1,720,973 research outputs found
DEXAMETHASONE INJECTION IN SURGERY OF LOWER THIRD MOLARS: A RETROSPECTIVE CLINICAL STUDY
No full textAim: the aim of this study is to evaluate the efficacy of two different dosages of dexamethasone, i.e. 2 and 4 mg injected
submucosally to reduce postoperative discomfort after mandibular third molar surgery.
Methods: the study was conducted on 150 patients subjected
to surgical removal of an impacted third molar. Patients were
randomly divided into three groups: G1 (n = 50) received 4 mg/1
ml dexamethasone submucosally; G2 (n = 50) received 2 mg/0,5
ml dexamethasone submucosally; G3 (n = 50) received saline
submucosally. The drug was administered after wound closure
through silk sutures. Pain, swelling, trismus, analgesic consumption and operation time were comparatively evaluated at
three different time point: T0 before surgery, T1
on 3rd and T2
on
7th day after surgery. The sutures were removed on the 7th day.
Results: G2 showed statistically significant reduction in swelling
considering male gender. The differences between the time points
where statistically significant in G2 under 25 years old when trismus was analyzed. Difference between G2 and G3 was statistically significant at T1 when compared in painkillers assumption.
Conclusion: it can be concluded that better post-operative values were obtained with 2 mg dexamethasone infiltration in order
to reduce trismus in subjects under 25 years old. The statistical
analysis showed positive effects in female patients with 4 mg dose of dexamethasone in the aperture evaluation and oedema
Recycling alginate composites for thermal insulation
Full text linkWe present a new method for the total functional recycling of alginate-based composite materials made via ionotropic gelation. The original material, an alginate/fiberglass foam with thermal insulation characteristics, was produced following a patented process in which fiberglass waste is embedded into the polyanionic gel matrix, and the resulting compound is then freeze-dried. The functional recycling is carried out by disassembling the ionic matrix – which is initially formed by the interaction between a cation (e.g. calcium) and the negatively charged alginate backbone – with the use of a chelator (Ethylenediaminetetraacetic acid disodium salt) with a high affinity for the cations, thus obtaining a homogeneous solution. An ionotropic gel can then be re-formed upon deactivation of the chelating activity under mild acid conditions. We managed to maintain or improve the thermal, mechanical and acoustic performances of the original material and we successfully tested the possibility of multiple recycling cycles
Hyaluronic acid/lactose-modified chitosan electrospun wound dressings – Crosslinking and stability criticalities
Full text linkPolysaccharide electrospun wound dressings should be an effective strategy in the field of wound care, as they combine an extracellular matrix-like structure with excellent biomimicry. However, their high hydrophilicity and large surface area cause a rapid dissolution in aqueous environments, compromising their clinical employment. In the present paper, electrospun membranes prepared using hyaluronic acid, a bioactive lactose-modified chitosan (CTL), and polyethylene oxide have been crosslinked using glutaraldehyde, genipin, EDC/NHS or thermal treatments, obtaining very poor results in terms of membrane stability. Therefore, carbonyldiimidazole (CDI) and methacrylic anhydride were investigated in an innovative way, where CDI proved to be the best compromise between nanofiber water resistance, architecture maintenance and degradability. Indeed, the swelling and degradation behavior as well as the water vapor permeability of these matrices were tested, revealing the effectiveness of the electrospun products in absorbing large amount of liquid while maintaining the balance between water retention and gas permeability
ASSESSMENT OF THE BEHAVIOR OF DENTAL PULP STEM CELLS CULTURED ON PEEK AND TITANIUM SAMPLES
No full textAim: the following work assessed the behavior of human Dental
Pulp Stem Cells (hDPSC) on PEEK and Titanium samples, in particular their ability to adhere, proliferate and differentiate into osteoblasts.
Methods: surface modifications were made to the samples by
pre-established protocols of sandblasting and laser micropatterning, to modulate surface roughness. After roughening treatments, samples were divided into two groups: nontreated
and treated with air-plasma cleaning process to modulate surface wettability. The hDPSCs were harvested from dental elements and, after expansion in the proper medium, were seeded on the samples to study their behavior. The analyses for
the adhesion and the proliferation were performed by Scanning Electron Microscopy and Alamar Blue test, while the differentiation in osteoblasts was evaluated by measuring AlkalinePhosphatase activity.
Results: all the samples tested are able to support hDPSCs
adhesion, proliferation and differentiation in osteoblasts with
differences depending on the material nature and surface. Laser micropatterned titanium samples, in particular, were the
best performing in terms of cell differentiation.
Air-plasma treatment does not affect cell adhesion and proliferation but improves cell differentiation, in particular on Titanium samples.
Conclusion: PEEK and Titanium are confirmed as excellent
materials to support the adhesion, the proliferation and the differentiation of the hDPSCs. The biological behavior is stron
Alginate-Sr/Mg Containing Bioactive Glass Scaffolds: The Characterization of a New 3D Composite for Bone Tissue Engineering
Full text linkIn bone regeneration, combining natural polymer-based scaffolds with Bioactive Glasses (BGs) is an attractive strategy to improve the mechanical properties of the structure, as well as its bioactivity and regenerative potential. Methods: For this purpose, a well-studied alginate/hydroxyapatite (Alg/HAp) porous scaffold was enhanced with an experimental bioglass (BGMS10), characterized by a high crystallization temperature and containing therapeutic ions such as strontium and magnesium. This resulted in an improved biological response compared to 45S5 Bioglass (R), the "gold" standard among BGs. Porous composite scaffolds were fabricated by freeze-drying technique and characterized by scanning electron microscopy and microanalysis, infrared spectroscopy, and microcomputed tomography. The mechanical properties and cytocompatibility of the new scaffold composition were also evaluated. The addition of bioglass to the Alg/HAp network resulted in a slightly lower porosity. However, despite the change in pore size, the MG-63 cells were able to better adhere and proliferate when cultured for one week on a BG scaffold compared to the control Alg/HAp scaffolds. Thus, our findings indicate that the combination of bioactive glass BGMS10 does not affect the structural and physicochemical properties of the Alg/HAp scaffold and confers bioactive properties to the structures, making the Alg/HAp-BGMS10 scaffold a promising candidate for future application in bone tissue regeneration
Advantages of agarose on alginate for the preparation of polysaccharide/hydroxyapatite porous bone scaffolds compatible with a proline-rich antimicrobial peptide
No full textThe optimized proline-rich antimicrobial peptide B7-005 was loaded on bone scaffolds based on polysaccharides and hydroxyapatite. Alginate was firstly chosen in order to exploit its negative charges, which allowed an efficient B7-005 loading but hindered its release, due to the strong interactions with the positive charged peptide. Hence, alginate was substituted with agarose which allowed to prepare scaffolds with similar structure, porosity, and mechanical performance than the ones prepared with alginate and hydroxyapatite. Moreover, agarose scaffolds could release B7-005 within the first 24 h of immersion in aqueous environment. The peptide did not impaired MG-63 cell adhesion and proliferation in the scaffold, and a positive cell proliferation trend was observed up to two weeks. The released B7-005 was effective against the pathogens E. coli, K. pneumoniae, and A. baumannii, but not against S. aureus and P. aeruginosa, thus requiring further tuning of the system to improve its antimicrobial activity
"A lactose-modified chitosan accelerates chondrogenic differentiation in mesenchymal stem cells spheroids"
Full text linkSpheroids derived from human mesenchymal stem cells (hMSCs) are of limited use for cartilage regeneration, as the viability of the cells progressively decreases during the period required for chondrogenic differentiation (21 days). In this work, spheroids based on hMSCs and a lactose-modified chitosan (CTL) were formed by seeding cells onto an air-dried coating of CTL. The polymer coating can inhibit cell adhesion and it is simultaneously incorporated into spheroid structure. CTL-spheroids were characterized from a morphological and biological perspective, and their properties were compared with those of spheroids obtained by seeding the cells onto a non-adherent surface (agar gel). Compared to the latter, smaller and more viable spheroids form in the presence of CTL as early as 4 days of culture. At this time point, analysis of stem cells differentiation in spheroids showed a remarkable increase in collagen type-2 (COL2A1) gene expression (~700-fold compared to day 0), whereas only a 2-fold increase was observed in the control spheroids at day 21. These results were confirmed by histological and transmission electron microscopy (TEM) analyses, which showed that in CTL-spheroids an early deposition of collagen with a banding structure already occurred at day 7. Overall, these results support the use of CTL-spheroids as a novel system for cartilage regeneration, characterized by increased cell viability and differentiation capacity within a short time-frame. This will pave the way for approaches aimed at increasing the success rate of procedures and reducing the time required for tissue regeneration
An ex-situ approach for cultivating coralline algae in a restoration perspective
No full textMediterranean coralligenous reefs are hotspots of biodiversity, but they are declining due to multiple impacts, prompting a growing number of conservation and restoration efforts. Restoration through the outplanting of the habitat foundation species, crustose coralline algae (CCA, Rhodophyta, Corallinophycidae), is still largely unexplored, although they make a major contribution to building these valuable ecosystems. In this study, we tested the feasibility of ex-situ culture of Lithophyllum stictiforme, one of the most common CCA of the coralligenous reefs, with nutrient-enriched artificial seawater medium, contributing to the knowledge of early life stage development and calcification. Thalli fragments with conceptacles were collected at a depth of 28 m (Costa Paradiso, northern Sardinia). We tested two light intensities, (L− 40 μmol photons m−2s−1, L+160 μmol photons m−2s−1) and two temperatures, (T− 14 °C, T+ 20 °C), the lower settings were chosen to simulate conditions at the sampling site, while the higher values were explored as potential growth promoters. Spore settlement, density and growth were estimated for two-weeks. Calcification was analyzed at the end of the culture period using Scanning Electron Microscopy in combination with Energy Dispersive Spectroscopy (SEM-EDS). The L− treatments had a positive effect on germination success and density, whereby the growth of the germination disc was enhanced in the L−T+ treatment. SEM-EDS showed that the marginal area of the germination discs had a higher Ca content than the core area, and that the L− treatments promoted a higher cell wall Ca percentage
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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