Dispersion and Functionalization of Nanoparticles Synthesized by Gas Aggregation Source: Opening New Routes Toward the Fabrication of Nanoparticles for Biomedicine.

The need to find new nanoparticles for biomedical applications is pushing the limits of the fabrication methods. New techniques with versatilities beyond the extended chemical routes can provide new insight in the field. In particular, gas aggregation sources offer the possibility to fabricate nanoparticles with controlled size, composition, and structure out of thermodynamics. In this context, the milestone is the optimization of the dispersion and functionalization processes of nanoparticles once fabricated by these routes as they are generated in the gas phase and deposited on substrates in vacuum or ultra-high vacuum conditions. In the present work we propose a fabrication route in ultra-high vacuum that is compatible with the subsequent dispersion and functionalization of nanoparticles in aqueous media and, which is more remarkable, in one single step. In particular, we will present the fabrication of nanoparticles with a sputter gas aggregation source using a Fe50B50 target and their further dispersion and functionalization with polyethyleneglycol (PEG). Characterization of these nanoparticles is carried out before and after PEG functionalization. During functionalization, significant boron dissolution occurs, which facilitates nanoparticle dispersion in the aqueous solution. The use of different complementary techniques allows us to prove the PEG attachment onto the surface of the nanoparticles, creating a shell to make them biocompatible. The result is the formation of nanoparticles with a structure mainly composed by a metallic Fe core and an iron oxide shell, surrounded by a second PEG shell dispersed in aqueous solution. Relaxivity measurements of these PEG-functionalized nanoparticles assessed their effectiveness as contrast agents for magnetic resonance imaging (MRI) analysis. Therefore, this new fabrication route is a reliable alternative for the synthesis of nanoparticles for biomedicine.

Pancreatic metaplasia of gastric mucosa associated with gastroduodenal ulcer.

Metaplasia represents the process of transforming a well-differentiated adult tissue into another type of adult tissue. Pancreatic metaplasia of the gastric mucosa represents the process in which the normal mucosa of the stomach is replaced with pancreatic formations, which mimic the structure of pancreatic acini. We describe the case of a male patient aged 39 who was admitted for abdominal pain, vomiting, hematemesis, melena, pale teguments, intense perspiration and nausea. The patient underwent surgery for suturing a perforated duodenal ulcer five years prior to this episode (2002). A gastric ulcer complicated with superior digestive bleeding and a chronic duodenal ulcer complicated with partial stenosis and perivisceritis were found during surgery. Gastric wall fragments were harvested and underwent usual histological techniques and immunohistochemistry. We found an ulceration from the gastric mucosa to the submucosa, covered by fibrino-leukocytic detritus. In the mucosal chorion we found numerous round or oval shaped nested formations which occupied the lower two thirds of the chorion, to the muscularis mucosae. Some metaplasic acini contain cells variable in shape, color and immunophenotype. Surrounding the nested acini we found tubular formations, formed of cubic shaped cells, representing excretory canals which were continued by gastric glands or opened directly in the crypts of the gastric epithelium.

The involvement of metalloproteinases and their tissular inhibitors in the processes of periodontal orthodontic remodeling.

The orthodontic treatment uses forces that produce structural and biochemical changes in the periodontal space breaking the balance between the synthesis and the breakdown of the collagen in the periodontium. Matrix metalloproteinases (MMP) plays a central role in the normal tissular remodeling processes, those in the tissular morphogenesis and the tissular repair (including the remodeling of the periodontal space of the periodontal ligament, during the dental orthodontic translations). The inter-relation between the molecular mechanism of orthodontic remodeling and MMPs is still unclear.

Annexin A3 expression after stroke in the aged rat brain.

In an effort to identify new proteins involved in functional recovery after cerebral ischemia, young (3 months) and aged (18 months) male rats were subjected to middle cerebral artery (MCA) occlusion. Brains were harvested at 3- and 14-days post ischemia and proteins from the peri-infarcted and the corresponding contralateral area and total proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis followed by mass spectrometry analysis. Annexin A3 (ANXA3) was identified as one upregulated protein in the post-ischemic rat brain. Using western blotting, real-time PCR and immunohistochemistry, we confirmed that at 3-14 days post-stroke, ANXA3 expression in the peri-infarct area was consistently increased over the corresponding area of control rats. Double staining revealed that ANXA3 is produced by activated microglial cells. We found that aged rats also had more newly proliferating cells expressing ANXA3 than young rats do. Occasionally, ANXA3-immunopositive cells wraped around neurons, suggesting that annexin A3 may be involved in the removal of dying neurons after stroke.

The attachment affinity of hemoglobin toward silver-containing bioactive glass functionalized with glutaraldehyde.

Bioactive glasses belonging to the 56SiO2·(40 - x)CaO·4P2O5·xAg2O system, with x = 0, 2, and 8 mol %, were surface functionalized with the protein coupling agent glutaraldehyde (GA) and further evaluated in terms of hemoglobin affinity. The bare and GA-functionalized samples were investigated before and after protein attachment, by electron paramagnetic resonance (EPR) spectroscopy combined with spin-labeling procedure. Methanethiosulfonate spin label was used to explore the local environment of ß-93 cysteine in horse hemoglobin, in terms of spin label side chain mobility. The EPR simulation methods were employed to quantify the rotational correlational times and fraction of the immobilized spin labels. The EPR absorption spectrum was further exploited to estimate the amount of hemoglobin loaded on the substrates. The surface elemental composition obtained by X-ray photoelectron spectroscopy revealed similar tendency in terms of surface coverage. Changes in surface architecture, that is, changes in surface morphology after protein coverage, were observed by scanning electron microscopy. It was concluded that GA improves the stability of protein attachment and induces polymerization of hemoglobin molecules.

Conservative treatment of dental trauma: case presentation-direct adhesive restoration techniques of the 4 upper incisors with different types of fractures on the coronal level.

Dental trauma creates serious functional, aesthetic and psychological problems for the patient. The known developments in recent years in the area of materials and techniques related to direct composite resin restorations provide for the dentists direct conservative solutions that allow both morphology and aesthetic restoration and preservation of pulp vitality in many of the clinical situations encountered. A careful clinical examination and an accurate diagnosis (in terms of classification of the trauma) will allow the dentist to choose the most conservative therapeutic solution. We recommend the use of the diagnostic and therapeutic guidelines mentioned in the article.

Collagen IV and MMP-9 expression in hypertrophic gingiva during orthodontic treatment.

INTRODUCTION: In the present study, we aimed to assess MMP-9 and type IV collagen in the gingival tissue in patients with gingival overgrowth (GO) after orthodontic treatment, with or without clinical signs of inflammation to appreciate the role of balance between those two markers in the onset of GO during tooth movement. MATERIALS: Gingival tissue was harvested from 45 patients divided in three groups: 15 patients with orthodontic appliance that developed GO on at least two teeth; 15 patients with chronic gingivitis with GO; 15 patients (control group) with healthy periodontal tissues, without clinical gingival changes, in whom the first premolar was planned for extraction for orthodontic purposes (canine distalization). METHODS: The tissue samples obtained by gingivectomy were fixed in 10% neutral formalin solution for 48 hours and then included in paraffin with the usual technique. The histologic examination was performed using classic Hematoxylin-Eosin technique. Double immunofluorescence was performed for anti-MMP-9 and anti-collagen IV antibodies. RESULTS: MMP-9/collagen IV double stainings showed an increase of fibrosis and inflammation in different degrees. CONCLUSIONS: The mechanical stress induced by the orthodontic devices, might be the key players in driving both the inflammation and the fibrotic reaction.

Gingival inflammatory infiltrate analysis in patients with chronic periodontitis and diabetes mellitus.

UNLABELLED: Diabetes mellitus and periodontal disease are two pathological entities that destructively emphasize each other. The aim of our study was the histological and immunohistochemical analyze of the inflammatory infiltrate in the gingival tissue at patients with diabetes mellitus (DM) and periodontal disease. MATERIALS AND METHODS: The study was achieved on gingival tissue from 40 patients with DM and specific symptoms of periodontal disease. We used Hematoxylin-Eosin and trichromic Goldner-Szekely staining and CD20cy and CD45RO antibodies. RESULTS: In patients with DM under 10 years, we found an intense periodontal lymphocyte inflammatory infiltrate and in patients with a DM evolution more than 10 years, the lymphocyte inflammatory infiltrate had a less intensity. The pattern was mostly diffuse in lamina propria. Many patients had a very abundant plasmocyte infiltrate. During immunohistochemical exam, 25 cases presented CD20 positive immunostaining. The intensity of the inflammatory infiltrate with B-lymphocytes was very low (score 1). All immunohistochemical analyzed cases presented CD45RO positive immunostaining, with a mixed pattern of the T-cell lymphocyte infiltrate. CONCLUSIONS: The nflammatory infiltrate in diabetic periodontal disease was polymorph, mostly with a diffuse pattern in gingival chorion. The intensity of the lymphocyte infiltrate was higher in patients with chronic periodontitis and DM less than 10 years. Positive CD45RO T-lymphocytes were more numerous compared to positive CD20 B-lymphocytes and they were present intra and under epithelial in the gingival of all the patients, no matter of the DM time evolution.

Matrix metalloproteinase 9 levels in gingival crevicular fluid in patients after periodontal microsurgery for orthodontic induced gingival hypertrophy.

INTRODUCTION: In this study, we aim to compare the levels of matrix metalloproteinase 9 (MMP9) in the gingival crevicular fluid (GCF), as indicators for healing, in two groups of patients - operated with a classic periodontal surgical technique and the same technique but using a dental microscope. MATERIALS: We included 14 patients with ages between 12 and 26 years, average 14±6.2 years. Eight patients were women and six men. All patients presented gingival hypertrophy because of the orthodontic treatment on the mandibular arch. We performed gingivectomy on one-half of the mandibular arch by classic periodontal surgery and on the other half of the mandibular arch by a microscope-assisted gingivectomy. METHODS: In the hypertrophied gingiva, the expression of MMP9 was identified using immunohistochemical-staining techniques. For immunological determination of MMP9 in GCF we performed Elisa tests. RESULTS: We found different levels in different moments of the healing process for the two hemiarcades. CONCLUSIONS: We consider that faster healing in case of microscope-assisted gingivectomy may be related to the expression of MMP-9 in the GCF.

Correlations between the gingival crevicular fluid MMP8 levels and gingival overgrowth in patients with fixed orthodontic devices.

UNLABELLED: Levels of metalloproteinase 8 (MMP8) in gingival crevicular fluid were studied in case of treatment with fixed orthodontic appliances. It were found a relationship between its levels and stages of the treatment under a good control of the bacterial plaque. Gingival overgrowth (GO) during the orthodontic treatment was traditionally considered as an inflammatory reaction consecutive of bacterial plaque accumulation because of difficult hygiene in those patients. Our study starts from the hypothesis that the gingival volume growth during the fixed orthodontic treatment appears at the beginning, without any inflammatory signs, as a result of the mechanical stress and periodontal remodeling during the orthodontic dental movement, the MMP8 acting as an indicator of this situation. MATERIAL AND METHODS: Twenty-two patients received a fixed orthodontic treatment. Periodontal examination took place one hour before and one hour, four and eight hours and weekly after until eight weeks. At each session gingival crevicular fluid (GCF) was sampled and the level of MMP8 was determined. At the appearance of gingival overgrowth (GO) gingivectomy was performed. RESULTS: In the 13 patients that did not develop gingival overgrowth, the levels of MMP8 increased in the first 4-8 hours after orthodontic appliance and then fall to the initial level. In the nine patients with gingival overgrowth, the MMP8 levels in GCF continued to rise until the appearance of GO. In cases of GO with inflammation the levels of MMP8 were significantly higher than in cases of GO without inflammation. The expression of MMP8 in hypertrophied gingiva was more intensive in cases of GO with inflammation. CONCLUSIONS: It is possible that the MMP8 values in GCF to be a marker of the GO onset. MMP8 determination and monitoring at shorter time intervals may lead to a better control of the bacterial plaque and avoidance of gingival inflammation.