Three-Dimensional Printed Titanium Scaffolds Enhance Osteogenic Differentiation and New Bone Formation by Cultured Adipose Tissue-Derived Stem Cells Through the IGF-1R/AKT/Mammalian Target of Rapamycin Complex 1 (mTORC1) Pathway.

BACKGROUND This study aimed to investigate the effects of three-dimensional (3D) printed titanium (3DTi) scaffolds on osteogenic differentiation and new bone formation by 3D cultured adipose tissue-derived stem cells (ADSCs) in vitro, and the effects of bone regeneration in vivo using a full-thickness mandibular defect rat model, and the mechanisms involved. MATERIAL AND METHODS Alpha-beta titanium alloy (Ti6Al4V) 3DTi scaffolds were prepared with Cellmatrix hydrogel and 3D culture medium. ADSCs were impregnated into the 3DTi scaffolds. ADSC viability and proliferation were assessed using the cell counting kit-8 (CCK-8) assay, and alkaline phosphatase (ALP) levels were measured. Real-time polymerase chain reaction (RT-PCR) and Western blot were performed to assess the expression of osteogenesis-related mRNA for RUNX2, OPN, OCN, and IGF-1 genes and proteins. A rat model of full-thickness mandibular defect was evaluated with micro-computed tomography (microCT) scanning, and histochemistry with Alizarin red and von Giesen's stain were used to evaluate osteogenesis. RESULTS ADSC viability and proliferation were not affected by culture with 3DTi scaffolds. Expression of osteogenesis-related mRNA and proteins for RUNX2, OPN, OCN, and IGF-1, expression of ALP, and histochemical findings showed that the use of 3DTi scaffolds enhanced osteogenic differentiation and new bone formation by ADSCs, with upregulation of components of the IGF-1R/AKT/mTORC1 pathway. CONCLUSIONS The 3D culture of ADSCs with 3DTi scaffolds enhanced osteogenic differentiation and new bone formation through the IGF-1R/AKT/mTORC1 pathway. This improved method of osteointegration may have clinical application in the preparation of bone grafts before implantation for improved repair of mandibular bone defects.

Root-shaped antibacterial alginate sponges with enhanced hemostasis and osteogenesis for the prevention of dry socket.

Tooth extraction commonly causes uncontrolled bleeding, loss of blood clots, and bacterial infection, leading to the dry socket and bone resorption. Thus, it is highly attractive to design a bio-multifunctional scaffold with outstanding antimicrobial, hemostatic, and osteogenic performances for avoiding dry sockets in clinical applications. Herein, alginate (AG)/quaternized chitosan (Qch)/diatomite (Di) sponges were fabricated via electrostatic interaction, Ca2+ cross-linking, as well as lyophilization methods. The composite sponges are facilely made into the shape of the tooth root, which could be well integrated into the alveolar fossa. The sponge shows a highly interconnected and hierarchical porous structure at the macro/micro/nano levels. The prepared sponges also possess enhanced hemostatic and antibacterial abilities. Moreover, in vitro cellular assessment indicates that the developed sponges have favorable cytocompatibility and significantly facilitate osteogenesis by upregulating the formation of alkaline phosphatase and calcium nodules. The designed bio-multifunctional sponges display great potential for trauma treatment after tooth extraction.

Antibacterial quaternary ammonium chitosan/carboxymethyl starch/alginate sponges with enhanced hemostatic property for the prevention of dry socket.

Tooth extraction commonly leads to postoperative wound bleeding, bacterial infection, and even the occurrence of dry socket. Therefore, developing a biomedical material with favorable antibacterial and excellent hemostatic properties to prevent the post-extraction dry socket is necessary. Herein, quaternary ammonium chitosan/ carboxymethyl starch/alginate (ACQ) sponges are developed via Ca2+ cross-linking, electrostatic interaction, and lyophilization methods. The results show that the bio-multifunctional sponges exhibit interconnected porous structures with significant fluid absorption rates and suitable water vapor transmission rates. In vitro cellular and hemolysis experiments indicate that the developed sponges have acceptable biocompatibility. Notably, the constructed sponges effectively inhibit the growth of E. coli, S. aureus, and C. albicans, as well as achieve rapid hemostasis in the mouse liver injury and mini-pig tooth extraction models by absorbing blood and promoting red blood cell adhesion. Thus, the created bio-multifunctional sponges show tremendous promise as a hemostatic material for wound management after tooth extraction.

Changes of liposome and antioxidant activity in immature rice during seed development.

For the past several decades, only a few studies were conducted on the change in immature rice liposomes during seed development. To evaluate and compare the lipid material of different degrees of developing rice grains, this paper focused on fresh rice seeds from only one most popular species of Dasan divided into five growth periods. The lipid components of fresh rice, especially γ-oryzanol and fatty acids equipped with extremely beneficial phytonutrients, were investigated. The results illustrated that the level of extracted liposome increased gradually along with the development of rice and in the third stage of development, the level of liposome achieved maximum. And then, instead of increasing, it was decreased at later stages of development. Moreover, the antioxidant activity of fresh edible rice (FER) was also evaluated by DPPH and ABTS assay. It was shown that FER has the higher antioxidant activity than the ripened rice seed on lipids, which will improve FER using on the functional foods and help provide certainly theoretical basis in food processing industry.

Anterior retropharyngeal approach to C1 for percutaneous vertebroplasty under C-arm fluoroscopy.

BACKGROUND CONTEXT: Percutaneous vertebroplasty (PVP) has proven to be a valuable palliative treatment option for patients with medically refractory painful osteolytic metastases of the spine. Percutaneous vertebroplasty of the atlas has been reported in only seven articles and has been performed with different techniques and approaches. PURPOSE: To describe the technique we used to perform PVP of a lytic lesion of the lateral mass of C1 via anterior retropharyngeal approach guided by C-arm fluoroscopy. STUDY DESIGN: A technical report. PATIENT SAMPLE: It included a 75-year-old man with known metastatic lung carcinoma and incapacitating right suboccipital and neck pain refractory to conventional medical treatment. Radiologic evaluation showed revealed osteolytic destruction of C1 and C2, mainly invading the right lateral mass of C1 and the vertebral body of C2. OUTCOME MEASURES: The right suboccipital and neck pain was measured using the visual analog scale (VAS). METHODS: Under C-arm fluoroscopy, a novel anterior retropharyngeal approach, through the vertebral body of C2 into the metastatic osteolytic vertebral lesion of C1, was performed to achieve the PVP in C1 followed by a PVP in C2. RESULTS: Immediately after the operation, the patient reported substantial pain relief (from VAS 9/10 preoperatively to 3/10). At 12 hours postoperatively, the range of motion was also improved. There were no surgery-related complications. The immediately postoperative cervical plain film and computed tomography scan showed adequate filling of the osteolytic lesion without the obvious leakage of bone cement. Clinical follow-up at 3 months revealed that this pain condition was improved and maintained (VAS 1/10). CONCLUSIONS: When the transoral approach is unsuitable or contraindicated, the anterior retropharyngeal approach could be an efficacious alternative in selected patients with C1 metastasis, providing adequate filling of bone cement and significant pain relief. Based on our preliminary exploration, only assisted by C-arm fluoroscopy, this approach is feasible to achieve PVP in C1 under local anesthesia and intravenous analgesia. Nevertheless, when considering the substantial potential risks, this technically challenging procedure should be performed by experienced operators.

[Effect of casein osphopeptide-amorphous calcium phosphate solution in preventing enamel demineralization].

OBJECTIVE: To evaluate the effects of casein osphopeptide-amorphous calcium phosphate (CPP-ACP) in preventing enamel demineralization. METHODS: Enamel blocks were prepared from premolars extracted from orthodontic patients. The specimens were treated for 30 min daily for 7 days with one of the following agents: deionized water (negative control), CPP-ACP paste, and NaF solutions (positive controls) (0.2% and 2%). After the treatments, the specimens were immersed in a demineralizing solution (pH 4.5) for 7 days. The morphology and depth of the lesion were observed using scanning electron microscopy, and the content of Ca, P, Mg in the demineralized enamel was measured by electron probe micro-analyzer. RESULTS: The demineralization rates in all the treatment groups were significantly smaller than those in the control group after 7 days of demineralization. CONCLUSION: The application of CPP-ACP to the enamel surfaces can inhibit enamel demineralization with an equivalent effect to 0.2% NaF.

Orthodontic tooth movement in alveolar cleft repaired with a tissue engineering bone: an experimental study in dogs.

Tissue engineering approaches have been successfully used in repairing bone defects and have become a viable alternative to autologous bone. The aim of the present study was to investigate if a construct of porous beta-tricalcium phosphate (ß-TCP) combined with osteogenically induced bone marrow stromal cells (bMSCs) could repair alveolar cleft, and allow for subsequent orthodontic tooth movement in a canine model. Twelve alveolar osteotomy surgeries in six animals were made bilaterally and randomly implanted by (1) tissue-engineered bone complex of bMSCs/ß-TCP (group A, n=4), (2) ß-TCP alone (group B, n=4), and (3) autologous bone obtained from iliac bone (group C, n=4). Contralateral alveolar defects were created in one animal and left untreated to serve as blank control to observe spontaneous healing of the defects. Sequential fluorescent labeling and radiographic observation was used to evaluate new bone formation and mineralization in each defect. Orthodontic tooth movement was initiated 8 weeks after surgical operation for 12 weeks, and then the dogs were sacrificed for histological and histomorphometric analysis. Results indicated that the tissue-engineered complex with bMSCs/ß-TCP dramatically promoted new bone formation and mineralization and achieved a favorable height of the repaired alveolar when compared with ß-TCP alone, which absorbed severely. The overall effect of the tissue-engineered bone was equivalent to autologous bone; the physiological function of the alveolar bone was restored by allowing the adjacent teeth to move into the newly formed bone in the grafted region. This study demonstrated that the tissue engineering bone from the combination of ß-TCP and bMSCs is a feasible clinical approach for patients with alveolar cleft and the subsequent orthodontic tooth movement.