hDPSCs, elevating the ALP activity, the expression of osteogenic marker genes and bone matrix formation with 1.5-2-fold increases. The 3% IONP incorporation showed the most enhancement among all groups. Activation of the extracellular signal-related kinases WNT/ß-catenin in DPSCs was observed, and this activation was attenuated by the WNT inhibitor DKK1. The results indicated that the osteogenic behavior of hDPSCs was likely driven by CPC + IONP via the WNT signaling pathway. In conclusion, incorporate IONP into CPC scaffold remarkably enhanced the spreading, osteogenic differentiation and bone mineral synthesis of stem cell. Therefore, this method had great potential for bone tissue engineering. The novel CPC + IONP composite scaffolds with stem cells are promising to provide an innovative strategy to enhance bone regenerative therapies.

Novel magnetic calcium phosphate-stem cell construct with magnetic field enhances osteogenic differentiation and bone tissue engineering.

Superparamagnetic iron oxide nanoparticles (IONPs) are promising bioactive additives to fabricate magnetic scaffolds for bone tissue engineering. To date, there has been no report on osteoinductivity of IONP-incorporated calcium phosphate cement (IONP-CPC) scaffold on stem cells using an exterior static magnetic field (SMF). The objectives of this study were to: (1) develop a novel magnetic IONP-CPC construct for bone tissue engineering, and (2) investigate the effects of IONP-incorporation and SMF application on the proliferation, osteogenic differentiation and bone mineral synthesis of human dental pulp stem cells (hDPSCs) seeded on IONP-CPC scaffold for the first time. The novel magnetic IONP-CPC under SMF enhanced the cellular performance of hDPSCs, yielding greater alkaline phosphatase activities (about 3-fold), increased expressions of osteogenic marker genes, and more cell-synthesized bone minerals (about 2.5-fold), compared to CPC control and nonmagnetic IONP-CPC. In addition, IONP-CPC induced more active osteogenesis than CPC control in rat mandible defects. These results were consistent with the enhanced cellular performance by magnetic IONP in media under SMF. Moreover, nano-aggregates were detected inside the cells by transmission electron microscopy (TEM). Therefore, the enhanced cell performance was attributed to the physical forces generated by the magnetic field together with cell internalization of the released magnetic nanoparticles from IONP-CPC constructs.

Magnetic Cell-Scaffold Interface Constructed by Superparamagnetic IONP Enhanced Osteogenesis of Adipose-Derived Stem Cells.

One of the key factors in tissue engineering and regenerative medicine is to optimize the interaction between seed cells and scaffolds such that the cells can grow in naturally biomimetic conditions. Their similarity to macromolecules and many unique properties mean that functional nanoparticles have promising potential for the modification and improvement of traditional scaffolds to obtain excellent biocompatibility, tunable stiffness, physical sensing, and stimulus-response capabilities. In the present study, we report magnetic poly(lactic- co-glycolic acid)/polycaprolactone (PLGA/PCL) scaffolds that were fabricated using a combination of the electrospinning technique and layer-by-layer assembly of superparamagnetic iron oxide nanoparticles (IONPs). PLGA/PCL scaffolds assembled with gold nanoparticles were prepared using the same method for comparison. The results showed that the assembled film of nanoparticles on the surface greatly enhanced the hydrophilicity and increased the elastic modulus of the scaffold, which subsequently improved the osteogenesis of the stem cells. Furthermore, the magnetic property of the IONPs proved to be the key factor in enhancing osteogenic differentiation, which explained the superior osteogenic capacity of the magnetic scaffolds compared with that of the gold nanoparticle-assembled scaffold. These results demonstrated the importance of magnetic nanomaterials as a bioactive interface between cells and scaffolds and will promote the design of biomaterials to improve tissue engineering and regenerative medicine efficacy.