3D printed PCL/ß-TCP cross-scale scaffold with high-precision fiber for providing cell growth and forming bones in the pores.

Scaffolds prepared by 3D printing are increasingly used in the field of bone tissue repair. However, on traditional 3D printed bone tissue engineering scaffolds, cells can only grow on the fiber surface and form bone. We designed a scaffold with a cross-scale structure of PCL/ß-TCP, which contains thick fibers with a diameter of 500 µm printed by FDM. And in the pores of the coarse fiber, the ultra-high precision fine fiber grid with a diameter of about 10 µm is filled by MEW mode. In cell experiments, cells can not only grow on the thick fiber surface of the cross-scale scaffold. At the same time, the mesh structure of fine fibers provides a bridge for cell growth, allowing cells to pass through the pores of thick fibers and grow in the pores and gradually cover the pores of the scaffold. In the osteoinduction experiment, ß-TCP in the PCL/ß-TCP composite provides Ca2+ and PO43- to the scaffold, which effectively promotes the osteogenic differentiation of cells on the scaffold. Compared with traditional scaffolds, the osteogenic performance of cross-scale scaffolds is greatly improved. Not only did bone form on the surface of the scaffold, but also obvious ALP expression and effective calcium precipitation appeared in the pores of the scaffold. This can effectively speed up the repair of bone defects. We believe that the 3D printed PCL/ß-TCP cross-scale scaffold with high-precision fibers has great application prospects in the field of bone tissue engineering.

Advances in tissue engineering of vasculature through three-dimensional bioprinting.

BACKGROUND: A significant challenge facing tissue engineering is the fabrication of vasculature constructs which contains vascularized tissue constructs to recapitulate viable, complex and functional organs or tissues, and free-standing vascular structures potentially providing clinical applications in the future. Three-dimensional (3D) bioprinting has emerged as a promising technology, possessing a number of merits that other conventional biofabrication methods do not have. Over the last decade, 3D bioprinting has contributed a variety of techniques and strategies to generate both vascularized tissue constructs and free-standing vascular structures. RESULTS: This review focuses on different strategies to print two kinds of vasculature constructs, namely vascularized tissue constructs and vessel-like tubular structures, highlighting the feasibility and shortcoming of the current methods for vasculature constructs fabrication. Generally, both direct printing and indirect printing can be employed in vascularized tissue engineering. Direct printing allows for structural fabrication with synchronous cell seeding, while indirect printing is more effective in generating complex architecture. During the fabrication process, 3D bioprinting techniques including extrusion bioprinting, inkjet bioprinting and light-assisted bioprinting should be selectively implemented to exert advantages and obtain the desirable tissue structure. Also, appropriate cells and biomaterials matter a lot to match various bioprinting techniques and thus achieve successful fabrication of specific vasculature constructs. CONCLUSION: The 3D bioprinting has been developed to help provide various fabrication techniques, devoting to producing structurally stable, physiologically relevant, and biologically appealing constructs. However, although the optimization of biomaterials and innovation of printing strategies may improve the fabricated vessel-like structures, 3D bioprinting is still in the infant period and has a great gap between in vitro trials and in vivo applications. The article reviews the present achievement of 3D bioprinting in generating vasculature constructs and also provides perspectives on future directions of advanced vasculature constructs fabrication.

Lactoferrin/Calcium Phosphate-Modified Porous Ti by Biomimetic Mineralization: Effective Infection Prevention and Excellent Osteoinduction.

The surface modification of titanium (Ti) can enhance the osseointegration and antibacterial properties of implants. In this study, we modified porous Ti discs with calcium phosphate (CaP) and different concentrations of Lactoferrin (LF) by biomimetic mineralization and examined their antibacterial effects and osteogenic bioactivity. Firstly, scanning electron microscopy (SEM), the fluorescent tracing method, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and the releasing kinetics of LF were utilized to characterize the modified Ti surface. Then, the antibacterial properties against S. sanguis and S. aureus were investigated. Finally, in vitro cytological examination was performed, including evaluations of cell adhesion, cell differentiation, extracellular matrix mineralization, and cytotoxicity. The results showed that the porous Ti discs were successfully modified with CaP and LF, and that the LF-M group (200 µg/mL LF in simulated body fluid) could mildly release LF under control. Further, the LF-M group could effectively inhibit the adhesion and proliferation of S. sanguis and S. aureus and enhance the osteogenic differentiation in vitro with a good biocompatibility. Consequently, LF-M-modified Ti may have potential applications in the field of dental implants to promote osseointegration and prevent the occurrence of peri-implantitis.

Efficacy of aromatherapy on dental anxiety: A systematic review of randomised and quasi-randomised controlled trials.

OBJECTIVES: To evaluate the efficacy of aromatherapy on dental anxiety. METHODS: A detailed protocol was registered a priori (PROSPERO: CRD42019141093). PubMed, EMBASE, CDSR, CENTRAL, CNKI and grey literature databases were searched from inception to 10 January 2020. Randomised controlled trials (RCTs) and quasi-randomised controlled trials (CCTs) that examined the effects of aromatherapy on dental anxiety, compare to either negative control (i.e. no aromatherapy) or other positive control approaches (e.g. music), were included. The risk of bias of the selected studies was evaluated using the Cochrane Collaboration's tool and ROBINS-I, while the certainty of evidence was assessed using GRADE. A narrative synthesis was performed, rather than meta-analysis, due to the high level of heterogeneity across studies. RESULTS: Eleven RCTs and six CCTs were included. The risk of bias was identified as either high or unclear in RCTs, and moderate to serious in CCTs. Performance bias and detection bias were the most prevalent in RCTs, followed by selection bias and reporting bias. As to CCTs, greater risk of bias was found in the selection of participants into the study and in the measurement of outcomes. Based on the selected studies, the most commonly used aromatherapy for dental anxiety management was lavender fragrance, followed by orange. Compared to the negative control condition, aromatherapy might reduce the anxiety-related physiological parameters and psychometric rating, pain, and mood, alertness, and calmness compared to the negative control condition; and there might be no intergroup difference in such outcomes between aromatherapy and music. However, GRADEs of the relevant evidence were judged as low to very low. CONCLUSIONS: Compared to the negative control condition, aromatherapy is more effective to reduce dental anxiety and has comparable effects on dental anxiety compared to music intervention; however, the certainty of evidence is relatively limited. Further high-quality randomised trials with robust study design and large sample size are warranted to confirm our findings and to confirm the role of aromatherapy in relieving dental anxiety.

3D printing of metal-organic framework incorporated porous scaffolds to promote osteogenic differentiation and bone regeneration.

Bone substitute biomaterials, whose compositions and structures both play vital roles in bone defect healing, hold promising prospects in the clinical treatment of bone defects. Three-dimensional (3D) printed porous scaffolds incorporating osteoinductive components are considered as ideal bone grafts, because of the accurate control of structure parameters and the capacity to enhance bone tissue regeneration. Our previous studies demonstrated that nanoscale zeolitic imidazolate framework-8 (nanoZIF-8), a subclass of metal organic frameworks (MOFs), presented minimal cytotoxicity, inhibited bacterial activities, and promoted osteogenesis both in vitro and in vivo. However, the application of nanoZIF-8 in the 3D printed scaffold system remains unknown. In this study, nanoZIF-8 was incorporated into composite scaffolds composed of polycaprolactone (PCL) and dicalcium phosphate dihydrate (DCPD) via extrusion-based 3D printing technology. The results revealed that the composite scaffolds possessed increased mechanical strength and exhibited homogeneous structure with highly interconnected macropores. In vitro studies indicated that scaffolds showed biocompatibility to bone mesenchymal stem cells (BMSCs), significantly up-regulated the expression of osteogenesis-related genes and proteins, and facilitated the extracellular matrix mineralization. In vivo results showed that 3D printed porous scaffolds promoted new bone formation and enhanced micro-architecture at the critical defect sites (Φ10 mm) in rabbits, compared with the blank control group. Moreover, composite scaffolds significantly improved calvarial defect healing in comparison with scaffolds without nanoZIF-8 incorporation. In summary, nanoZIF-8 modified 3D printed porous composite scaffolds demonstrated great potential in the treatment of critical-sized bone defects, proving the effectiveness of MOF incorporation in 3D printed composite scaffolds to promote osteogenesis in the field of bone tissue engineering.

Development and validation of prognostic index based on autophagy-related genes in patient with head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide, accounting for almost 50% of all malignancies in developing nations. Autophagy plays a vital role in cancer initiation, malignant progression, and resistance to treatment. However, autophagy-related gene sets have rarely been analyzed in HNSCC. Hence, it is necessary to assess its clinical and pathological significance in a larger cohort of patients with HNSCC. The purpose of this study was to establish a novel autophagy-related prognostic marker for HNSCC. We screened 232 autophagy-related genes (ARGs) and identified 38 differentially expressed ARGs in The Cancer Genome Atlas (TCGA) cohorts. The prognosis-related ARGs signature, established using the univariate and multivariate Cox proportional regression models, consists of 10 ARGs that could divide patients into high-risk and low-risk groups. Survival analysis indicated that patients in the high-risk group had dramatically shorter overall survival compared with their low-risk counterparts. Cox regression analysis further confirmed the independent prognostic value of the autophagy-related signature, and the area under the receiver operating characteristic curve of the combined prognostic model was 0.722. Finally, the efficacy of autophagy-related signature was also validated by an independent cohort from the Gene Expression Omnibus (GEO) database. Collectively, we successfully constructed a novel autophagy-related signature for the prediction of prognosis in patients with HNSCC.

Canine edge width and height affect dental esthetics in maxillary canine substitution treatment.

BACKGROUND: To investigate the effect of canine edge width and height on dental esthetics in maxillary canine substitution treatment. METHODS: A total of 127 canine substitution treatment cases were screened and evaluated by a panel of orthodontic experts and laypersons in the pilot study. The top five subjects with the esthetically most pleasant canine substitution were included in the study, resulting in 140 computerized images displaying only the upper dentition, with different canine edge widths (0%, 12.5%, 25%, 37.5%, 50%, 62.5%, and 75% of the central clinical width) and heights (- 0.5 mm, 0 mm, 0.5 mm, and 1.0 mm vertically relative to the central incisor edge) finally used for the esthetic evaluation by 101 observers (41 orthodontists and 60 laypersons). The ordered logistic regression analysis, the univariate analysis of variance, the chi-square, and Fisher's exact tests were used for statistical analyses. RESULTS: The most esthetic canine shape for canine substitution was found to be a shape with the edge width of 62.5% of the central incisor width and the edge height of 0.5 mm gingival to the central incisor edge (P < 0.05). The canine edge width of 50-75% and height of 0.5-0 mm gingival to the central incisor edge were generally considered to be esthetic by all observers. Orthodontists and laypersons had the same ranking on the top two most esthetic canine shapes (edge width and height 62.5% and 0.5 mm gingival; 50% and 0 mm incisal) as well as the bottom two most unesthetic canine shape (0% and 0.5 mm gingival; 75% and 1 mm incisal). Male and female observers generally had similar esthetic grades and rankings on the canine shapes (P > 0.05). CONCLUSIONS: The most esthetic canine shape for canine substitution is a shape with the canine edge width of 62.5% of the central incisor width and the edge height of 0.5 mm gingival to the central incisor edge. The different collocations of the canine edge width and height affect dental esthetics of the canine during canine substitution treatment.

[The effect of valsartan on the expression of the receptor for advanced glycation end products in human glomerular mesangial cells].

OBJECTIVE: To elucidate the effect of valsartan on human glomerular mesangial cells oxidative stress and the expression of the receptor for advanced glycation end products (RAGE) induced by the advanced glycation end-products (AGEs). METHODS: Human glomerular mesangial cells were treated with advanced glycation end-product-bovine serum albumin (AGE-BSA) in the presence of valsartan. The reactive oxygen species (ROS) in cells were measured by Flow cytometry, and the mRNA of p47 phox, which was the primary subunits of NADPH oxidase, was detected by semi-quantitative reberse transcription polymerase chain reaction (RT-PCR). The mRNA of RAGE was detected by RT-PCR and the RAGE protein was assayed by immunocytochemistry. RESULTS: The product of ROS, and the expression of p47 phox and RAGE in mesangial cells, which were treated with AGE-BSA in the presence of valsartan, were down-regulated compared with the groups treated with AGE-BSA (P < 0.05). Valsartan dose-dependently and time-dependently inhibited the AGE-elicited overexpression of RAGE, ROS and p47(phox) in mesangial cells. CONCLUSION: Valsartan could inhibit RAGE expression through downregulation of oxidative stress.