Omic Studies on In Vitro Cystinosis Model: siRNA-Mediated CTNS Gene Silencing in HK-2 Cells

Cystinosis is an autosomal recessive disease caused by mutations in the CTNS gene encoding a protein called cystinosine, which is a lysosomal cystine transporter. Disease-causing mutations lead to accumulation of cystine crystals in the lysosomes, thereby causing dysfunction of vital organs. Determination of the increased leukocyte cystine level is one of the most used methods for diagnosis. However, this method is expensive, difficult to perform, and may yield different results in different laboratories. In this study, a disease model was created with CTNS gene-silenced HK2 cells, which can mimic cystinosis in cell culture, and multiomics methods (ie, proteomics, metabolomics, and fluxomics) were implemented at this cell culture to investigate new biomarkers for the diagnosis. CTNS-silenced cell line exhibited distinct metabolic profiles compared with the control cell line. Pathway analysis highlighted significant alterations in various metabolic pathways, including alanine, aspartate, and glutamate metabolism; glutathione metabolism; aminoacyl-tRNA biosynthesis; arginine and proline metabolism; beta-alanine metabolism; ascorbate and aldarate metabolism; and histidine metabolism upon CTNS silencing. Fluxomics analysis revealed increased cycle rates of Krebs cycle intermediates such as fumarate, malate, and citrate, accompanied by enhanced activation of inorganic phosphate and ATP production. Furthermore, proteomic analysis unveiled differential expression levels of key proteins involved in crucial cellular processes. Notably, peptidyl-prolyl cis-trans isomerase A, translation elongation factor 1-beta (EF-1beta), and 60S acidic ribosomal protein decreased in CTNS-silenced cells. Additionally, levels of P0 and tubulin α-1A chain were reduced, whereas levels of 40S ribosomal protein S8 and Midasin increased. Overall, our study, through the utilization of an in vitro cystinosis model and comprehensive multiomics approach, led to the way toward the identification of potential new biomarkers while offering valuable insights into the pathogenesis of cystinosis.

Human iPSC-derived renal collecting duct organoid model cystogenesis in ADPKD

In autosomal dominant polycystic kidney disease (ADPKD), renal cyst lesions predominantly arise from collecting ducts (CDs). However, relevant CD cyst models using human cells are lacking. Although previous reports have generated in vitro renal tubule cyst models from human induced pluripotent stem cells (hiPSCs), therapeutic drug candidates for ADPKD have not been identified. Here, by establishing expansion cultures of hiPSC-derived ureteric bud tip cells, an embryonic precursor that gives rise to CDs, we succeed in advancing the developmental stage of CD organoids and show that all CD organoids derived from PKD1-/- hiPSCs spontaneously develop multiple cysts, clarifying the initiation mechanisms of cystogenesis. Moreover, we identify retinoic acid receptor (RAR) agonists as candidate drugs that suppress in vitro cystogenesis and confirm the therapeutic effects on an ADPKD mouse model in vivo. Therefore, our in vitro CD cyst model contributes to understanding disease mechanisms and drug discovery for ADPKD.

An Overview of Current Glaucomatous Trabecular Meshwork Models

PURPOSE

To provide an overview of the existing alternative models for studying trabecular meshwork (TM).

METHODS

Literature review.

RESULTS

The TM is a complex tissue that regulates aqueous humor outflow from the eye. Dysfunction of the TM is a major contributor to the pathogenesis of open-angle glaucoma, a leading cause of irreversible blindness worldwide. The TM is a porous structure composed of trabecular meshwork cells (TMC) within a multi-layered extracellular matrix (ECM). Although dysregulation of the outflow throughout the TM represents the first step in the disease process, the underlying mechanisms of TM degeneration associate cell loss and accumulation of ECM, but remain incompletely understood, and drugs targeting the TM are limited. Therefore, experimental models of glaucomatous trabeculopathy are necessary for preclinical screening, to advance research on this disease's pathophysiology, and to develop new therapeutic strategies targeting the TM. Traditional animal models have been used extensively, albeit with inherent limitations, including ethical concerns and limited translatability to humans. Consequently, there has been an increasing focus on developing alternative in vitro models to study the TM. Recent advancements in three-dimensional cell culture and tissue engineering are still in their early stages and do not yet fully reflect the complexity of the outflow pathway. However, they have shown promise in reducing reliance on animal experimentation in certain aspects of glaucoma research.

CONCLUSION

This review provides an overview of the existing alternative models for studying TM and their potential for advancing research on the pathophysiology of open-angle glaucoma and developing new therapeutic strategies.

Eicosapentaenoic acid reduces the proportion of IL-17A-producing T cells in a 3D psoriatic skin model

Psoriasis is a skin disease presenting as erythematous lesions with accentuated proliferation of epidermal keratinocytes, infiltration of leukocytes, and dysregulated lipid metabolism. T cells play essential roles in the disease. n-3 polyunsaturated fatty acids are anti-inflammatory metabolites, which exert an immunosuppressive effect on healthy T cells. However, the precise mechanistic processes of n-3 polyunsaturated fatty acids on T cells in psoriasis are still unrevealed. In this study, we aimed to evaluate the action of eicosapentaenoic acid (EPA) on T cells in a psoriatic skin model produced with T cells. A coculture of psoriatic keratinocytes and polarized T cells was prepared using culture media, which was either supplemented with 10 μM EPA or left unsupplemented. Healthy and psoriatic skin substitutes were produced according to the self-assembly method. In the coculture model, EPA reduced the proportion of IL-17A-positive cells, while increasing that of FOXP3-positive cells, suggesting an increase in the polarization of regulatory T cells. In the 3D psoriatic skin model, EPA normalized the proliferation of psoriatic keratinocytes and diminished the levels of IL-17A. The expression of the proteins of the signal transducer and activator of transcription was influenced following EPA supplementation with downregulation of the phosphorylation levels of signal transducer and activator of transcription 3 in the dermis. Finally, the NFκB signaling pathway was modified in the EPA-supplemented substitutes with an increase in Fas amounts. Ultimately, our results suggest that in this psoriatic model, EPA exerts its anti-inflammatory action by decreasing the proportion of IL-17A-producing T cells.

Morroniside interaction with poly (ADP-ribose) polymerase accentuates metabolic mitigation of alloxan-induced genotoxicity and hyperglycaemia: a molecular docking based in vitro and in vivo experimental therapeutic insight

The present study tends to evaluate the possible potential of bio-active Morroniside (MOR), against alloxan (ALX)-induced genotoxicity and hyperglycaemia. In silico prediction revealed the interaction of MOR with Poly (ADP-ribose) polymerase (PARP) protein which corroborated well with experimental in vitro L6 cell line and in vivo mice models. Data revealed the efficacy of MOR in the selective activation of PARP protein and modulating other stress proteins NF-κB, and TNF-α to initiate protective potential against ALX-induced genotoxicity and hyperglycaemia. Further, the strong interaction of MOR with CT-DNA (calf thymus DNA) analyzed through CD spectroscopy, UV-Vis study and ITC data revealed the concerted action of bio-factors involved in inhibiting chromosomal aberration and micronucleus formation associated with DNA damage. Finally, MOR does not play any role in microbial growth inhibition which often occurs due to hyperglycemic dysbiosis. Thus, from the overall findings, we may conclude that MOR could be a potential drug candidate for the therapeutic management of induced-hyperglycaemia and genotoxicity.Communicated by Ramaswamy H. Sarma.

Application of in-vitro-cultured primary hepatocytes to evaluate species translatability and AAV transduction mechanisms of action

Recombinant adeno-associated virus (AAV) is an effective platform for therapeutic gene transfer; however, tissue-tropism differences between species are a challenge for successful translation of preclinical results to humans. We evaluated the use of in vitro primary hepatocyte cultures to predict in vivo liver-directed AAV expression in different species. We assessed whether in vitro AAV transduction assays in cultured primary hepatocytes from mice, nonhuman primates (NHPs), and humans could model in vivo liver-directed AAV expression of valoctocogene roxaparvovec (AAV5-hFVIII-SQ), an experimental gene therapy for hemophilia A with a hepatocyte-selective promoter. Relative levels of DNA and RNA in hepatocytes grown in vitro correlated with in vivo liver transduction across species. Expression in NHP hepatocytes more closely reflected expression in human hepatocytes than in mouse hepatocytes. We used this hepatocyte culture model to assess transduction efficacy of a novel liver-directed AAV capsid across species and identified which of 3 different canine factor VIII vectors produced the most transgene expression. Results were confirmed in vivo. Further, we determined mechanisms mediating inhibition of AAV5-hFVIII-SQ expression by concomitant isotretinoin using primary human hepatocytes. These studies support using in vitro primary hepatocyte models to predict species translatability of liver-directed AAV gene therapy and improve mechanistic understanding of drug-drug interactions.

Optimization of environmental factors in a dual in vitro biofilm model of Candida albicans-Streptococcus mutans

The biofilm formation of Streptococcus mutans-Candida albicans is an important virulence factor for dental caries. The purpose of this study was to determine the effect of some environmental conditions on the biofilm formation like inoculation concentration, temperature, sugar, amino acid, metal ions and saliva, and then establish a persistent in vitro biofilm model for further research. Based on the single factor experiment, the factors participating in the biofilm formation including sugar, inoculation concentration, and saliva increased the biofilm mass, while amino acid, metal ions, temperatures reduced biofilm mass. Optimal conditions for biofilm formation were the inoculation dosage of S. mutans and C. albicans of 10⁸ and 10⁷ , respectively, the addition of 0·3 g l^-1 sucrose and sterile saliva. These results contribute to a deep understanding of the factors involved in oral biofilm formation of the important cariogenic pathogen S. mutans and the opportunistic pathogen C. albicans to study better for biofilm and promote the design of new therapeutic approaches. The present research also provides a model for evaluating the therapeutic potential for drugs in the future.

Murine Ex Vivo Cultured Alveolar Macrophages Provide a Novel Tool to Study Tissue-Resident Macrophage Behavior and Function

Tissue-resident macrophages are of vital importance as they preserve tissue homeostasis in all mammalian organs. Nevertheless, appropriate cell culture models are still limited. Here, we propose a novel culture model to study and expand murine primary alveolar macrophages (AMs), the tissue-resident macrophages of the lung, in vitro over several months. By providing a combination of granulocyte-macrophage colony-stimulating factor, TGFβ, and the PPARγ activator rosiglitazone, we maintain and expand mouse ex vivo cultured AMs (mexAMs) over several months. MexAMs maintain typical morphologic features and stably express primary AM surface markers throughout in vitro culture. They respond to microbial ligands and exhibit an AM-like transcriptional profile, including the expression of AM-specific transcription factors. Furthermore, when transferred into AM-deficient mice, mexAMs efficiently engraft in the lung and fulfill key macrophage functions, leading to a significantly reduced surfactant load in those mice. Altogether, mexAMs provide a novel, simple, and versatile tool to study AM behavior in homeostasis and disease settings.

Injectable oxygenation therapeutics: evaluating the oxygen delivery efficacy of artificial oxygen carriers and kosmotropes in vitro

The aim of this paper was to utilise an existing in vitro setup to quantify the oxygen offloading capabilities of two different subsets of injectable oxygenation therapeutics: (1) artificial oxygen carriers (AOCs), which bind or dissolve oxygen and act as transport vectors, and (2) kosmotropes, which increase water hydrogen bonding and thereby decrease the resistance to oxygen movement caused by the blood plasma. Dodecafluoropentane emulsion (DDFPe) was chosen to represent the AOC subset while trans sodium crocetinate (TSC) was selected to represent the kosmotrope subset. PEG-Telomer-B (PTB), the surfactant utilised to encapsulate DDFP in emulsion form, was also tested to determine whether it affected the oxygen transport ability of DDFPe. The in vitro set-up was used to simulate a semi closed-loop circulatory system, in which oxygen could be delivered from the lungs to hypoxic tissues. Results of this study showed that (1) 0.5 ml of a PFC outperformed 6.25 ml of a kosmotrope in a controlled, in vitro setting and (2) that PTB and sucrose do not contribute to the overall oxygen transportation efficacy of DDFPe. These results could be therapeutically beneficial to ongoing and future pre-clinical and clinical studies involving various oxygenation agents.

A Simplified, Fully Defined Differentiation Scheme for Producing Blood-Brain Barrier Endothelial Cells from Human iPSCs

Human induced pluripotent stem cell (iPSC)-derived developmental lineages are key tools for in vitro mechanistic interrogations, drug discovery, and disease modeling. iPSCs have previously been differentiated to endothelial cells with blood-brain barrier (BBB) properties, as defined by high transendothelial electrical resistance (TEER), low passive permeability, and active transporter functions. Typical protocols use undefined components, which impart unacceptable variability on the differentiation process. We demonstrate that replacement of serum with fully defined components, from common medium supplements to a simple mixture of insulin, transferrin, and selenium, yields BBB endothelium with TEER in the range of 2,000-8,000 Ω × cm² across multiple iPSC lines, with appropriate marker expression and active transporters. The use of a fully defined medium vastly improves the consistency of differentiation, and co-culture of BBB endothelium with iPSC-derived astrocytes produces a robust in vitro neurovascular model. This defined differentiation scheme should broadly enable the use of human BBB endothelium for diverse applications.

Influence of Sampling Site and Fluid Flow on the Accuracy of Total Body Clearance Calculation

Studies have showed that by assuming arteriovenous drug concentrations are homogenous after intravenous injection, the determination of total body clearance based on venous drug concentrations is often inaccurate. This study considers the use of a fluidic pharmacokinetic profile generator where 28 different profile types were generated corresponding to a physiological model with varying sampling sites, administration locations, and fluid flow rates. Clearance was calculated using established equations, commercial software, and recently proposed models. The results show large differences in clearance values calculated with published equations and commercial software relative to the actual value of clearance. Alterations in sampling site, administration location, and fluid flow rates each influence the extent of calculation errors. The data show that a significant drug concentration gradient exists within the central circulatory system. The results show that the best way to address this issue would be to inject the drug at a peripheral location to allow for sufficient mixing and then sample from a large vein. Extrapolating for missing data can also lead to large errors in clearance calculation; this can be addressed by collecting more samples early after IV bolus administration or by collecting data during steady state conditions for an IV infusion.

Derivation of Brain Capillary-like Endothelial Cells from Human Pluripotent Stem Cell-Derived Endothelial Progenitor Cells

The derivation of human brain capillary endothelial cells is of utmost importance for drug discovery programs focusing on diseases of the central nervous system. Here, we describe a two-step differentiation protocol to derive brain capillary-like endothelial cells from human pluripotent stem cells. The cells were initially differentiated into endothelial progenitor cells followed by specification into a brain capillary-like endothelial cell phenotype using a protocol that combined the induction, in a time-dependent manner, of VEGF, Wnt3a, and retinoic acid signaling pathways and the use of fibronectin as the extracellular matrix. The brain capillary-like endothelial cells displayed a permeability to lucifer yellow of 1 × 10⁻³ cm/min, a transendothelial electrical resistance value of 60 Ω cm² and were able to generate a continuous monolayer of cells expressing ZO-1 and CLAUDIN-5 but moderate expression of P-glycoprotein. Further maturation of these cells required coculture with pericytes. The study presented here opens a new approach for the study of soluble and non-soluble factors in the specification of endothelial progenitor cells into brain capillary-like endothelial cells.

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Derivation of BCLECs from iPSCs in chemically defined medium in two steps

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Specification of EPCs into BCLECs requires the activation of VEGF, Wnt3a, and RA

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Fibronectin seems a sufficient substrate for the specification of EPCs into BCLECs

Transdermal Delivery of Sumatriptan Succinate Using Iontophoresis and Dissolving Microneedles

This study focuses on the in vitro transdermal transport of sumatriptan succinate using combined iontophoresis and dissolving polymeric microneedle arrays. Permeation experiments were performed to evaluate the effects of formulation parameters on drug release from polyvinylpyrrolidone systems under mild electrical current (≤500 μA/cm²). The preparations consisted of hydrophilic, positively charged molecules encapsulated in a water-soluble and biocompatible polymeric material. Current densities of 100, 300, and 500 μA/cm² were applied during a 6-h period using silver/silver chloride electrodes. The circular array consisted of 600 needles and occupied a 0.785 cm² area. Tests, carried out with Franz diffusion cells and skin of Göttingen minipigs, showed that small decreases in the polymer concentration led to negligible lag times and marked increases in the cumulative amount of drug permeated in 6 h (Q_6h) and in the flux (J_ss). At 500 μA/cm², Q_6h and J_ss nearly doubled for a microneedle loaded with 5% (w/w) sumatriptan and 20% (w/w) PVP (lag time = 0 min; Q_6h = 2888 μg/cm²; J_ss = 490 μg/cm²/h) relative to a system loaded with 5% (w/w) drug and 30% (w/w) PVP (lag time = 36 min; Q_6h = 1437 μg/cm²; J_ss = 266 μg/cm²/h).

Neuron-Glia Interactions Increase Neuronal Phenotypes in Tuberous Sclerosis Complex Patient iPSC-Derived Models

Tuberous sclerosis complex (TSC) is a rare neurodevelopmental disorder resulting from autosomal dominant mutations in the TSC1 or TSC2 genes, leading to a hyperactivated mammalian target of rapamycin (mTOR) pathway, and gray and white matter defects in the brain. To study the involvement of neuron-glia interactions in TSC phenotypes, we generated TSC patient induced pluripotent stem cell (iPSC)-derived cortical neuronal and oligodendrocyte (OL) cultures. TSC neuron mono-cultures showed increased network activity, as measured by calcium transients and action potential firing, and increased dendritic branching. However, in co-cultures with OLs, neuronal defects became more apparent, showing cellular hypertrophy and increased axonal density. In addition, TSC neuron-OL co-cultures showed increased OL cell proliferation and decreased OL maturation. Pharmacological intervention with the mTOR regulator rapamycin suppressed these defects. Our patient iPSC-based model, therefore, shows a complex cellular TSC phenotype arising from the interaction of neuronal and glial cells and provides a platform for TSC disease modeling and drug development.

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TSC neuron mono-cultures show an increase in network activity and dendritic branching

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TSC co-cultures show hypertrophy and an increase in axonal length and OL proliferation

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mTOR regulators normalize TSC neuronal and glial phenotypes

Loss of Bin1 Promotes the Propagation of Tau Pathology

Tau pathology propagates within synaptically connected neuronal circuits, but the underlying mechanisms are unclear. BIN1-amphiphysin2 is the second most prevalent genetic risk factor for late-onset Alzheimer's disease. In diseased brains, the BIN1-amphiphysin2 neuronal isoform is downregulated. Here, we show that lowering BIN1-amphiphysin2 levels in neurons promotes Tau pathology propagation whereas overexpression of neuronal BIN1-amphiphysin2 inhibits the process in two in vitro models. Increased Tau propagation is caused by increased endocytosis, given our finding that BIN1-amphiphysin2 negatively regulates endocytic flux. Furthermore, blocking endocytosis by inhibiting dynamin also reduces Tau pathology propagation. Using a galectin-3-binding assay, we show that internalized Tau aggregates damage the endosomal membrane, allowing internalized aggregates to leak into the cytoplasm to propagate pathology. Our work indicates that lower BIN1 levels promote the propagation of Tau pathology by efficiently increasing aggregate internalization by endocytosis and endosomal trafficking.

Electrical pulse stimulation of cultured skeletal muscle cells as a model for in vitro exercise - possibilities and limitations

The beneficial health-related effects of exercise are well recognized, and numerous studies have investigated underlying mechanism using various in vivo and in vitro models. Although electrical pulse stimulation (EPS) for the induction of muscle contraction has been used for quite some time, its application on cultured skeletal muscle cells of animal or human origin as a model of in vitro exercise is a more recent development. In this review, we compare in vivo exercise and in vitro EPS with regard to effects on signalling, expression level and metabolism. We provide a comprehensive overview of different EPS protocols and their applications, discuss technical aspects of this model including critical controls and the importance of a proper maintenance procedure and finally discuss the limitations of the EPS model.

Incorporation of staphylococci into titanium-grown biofilms: an in vitro "submucosal" biofilm model for peri-implantitis

Objectives

Staphylococcus spp. are postulated to play a role in peri‐implantitis. This study aimed to develop a “submucosal” in vitro biofilm model, by integrating two staphylococci into its composition.

Materials and methods

The standard “subgingival” biofilm contained Actinomyces oris, Fusobacterium nucleatum, Streptococcus oralis, Veillonella dispar, Campylobacter rectus, Prevotella intermedia, Streptococcus anginosus, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, and was further supplemented with Staphyoccous aureus and/or Staphylococcus epidermidis. Biofilms were grown anaerobically on hydroxyapatite or titanium discs and harvested after 64 h for real‐time polymerase chain reaction, to determine their composition. Confocal laser scanning microscopy and fluorescence in situ hybridization were used for identifying the two staphylococci within the biofilm.

Results

Both staphylococci established within the biofilms when added separately. However, when added together, only S. aureus grew in high numbers, whereas S. epidermidis was reduced almost to the detection limit. Compared to the standard subgingival biofilm, addition of the two staphylococci had no impact on the qualitative or quantitative composition of the biofilm. When grown individually in the biofilm, S. epidermidis and S. aureus formed small distinctive clusters and it was confirmed that S. epidermidis was not able to grow in presence of S. aureus.

Conclusions

Staphyoccous aureus and S. epidermidis can be individually integrated into an oral biofilm grown on titanium, hence establishing a “submucosal” biofilm model for peri‐implantitis. This model also revealed that S. aureus outcompetes S. epidermidis when grown together in the biofilm, which may explain the more frequent association of the former with peri‐implantitis.

Physical disruption of oral biofilms by sodium bicarbonate: an in vitro study

OBJECTIVES

Sodium bicarbonate has been shown clinically to be efficacious at removing dental plaque; however, its effect of mechanism against biofilms has not been evaluated in vitro. Here, we used a well-established in vitro plaque biofilm model to investigate the disruption of dental plaque biofilms.

METHODS

Biofilms were grown in a constant depth film fermentor for up to 14 days. The fermentor was inoculated with pooled human saliva and growth maintained with artificial saliva. After various time points, replicate biofilms were removed and subjected to treatment at varying concentrations of sodium bicarbonate. Disruption of the plaque was assessed by viable counts and microscopy.

RESULTS

The viable count results showed that younger biofilms were less susceptible to the action of sodium bicarbonate; however, biofilms of 7 days and older were increasingly susceptible to the material with the oldest biofilms being the most susceptible. Sixty-seven percentage of sodium bicarbonate slurry was able to reduce the number of organisms present by approx. 3 log10 . These quantitative data were corroborated qualitatively with both confocal and electron microscopy, which both showed substantial qualitative removal of mature biofilms.

CONCLUSIONS

The results from this study have shown that sodium bicarbonate is able to disrupt mature dental plaque grown in vitro and that its reported efficacy in maintaining oral hygiene may be related to this key factor.

MicroRNA-122: a novel hepatocyte-enriched in vitro marker of drug-induced cellular toxicity

Emerging hepatic models for the study of drug-induced toxicity include pluripotent stem cell-derived hepatocyte-like cells (HLCs) and complex hepatocyte-non-parenchymal cellular coculture to mimic the complex multicellular interactions that recapitulate the niche environment in the human liver. However, a specific marker of hepatocyte perturbation, required to discriminate hepatocyte damage from non-specific cellular toxicity contributed by non-hepatocyte cell types or immature differentiated cells is currently lacking, as the cytotoxicity assays routinely used in in vitro toxicology research depend on intracellular molecules which are ubiquitously present in all eukaryotic cell types. In this study, we demonstrate that microRNA-122 (miR-122) detection in cell culture media can be used as a hepatocyte-enriched in vitro marker of drug-induced toxicity in homogeneous cultures of hepatic cells, and a cell-specific marker of toxicity of hepatic cells in heterogeneous cultures such as HLCs generated from various differentiation protocols and pluripotent stem cell lines, where conventional cytotoxicity assays using generic cellular markers may not be appropriate. We show that the sensitivity of the miR-122 cytotoxicity assay is similar to conventional assays that measure lactate dehydrogenase activity and intracellular adenosine triphosphate when applied in hepatic models with high levels of intracellular miR-122, and can be multiplexed with other assays. MiR-122 as a biomarker also has the potential to bridge results in in vitro experiments to in vivo animal models and human samples using the same assay, and to link findings from clinical studies in determining the relevance of in vitro models being developed for the study of drug-induced liver injury.

Contour analysis of an implant--soft tissue interface

BACKGROUND AND OBJECTIVE

Studies of peri-implant soft tissue on in vivo models are commonly based on histological sections prepared using undecalcified or 'fracture' techniques. These techniques require the cutting or removal of implant during the specimen preparation process. The aim of this study is to explore a new impression technique that does not require any cutting or removal of implant for contour analysis of soft tissue around four types of titanium (Ti) surface roughness using an in vitro three-dimensional oral mucosal model (3D OMM).

METHODS

The 3D OMM was constructed by co-culturing a keratinocyte cell line TR146 and human oral fibroblasts on to an acellular dermis scaffold. On the fourth day, a Ti disk was placed into the model. Four types of Ti surface topographies, i.e. polished, machined, sandblasted and anodized were tested. After 10 d of culture, the specimens were processed based on undecalcified (ground sectioning), electropolishing and impression techniques for contour analysis of the implant-soft tissue interface.

RESULTS

Under light microscopic examination of the ground and electropolishing sections, it was found that the cell line-based oral mucosa formed a peri-implant-like epithelium attachment on to all four types of Ti surfaces. In contour analysis, the most common contour observed between the cell line-based oral mucosa and Ti surface was at an angle ranging between 45° and 90°.

CONCLUSION

The in vitro cell line-based 3D OMM formed a peri-implant-like epithelium at the implant-soft tissue interface. The contour of the implant-soft tissue interface for the four types of Ti surface was not significantly different.