Browsing by Author "Jamal, Mohamed"

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Awareness of Periodontal Health among Pregnant Females in Government Setting in United Arab Emirates
(2023) Khamis, Amar Hassan; Tawfik, Abdel Rahman; Bain, Crawford; Jamal, Mohamed; Atieh, Momen; Shah, Maanas
Objective: Periodontal disease is one of the most common infectious diseases. Several factors are associated with increased susceptibility of periodontal disease such as hormonal changes during pregnancy. Although pregnancy does not directly cause gingivitis, it can aggravate preexisting periodontal disease. This study aimed to evaluate knowledge of the association between periodontal disease and pregnancy in pregnant females. Materials and Methods: A convenience sample of pregnant females attending two United Arab Emirates government hospitals was recruited for this study. A 23-item questionnaire was developed with four sections, covering sociodemographic details, oral hygiene, oral symptoms during pregnancy, and knowledge of periodontal health during pregnancy. The study was conducted between April and October 2017. All participants consented to the survey. Results: A total of 100 participants with a mean age of 31 years (± 5.9) completed the survey. Most respondents brushed their teeth 2 to 3 times a day (65%), used a manual toothbrush (93%) but only visited the dentist when in pain (62%). Few respondents self-reported any gingival signs and symptoms during pregnancy; 38% had bleeding gums, 27% had no gum swelling, and 34% had bad odor/taste/smell. Only 21% of pregnant females lost a tooth/teeth during pregnancy, 15% believed that pregnancy increased the likelihood of gum disease, and 66% of gynecologists did not advise a visit to the dentist. Housewives were significantly less knowledgeable about periodontal health than students/employed respondents (p = 0.01). Quality of knowledge was not associated with educational attainment (< 0.06). Respondents > 30 years of age were more likely to believe in “a tooth for a baby” than younger participants aged < 30 years (p < 0.05). A logistic regression model showed that educational attainment was not a predictor for the belief in “a tooth for a baby” but age was a significant predictor (odds ratio = 2.0).
Awareness, attitude, and practice of regenerative endodontic procedures among clinicians from different dental specialties
(2020) Jamal, Mohamed; Khawaja, Summayah
Introduction: This study assessed the opinions on and practice of regenerative endodontic procedures(REPs) among clinicians from different dental specialties. Materials and Methods: After the Institutional Review Board approval, 205 clinicians participated in a web-based survey and were asked about their educational level, professional status, opinion toward REPs, and preferred technique when performing REPs. Results: Although approximately 65% of participants were unsure or did not believe that there is enough evidence to support REPs, 78.2% believed that REPs are a better treatment option than apexification and 70.5% that they could be a future alternative to osseointegrated implants. The results also revealed variability in the preferred techniques to perform REPs, with 40.4% preferring the use of a mixture of antibiotics to disinfect the root canal space, whereas 20.2% preferred calcium hydroxide. Almost 66% were using ≥1 mg/mL of each antibiotic in the mixture, whereas 44.6% were using 0.1 mg/mL. Approximately 40% of participants used techniques that differ from the American Association of Endodontists’ clinical considerations for REPs. Interestingly, attending a continuing dental education course (CDE) significantly reduced the participants’ uncertainty toward REPs and increased their willingness to perform it themselves (P < 0.001). Conclusions: This survey revealed a positive attitude toward and general acceptance of REPs by dentists. It also showed considerable variability in techniques used to perform REPs. Conducting more CDE may increase the awareness of REPs among different dental specialties and reducing variability in techniques.
The C‑shaped root canal systems in mandibular second molars in an Emirati population
(2021) Khawaja, Summayah; Chaudhry, Jahanzeb; Hassan Khamis, Amar; El Abed, Rashid; Ghoneima, Ahmed; Jamal, Mohamed
Abstract: Our study aimed to describe the root and canal morphology of mandibular second molars in Emirati population and to study the prevalence and types of morphological change in C-shaped canal confguration along the root length in an efort to describe C-shaped molars as a unit. Cone beam computed tomography (CBCT) scans of Emirati patients were analyzed in multiple plans and root and canal confguration of mandibular second molars were evaluated. Moreover, specifc types of morphological change in C-shaped canal confguration along root length were studied and reconstructed using 3D reconstruction software. A total of 508 mandibular second molars were evaluated. Among the non-C-shaped mandibular second molars, two separate roots were the most prevalent root morphology (78.3%). The mesial root’s most common root canal confguration was Vertucci Type II (46.5%), and in the distal root, Vertucci Type I (90.5%). The prevalence of C-shaped mandibular second molars was 17.9% and was signifcantly prevalent (P< 0.001) in females. Specifc types of morphological change in C-shaped molars along the root length were observed and described for the frst time, in which the most common types of morphological change were C1-C2-C3d (18%), C1-C3c-C3d (15.4%), C4-C3c-C3d (7.7%), and C3c-C3c-C3d (7.7%). This study showed wide variations in the root and canal morphology in mandibular second molars in Emirati population with a relatively high prevalence of C-shaped canal confguration (17.9%). Moreover, specifc types of morphological change in C-shaped confguration were detected and described for the frst time in this population.
A Call for Action to Safely Deliver Oral Health Care during and Post COVID-19 Pandemic
(2020) Jamal, Mohamed
Abstract: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak started just a couple of months ago and it grew rapidly causing several deaths and morbidities. The mechanism behind the transmission of the virus is still not completely understood despite a multitude of new specific manuscripts being published daily. This article highlights the oral cavity as a possible viral transmission route into the body via the Angiotensin converting enzyme 2 receptor. It also provides guidelines for routine protective measures in the dental office while delivering oral health care.
Complete Obturation—Cold Lateral Condensation vs. Thermoplastic Techniques: A Systematic Review of Micro-CT Studies
(2021) Jamal, Mohamed
Abstract: To prevent re-infection and provide a hermetic seal of the root canal system, an endodontist must aim to produce a void-free obturation. This review aimed to compare the completeness of root canal obturation between the two most prevalent methods—cold lateral condensation and warm gutta-percha techniques—using micro-CT (PROSPERO reg no. 249815). Materials and Methods: A search of Scopus, Embase, PubMed (Medline via PubMed), and Web of Science databases was done without any time restriction according to the PRISMA protocol. Articles that compared both techniques and were published in English were included. Data was extracted and the risk of bias was assessed using an adapted tool based on previous studies. Results: A total of 141 studies were identified by the search. Following the screening and selection of articles, 9 studies were included for review. Data was extracted manually and tabulated. Most studies had a moderate risk of bias. None determined operator skill in both methods before comparison. The data extracted from the included studies suggests that both techniques produce voids in the obturation. The thermoplasticized gutta-percha techniques may result in fewer voids compared to cold lateral condensation. Conclusion: Considering the limitations of the included studies, it was concluded that neither technique could completely obturate the root canal. Thermoplasticized gutta-percha techniques showed better outcomes despite a possible learning bias in favor of cold lateral condensation. Establishing operator skills before comparison may help reduce this bias.
Derivation and characterization of putative craniofacial mesenchymal progenitor cells from human induced pluripotent stem cells
(2018) Jamal, Mohamed
Abstract: The introduction and widespread adoption of induced pluripotent stem cell (iPSC) technology has opened new avenues for craniofacial regenerative medicine. Neural crest cells (NCCs) are the precursor population to many craniofacial structures, including dental and periodontal structures, and iPSC-derived NCCs may, in the near future, offer an unlimited supply of patient-specific cells for craniofacial repair interventions. Here, we used an established protocol involving simultaneous Wnt signaling activation and TGF-β signaling inhibition to differentiate three human iPSC lines to cranial NCCs. We then derived a mesenchymal progenitor cell (NCC-MPCs) population with chondrogenic and osteogenic potential from cranial NCCs and investigated their similarity to widely studied human postnatal dental or periodontal stem/progenitor cells. NCC-MPCs were quite distinct from both their precursor cells (NCCs) and bone-marrow mesenchymal stromal cells, a stromal population of mesodermal origin. Despite their similarity with dental stem/progenitor cells, NCC-MPCs were clearly differentiated by a core set of 43 genes, including ACKR3 (CXCR7), whose expression (both at transcript and protein level) appear to be specific to NCC-MPCs. Altogether, our data demonstrate the feasibility of craniofacial mesenchymal progenitor derivation from human iPSCs through a neural crest-intermediate and set the foundation for future studies regarding their full differentiation repertoire and their in vivo existence.
Effect from Autoclave Sterilization and Usage on the Fracture Resistance of Heat-Treated Nickel–Titanium Rotary Files
(2023) El Abed, Rashid; Alshehhi, Aisha; Alkhatib, Zuhair; Hassan Khamis, Amar; Jamal, Mohamed
Abstract: This study aimed to assess the effect of mechanical loading and heating on the cyclic fatigue and torsional fracture resistances of heat-treated nickel–titanium files after usage and autoclaving. Sixty files (One Curve) were tested for cyclic fatigue and torsional fracture resistances using customized devices. The files were divided into three groups according to the test conditions (n = 10); new (group-N), used for simulated canal shaping (group-U), and sterilized after use (group-S). For cyclic fatigue resistances, the files were freely rotated in a curved metal canal under body temperature; the time elapsed to fracture was recorded and the numbers of cycles to fracture (NCF) were calculated. For the torsional resistances, the file tip was fixed and rotated until the file fractured. The maximum torsional load and distortion angle were recorded. The toughness was calculated. Fracture fragments were examined with a scanning electron microscope. Data were analyzed using a one-way analysis of variance and Tukey’s post hoc test at the significance level of 95%. Group-U showed significantly higher NCF than group-S (p < 0.05). However, there was no significant differences between groups-N and -S in the NCF (p > 0.05). Group-N showed a significantly bigger distortional angle and higher torsional toughness than groups-U and -S, but the ultimate torsional strength did not have significant difference between the groups. Under the limitation of this study, autoclave sterilization after single-usage did not improve the fracture resistance of heat-treated One Curve nickel–titanium files.
Effect from usage and autoclave sterilization on torsional fracture resistance of heat-treated nickel-titanium instruments: an in-vitro study
(2023) Alshehhi, Aisha; Alkhatib, Zuhair; Jamal, Mohamed; El Abed, Rashid
Introduction: This study aimed to evaluate the effect from usage and autoclaving on torsional fracture resistance of heat-treated nickel-titanium rotary instruments. ProTaper Gold F2 (PG) and TruNatomy Prime (TN) were selected. For group-N, new files were tested to make a baseline torsional resistance. For group-U, files underwent instrumentation in a J-shaped canal block, and files were tested. For group-S, files underwent instrumentation as in the group-U and followed by autoclave sterilization then were tested. Maximum torsional strength and distortion angel until fracture were measured using a customized device and toughness was calculated. Statistical analysis was conducted at the significance level of 95%. The topographic appearances of torsional fracture fragments were examined under scanning electron microscopy. PG showed significantly higher torsional strength after usage and sterilization; however, TN had reduced torsional strength (p < 0.05). PG showed significantly higher torsional strength in group-S than subgroup-N, while TN showed significantly lower torsional strength in group-U than group-N (p < 0.05). Regardless of the test conditions, PG showed significantly higher torsional strength and toughness than TN while TN had bigger distortion angle than PG (p < 0.05). The mechanical loads from usage and heat application during sterilization may result in alteration of torsional resistances according to geometry and alloy characteristics.
Effect of sonic irrigation activation at different frequencies in smear layer removal; An in vitro ‎experimental study
(2022) Aalmohamed, Eiman; Ahmed, Fatemeh; Alfardan, Layal; El Abed, Rashid; Hassan Khamis, Amar; Jamal, Mohamed
Introduction: The aim of this study was to compare the vibration/oscillation frequencies of WaterPik and ‎EndoActivator devices and their effectiveness in smear layer (SL) removal.‎ Materials and Methods: The root canal of 60 single‑rooted extracted human premolars were prepared until ProTaper Universal F2 ‎file, and randomly grouped according to the irrigation activation technique used: EndoActivator group; ‎WaterPik group; manual dynamic agitation (MDA) group; and control group (conventional irrigation with ‎no activation). The vibration/oscillation frequencies of EndoActivator and WaterPik devices were ‎measured using a digital tachometer. Electron microscopy images of all specimens were evaluated for ‎SL removal according to a modified Hülsmann scoring system. Data were statistically analyzed.‎ Results: The mean vibration frequency of the EndoActivator was significantly higher than that of WaterPik (200.6 ‎‎± 2.1 and 185.2 ± 2.744 Hz, respectively). A significant difference was detected in the SL removal along ‎the full length of the canal between the experimental and control groups (P ˂ 0.001). EndoActivator and ‎MDA groups had significantly more samples with no to minimum SL at the coronal and middle thirds ‎compared to the apical third, whereas there was no significant difference among the thirds in the ‎WaterPik group. At the apical third, the WaterPik group had significantly more samples with no to ‎minimum SL (60%) than WaterPik and MDA groups (20% and 26.7%, respectively).‎ Conclusion: WaterPik was as effective as MDA and EndoActivator in SL removal, with better performance at the ‎apical third, probably attributed to the lower vibration/oscillation frequency of WaterPik.‎
Evaluation of Mental Foramen and Mandibular Canal Course and Location in an Emirati Subpopulation
(2024) Alazemia, Abdulaziz; Al Muhairi, Eman; Abdunabi, Farida; Chaudhry, Jahanzeb; Moharamzadeh, Keyvan; El Abed, Rashid; Jamal, Mohamed
Abstract Introduction and aims: Violations of the mandibular canal (MC) and mental foramen (MF)and subsequent injuries to their neurovascular bundle have been reported after surgical and nonsurgical dental procedures. Besides using advanced technologies such as cone-beam computed tomography (CBCT), clinicians should be aware of the anatomy and location of MCand MFin different populations. This study aims to describe the morphologic characteristics of the MF, MC, and its intrabony location in relation to the apices of mandibular posterior teeth in an Emirati subpopulation using CBCT. Methods: A total of 3700 CBCT scans were screened, and 154 scans that met the inclusion and exclusion criteria were randomly selected. The scans were assessed using 3-dimensional multiplanar imaging for the following structures: the location of MF and the MC course, its intrabony location, and its relationship to the apices of the mandibular posterior teeth. The data were analysed statistically using SPSS software. Results: The MC ran lingually and inferiorly at the posterior region and became more buccal and superior towards the MF. The distal root of the mandibular second molar was found to be the closest root to the MC (2.06 § 1.83 mm). Moreover, the most common location of the MFwasdistal to the contact area between the 2 premolars (0.83 § 1.84 mm) with a significant negative correlation to age (with and increase in age, the MF moves distally). The distance between the root apices and the MC was statistically significantly affected by age (positive correlation) and gender (male patients had a greater distance). Conclusions: The common course of the MC is lingual and inferior posteriorly and becomes more buccal and superior towards the MF, which is located mostly between the mandibular first and second premolars. Furthermore, the distal root of the mandibular second molar is the closest to the MC and has a positive relationship with age.
Evaluation of root and canal morphology of maxillary permanent first molars in an Emirati population; a cone-beam computed tomography study
(2020) Al Mheiri, Eman; Chaudhry, Jahanzeb; El Abed, Rashid; Hassan Khamis, Amar; Jamal, Mohamed
Background: The aim of this study was to analyze the root and canal morphology of the maxillary permanent first molars in an Emirati population using cone-beam computed tomography (CBCT). Methods: Two hundred and sixty-one CBCT scans were acquired. The data were extracted and anonymized to remove all patient identifiers. Two observers (an endodontic resident and an endodontist) evaluated all scans on diagnostic quality monitors. Results: The prevalence of a second mesiobuccal canal (MB2) was 80.1% in all examined samples. Type II Vertucci classification, was the most common canal configuration (59%) in the mesiobuccal root, followed by Types I (19.9%) and IV (15.3%), while Type III was the least common (5.7%). Types I, II, and IV were significantly more common in the 21–40-year age group (P < 0.001), while Type III was observed significantly more often in the < 20-year age group (P < 0.001). No significant effect of gender on the prevalence of Vertucci classification in the mesiobuccal root of maxillary first molars (P = 0.74) was found. Analysis of bilateral symmetry showed that 80% teeth had perfect bilateral symmetry, whereas 20% were asymmetrical. Type II canal configuration showed the highest prevalence of bilateral symmetry (48.7%), followed by Type I (15%) and Type IV (10%), while Type III showed the least prevalence of symmetry (3%). Conclusions: This was the first study to analyze the prevalence of MB2 canal in an Emirati population. Our results indicate high prevalence of MB2 (80.1%) and emphasize the importance of using advanced techniques to locate the MB2 canal.
Fracture Resistance of Heat-Treated Nickel-Titanium Rotary Files After Usage and Autoclave Sterilization: an in vitro study
(2022-08) El Abed, Rashid; Alshehhi, Aisha; Hassan Khamis, Amar; Jamal, Mohamed
Introduction: This study aimed to evaluate the dynamic cyclic fatigue resistance of heat treated nickel-titanium (NiTi) files after usage and autoclaving. Methods: Two heat-treated NiTi file systems with tip sizes of #25 (ie, ProTaper Gold F2 [Dentsply Sirona, Charlotte, NC] and TruNatomy Prime [Dentsply Sirona]) were selected. Files of each system were divided into 3 experimental subgroups (n 5 10). For subgroup 1, new files were tested to establish the baseline number of cycles to failure (NCF). For subgroup 2, files underwent canal instrumentation in a simulated J-shaped canal block with 35 of curvature and a 16.5-mm length. The simulated canals were pre-enlarged using stainless steel files #10K and #15K. After instrumentation, the files were tested. For subgroup 3, files underwent canal instrumentation as in subgroup 2 followed by autoclave sterilization and then were tested for cyclic failure. The cyclic fatigue test was performed in dynamic pecking motion under body temperature. The time to fracture was recorded and calculated into NCF. Fracture fragment lengths were measured using a digital microcaliper. Statistical analysis was conducted using the independent t test and multifactorial analysis of variance with 95% significance. Scanning electron microscopy was used to examine the topographic characteristics after cyclic fatigue tests. Results: There were no significant differences between file systems in subgroup 1 using new files (P , .05). Although PG reduced the NCF after use, TN showed a significantly increased NCF (P , .05). However, after sterilization, TN showed a reduced NCF compared with the used one (P , .05). Conclusions: Cyclic loading by usage and heat treatment during sterilization may result in different cyclic fatigue resistance according to the geometry and alloy characteristics. (J Endod 2022;48:1428–1433.)
Growth and Differentiation of Dental Stem Cells of Apical Papilla on Polycaprolactone Scaffolds
(2018) Jamal, Mohamed
Abstract: Biodegradable scaffolds are useful tools in the field of tissue engineering and regenerative medicine. The aim of this study was to test the potential of the human stem cells of apical papilla (SCAP) to attach, proliferate and differentiate on a polycaprolactone (PCL)-based scaffolds. SCAP were extracted from the root apical papillae of freshly extracted immature premolar teeth by using enzymatic digestion. Porous PCL scaffolds were fabricated using particle leaching method and NaCl or mannitol as porogens. SCAP of passage 3 were seeded on non-porous and porous PCL scaffolds for up to 14 days. For control, cells were cultured on glass coverslips. Picogreen DNA quantification was used to assay for cell proliferation. Cell differentiation and development of calci-fication nodules were examined using scan-ning electron microscopy and alizarin red staining. SCAP showed a comparable attachment, growth and proliferation patterns on PCL scaffolds and coverslips. Cell proliferation was enhanced on mannitol scaffolds at all time points. Calcification nodules were detected in all PCL scaffolds while it was not present on glass coverslips. These nodules were detected on NaCl-scaffolds by day 7 and on mannitol and non-porous scaffolds by day 14. In conclusion, SCAP were able to attach, proliferate and differentiate on PCL scaffolds without using any inductive media, indicating their potential application for dental tissue regeneration.
Microbial Metabolic Genes Crucial for S. aureus Biofilms: An Insight From Re-analysis of Publicly Available Microarray Datasets
(2021) Nassar, Rania; Hachim, Mahmood Yaseen; Kaklamanos, Eleftherios G; Jamal, Mohamed; Senok, Abiola
Abstract: Bacterial biofilms are microbial lifestyles found in all environments. Up to 80% of human infections and 60–70% of hospital-acquired infections have a biofilm origin, with Staphylococcus aureus one of the leading causes of these infections. Microorganisms in biofilms exhibit significant antimicrobial resistance which poses important treatment challenges, hence the urgent need to identify novel antibiofilm strategies. Microbes form biofilms in response to various factors, and once these 3-dimentional structures form they are highly recalcitrant to removal. The switch from planktonic lifestyle to the biofilm protected mode of growth results in a phenotypic shift in the behavior of the microorganisms in terms of growth rate and gene expression. Given these changes, investigation of microbial gene expression and their modulation at different stages of biofilm maturation is needed to provide vital insight into the behavior of biofilm cells. In this study, we analyzed publicly available transcriptomic dataset of S. aureus biofilms at different stages of maturation to identify consistently upregulated genes irrespective of the biofilm maturation stage. Our reanalysis identified a total of 6 differentially expressed genes upregulated in both 48 and 144-h old S. aureus biofilms. Functional analysis revealed that these genes encode for proteins which play a role in key microbial metabolic pathways. However, these genes, as yet, are unrelated or fully studied in the context of biofilm. Moreover, the findings of this in silico work, suggest that these genes may represent potential novel targets for the development of more effective antibiofilm strategies against S. aureus biofilm-associated infections.
Overview of transnational recommendations for COVID-19 transmission control in dental care settings
(2020) Jamal, Mohamed; Shah, Maanas; Khawaja, Summayah; El Abed, Rashid
Abstract: On 11 March 2020, the World Health Organization (WHO) declared the coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) as a pandemic. Until an effective treatment or a vaccine is developed, the current recommendations are to contain the disease, and control its transmission. It is now clear that the primary mode of SARS-CoV-2 transmission is aerosol/droplet spread, and by contacting virus-contaminated surfaces acting as fomites (inanimate vectors). Furthermore, recent data indicate that the live virus particles are present in saliva, and, more alarmingly, asymptomatic individuals may transmit the infection. By virtue of the nature of the practice of dentistry where intrinsically, a high volume of aerosols is produced, as well as the close proximity of dentists and patients during treatment, dentists and allied health staff are considered the highest risk health professional group for acquiring SARS-CoV-2 during patient management. Therefore, several organizations and specialty associations have proposed guidelines and recommendations for limiting the transmission of SARS-COV-2 from carriers to dentists and vice versa. This paper aims to provide a review of these guidelines, and concludes with a brief look at how the practice of dentistry may be impacted by COVID-19, in the post-pandemic era.
Specific mesoderm subset derived from human pluripotent stem cells ameliorates microvascular pathology in type 2 diabetic mice
(2022-03) Jamal, Mohamed
Abstract: Human induced pluripotent stem cells (hiPSCs) were differentiated into a specific mesoderm subset characterized by KDR+CD56+APLNR+ (KNA+) expression. KNA+ cells had high clonal proliferative potential and specification into endothelial colony-forming cell (ECFCs) phenotype. KNA+ cells differentiated into perfused blood vessels when implanted subcutaneously into the flank of nonobese diabetic/severe combined immunodeficient mice and when injected into the vitreous of type 2 diabetic mice (db/db mice). Transcriptomic analysis showed that differentiation of hiPSCs derived from diabetics into KNA+ cells was sufficient to change baseline differences in gene expression caused by the diabetic status and reprogram diabetic cells to a pattern similar to KNA+ cells derived from nondiabetic hiPSCs. Proteomic array studies performed on retinas of db/db mice injected with either control or diabetic donor– derived KNA+ cells showed correction of aberrant signaling in db/db retinas toward normal healthy retina. These data provide “proof of principle” that KNA+ cells restore perfusion and correct vascular dysfunction in db/db mice.
Taurine Augments Telomerase Activity and Promotes Chondrogenesis in Dental Pulp Stem Cells
(2021) Jamal, Mohamed
Background: Stem cell therapy has become an advanced and state-of-the-art procedure to regenerate lost tissues of the human body. Cartilage repair is a challenging task in which stem cells find potential application. One of the important biologic modifiers that can cause chondrogenic differentiation of stem cells is taurine. However, taurine has not been investigated for its effects on dental pulp derived stem cell (DPSC) chondrogenic differentiation. Objective: The objective of the study was to investigate if taurine administration to DPSCs heralds chondrogenic differentiation as ascertained by expression of SOX9, COL2A1, ACAN, ELN, and COMP. The study also investigated if the differentiated cells synthesized glycosaminoglycans, a marker of cartilage formation. The study also aimed to assess proliferative activity of the cells after taurine administration by measuring the hTERT gene and protein expression. Materials and methods: DPSCs were obtained from a molecular biology laboratory and characterization of stem cell markers was done by flow cytometry. The cells were subjected to a MTT assay using various concentrations of taurine. Following this, hTERT gene and protein estimation was done in the control, telomerase inhibitor treated DPSC (TI-III), 10 µM taurine treated DPSC, and TI-III + 10 µM taurine treated DPSCs. A polymerase chain reaction was done to assess gene expression of SOX9, COL2A1, ACAN, ELN, and COMP genes and glycosaminoglycans were estimated in control cells, Induced DPSCs, induced and TI-III treated DPSCs, and 10 µM taurine treated DPSCs. Results: DPSCs expressed CD73, CD90, and CD105 and did not express CD34, CD45, and HLA-DR, which demonstrated that they were mesenchymal stem cells. The MTT assay revealed that various concentrations of taurine did not affect the cell viability of DPSCs. A concentration of 10 µM of taurine was used for further assays. With regard to the hTERT gene and protein expression, the taurine treated cells expressed the highest levels that were statistically significant compared to the other groups. Taurine was also found to restore hTERT expression in telomerase inhibitor treated cells. With regard to chondrogenesis related genes, taurine administration significantly increased the expression of SOX9, COL2A1, ACAN, and ELN genes in DPSCs and caused a significant increase in glycosaminoglycan production by the cells. Conclusions: Taurine can be regarded a biologic modifier that can significantly augment chondrogenic differentiation of DPSCs and can find potential applications in regenerative medicine in the area of cartilage regeneration.
The Use of Stem Cell-Derived Organoids in Disease Modeling: An Update
(2021) Jamal, Mohamed
Abstract: Organoids represent one of the most important advancements in the field of stem cells during the past decade. They are three-dimensional in vitro culturing models that originate from self-organizing stem cells and can mimic the in vivo structural and functional specificities of body organs. Organoids have been established from multiple adult tissues as well as pluripotent stem cells and have recently become a powerful tool for studying development and diseases in vitro, drug screening, and host–microbe interaction. The use of stem cells—that have self-renewal capacity to proliferate and differentiate into specialized cell types—for organoids culturing represents a major advancement in biomedical research. Indeed, this new technology has a great potential to be used in a multitude of fields, including cancer research, hereditary and infectious diseases. Nevertheless, organoid culturing is still rife with many challenges, not limited to being costly and time consuming, having variable rates of efficiency in generation and maintenance, genetic stability, and clinical applications. In this review, we aim to provide a synopsis of pluripotent stem cell-derived organoids and their use for disease modeling and other clinical applications.