Evaluation of the time-dependent osteogenic activity of glycerol incorporated magnesium oxide nanoparticles in induced calvarial defects.

Introduction: Magnesium-based biomaterials have been explored for their potential as bone healing materials, as a result of their outstanding biodegradability and biocompatibility. These characteristics make magnesium oxide nanoparticles (MgO NPs) a promising material for treating bone disorders. The purpose of this investigation is to assess the osteogenic activity of newly-developed locally administered glycerol-incorporated MgO NPs (GIMgO NPs) in rabbits' calvarial defects. Materials and methods: Characterization of GIMgO was done by X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Bilateral calvarial defects were created in eighteen New Zealand Rabbits, of which they were divided into 3 groups with time points corresponding to 2, 4, and 6 weeks postoperatively (n = 6). One defect was implanted with absorbable gel foam impregnated with GIMgO NPs while the other was implanted with gel foam soaked with glycerol (the control). The defects were assessed using histological, Micro-Computed Tomography (Micro-CT), and histometric evaluation. Results: The characterization of the GIMgO nanogel revealed the presence of MgO NPs and glycerol as well as the formation of the crystalline phase of the MgO NPs within the nanogel sample. The histological and micro-CT analysis showed time-dependent improvement of healing activity in the calvarial defects implanted with GIMgO NPs when compared to the control. Furthermore, the histometric analysis demonstrated a marked increase in the total area of new bone, connective tissue, new bone area and volume in the GIMgO NPs implanted site. Statistically, the amount of new bone formation was more significant at 6 weeks than at 2 and 4 weeks postoperatively in the calvarial defects implanted with GIMgO NPs as compared to the control. Conclusion: The locally applied GIMgO NPs demonstrated efficacy in promoting bone formation, with more significant effects observed over an extended period. These findings suggest its suitability for clinical use as a therapeutic alternative to enhance bone healing.

Management of internal derangement of temporomandibular joint disc displacement with reduction using two different lines of treatment / Manejo do desarranjo interno do deslocamento de disco temporomandibular com redução utilizando dois tipos diferentes de tratamento

Objetive: This study was to compare the effectiveness of arthrocentesis versus the insertion of anterior repositioning splint (ARS) in improving the mandibular range of motion (MRM) for patients with the temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). Methods: 36 patients diagnosed as ADDwR were recruited and divided randomly into two groups. The first group (G1) was treated by arthrocentesis, and the second (G2) was treated using ARS. All patients were reexamined after six months. Results: Except that for protrusive movement, there were significant differences between the two groups for the percentage changes of the MRM as measured by the amount of pain free opening, unassisted opening, maximum assisted opening, right lateral and left lateral movements (p < 0.05). Conclusion: Within the context of the current study, the non-invasive, lower cost ARS, provided better results in improving the MRM when managing ADDwR cases. (AU)

Objetivo: O presente estudo comparou a eficácia da Artrocentese em relação à inserção da Placa Reposicionadora Anterior (PRA) na melhoria da Amplitude de Movimento Mandibular (AMM) para pacientes que apresentam Deslocamento de Disco Anterior com Redução (DDAcR) da Articulação Temporomandibular (ATM). Método: 36 pacientes diagnosticados como DDAcR foram recrutados e divididos aleatoriamente em dois grupos. O primeiro grupo (G1) foi tratado através da Artrocentese e o segundo (G2), tratado com a PRA. Todos os pacientes foram reexaminados após seis meses. Resultados: Com exceção do movimento protrusivo, houve diferenças significativas entre os dois grupos para as mudanças percentuais das medidas de AMM pela quantidade de abertura sem dor, abertura sem assistência, abertura máxima com assistência, movimentos laterais direitos e laterais esquerdos (p < 0,05). Conclusão: Dentro do contexto do estudo atual, a PRA, não invasiva e de menor custo, proporcionou melhores resultados na melhoria da AMM no gerenciamento de casos de DDAcR (AU)

Evaluation of lower facial heights as related to different anthropometric measurements in dentate and completely edentulous subjects.

OBJECTIVE: The aim was to compare two measurements of lower facial height (base of chin-subnasale and base of chin- tip of the nose) as related to different anthropometric measurements in dentate and completely edentulous subjects. METHOD AND MATERIALS: This cross-sectional study was conducted on 132 male subjects (group 1 [G1], 120 dentate subjects; and group 2 [G2], 12 completely edentulous subjects). Base of chin-subnasale measurement (FM1), base of chin-tip of the nose measurement (FM2), Willis' measurement (FM3), glabella-subnasale measurement (FM4), length of the index finger measurement (AM1), and tip of thumb-tip of index finger measurement (AM2) of subjects of G1 and G2 were measured by using a modified caliper while the subjects in G1 closed in centric occlusion, and the subjects of G2 were asked to close the maxillary and mandibular complete dentures in centric relation. Statistical analysis was carried out by using paired t test, Pearson's correlation (PC), and regression analysis. RESULTS: There were no significant differences between G1FM1 and G1FM3, G1FM1 and G1FM4, G1FM1 and G1AM2 (P > .05), and PCs were R = 0.74, R = -0.35, and R = -0.32 respectively. However, there were significant differences between G1FM2 and G1FM3, G1FM2 and G1FM4, G1FM2 and G1AM2 (P ≤ .05), and there were significant differences between G2FM2 and different measurements of G2 (P ≤ .05). CONCLUSION: The use of the linear equation to predict the possible base of chin-subnasale measurement through the Willis' measurement was recommended and could be used as a guide during restoration of the vertical dimension of occlusion when it has been lost.

Depot injectable biodegradable nanoparticles loaded with recombinant human bone morphogenetic protein-2: preparation, characterization, and in vivo evaluation.

OBJECTIVE: The aim of this study is to utilize the biocompatibility characteristics of biodegradable polymers, viz, poly lactide-co-glycolide (PLGA) and polycaprolactone (PCL), to prepare sustained-release injectable nanoparticles (NPs) of bone morphogenetic protein-2 (BMP-2) for the repair of alveolar bone defects in rabbits. The influence of formulation parameters on the functional characteristics of the prepared NPs was studied to develop a new noninvasive injectable recombinant human BMP-2 (rhBMP-2) containing grafting material for the repair of alveolar bone clefts. MATERIALS AND METHODS: BMP-2 NPs were prepared using a water-in-oil-in-water double-emulsion solvent evaporation/extraction method. The influence of molar ratio of PLGA to PCL on a suitable particle size, encapsulation efficiency, and sustained drug release was studied. Critical size alveolar defects were created in the maxilla of 24 New Zealand rabbits divided into three groups, one of them treated with 5 µg/kg of rhBMP-2 NP formulations. RESULTS: The results found that NPs formula prepared using blend of PLGA and PCL in 4:2 (w/w) ratio showed the best sustained-release pattern with lower initial burst, and showed up to 62.7% yield, 64.5% encapsulation efficiency, 127 nm size, and more than 90% in vitro release. So, this formula was selected for scanning electron microscope examination and in vivo evaluation. Histomorphometric analysis showed 78% trabecular bone fill, mostly mature bone in the defects treated with rhBMP-2 in NPs within 6 weeks. CONCLUSION: The prepared NPs prolonged the release and the residence time of rhBMP-2 in rabbits, which led to the formation of adequate bone in critical size alveolar bone defects in 6 weeks. This noninvasive method has application for the primary restoration of alveolar bone defects.

Soy polysaccharide as a novel superdisintegrant in sildenafil citrate sublingual tablets: preparation, characterization, and in vivo evaluation.

Sildenafil citrate (SC), a drug used to treat erectile dysfunction, is available in tablet form but has three major problems. First, the drug displays inadequate aqueous solubility, which delays the onset of its action. Second, the drug undergoes extensive first-pass metabolism, resulting in a low (40%) bioavailability. Third, the gastrointestinal effects of SC include dyspepsia and a burning sensation. The aim of this research was to prepare SC as a sublingual tablet utilizing soy polysaccharide as novel superdisintegrant to mitigate the abovementioned problems. The solubility of SC in various hydrophilic carrier solutions was estimated in order to prepare the drug as a coprecipitate. Sublingual tablets were prepared and evaluated for hardness, friability, drug content, wetting time, water absorption ratio, in vitro dispersion time, dissolution rate, and stability study. The pharmacokinetic study of the tablets was carried out on healthy volunteers. The results indicated that the co-precipitation of SC with polyvinylpyrollidone K30 enhanced the solubility of SC by more than eight folds. The tablet contained 8% soy polysaccharide as a superdisintegrant and provided a wetting time of 25 seconds, and in vitro dispersion times of 55 seconds. The drug release was found to be 95.6%. The prepared SC sublingual tablet also exhibited a rapid onset of action, and its bioavailability was enhanced 1.68-fold compared with that of the marketed tablets. It can be concluded that SC sublingual tablet is a promising formulation that results in higher solubility, faster dispersion and onset of action, higher release rate, and higher systemic bioavailability.

Solid lipid nanoparticles loaded with iron to overcome barriers for treatment of iron deficiency anemia.

According to the World Health Organization, 46% of the world's children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs) were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In conclusion, Fe-SLNs could be a promising carrier for iron with enhanced oral bioavailability.

Intranasal in situ gel loaded with saquinavir mesylate nanosized microemulsion: preparation, characterization, and in vivo evaluation.

Saquinavir mesylate (SM) is a protease inhibitor with activity against human immunodeficiency virus type 1 (HIV-1) and is available in tablet form, which has three major problems. First, the drug undergoes extensive first pass metabolism. Second, the drug has a poor aqueous solubility. And third, it has low GIT permeability and absorption. These constrains lead to decrease oral bioavailability (4% only) and administration of large doses which increase the incidence of occurrence of the side effects. The aim of this research was to utilize nanotechnology to formulate (SM) into a nasal in situ nanosized microemulsion gel (NEG) to provide a solution for the previously mentioned problems. The solubility of (SM) in various oils, surfactants, and cosurfactants was estimated. Pseudo-ternary phase diagrams were developed and various nanosized microemulsion (NE) were prepared, and subjected to characterization, stability study, and droplet size measurements. Gellan gum was used as an in situ gelling agent. The gel strength, critical ionic concentration, gelation characteristics, in vitro release, and ex vivo nasal permeation were determined. The pharmacokinetic study was carried out in rabbits. Stable NEs were successfully developed with a droplet size range of 25-61 nm. A NEG composed of 17.5% Labrafac PG, 33% Labrasol, and 11% Transcutol HP successfully provided the maximum in vitro and ex vivo permeation, and enhanced the bioavailability in the rabbits by 12-fold when compared with the marketed tablets. It can be concluded that the nasal NEG is a promising novel formula for (SM) that has higher nasal tissue permeability and enhanced systemic bioavailability.