Reconstruction of mandibular defects using synthetic octacalcium phosphate combined with bone matrix gelatin in rat model.

BACKGROUND: Regeneration of bone defects remains a challenge for maxillofacial surgeons. The objective of this study was to assess the osteogenic potential of octacalcium phosphate (OCP) and bone matrix gelatin (BMG) alone and in combination with together in artificially created mandibular bone defects. MATERIALS AND METHODS: In this experimental study Forty-eight male Sprague-Dawley rats (6-8 weeks old) were randomly divided into four groups. Defects were created in the mandible of rats and filled with 10 mg of OCP, BMG, or a combination of both (1/4 ratio). Defects were left unfilled in the control group. To assess bone regeneration and determine the amount of the newly formed bone, specimens were harvested at 7, 14, 21, and 56 days postimplantation. The specimens were processed routinely and studied histologically and histomorphometrically using the light microscope and eyepiece graticule. The amount of newly formed bone was quantitatively measured using histomorphometric methods. Histomorphometric data were analyzed using SPSS software. Mean, standard deviation, mode, and medians were calculated. Tukey HSD test was used to compare the means in all groups. P < 0.05 was considered as statistically significant (i.e., 5% significant level). RESULTS: In the experimental groups, the new bone formation was initiated from the margin of defects during the 7-14 days after implantation. By the end of study, the amount of newly formed bone increased and relatively matured, and almost all of the implanted materials were absorbed. In the control group, slight amount of new bone had been formed at the defect margins (next to the host bone) on day 56. The histomorphometric analysis revealed statistically significant differences in the amount of newly formed bone between the experimental and the control groups (P < 0.001). CONCLUSION: Combination of OCP/BMG may serve as an optimal biomaterial for the treatment of mandibular bone defects.

Proliferation, odontogenic/osteogenic differentiation, and cytokine production by human stem cells of the apical papilla induced by biomaterials: a comparative study.

INTRODUCTION: Clinical applications of bioactive materials are increasing in biomedical tissue engineering. This study sought to assess the effect of calcium enriched mixture (CEM) cement, Biodentine, mineral trioxide aggregate (MTA), octacalcium phosphate (OCP), and Atlantik on proliferation, odontogenic/osteogenic differentiation, and pro-inflammatory cytokine production by human stem cells of the apical papilla (SCAPs). MATERIALS AND METHODS: Proliferation of SCAPs treated with different biomaterials was evaluated using trypan blue exclusion test and flow cytometry. Differentiation of cells was evaluated using ALP activity, alizarin red staining, and RT-PCR. The expression of genes of pro-inflammatory cytokines was also evaluated using RT-PCR. RESULTS: The SCAPs treated with biomaterials showed significantly higher proliferation, increased ALP activity, higher number of calcified nodules, and up-regulation of genes related to odontogenic/osteogenic markers compared to the control group. The expression of pro-inflammatory cytokines increased in all groups compared to the control group. CONCLUSION: The tested biomaterials could induce odontogenic/osteogenic differentiation in SCAPs. MTA had a greater potential for induction of differentiation of SCAPs to odontoblast-like cells while OCP had higher potential to induce differentiation of SCAPs to osteoblast-like cells (MTA↔ BD↔ CEM↔ Atlantik↔ OCP).

Histomorphometric Analysis of Newly-formed Bone Using Octacalcium Phosphate and Bone Matrix Gelatin in Rat Tibial Defects.

BACKGROUND: Repair of bone defects is challenging for reconstructive and orthopedic surgeons. In this study, we aimed to histomorphometrically assess new bone formation in tibial bone defects filled with octacalcium phosphate (OCP), bone matrix gelatin (BMG), and a combination of both. METHODS: A total of 96 male Sprague Dawley rats aged 6-8 weeks weighing 120-150 g were randomly allocated into three experimental (OCP, BMG, and OCP/BMG) and one control group (n=24 in each group). The defects in experimental groups were filled with OCP (6 mg), BMG (6 mg), or a combination of OCP and BMG (6 mg, 2:1 ratio). No material was used to fill the defects in the control group and the defect was only covered with Surgicel. Samples were taken on days 7, 14, 21, and 56 after the surgery. The sections were stained with hematoxylin-eosin (H&E) and assessed using light microscopy. RESULTS: In our experimental groups, bone formation was started from the margins of the defect towards the center with an increasing rate during the study period. Moreover, the formed bone was more mature. Bone formation in our control group was only limited to the margins of the defect. The newly formed bone mass was significantly higher in the experimental groups (P=0.001). CONCLUSION: OCP, BMG, and OCP/BMG compound enhanced osteoinduction in long bones.

Octacalcium phosphate/gelatin composite facilitates bone regeneration of critical-sized mandibular defects in rats: A quantitative study.

Background. Regeneration of bone defects remains a challenge for maxillofacial surgeons. The present study aimed to compare the effects of octacalcium phosphate (OCP) and the combination of octacalcium phosphate/gelatin (OCP/Gel) on mandibular bone regeneration in rats Methods. In the present study, 36 male Sprague-Dawley rats were used. The animals were randomly assigned to the following experimental groups: OCP (n=12), OCP/Gel (n=12), and the control group (n=12). Defects were created in the rat mandibles and filled with 10 mg of OCP and OCP/Gel disks in the experimental groups. In the control group, however, no substance was administered. Samples were taken on days 7, 14, 21 and 56, respectively, after the implantation. Sections (5 µ) were prepared and stained by H&E. The sections were studied, and the volume fraction of newly formed bone was measured by Dunnett's T3 test based on the significance level (P=0.05). Results. In the experimental groups, the new bone formation began from the margin of defects 7‒14 days after the implantation. During the healing process, the newly formed bone healed a larger area of the defects and grew structurally. In the control group, the defects were primarily filled with dense connective tissue, and only a small amount of new bone was formed. The present study showed a statistically significant difference in the volume of newly formed bone between the experimental groups and the control group (P<0.001). Conclusion. OCP/Gel composite can be beneficial in the healing process of mandibular bone defects.

Efficacy of Octacalcium Phosphate and Octacalcium Phosphate/Gelatin Composite on the Repair of Critical-Sized Calvarial Defects in Rats.

OBJECTIVES: The healing of bone defects in the craniofacial region is an important clinical issue. We aimed to compare the effects of octacalcium phosphate (OCP) and the combination of OCP/gelatin (OCP/Gel) on calvarial bone regeneration in rats. MATERIALS AND METHODS: In this study, 72 male Sprague Dawley rats were randomly assigned to the OCP (n=24), OCP/Gel (n=24), and control groups (n=24). Lesions with a diameter of 9 mm were created in the parietal bone and were filled with 9-mg OCP and OCP/Gel disks. In the control group, no substance was implanted in the defect. Sampling was performed on days 10, 14, 21, and 28 after the implantation. After tissue processing, 5-µm sections were prepared and stained by hematoxylin and eosin (H&E) stain. The sections were studied, and the volume fraction of the newly formed bone was assessed by Kruskal-Wallis test at a significance level of 0.05. RESULTS: In the experimental groups, new bone formation was detected at the margins of the defects 10 days after the implantation. With the progression of the healing process, the newly formed bone covered greater areas of the defects and developed a more mature structure. In the control group, the defects were primarily filled with a dense connective tissue with small islands of new bone. The results of histomorphometric assessments showed that the volume of the newly formed bone in the experimental groups had a significant statistical difference with that in the control group (P<0.001). CONCLUSIONS: The OCP/Gel composite can be useful in the healing process of calvarial bone defects.

Multipotent Stem Cell and Current Application.

Stem cells are self-renewing and undifferentiated cell types that can be differentiate into functional cells. Stem cells can be classified into two main types based on their source of origin: Embryonic and Adult stem cells. Stem cells also classified based on the range of differentiation potentials into Totipotent, Pluripotent, Multipotent, and Unipotent. Multipotent stem cells have the ability to differentiate into all cell types within one particular lineage. There are plentiful advantages and usages for multipotent stem cells. Multipotent Stem cells act as a significant key in procedure of development, tissue repair, and protection. Multipotent Stem cells have been applying in treatment of different disorders such as spinal cord injury, bone fracture, autoimmune diseases, rheumatoid arthritis, hematopoietic defects, and fertility preservation.

Antiproliferative and Antioxidant Effects of Withania coagulans Extract on Benign Prostatic Hyperplasia in Rats.

BACKGROUND: Benign prostate hyperplasia (BPH) is a common urological disorder in elderly men. Phytotherapy is frequently used to alleviate the symptoms of this condition. OBJECTIVES: The present study investigated the effect of Withania coagulans extract (WCE), which is known to have antioxidant, anti-inflammatory, antihyperglycemic, and anti-cancer properties, on testosterone-induced BPH in rats. MATERIALS AND METHODS: Forty Wistar rats were divided into five groups (each n = 8): the control group, the untreated BPH group, and three WCE-treated groups (WCE250, 500, and 1000). BPH was induced with 3 mg/kg subcutaneous injections of testosterone propionate for four weeks. WCE was concomitantly administrated by oral gavage. At the end of the induction schedule, the animals were sacrificed and their prostate glands were dissected, weighed, and fixed for histological examination (H&E and proliferating cell nuclear antigen [PCNA] staining). Half of each sample was prepared for measurement of malondialdehyde (MDA) and total antioxidant capacity (TAC) levels in the prostate. RESULTS: The present study revealed that BPH caused elevation of MDA levels, suppression of TAC levels, and increased PCNA expression in the prostate gland. Interestingly, in a dose-dependent manner, WCE caused decreased MDA levels and increased TAC levels in the prostate gland, compared to the untreated BPH group. Histopathological examinations showed a reduction in PCNA expression in the prostate epithelium of the WCE animals. CONCLUSIONS: W. coagulans inhibits the development of BPH can be useful for the treatment of this condition.