Tissue Engineering of Necrotic Dental Pulp of Immature Teeth with Apical Periodontitis in Dogs: Radiographic and Histological Evaluation.

AIM: To evaluate tissue engineering technology to regenerate pulp-dentin like tissues in pulp canals of immature necrotic permanent teeth with apical periodontitis in dogs. STUDY DESIGN: The study was performed on 36 teeth in 12 dogs. The experiment was carried out using split mouth design. In each dog 3 teeth were selected for implementing the study procedure. Apical periodontitis was induced in Group A and B teeth. Group (A): immature upper left 2nd permanent incisors that were transplanted with a construct of autologous dental pulp stem cells with growth factors seeded in a chitosn hydrogel scaffold. Group (B): immature upper right 2nd permanent incisor that received only growth factors with scaffold. A third tooth in each dog was selected randomly for isolation of dental pulp stem cells (DPSCs). Both groups were closed with a double coronal seal of white MTA (Mineral trioxide aggregate) and glass ionomer cement. Both groups were monitored radiographically for 4 months and histologically after sacrificing the animals. RESULTS: There was no statistically significant difference in radiographic findings between group (A) and group (B) for healing of radiolucencies, while there was statistically significant difference between group (A) and group (B) regarding radicular thickening, root lengthening and apical closure. Histologically, group (A) teeth showed regeneration of pulp- dentin like tissue while group (B) teeth did not show any tissue regeneration. CONCLUSION: Dental pulp stem cells and growth factors incorporated in chitosan hydrogel are able to regenerate pulp- dentine like tissue and help in complete root maturation of non-vital immature permanent teeth with apical periodontitis in dogs.

Potential of bone marrow mesenchymal stem cells in management of Alzheimer's disease in female rats.

Alzheimer's disease (AD) has been called the disease of the century with significant clinical and socioeconomic impacts. Pharmacological treatment has limited efficacy and only provides symptomatic relief without long-term cure. Accordingly, there is an urgent need to develop novel and effective medications for AD. Stem cell-based therapy is a promising approach to handling neurodegenerative diseases. Therefore, the current study aimed to explore the possible therapeutic role of single intravenous injection of bone marrow derived mesenchymal stem cells (BM-MSCs) after 4 months in management of AD in the experimental model. The work also extended to compare the therapeutic potential of BM-MSCs with 2 conventional therapies of AD; rivastigmine and cerebrolysin administered daily. BM-MSCs were able to home at the injured brains and produced significant increases in the number of positive cells for choline acetyltransferase (ChAT) and survivin expression, as well as selective AD indicator-1 (seladin-1) and nestin gene expression. Histopathological examination indicated that BM-MSCs could remove beta-amyloid plaques from hippocampus. Significant improvement in these biomarkers was similar to or better sometimes than the reference drugs, clearly showing the potential therapeutic role of BM-MSCs against AD through their anti-apoptotic, neurogenic and immunomodulatory properties.

Bridging defects in chronic spinal cord injury using peripheral nerve grafts combined with a chitosan-laminin scaffold and enhancing regeneration through them by co-transplantation with bone-marrow-derived mesenchymal stem cells: case series of 14 patients.

OBJECTIVE: To investigate the effect of bridging defects in chronic spinal cord injury using peripheral nerve grafts combined with a chitosan-laminin scaffold and enhancing regeneration through them by co-transplantation with bone-marrow-derived mesenchymal stem cells. METHODS: In 14 patients with chronic paraplegia caused by spinal cord injury, cord defects were grafted and stem cells injected into the whole construct and contained using a chitosan-laminin paste. Patients were evaluated using the International Standards for Classification of Spinal Cord Injuries. RESULTS: Chitosan disintegration leading to post-operative seroma formation was a complication. Motor level improved four levels in 2 cases and two levels in 12 cases. Sensory-level improved six levels in two cases, five levels in five cases, four levels in three cases, and three levels in four cases. A four-level neurological improvement was recorded in 2 cases and a two-level neurological improvement occurred in 12 cases. The American Spinal Impairment Association (ASIA) impairment scale improved from A to C in 12 cases and from A to B in 2 cases. Although motor power improvement was recorded in the abdominal muscles (2 grades), hip flexors (3 grades), hip adductors (3 grades), knee extensors (2-3 grades), ankle dorsiflexors (1-2 grades), long toe extensors (1-2 grades), and plantar flexors (0-2 grades), this improvement was too low to enable them to stand erect and hold their knees extended while walking unaided. CONCLUSION: Mesenchymal stem cell-derived neural stem cell-like cell transplantation enhances recovery in chronic spinal cord injuries with defects bridged by sural nerve grafts combined with a chitosan-laminin scaffold.

Stem-Cell-Based Therapy: The Celestial Weapon against Neurological Disorders.

Stem cells are a versatile source for cell therapy. Their use is particularly significant for the treatment of neurological disorders for which no definitive conventional medical treatment is available. Neurological disorders are of diverse etiology and pathogenesis. Alzheimer's disease (AD) is caused by abnormal protein deposits, leading to progressive dementia. Parkinson's disease (PD) is due to the specific degeneration of the dopaminergic neurons causing motor and sensory impairment. Huntington's disease (HD) includes a transmittable gene mutation, and any treatment should involve gene modulation of the transplanted cells. Multiple sclerosis (MS) is an autoimmune disorder affecting multiple neurons sporadically but induces progressive neuronal dysfunction. Amyotrophic lateral sclerosis (ALS) impacts upper and lower motor neurons, leading to progressive muscle degeneration. This shows the need to try to tailor different types of cells to repair the specific defect characteristic of each disease. In recent years, several types of stem cells were used in different animal models, including transgenic animals of various neurologic disorders. Based on some of the successful animal studies, some clinical trials were designed and approved. Some studies were successful, others were terminated and, still, a few are ongoing. In this manuscript, we aim to review the current information on both the experimental and clinical trials of stem cell therapy in neurological disorders of various disease mechanisms. The different types of cells used, their mode of transplantation and the molecular and physiologic effects are discussed. Recommendations for future use and hopes are highlighted.

Therapeutic applications of mesenchymal stroma cells in pediatric diseases: current aspects and future perspectives.

Mesenchymal stem cells or stroma cells (MSCs) were recently proven to play various therapeutic roles when used in clinical trials to control various inflammatory, neoplastic and immunologic diseases in children. Clinical trials show some promising results, particularly in diseases where conventional therapy is still ineffective. However, experimental studies sometimes show conflicting results. This review aims to assess the current therapeutic role of MSCs in the control of several pediatric diseases and elaborate on their future applications by reviewing published studies. A review of published studies on this subject based on Pubmed and Medical Subject Heading databases, with search for all relevant articles focusing on results of clinical trials to evaluate the clinical applications of MSCs. The review includes documentation of positive as well as negative applications of MSCs focused on pediatric diseases. MSCs have important immunosuppressive and antifibrotic effects that need to be employed to help patients with diseases for which no conventional management has proven to be effective. They may be also be used as an adjuvant to conventional therapeutic modalities to consolidate recovery. This review sheds light on the significance of the use of MSCs for the treatment of various pediatric diseases and focuses on promising applications. Most of the reported studies agree about the favorable use of MSCs in various diseases; however, more clinical trials, involving larger numbers of patients, need to be conducted in order to refine the outcome of the therapeutic methods and establish standardized protocols.

Induction of Osteogenic Differentiation of Mesenchymal Stem Cells by Bioceramic Root Repair Material.

This study aimed to evaluate the osteogenic activity of Endosequence Root Repair Material (ERRM) putty using rat mesenchymal stem cells (MSCs). The extract of set ERRM and ProRoot-mineral trioxide aggregate (MTA) (control) was cocultured with rat MSCs and incubated for one, three, and seven days. The cell viability and proliferation were assessed. A quantitative real-time polymerase chain reaction for bone morphogenetic protein-2 (BMP-2), alkaline phosphatase, bone sialoprotein, and osteocalcin gene expression was performed. Both materials enhanced cell viability and proliferation, which increased over time. On day seven, the cells treated with either material exhibited significantly greater cell viability compared with control untreated cells. MSCs treated with either material showed deeper alkaline phosphatase staining after three days compared to control untreated cells. Treated MSCs also exhibited upregulation of the gene expression of bone morphogenetic protein-2, alkaline phosphatase, bone sialoprotein, and osteocalcin. Both ERRM and ProRoot-MTA enhance the osteogenic differentiation of MSCs.

Updates in the pathophysiological mechanisms of Parkinson's disease: Emerging role of bone marrow mesenchymal stem cells.

AIM: To explore the approaches exerted by mesenchymal stem cells (MSCs) to improve Parkinson's disease (PD) pathophysiology. METHODS: MSCs were harvested from bone marrow of femoral bones of male rats, grown and propagated in culture. Twenty four ovariectomized animals were classified into 3 groups: Group (1) was control, Groups (2) and (3) were subcutaneously administered with rotenone for 14 d after one month of ovariectomy for induction of PD. Then, Group (2) was left untreated, while Group (3) was treated with single intravenous dose of bone marrow derived MSCs (BM-MSCs). SRY gene was assessed by PCR in brain tissue of the female rats. Serum transforming growth factor beta-1 (TGF-ß1), monocyte chemoattractant protein-1 (MCP-1) and brain derived neurotrophic factor (BDNF) levels were assayed by ELISA. Brain dopamine DA level was assayed fluorometrically, while brain tyrosine hydroxylase (TH) and nestin gene expression were detected by semi-quantitative real time PCR. Brain survivin expression was determined by immunohistochemical procedure. Histopathological investigation of brain tissues was also done. RESULTS: BM-MSCs were able to home at the injured brains and elicited significant decrease in serum TGF-ß1 (489.7 ± 13.0 vs 691.2 ± 8.0, P < 0.05) and MCP-1 (89.6 ± 2.0 vs 112.1 ± 1.9, P < 0.05) levels associated with significant increase in serum BDNF (3663 ± 17.8 vs 2905 ± 72.9, P < 0.05) and brain DA (874 ± 15.0 vs 599 ± 9.8, P < 0.05) levels as well as brain TH (1.18 ± 0.004 vs 0.54 ± 0.009, P < 0.05) and nestin (1.29 ± 0.005 vs 0.67 ± 0.006, P < 0.05) genes expression levels. In addition to, producing insignificant increase in the number of positive cells for survivin (293.2 ± 15.9 vs 271.5 ± 15.9, P > 0.05) expression. Finally, the brain sections showed intact histological structure of the striatum as a result of treatment with BM-MSCs. CONCLUSION: The current study sheds light on the therapeutic potential of BM-MSCs against PD pathophysiology via multi-mechanistic actions.

The therapeutic effects of bone marrow-derived mesenchymal stem cells and simvastatin in a rat model of liver fibrosis.

Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) proteins including collagen that occurs in most types of chronic liver diseases. Studies concerning the capacity of mesenchymal stem cells (MSCs) and simvasatain (SIMV) to repair fibrotic tissues through reducing inflammation, collagen deposition, are still controversial. This study aimed to investigate the therapeutic efficacy of bone marrow (BM)-derived MSCs and SIMV on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Rats were divided into: normal, CCl4, CCl4/MSCs, CCl4/SIMV, CCl4/MSCs/SIMV, and SIMV groups. BM-derived MSCs were detected by RT-PCR of CD29 and were then infused into the tail vein of female rats that received CCl4 injection to induce liver fibrosis. Sex-determining region Y (SRY) gene on Y-chromosome gene was assessed by PCR to confirm homing of the male stem cells in liver tissue of the female recipients. Serum liver function tests, liver procollagens I and III, tissue inhibitors of metalloproteinase-1 (TIMP-1), endoglin, matrix metalloproteinase-1 (MMP-1) gene expressions, transforming growth factor-beta (TGF-ß1) immunostaining, and histopathologicl examination were performed. MSCs and SIMV decreased liver procollagens I and III, TIMP-1 and endoglin gene expressions, TGF-ß1 immunostaining, and serum liver function tests compared with the CCl4 group. MMP-1 expression was increased in the CCl4/MSCs group. Histopathological examination as well as fibrosis score supports the biochemical and molecular findings. It can be concluded that MSCs and SIMV were effective in the treatment of hepatic CCl4-induced fibrosis-rat model. Treatment with MSCs was superior to SIMV. This antifibrotic effect can be attributed to their effect on the MMPs/TIMPs balance which is central in fibrogenesis.

Efficacy of mesenchymal stem cells in suppression of hepatocarcinorigenesis in rats: possible role of Wnt signaling.

BACKGROUND: The present study was conducted to evaluate the tumor suppressive effects of bone marrow derived mesenchymal stem cells (MSCs) in an experimental hepatocellular carcinoma (HCC) model in rats and to investigate the possible role of Wnt signaling in hepato-carcinogenesis. METHODS: Ninety rats were included in the study and were divided equally into: Control group, rats which received MSCs only, rats which received MSCs vehicle only, HCC group induced by diethylnitroseamine (DENA) and CCl(4), rats which received MSCs after HCC induction, rats which received MSCs before HCC induction. Histopathological examination and gene expression of Wnt signaling target genes by real time, reverse transcription-polymerase chain reaction (RT-PCR) in rat liver tissue, in addition to serum levels of ALT, AST and alpha fetoprotein were performed in all groups. RESULTS: Histopathological examination of liver tissue from animals which received DENA-CCl(4) only, revealed the presence of anaplastic carcinoma cells and macro-regenerative nodules type II with foci of large and small cell dysplasia. Administration of MSCs into rats after induction of experimental HCC improved the histopathological picture which showed minimal liver cell damage, reversible changes, areas of cell drop out filled with stem cells. Gene expression in rat liver tissue demonstrated that MSCs downregulated ß-catenin, proliferating cell nuclear antigen (PCNA), cyclin D and survivin genes expression in liver tissues after HCC induction. Amelioration of the liver status after administration of MSCs has been inferred by the significant decrease of ALT, AST and Alpha fetoprotein serum levels. Administration of MSCs before HCC induction did not show any tumor suppressive or protective effect. CONCLUSIONS: Administration of MSCs in chemically induced HCC has tumor suppressive effects as evidenced by down regulation of Wnt signaling target genes concerned with antiapoptosis, mitogenesis, cell proliferation and cell cycle regulation, with subsequent amelioration of liver histopathological picture and liver function.

The Clinical Use of Human Culture-Expanded Autologous Bone Marrow Mesenchymal Stem Cells Transplanted on Platelet-Rich Fibrin Glue in the Treatment of Articular Cartilage Defects: A Pilot Study and Preliminary Results.

OBJECTIVE: To test the hypothesis that platelet-rich fibrin glue (PR-FG) can be used clinically as a scaffold to deliver autologous culture-expanded bone marrow mesenchymal stem cells (BM-MSCs) for cartilage repair and to report clinical results 1 y after implantation of MSCs PR-FG. PATIENTS AND METHODS: Autologous BM-MSCs were culture expanded, placed on PR-FG intraoperatively, and then transplanted into 5 full-thickness cartilage defects of femoral condyles of 5 patients and covered with an autologous periosteal flap. Patients were evaluated clinically at 6 and 12 mo by the Lysholm and Revised Hospital for Special Surgery Knee (RHSSK) scores and radiographically by x-rays and magnetic resonance imaging (MRI) at the same time points. Repair tissue in 2 patients was rated arthroscopically after 12 mo using the International Cartilage Repair Society (ICRS) Arthroscopic Score. STUDY DESIGN: Case series; level of evidence 4. RESULTS: All patients' symptoms improved over the follow-up period of 12 mo. Average Lysholm and RHSSK scores for all patients showed statistically significant improvement at 6 and 12 mo postoperatively (P < 0.05). There was no statistically significant difference between the 6 and 12 mo postoperative clinical scores (P = 0.18). ICRS arthroscopic scores were 8/12 and 11/12 (nearly normal) for the 2 patients who consented to arthroscopy. MRI of 3 patients at 12 mo postoperatively revealed complete defect fill and complete surface congruity with native cartilage, whereas that of 2 patients showed incomplete congruity. CONCLUSION: Autologous BM-MSC transplantation on PR-FG as a cell scaffold may be an effective approach to promote the repair of articular cartilage defects of the knee in human patients.

Role of polyunsaturated fatty acids in the management of Egyptian children with autism.

OBJECTIVE: Estimation of free polyunsaturated fatty acids (PUFAs) in blood and evaluation of behavior of autistic children before and after taking fish oil (Efalex) were performed. DESIGN AND METHODS: 30 autistic children (18 males and 12 females) aged 3-11 years and 30 healthy children as control group were included in this study. Tandem mass spectrometry and CARS were used to estimate the free PUFAs from dried blood spot and to evaluate the autistic behavior respectively. RESULTS: Before taking Efalex, linolenic acid showed a significant reduction (71%), followed by docosahexaenoic acid (65%) and arachidonic acid (45%), while linoleic acid was the least affected PUFA (32%). After taking Efalex, 66% of autistic children showed clinical and biochemical improvement, linolenic acid and docosahexaenoic acid showed the highest levels after Efalex supplementation. CONCLUSION: PUFA supplementation may play an important role in ameliorating the autistic behavior.