Development of a Topical Insulin Polymeric Nanoformulation for Skin Burn Regeneration: An Experimental Approach

Insulin is a peptide hormone with many physiological functions, besides its use in diabetes treatment. An important role of insulin is related to the wound healing process—however, insulin itself is too sensitive to the external environment requiring the protective of a nanocarrier. Polymer-based nanoparticles can protect, deliver, and retain the protein in the target area. This study aims to produce and characterize a topical treatment for wound healing consisting of insulin-loaded poly-DL-lactide/glycolide (PLGA) nanoparticles. Insulin-loaded nanoparticles present a mean size of approximately 500 nm and neutral surface charge. Spherical shaped nanoparticles are observed by scanning electron microscopy and confirmed by atomic force microscopy. SDS-PAGE and circular dichroism analysis demonstrated that insulin preserved its integrity and secondary structure after the encapsulation process. In vitro release studies suggested a controlled release profile. Safety of the formulation was confirmed using cell lines, and cell viability was concentration and time-dependent. Preliminary safety in vivo assays also revealed promising results.     

Boccia game simulator: Serious game adapted for people with disabilities

Integration in the world of sport is one way for individuals with disabilities or motor disorders to feel more socially integrated, independent, and confident. Boccia is a Paralympic sport, which is increasingly getting more attention around the world. These facts have contributed to the objectives of this work. Including it in the serious games category enables to develop and rehabilitate the cognitive capabilities. The main focus was BC3 classification athletes (users with limited motor characteristics that require the use of an assistive device—a ramp, in this case). This paper describes a realistic Boccia game simulator adapted for people with disabilities that integrates a set of features that includes real physics and social features. These features can be used to enhance the interest of nonpractitioners of the sport and to improve the training conditions. The official Boccia regulation was added to the design of the simulator. The usability and approximation to the reality of the simulator were tested and validated based on the tests performed and data collected via a survey of users with no motor or psychological disorders. Realism and usability rating was almost excellent, and good results were achieved at the assessment of the game experience.     

Influence of the chemical structure of additives poly(ethylene-co-vinyl acetate)-based on the pour point of crude oils

One of the methods to prevent wax precipitation, during petroleum production, transport, and refining, is the use of polymer additives that can reduce the oil pour point. However, no single additive work for all types of crude oil and this relation is not yet well known. In this study, a family of polymers based on poly(ethylene-co-vinyl acetate), containing hydroxyl groups and long pendant hydrocarbon chains (from C6 to C18), were synthesized and characterized by H¹ nuclear magnetic resonance and solubility test. Four crude oil samples containing different amounts and size distribution of the wax were used. The additive's action is favored by higher contents of iso + cycloalkanes and lower contents of n-paraffins with larger chain sizes. The presence of the CH₃COO group in the copolymers promoted the lowering of the pour point, supported by a low OH concentration and the presence of a long pendant hydrocarbon chain: the best results were obtained with C10 and C12 chain lengths. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48969.     

Conjugation to Albumin‐Binding Molecule Tags as a Strategy to Improve Both Efficacy and Pharmacokinetic Properties of the Complement Inhibitor Compstatin

The compstatin family of complement inhibitors has shown promise in various immuno‐inflammatory disorders. Although recent analogues show beneficial pharmacokinetics, further extension of the plasma half‐life is expected to benefit systemic application of these peptidic inhibitors. We therefore synthesized conjugates of compstatin analogues and albumin‐binding molecules (ABM) to increase circulatory residence. Equilibrium dialysis in complement‐depleted serum showed a marked increase in plasma protein binding from <8 % to >99 % for a resulting chimera (ABM2‐Cp20). Further analysis confirmed interaction with albumin from different species, primarily via site II. Importantly, ABM2‐Cp20 bound 20‐fold stronger to its target protein C3b (K_D=150 pM ) than the parent peptide. Kinetic and in silico analysis suggested that ABM2 occupies a secondary site on C3b and improves the dissociation rate via additional contacts. Addition of an ABM modifier thereby not only improved plasma protein binding but also produced the most potent compstatin analogue to date with potential implications for the treatment of systemic complement‐related diseases.     

Residues of different gel formulations on dentinal walls: A SEM/EDS analysis

The aim of this study was to evaluate the presence of residues of sodium hypochlorite gel, chlorhexidine gel, and EDTA gel on dentinal walls after canal preparation through chemical SEM‐ elemental chemical microanalysis (EDS) analysis. Forty‐eight single‐rooted teeth were selected. They had their crowns sectioned and were instrumented with a reciprocating system. The canals were irrigated with 5 mL of saline solution during root canal preparation. After instrumentation, the root canals were irrigated with 3 mL 17% EDTA followed by 1 min of ultrasonic passive activation (3× 20 sec) to remove the smear layer, and then irrigated with 3 mL of saline solution. The specimens were randomized into three groups (n = 12) according to the chemical substance that filled the root canal for 30 min: GI: 5.5% sodium hypochlorite gel; GII: 2% chlorhexidine gel; GIII: 24% EDTA gel; Negative control group: no substance was used. Then, the root canals were irrigated with 6 mL of saline solution followed by 1 min of ultrasonic passive activation (3× 20 sec). After ultrasonic activation, the canals were irrigated with 2 mL saline. The roots were sectioned, and the percentage of each chemical element present in the samples was analyzed through chemical SEM‐EDS microanalysis. All experimental groups showed a significantly higher percentage of chemical elements (Na and/or Cl) than the control group (P < 0.03). This in vitro study has shown that, regardless of chemical solutions used even after the final irrigation protocol, chemical residues of different substances remained attached to the root canal walls. Microsc. Res. Tech. 78:495–499, 2015. © 2015 Wiley Periodicals, Inc.     

Methicillin‐Resistant Staphylococcus aureus in Raw Meats and Prepared Foods in Public Hospitals in Salvador,Bahia, Brazil

This study investigated the presence of methicillin‐resistant Staphylococcus aureus (MRSA) in raw meat and fish and foods prepared from them for patient consumption in public hospitals in Salvador, Bahia, in northeastern Brazil. A total of 114 samples of raw meat and fish (chicken, n = 30; beef, n = 30; pork, n = 24; and fish, n = 30) and 63 samples of prepared foods (made with chicken, n = 15; beef, n = 15; pork, n = 15; and fish, n = 18) were collected from the kitchens of 10 different hospitals. Of the 114 investigated raw meat and fish samples, 28.1% were positive for MRSA, which comprised 23.3% beef, 23.3% chicken, 37.5% pork, and 30% fish samples. Of the prepared foods, 9.5% were positive for MRSA, which comprised 5.6% chicken products, 6.7% pork products, and 22.2% fish products. MRSA contamination was not detected in prepared beef dishes. A statistical analysis showed no association between the presence of MRSA and the type of raw food (P > 0.05). The high prevalence of MRSA among the raw foods tested and the presence of the microorganism in prepared foods emphasizes the necessity of enforcing hygienic practices within hospital kitchens.     

Chitosan impregnated gutta-percha points: antimicrobial in vitro evaluation and mechanical properties

Chitosan-impregnated gutta-percha points (ChitGPP) were tested for their ability to inhibit the growth of microorganisms usually involved in root canal infections. Their mechanical properties were also studied and compared with the commonly used commercial points in endodontics. ChitGPP were more efficient in reducing the microbial load than those without chitosan. ChitGPP also possess better tensile and elastic properties than commercial ones. After six months of storage, ChitGPP’s were still able to reduce the bacterial load by 1 log, suggesting that impregnation of gutta-percha points with chitosan could be a good alternative to obtain gutta-percha points with improved antimicrobial properties.     

Processing and properties of tape-cast alumina/zirconia laminates composites

In the present work, laminar ceramic structures formed by layers of alumina and partially stabilized zirconia were fabricated by water-based tape casting. Rheological, physical and mechanical properties of slurries and laminates were evaluated. The laminates consisted of stacked alumina and zirconia green tapes produced by thermopressing. Pyrolysis was carried out at 450 °C and sintering at 1500 °C. The alumina/zirconia laminates were studied for a better understanding of the formation behavior and crack propagation at the laminate interface. The flexural strength values of laminates depend on the stress state on their surface. The laminates with the highest amount of zirconia layers presented low strength values (6.7 MPa), while the laminates with more alumina layers had a higher strength level (57.7 MPa). This is because these laminates have alumina layers on the surface which are in a state of residual compressive stress.