scholarly journals The biological seal of the implant–soft tissue interface evaluated in a tissue-engineered oral mucosal model

2012 ◽  
Vol 9 (77) ◽  
pp. 3528-3538 ◽  
Author(s):  
Wen L. Chai ◽  
Ian M. Brook ◽  
Anders Palmquist ◽  
Richard van Noort ◽  
Keyvan Moharamzadeh

For dental implants, it is vital that an initial soft tissue seal is achieved as this helps to stabilize and preserve the peri-implant tissues during the restorative stages following placement. The study of the implant–soft tissue interface is usually undertaken in animal models. We have developed an in vitro three-dimensional tissue-engineered oral mucosal model (3D OMM), which lends itself to the study of the implant–soft tissue interface as it has been shown that cells from the three-dimensional OMM attach onto titanium (Ti) surfaces forming a biological seal (BS). This study compares the quality of the BS achieved using the three-dimensional OMM for four types of Ti surfaces: polished, machined, sandblasted and anodized (TiUnite). The BS was evaluated quantitatively by permeability and cell attachment tests. Tritiated water (HTO) was used as the tracing agent for the permeability test. At the end of the permeability test, the Ti discs were removed from the three-dimensional OMM and an Alamar Blue assay was used for the measurement of residual cells attached to the Ti discs. The penetration of the HTO through the BS for the four types of Ti surfaces was not significantly different, and there was no significant difference in the viability of residual cells that attached to the Ti surfaces. The BS of the tissue-engineered oral mucosa around the four types of Ti surface topographies was not significantly different.

2021 ◽  
Vol 22 (2) ◽  
pp. 475
Author(s):  
Parastoo Memarian ◽  
Francesco Sartor ◽  
Enrico Bernardo ◽  
Hamada Elsayed ◽  
Batur Ercan ◽  
...  

Carbon enriched bioceramic (C-Bio) scaffolds have recently shown exceptional results in terms of their biological and mechanical properties. The present study aims at assessing the ability of the C-Bio scaffolds to affect the commitment of canine adipose-derived mesenchymal stem cells (cAD-MSCs) and investigating the influence of carbon on cell proliferation and osteogenic differentiation of cAD-MSCs in vitro. The commitment of cAD-MSCs to an osteoblastic phenotype has been evaluated by expression of several osteogenic markers using real-time PCR. Biocompatibility analyses through 3-(4,5-dimethyl- thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), lactate dehydrogenase (LDH) activity, hemolysis assay, and Ames test demonstrated excellent biocompatibility of both materials. A significant increase in the extracellular alkaline phosphatase (ALP) activity and expression of runt-related transcription factor (RUNX), ALP, osterix (OSX), and receptor activator of nuclear factor kappa-Β ligand (RANKL) genes was observed in C-Bio scaffolds compared to those without carbon (Bio). Scanning electron microscopy (SEM) demonstrated excellent cell attachment on both material surfaces; however, the cellular layer on C-Bio fibers exhibited an apparent secretome activity. Based on our findings, graphene can improve cell adhesion, growth, and osteogenic differentiation of cAD-MSCs in vitro. This study proposed carbon as an additive for a novel three-dimensional (3D)-printable biocompatible scaffold which could become the key structural material for bone tissue reconstruction.


2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Jinkyu Lee ◽  
Sangmin Lee ◽  
Sung Min Kim ◽  
Heungsoo Shin

Abstract Background Fabrication of three-dimensional stem cell spheroids have been studied to improve stem cell function, but the hypoxic core and limited penetration of nutrients and signaling cues to the interior of the spheroid were challenges. The incorporation of polymers such as silica and gelatin in spheroids resulted in relatively relaxed assembly of composite spheroids, and enhancing transport of nutrient and biological gas. However, because of the low surface area between cells and since the polymers were heterogeneously distributed throughout the spheroid, these polymers cannot increase the cell to extracellular matrix interactions needed to support differentiation. Methods We developed the stem cell spheroids that incorporate poly(ι-lactic acid) single-segmented fibers synthesized by electrospinning and physical and chemical fragmentation. The proper mixing ratio was 2000 cells/μg fibers (average length of the fibers was 50 μm - 100 μm). The SFs were coated with polydopamine to increase cell binding affinity and to synthesize various-sized spheroids. The function of spheroids was investigated by in vitro analysis depending on their sizes. For statistical analysis, Graphpad Prism 5 software (San Diego, CA, USA) was used to perform one-way analysis of variance ANOVA with Tukey’s honest significant difference test and a Student’s t-test (for two variables) (P < 0.05). Results Spheroids of different sizes were created by modulating the amount of cells and fibers (0.063 mm2–0.322 mm2). The fibers in the spheroid were homogenously distributed and increased cell viability, while cell-only spheroids showed a loss of DNA contents, internal degradation, and many apoptotic signals. Furthermore, we investigated stemness and various functions of various-sized fiber-incorporated spheroids. In conclusion, the spheroid with the largest size showed the greatest release of angiogenic factors (released VEGF: 0.111 ± 0.004 pg/ng DNA), while the smallest size showed greater effects of osteogenic differentiation (mineralized calcium: 18.099 ± 0.271 ng/ng DNA). Conclusion The spheroids incorporating polydopamine coated single-segmented fibers showed enhanced viability regardless of sizes and increased their functionality by regulating the size of spheroids which may be used for various tissue reconstruction and therapeutic applications.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 203 ◽  
Author(s):  
Chun-Hao Tsai ◽  
Chih-Hung Hung ◽  
Che-Nan Kuo ◽  
Cheng-Yu Chen ◽  
Yu-Ning Peng ◽  
...  

Recently, cases of bone defects have been increasing incrementally. Thus, repair or replacement of bone defects is gradually becoming a huge problem for orthopaedic surgeons. Three-dimensional (3D) scaffolds have since emerged as a potential candidate for bone replacement, of which titanium (Ti) alloys are one of the most promising candidates among the metal alloys due to their low cytotoxicity and mechanical properties. However, bioactivity remains a problem for metal alloys, which can be enhanced using simple immersion techniques to coat bioactive compounds onto the surface of Ti–6Al–4V scaffolds. In our study, we fabricated magnesium-calcium silicate (Mg–CS) and chitosan (CH) compounds onto Ti–6Al–4V scaffolds. Characterization of these surface-modified scaffolds involved an assessment of physicochemical properties as well as mechanical testing. Adhesion, proliferation, and growth of human Wharton’s Jelly mesenchymal stem cells (WJMSCs) were assessed in vitro. In addition, the cell attachment morphology was examined using scanning electron microscopy to assess adhesion qualities. Osteogenic and mineralization assays were conducted to assess osteogenic expression. In conclusion, the Mg–CS/CH coated Ti–6Al–4V scaffolds were able to exhibit and retain pore sizes and their original morphologies and architectures, which significantly affected subsequent hard tissue regeneration. In addition, the surface was shown to be hydrophilic after modification and showed mechanical strength comparable to natural bone. Not only were our modified scaffolds able to match the mechanical properties of natural bone, it was also found that such modifications enhanced cellular behavior such as adhesion, proliferation, and differentiation, which led to enhanced osteogenesis and mineralization downstream. In vivo results indicated that Mg–CS/CH coated Ti–6Al–4V enhances the bone regeneration and ingrowth at the critical size bone defects of rabbits. These results indicated that the proposed Mg–CS/CH coated Ti–6Al–4V scaffolds exhibited a favorable, inducive micro-environment that could serve as a promising modification for future bone tissue engineering scaffolds.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jolanta Opiela ◽  
Joanna Romanek ◽  
Daniel Lipiński ◽  
Zdzisław Smorąg

The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were maturedin vitroin control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P<0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P<0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higherBaxmRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure.


2012 ◽  
Vol 91 (7) ◽  
pp. 642-650 ◽  
Author(s):  
K. Moharamzadeh ◽  
H. Colley ◽  
C. Murdoch ◽  
V. Hearnden ◽  
W.L. Chai ◽  
...  

Advances in tissue engineering have permitted the three-dimensional (3D) reconstruction of human oral mucosa for various in vivo and in vitro applications. Tissue-engineered oral mucosa have been further optimized in recent years for clinical applications as a suitable graft material for intra-oral and extra-oral repair and treatment of soft-tissue defects. Novel 3D in vitro models of oral diseases such as cancer, Candida, and bacterial invasion have been developed as alternatives to animal models for investigation of disease phenomena, their progression, and treatment, including evaluation of drug delivery systems. The introduction of 3D oral mucosal reconstructs has had a significant impact on the approaches to biocompatibility evaluation of dental materials and oral healthcare products as well as the study of implant-soft tissue interfaces. This review article discusses the recent advances in tissue engineering and applications of tissue-engineered human oral mucosa.


Author(s):  
Ho Yeon Kang ◽  
Hyeonjong Lee ◽  
Yong Kwon Chae ◽  
Seoung-Jin Hong ◽  
Yun Yeong Jeong ◽  
...  

This study evaluated the feasibility of a tooth preparation guide for prefabricated zirconia crowns (PZCs). Three-dimensional surface data for PZCs of the left maxillary primary first molar and left mandibular primary second molar were obtained using a model scanner. The tooth preparation data were digitally designed to harmonize with the adjacent teeth on the mixed dentition model and visualized using a color-coded map, which presents the required amount of tooth reduction. Twenty participants were recruited for preparing teeth with and without using the tooth preparation guide. The following three parameters were evaluated: tooth preparation time, harmony score, and amount of tooth reduction. The preparation time when using the guide was significantly reduced (p < 0.05), and a significant difference was observed in the harmony scores for the maxillary primary first molar preparation. Furthermore, the amount of tooth reduction was significantly different for both maxillary and mandibular primary molars (p < 0.05) in terms of the occlusal distal surface and buccal line angle in the maxillary primary first molars, and the smooth surfaces, proximal surfaces, and mesial line angles in the mandibular primary second molars. Thus, the results suggest that a tooth preparation guide could facilitate better tooth preparation for PZCs.


Author(s):  
I. M. Sebastine ◽  
D. J. Williams

Tissue engineering aims to restore the complex function of diseased tissue using cells and scaffold materials. Tissue engineering scaffolds are three-dimensional (3D) structures that assist in the tissue engineering process by providing a site for cells to attach, proliferate, differentiate and secrete an extra-cellular matrix, eventually leading cells to form a neo-tissue of predetermined, three-dimensional shape and size. For a scaffold to function effectively, it must possess the optimum structural parameters conducive to the cellular activities that lead to tissue formation; these include cell penetration and migration into the scaffold, cell attachment onto the scaffold substrate, cell spreading and proliferation and cell orientation. In vivo, cells are organized in functional tissue units that repeat on the order of 100 μm. Fine scaffold features have been shown to provide control over attachment, migration and differentiation of cells. In order to design such 3D featured constructs effectively understanding the biological response of cells across length scales from nanometer to millimeter range is crucial. Scaffold biomaterials may need to be tailored at three different length scales: nanostructure (&lt;1μm), microstructure (&lt;20–100μm), and macrostructure (&gt;100μm) to produce biocompatible and biofunctional scaffolds that closely resemble the extracellular matrix (ECM) of the natural tissue environment and promote cell adhesion, attachment, spreading, orientation, rate of movement, and activation. Identification of suitable fabrication techniques for manufacturing scaffolds with the required features at multiple scales is a significant challenge. This review highlights the effect and importance of the features of scaffolds that can influence the behaviour of cells/tissue at different length scales in vitro to increase our understanding of the requirements for the manufacture of functional 3D tissue constructs.


2001 ◽  
Vol 75 (11) ◽  
pp. 5335-5342 ◽  
Author(s):  
Kartik Chandran ◽  
Xing Zhang ◽  
Norman H. Olson ◽  
Stephen B. Walker ◽  
James D. Chappell ◽  
...  

ABSTRACT Mammalian reoviruses, prototype members of theReoviridae family of nonenveloped double-stranded RNA viruses, use at least three proteins—ς1, μ1, and ς3—to enter host cells. ς1, a major determinant of cell tropism, mediates viral attachment to cellular receptors. Studies of ς1 functions in reovirus entry have been restricted by the lack of methodologies to produce infectious virions containing engineered mutations in viral proteins. To mitigate this problem, we produced virion-like particles by “recoating” genome-containing core particles that lacked ς1, μ1, and ς3 with recombinant forms of these proteins in vitro. Image reconstructions from cryoelectron micrographs of the recoated particles revealed that they closely resembled native virions in three-dimensional structure, including features attributable to ς1. The recoated particles bound to and infected cultured cells in a ς1-dependent manner and were approximately 1 million times as infectious as cores and 0.5 times as infectious as native virions. Experiments with recoated particles containing recombinant ς1 from either of two different reovirus strains confirmed that differences in cell attachment and infectivity previously observed between those strains are determined by the ς1 protein. Additional experiments showed that recoated particles containing ς1 proteins with engineered mutations can be used to analyze the effects of such mutations on the roles of particle-bound ς1 in infection. The results demonstrate a powerful new system for molecular genetic dissections of ς1 with respect to its structure, assembly into particles, and roles in entry.


2017 ◽  
Vol 87 (5) ◽  
pp. 725-732
Author(s):  
Donghyun Hwang ◽  
Won-June Lee ◽  
Kyung-A Kim ◽  
Seung-Hak Baek ◽  
Young-Guk Park ◽  
...  

ABSTRACT Objective: To investigate the morphometric and histological alterations of the constricted alveolar ridge when affected by root thrusting with and without open-flap decortication. Materials and Methods: Eight beagles were divided into three groups: C, control without root thrusting; R, root thrusting only; RD, root thrusting with alveolar decortication. The ridge constriction model was prepared in 16 mandibular quadrants after extraction of the third premolars. Reciprocal root thrusting of the second and fourth premolars was performed toward the constricted ridge for 10 weeks, having a moment of 900 g-mm. Open-flap decortication was conducted on the constricted bone surface in group RD. Micro-CT-based histomorphometric analysis and trichrome-staining-based tissue fractional analysis were performed to evaluate morphometric and microstructural changes on the ridge. Results: Group R revealed a higher percentage of bone volume (P &lt; .001), lower bone mineral density (P &lt; .01), and higher trabecular number (P &lt; .001) than did group C, which was supported by a higher bone fraction woven to lamellar bone (P &lt; .05) resulting from histologic fractional analysis. However, group RD showed no significant difference from group C. Conclusions: Root thrusting toward the constricted ridge induced hypertrophic bone modeling with a high trabecular fraction on the ridge. However, combined open-flap decortication with root thrusting did not improve the volume or quality of the constricted ridge.


Author(s):  
Brilliant Margalin ◽  
S. P. Edijanto ◽  
Paulus B. Notopuro

Fibrin glue is a useful biological product to stop bleeding, adhesive tissue and accelerate wound healing. Preparation of Fibrin Glue requires fibrinogen and thrombin components. The routine cryoprecipitation method performed at the Blood Bank can be used to improve the quality of the fibrinogen component. The Freeze Drying process can increase the retention time of plasma products at room temperature. Yield Fibrinogen and Tensile Strength is a quantitative and qualitative parameter of preparation quality of fibrin glue. This study focused on finding differences between Tensile Strength and Yield Fibrinogen on fibrin glue preparative by cryoprecipitate with and without freeze drying methods.This study is in vitro laboratory experiments design by comparing the Yield Fibrinogen and Tensile Strength of fibrin glue preparation from cryoprecipitic plasma with and without freeze dried process. The results were analyzed comparatively using paired T test.The plasma fibrinogen content of the sample was 237.66 ± 67.10 mg / dL. The fibrinogen content of the cryoprecipitate component without freeze drying process was 327.74 ± 103.42 mg / dL with a yield fibrinogen of 1.38 ± 0.25. The fibrinogen content of the cryoprecipitate component with freeze drying process was 251.20 ± 103.91 mg / dL with yield fibrinogen 1.04 ± 0.25. Tensile strength of fibrin glue from cryoprecipitate without freeze drying process was found to average 0.52 ± 0.18. Tensile strength of fibrin glue from cryoprecipitate with freeze drying process was found to average 0.33 ± 0.12. There was a significant difference between yield fibrinogen and tensile strength of fibrin glue preparation of cryoprecipitation method with and without freeze dried process.There is a significant difference on yields fibrinogen and tensile strength in the preparation of fibrin glue by the freeze drying process which is probably due to changes in the structure and function of fibrinogen proteins.


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