THE EFFECTIVENESS OF STEM CELLS GRAFTING ON REGENERATION OF DENTAL PULP: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background: Great advances in tissue engineering open a new biological path to regenerate the damaged pulpal tissue. The new approach of stem cell transplantation to regeneration of tissues had been used in many medical fields with promising results including dental therapy. Aim of this istoreviewthe efficacy of stem cell grafting in regeneration of dental pulp from available animal and human studies for a systematic and meta-analysisreview. Methodology: AComprehensive electronic search with time and language restrictions was conducted. Several known databases were included Ex: PubMed, The Cochrane Library, Web of Science from 2000 to 2020.We combined the search terms and limited the study to the English language. Depending on PRISMA checklist, we removed duplicates, articles were screened based on title, abstract, and full text. The search resulted in 325 hits which after removing duplicates, exclusion studies the number of studies became 10. Results:In this review, The total samples used in this review was 40 samples from which 13 human patients had been included (mean age of 26.8 years old), 12 dogs, 3 mice and 12 inbred male miniature pigs using 94 teeth and molar. Moreover, all the used stem cells for dentine regeneration were adult mesenchymal stem cells however, the source of harvesting these stem cell differs between studies including adipose tissue and pulp CD31-SP, DPSCS, PDLSCs, Gdf11 gene,bone morphogenetic protein-2 (BMP-2),MDPSCs and SCAP. Furthermore, all types showed promising results however, some types gave better results over other including superior of adipose tissue CD31 SP over bone marrow CD31 SP and pulp stem progenitor (CD 105) cells over adipose CD105 cell. Conclusion: It was observed that stem cell grafting shows promising results in the regeneration of dental pulp in both animal and human studies with no side effect or toxicity. Therefore, we recommend widening the application of these techniques in human trials because of its safety and efficacy. Choice of carriers or type of stem cells up to our review should depend on the expenses, as there are no significant differences between them in both safety of efficacy profiles.

AN INSIGHT OF COVID-19 AND MUCORMYCOSIS

Mucormycosis is an infrequent infectious disease engendered by Mucorales fungi that primarily affects COVID-19-positive patients in India. Corticosteroids are frequently used to treat COVID-19. Corticosteroids vanquish the body’s immune response and raise blood sugar levels in diabetic COVID-positive patients and are often found with the Rhino-orbital cerebral Mucormycosis. Neutropenia, solid organ, and stem cell grafting, excessive intake of iron, and deferoxamine therapy are associated risk factors. The saprophytic fungus initially attacks the sinuses before spreading to the oral cavity, lungs, and eye orbit, causing an acute phase of inadequate blood supply to the tissue which finally led to Necrosis. If left untreated, it can result in temporary or permanent loss of vision, fever, headache, reddened and swollen skin near the nose or eyes, facial pain, and eventually death. Laboratory parameters, tissue biopsy, CT scan, and reverse transcriptase-polymerase chain reaction are few investigations. Amphotericin B and Micafungin are the commonest advisable anti-fungal medication. Surgical debridement or removal of contaminated tissue, particularly in infections of the rhino-orbito-cerebral, cutaneous, and gastrointestinal Mucormycosis, is required.

A PROSPECTIVE ANALYSIS OF VISUAL ACUITY AND ASTIGMATIC CHANGES AFTER PTERYGIUM EXCISION WITH LIMBAL STEM CELL GRAFTING

Objectives: The aim of this study was to assess if there is any signicant reduction in astigmatism and thus improvement in visual acuity after pterygium excision with limbal stem cell grafting. Methods: In this prospective study, patients with primary pterygium were included. Preoperative and postoperative corneal astigmatism, refractive astigmatism and visual acuity were analyzed. All patients underwent pterygium excision with limbal stem cell grafting. Results: Mean improvement in visual acuity of 0.09 log MAR units was observed (p <0.0001, statistically signicant).Mean corneal astigmatism for grade I, II and III was found to be 1.03 ± 0.68D, 1.69 ± 0.80D and 2.90 ± 1.06D respectively. Mean corneal astigmatism decreased by 1.29 D (p <0.0001, statistically signicant).A decrease of 0.77D in cylindrical power required was found after surgery (p <0.0001, statistically signicant). Conclusions: there is a signicant reduction in pterygium induced astigmatism and improvement in visual acuity on surgical removal of the pterygium.

Impact of Aging on the Characterization of Brown and White Adipose Tissue-Derived Stem Cells in Mice

Adipose tissue enriched with adipose tissue-derived stem cells (ASCs) is often used for stem cell-based therapies. However, the characteristics of ASCs from different types of adipose tissue have varying biochemical and functional properties. We aimed to investigate how age affected the biological and functional characteristics of ASCs from brown (BAT) and white adipose tissue (WAT). ASCs were obtained and cultured from mouse BAT and WAT at different ages: young (2 months of age) and older mice (22 months of age). Mesenchymal markers were characterized by flow cytometry, and cell proliferation, apoptosis, differentiation potential, senescence, and metabolism were then determined. The percentage of WAT was higher in elderly mice, and the percentage of BAT was higher in young mice. All ASC sample phenotypes were characterized as CD29+/CD44+/CD105+/CD45–; the proliferation rate was not statistically different among all age groups. However, the number of senescent cells and the percentage of apoptosis in elderly mouse ASCs were significantly increased, and the ability of osteogenic and lipogenic differentiation was decreased in these same animals. In addition, ASCs from young mice were more inclined to undergo osteogenic differentiation, especially BAT-ASCs, whose gene expression of fat-consuming components was also significantly higher than of WAT-ASCs. The results indicated that ASCs derived from both WAT and BAT possessed different characteristics of fat metabolism and cell differentiation relative to the osteo- and adipolineages. In particular, because BAT-ASCs from young mice contributed to fat consumption, if used for cell grafting, they may potentially be attractive vehicles for treating obesity.

Hyaluronan-Based Grafting Strategies for Liver Stem Cell Therapy and Tracking Methods

Cell adhesion is essential for survival, it plays important roles in physiological cell functions, and it is an innovative target in regenerative medicine. Among the molecular interactions and the pathways triggered during cell adhesion, the binding of cluster of differentiation 44 (CD44), a cell-surface glycoprotein involved in cell-cell interactions, to hyaluronic acid (HA), a major component of the extracellular matrix, is a crucial step. Cell therapy has emerged as a promising treatment for advanced liver diseases; however, so far, it has led to low cell engraftment and limited cell repopulation of the target tissue. Currently, different strategies are under investigation to improve cell grafting in the liver, including the use of organic and inorganic biomatrices that mimic the microenvironment of the extracellular matrix. Hyaluronans, major components of stem cell niches, are attractive candidates for coating stem cells since they improve viability, proliferation, and engraftment in damaged livers. In this review, we will discuss the new strategies that have been adopted to improve cell grafting and track cells after transplantation.