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The formation of highly concentrated and stable graphene derivatives dispersions remains a challenge towards their exploitation in various applications, including flexible optoelectronics, photovoltaics, 3D-printing, and biomedicine. Here, we demonstrate our extensive investigation on the dispersibility of graphene oxide (GO) and reduced graphene oxide (RGO) in 25 different solvents, without the use of any surfactant or stabilizer. Although there is a significant amount of work covering the general field, this is the first report on the dispersibility of: a) RGO prepared by a HI/AcOH assisted reduction process, the method which yields RGO of higher graphitization degree than the other well-known reductants met in the literature, b) both GO and RGO, explored in such a great range of solvents, with some of them not previously reported. In addition, through calculation of their Hansen Solubility Parameters (HSP), we confirmed their dispersibility behavior in each solvent, while we indirectly validated the most advanced graphitization degree of the studied RGO compared to other reported RGOs, since its HSPs exhibit the highest similarity with the respective ones of pure graphene. Finally, high concentrations of up to 189 μg mL−1 for GO and ~ 87.5 μg mL−1 for RGO were achieved, in deionized water and o-Dichlorobenzene respectively, followed by flakes size distribution and polydispersity indices estimation, through dynamic light scattering as a quality control of the effect of a solvent’s nature on the dispersion behavior of these graphene-based materials.

Τα μαγνητικά λιποσώματα μπορούν να αποτελέσουν την κατάλληλη πλατφόρμα για την ταυτόχρονη στοχευμένη μεταφορά/χορήγηση θεραπευτικών και διαγνωστικών ενώσεων. Οι ελεγχόμενες οπτικές ιδιότητες των μαγνητικών νανοσωματιδίων σε συνδυασμό με την ευελιξία των λιποσωμάτων ως φορέων μπορεί δυνητικά να ενισχύσει την αποτελεσματικότητα της αγωγής με την επιλεκτική μεταφορά φαρμάκων μέσω μαγνητικά καθοδηγούμενης εναπόθεσης και ταυτόχρονης στόχευσης με ενεργοποίηση μέσω υποδοχέα (π.χ., πεγκυλίωση και επιφανειακή τροποποίηση : προσδέτες και αντισώματα). Λόγω των οπτικών ιδιοτήτων τους, τα μαγνητικά νανοσωματίδια μπορούν να χρησιμεύσουν και ως σκιαγραφικές ουσίες κατά την μαγνητική απεικόνιση (MRI), επιτρέποντας την in vivo παρακολούθηση και μεταφορά των φαρμάκων με μη επεμβατικό τρόπο. Σκοπός αυτής της εργασίας ήταν αρχικά η παρασκευή μαγνητολιποσωμάτων, ο φυσικοχημικός χαρακτηρισμός τους καθώς και η μελέτη επίδρασης διαφόρων παραγόντων στις φυσικοχημικές ιδιότητες και την σταθερότητά τους. Κατά την παρασκευή των ΜΛ αρχικός στόχος ήταν ο εγκλωβισμός της μέγιστης δυνατής συγκέντρωσης USPIOs σε μονοστοιβαδιακά λιποσώματα μικρού μεγέθους (

Background:. Live Surgery Meetings have been established as a vey effective means to demonstrate certain surgical techniques and intraoperative decision-making. However, many authors still question the ethics of this approach. We present our experience as organizers of the Live Makeover Aesthetic Surgery Symposium, an annual international live surgery meeting taking place in Athens, Greece. Methods:. Throughout the course of our meetings, 2 surveys were performed, 1 after Live Makeover Aesthetic Surgery Symposium 3, comparing the educational value between live surgery and pre-recorded videos, and the second after LMASS 6, re-evaluating the educational value of live surgery, as well as the ethics of this educational method and the patient safety. In addition, we studied the results of the patients operated on in all of our meetings, and their level of satisfaction. Results:. Based on the results of the first survey, the superior educational value of live surgery was obvious. The second survey confirmed those valuable educational benefits. In addition, the concerns on both surgical outcomes and patient safety were minimal. The patients showed a very high level of satisfaction through their answers. The complications encountered were only 2 of the 49 live surgical demonstrations and were not directly related to the live demonstration. Conclusions:. Based on our study, live surgery is an effective, safe educational tool. However, strict guidelines have to be followed to ensure high educational value and patient safety. Based on our 9-year experience with our live surgery meeting, we provide detailed guidelines for optimal outcomes.

Aim: To evaluate the efficacy and safety of Flexible Bronchoscopy as first-line diagnosis and treatment modality in pediatric cases with Foreign body aspiration (FBA) Methods: We performed a retrospective study reviewing the clinical records of 219 children who underwent flexible bronchoscopy (FB) for suspected FBA, over a period of 26 years. We evaluated the success of FB in removal of foreign body using a retrieval basket at a referral tertiary hospital. Results: FBA was confirmed with bronchoscopy in 104 cases (47.5%), (mean age 3.13, range: 6 months-10 years, 68% males). The majority of the foreign bodies were nuts (52.5%), followed by other food particles (16%) and seeds (8%). The foreign body was located predominantly in the right bronchial tree (56%). The most common clinical signs and symptoms were cough (79.5%), reduced air entry (66.3%) and wheezing (29.4%). The most frequent radiological finding was unilateral hyperinflation (55.8%) followed by opacities (23%) and atelectasis (11.5%). Fifty-eight percent of the foreign bodies were removed with a rigid bronchoscope by ENT; over the last 7 years there has been an increasing trend to remove the inhaled foreign body with a basket through the FB. In 41% of the patients with FBA, foreign bodies were successfully removed during FB. Over the last 5 years, only in two patients, foreign body could not be removed with FB and they underwent rigid bronchoscopy. No serious complications were observed in these cases except cough. Conclusions: Flexible bronchoscopic extraction of a foreign body in the airway using a retrieval basket in children can be performed successfully with minimal complications.

Background:. Revision facelift is a very challenging operation. The goal of our study was to examine the most common problems that the facelift surgeon has to face in a revision case and to suggest ways of solving them. Methods:. A review of all patients from 2012 to 2017 in whom rhytidectomy was performed by the senior author was conducted. Results:. During the 5-year study period, the author performed 552 face lifts. After the review to confirm revision procedures, a total of 72 revision facelifts were found. On reviewing the most common problems encountered in our facelifts, we found that in addition to the stigmata of the primary facelift, which are thoroughly analyzed in our article, a new type of stigmata has been added nowadays to the revision facelift—that of the various noninvasive interventions that patients undergo after their first facelift, in their effort to postpone or avoid a second operation. In all the abovementioned cases, the surgeon has to modify his basic surgical plan accordingly, to be able to improve or solve all of those problems during the revision surgery. Conclusions:. The modern facelift surgeon often has to face much more than the stigmata of the primary facelift or the natural aging process. Thus, he/she should be appropriately trained to solve any problem we might encounter in a revision case.

18-α-Glycyrrhetinic acid (GA) is a bioactive compound extracted from licorice that exhibits many biological and pharmacological effects such as anti-inflammatory and antioxidant activities on the skin. However, its lipophilic nature results in poor bioavailability that limits clinical applications. Liposomes, presenting the ability to carry both hydrophobic and hydrophilic payloads and a good cytocompatibility, are effective to overcome this barrier. Furthermore, the addition of permeation enhancers such as ethanol into liposomal formulations helps the diffusion of these systems through the skin barrier. Here, we aimed to formulate GA-loaded ethanolic liposomes, using a natural soybean lecithin via a microfluidic approach. Using a fused deposition modeling (FDM) 3D printer we customized a microfluidic chip, and manufactured vesicles that presented spherical shape with a size of 202 ± 5.2 nm, a narrow size distribution and a good stability over a period of 30 days. After reaching a drug encapsulation efficiency of 63.15 ± 2.2%, liposomes were evaluated for their cytocompatibility and skin permeation potentiality after hydrogelation using xanthan gum. The in vitro release and permeation studies were performed using Franz diffusion cells comparing two different media and three synthetic membranes including a polymeric skin-mimicking membrane. The selected formulation presented no cytotoxicity and an increased permeation compared to GA saturated hydrogel. It could perform therapeutically better effects than conventional formulations containing free GA, as prolonged and controlled release topical dosage forms, which may lead to improved efficiency and better patient compliance.

Intra-articular (IA) injection of thermoresponsive hydrogels coupled with microparticles (MPs) possess the benefit of sustaining the anti-inflammatory drug effect within the joint cavity for rheumatoid arthritis treatment. Star-shaped thermoresponsive poly(polyethylene glycol) methacrylate [Poly(PEGMA)] copolymers were synthesized using free radical polymerization technique and fully characterized. Triamcinolone acetonide (TA)-loaded PLA/mPEG-PDL MPs, previously optimized, were integrated into the synthesized copolymer solutions at various concentrations and tested for their gelation temperatures. The MPs-in-hydrogel formulations were characterized using scanning electron microscope (SEM), viscosity measurements, ex vivo bioadhesion, and in vitro release studies. The anti-inflammatory effect of integrated systems was assessed in adjuvant-induced monoarthritic rat knee joints and compared to Kenacort and TA-loaded MPs. Two copolymers were successfully synthesized; G-1 = poly(PEGMA188-ME-co-PEGMA475-ME) and G-2 = poly(PEGMA246-EE-co-PEGMA475-ME). Using the tube inversion technique, the gel formation was found dependent on copolymer concentration. An irreversible aggregation was obtained at copolymer concentrations ≤10% (w/v), while a gel was formed at 20 and 30% (w/v) of both copolymers upon increasing temperature. The MP-hydrogel formulations were optimized at 20 and 30% (w/v) of G-1 and G-2 with gelation temperatures of 33 and 37 °C, respectively. SEM images revealed the porous microstructures of hydrogels and their adsorption on MP surfaces. The integrated formulas showed pseudoplastic behaviors, while the bioadhesion study confirmed their bioadhesiveness on excised cartilage. The in vitro release study confirmed drug sustainment from MPs-hydrogels compared to MPs. In vivo studies proved the superiority of MP-in-hydrogels in treatment of induced arthritis, relative to Kenacort and MPs alone, suggesting the applicability of this integrated platform in IA drug delivery.

Liposomes have been on the market as drug delivery systems for over 25 years. Their success comes from the ability to carry toxic drug molecules to the appropriate site of action through passive accumulation, thus reducing their severe side effects. However, the need for enhanced circulation time and site and time-specific drug delivery turned research focus on other systems, such as polymers. In this context, novel composites that combine the flexibility of polymeric nanosystems with the properties of liposomes gained a lot of interest. In the present work a mixed/chimeric liposomal system, composed of phospholipids and block copolymers, was developed and evaluated in regards with its feasibility as a drug delivery system. These innovative nano-platforms combine advantages from both classes of biomaterials. Thermal analysis was performed in order to offers an insight into the interactions between these materials and consequently into their physicochemical characteristics. In addition, colloidal stability was assessed by monitoring z-potential and size distribution over time. Finally, their suitability as carriers for biomedical applications was evaluated by carrying out in vitro toxicity studies.

Introduction: The applications of naturally obtained polymers are tremendously increased due to them being biocompatible, biodegradable, environmentally friendly and renewable in nature. Among them, polyhydroxyalkanoates are widely studied and they can be utilized in many areas of human life research such as drug delivery, tissue engineering, and other medical applications. Areas covered: This review provides an overview of the polyhydroxyalkanoates biosynthesis and their possible applications in drug delivery in the range of micro- and nano-size. Moreover, the possible applications in tissue engineering are covered considering macro- and microporous scaffolds and extracellular matrix analogs. Expert commentary: The majority of synthetic plastics are non-biodegradable so, in the last years, a renewed interest is growing to develop alternative processes to produce biologically derived polymers. Among them, PHAs present good properties such as high immunotolerance, low toxicity, biodegradability, so, they are promisingly using as biomaterials in biomedical applications.

Suspensions of zero valent iron nanoparticles (nZVI) are commonly used for the in situ remediation of groundwater contaminated with chlorinated solvents. Stable aqueous suspensions of zero-valent nano-particles (nZVI) are prepared by wet chemistry techniques and stabilized with a carboxyl-methyl-cellulose (CMC) coating. To enhance their penetration length along with their capacity to attach on oil/water interfaces, nanocomposites are prepared where the CMC-coated nZVI suspension is encapsulated in liposomes. The liposomes might be regarded as vehicles for the safe delivery of nZVI to hydrophobic pollutant targets. The integrity of synthesized liposomes membranes is evaluated with batch tests and flow-through tests in a pre-saturated with oil glass-etched pore network. For assessing the mobility and longevity of nZVI suspensions under flow-through conditions, visualization flow tests are performed on the glass-etched pore network for three types of suspensions: (i) CMC-coated nZVI; (ii) CMC-coated nZVI encapsulated in liposomes; (iii) mixture of CMC-coated nZVI and empty liposomes. The measured iron and lipid concentration breakthrough curves for all cases are interpreted by accounting for the transient changes caused on the particle size distribution in the suspension collected from the outlet. Albeit the CMC-coated nZVI are always very mobile, stable, and detectable in the effluent, a fraction of the liposomes or no liposomes are detected in the effluent, when injecting CMC-coated nZVI encapsulated in liposomes or mixed with empty liposomes, respectively. The flushing of the pore network with water, remobilizes the liposomes and withdraws them completely from the pore system.

Aim: To investigate epidemiological data of foreign body aspiration (FBA) over a 25 year period and define the sensitivity and specificity of clinical and radiological findings on diagnosis. Methods: We performed a retrospective study reviewing the clinical records of 176 children (mean age: 3.03 years, 60.8% male) who underwent flexible bronchoscopy for suspected FBA, over a period of 25 years. Results: FBA was confirmed with bronchoscopy in 78 cases (44.3%), (mean age 2.74, range: 6 months-10 years, 61.5% males). The majority of the foreign bodies were nuts (52.0%), followed by other food particles (16%) and seeds (14%). The foreign body was located predominantly in the right bronchial tree (56%). The average time between aspiration and diagnosis was 16 days (range: 1 day – 4 years), with the most common clinical signs and symptoms being cough (76.5%), reduced air entry (62.9%) and wheezing (28.6%). This triad was present in 20.6% of the patients. The most frequent radiological finding was unilateral hyperinflation (56.5%) followed by opacities (20.3%) and atelectasis (10.1%). Eighteen patients (23%) presented with normal X-rays. Most of the foreign bodies were removed with a rigid bronchoscope by ENT; over the last 5 years there has been an increasing trend to remove the inhaled foreign body with a basket through the flexible bronchoscope (15 cases). Conclusions: The clinical symptoms and the radiological findings alone are not sufficiently specific and sensitive in the diagnosis of FBA; children who present with a history of suspected FBA, should undergo diagnostic flexible endoscopy.

Polymeric hydrogels are common dosage forms designed for the topical administration of antimicrobial drugs to treat vaginal infections. One of the major advantages of using chitosan in these formulations is related to the intrinsic and broad antimicrobial activity exerted on bacteria and fungi by this natural polymer. Most vaginal yeast infections are caused by the pathogenic fungus Candida albicans. However, despite the anti-Candida activity towards and strains susceptibility to low molecular weight chitosan being documented, no information is available regarding the antimicrobial efficacy of mixed hydrogels in which chitosan is dispersed in a polymeric matrix. Therefore, the aim of the study is to evaluate the anti-Candida activity against eight different albicans and non-albicans strains of a mixed hydroxypropyl methylcellulose (HPMC)/chitosan hydrogel. Importantly, chitosan was dispersed in HPMC matrix either assembled in nanoparticles or in a monomolecular state to eventually correlate any variation in terms of rheological and mucoadhesive properties, as well as anti-Candida activity, with the chitosan form. Hydrogels containing 1% w/w chitosan, either as free polymer chain or assembled in nanoparticles, showed an improved mucoadhesiveness and an anti-Candida effect against all tested albicans and non-albicans strains. Overall, the results demonstrate the feasibility of preparing HPMC/CS mixed hydrogels intended for the prevention and treatment of Candida infections after vaginal administration.

Schwannoma is a neurogenic neoplasm rarely found in the sinonasal tract. It is a benign tumor arising from the sheath of myelinated nerve fibers that may occur in any part of the body. Its diagnosis and treatment can pose certain challenges. A 35-year-old woman presented to the senior surgeon with a nasal tip tumor that had been developing for almost 10 years. Ultrasound showed edema of the nose because of multiple solid nodes. The computed tomography (CT) scan did not show invasion of the bony framework around the tumor (maxilla, septum, nasal bones). Magnetic resonance imaging (MRI) showed a deviation of the septum and well-defined round nodes at the nasal tip with a thick layer of skin around them. Resection of the tumor was performed using open rhinoplasty. The limits of the excision were free of tumor, and histologic analysis of the tumor showed the characteristics of a schwannoma. At this writing, 2 years postoperatively, the patient is free of recurrence. Schwannoma of the nasal tip is a benign tumor that gradually causes aesthetic and functional disorders. Radiologic examinations can assist in its diagnosis. The treatment is surgical excision and histologic analysis of the specimen.

Tip surgery probably is the most challenging objective in modern rhinoplasty. The Goldman technique, despite its 50 years of history and its many variations proposed in the past, still remains a powerful tool for the surgeon who has to deal with an overprojected or broad nasal tip. A retrospective review was performed for all the patients who underwent surgery with the Goldman technique by the senior author from 2004 to 2009 for correction of the broad or overprojected nasal tip. The clinical and pathologic findings of these patients were reviewed, and an independent observer evaluated the pre- and postoperative photos of the patients using five parameters: projection, rotation, symmetry, shape, and distance of the tip-defining points. The evaluation was performed using a scale of −1 to +1 for each of the five parameters. Of the 205 patients who underwent the technique, 115 (56%) were patients with overprojected tips, and 90 (44%) were patients with broad (boxy) tips. A total of 189 cases (92.2%) involved primary rhinoplasties, and 16 cases (7.8%) involved revision. The mean follow-up period was 3 years (range, 1–5 years). During this period, complications were observed in five patients (2.4%), who underwent revision rhinoplasty with a successful result. The average score for the five parameters already mentioned for primary rhinoplasties according to the scale of −5 to +5 (resulting from the summation of all the parameters) showed a significant postoperative improvement (score, +4.3). The revision rhinoplasties showed significant improvement as well (score, +4.5). The Goldman technique is safe when performed by experienced surgeons and according to specific indications. This conclusion is indicated by the low rate of complications in the large series of patients in this study. When performed correctly, the Goldman technique provides a long-term aesthetic, functional, and natural result, which is the goal of modern functional rhinoplasty.

The DRV technique (followed by extrusion) was used for construction of hydrophilic-USPIO encapsulating liposomes. Magnetoliposomes (ML) were characterized for size, surface charge, entrapment, physical stability and magnetic properties (relaxivity). Results show that nanosized extruded-DRV MLs encapsulate higher amounts of USPIOs in comparison with sonicated vesicles. Fe (III) encapsulation efficiency (EE) is 12%, the highest reported to date for nanosized MLs. EE of MLs is influenced by ML membrane composition and polyethyleneglycol (PEG) coating. PEG-coating increases ML EE and stability; however, r 2 -to-r 1 ratios decrease (in comparison with non-PEGylated MLs). Most ML-types are efficient T2 contrast agents (because r 2 -to-r 1 ratios are higher than that of free USPIOs). Targeted MLs were formed by successfully immobilizing OX-26 monoclonal antibody on ML surface (biotin-streptavidin ligation), without significant loss of USPIOs. Targeted MLs retained their nanosize and integrity during storage for 1 month at 4°C and up to 2 weeks at 37°C. From the Clinical Editor Skouras and colleagues present a method for high encapsulation of hydrophilic USPIO-s in magnetoliposomes using the DRV extrusion technique. The goal is to optimize the production of MRI detectable contrast agents with functionalized homing capability based on immobilizing specific antibodies in the surface of magnetoliposomes.

Summary Surgeons often avoid the use of alloplastic materials in functional rhinoplasty due to potential complications. The aim of the present study is to present the outcomes following the use of alloplastic materials in a large series of patients, to identify and document the possible complications and to offer insight regarding the safety and the indications of the method. Materials and method Between February 2005 and August 2009, 58 patients underwent functional rhinoplasty using Medpor ® alloplastic materials by a single surgeon (A.S). The majority of the alloplastic materials were used to reconstruct defects of the nasal dorsum as well as to augment the columella and support the nasal tip. Results Medpor ® was used in the nasal dorsum in eight patients and in the columella in 50 patients. There were 10 cases of primary and 48 cases of secondary rhinoplasty. Follow-up time ranged from 1 to 5 years (mean: 3 years). Complications concerned three cases of postoperative infection and material rejection. All cases were successfully re-operated. Conclusion The use of Medpor ® alloplastic material in functional rhinoplasty comprises a safe method in selected patients due to the low complication rate, as shown in our series. It could therefore be considered as a useful alternative when reconstruction is problematic due to low quality or lack of available autologous grafts.