Antimicrobial Properties of Gallium(III)- and Iron(III)-Loaded Polysaccharides Affecting the Growth of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, In Vitro.

Antimicrobial resistance (AMR) has become a global concern as many bacterial species have developed resistance to commonly prescribed antibiotics, making them ineffective to treatments. One type of antibiotics, gallium(III) compounds, stands out as possible candidates due to their unique "Trojan horse" mechanism to tackle bacterial growth, by substituting iron(III) in the metabolic cycles of bacteria. In this study, we tested three polysaccharides (carboxymethyl cellulose (CMC), alginate, and pectin) as the binding and delivery agent for gallium on three bacteria (Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus) with a potential bioresponsive delivery mode. Two types of analysis on bacterial growth (minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC)) were carried out while iron(III)-loaded polysaccharide samples were also tested for comparison. The results suggested that gallium showed an improved inhibitory activity on bacterial growth, in particular gallium(III)-loaded carboxymethyl cellulose (Ga-CMC) sample showing an inhibiting effect on growth for all three tested bacteria. At the MIC for all three bacteria, Ga-CMC showed no cytotoxicity effect on human dermal neonatal fibroblasts (HDNF). Therefore, these bioresponsive gallium(III) polysaccharide compounds show significant potential to be developed as the next-generation antibacterial agents with controlled release capability.

External auditory canal: Inferior, posterior-inferior, and anterior canal wall overhangs.

OBJECTIVES: To characterize anatomic variants of the external ear canal (EAC), specifically canal wall overhangs. EAC overhangs are problematic since they obstruct the view of the tympanic membrane (TM) and middle ear, possibly creating diagnostic and surgical difficulties. METHODS: We reviewed pre-operative temporal bone CTs from children with cholesteatoma, and no history of EAC erosion or surgery. We measured the anterior canal wall overhang (ACOH), inferior (ICOH), and posterior-inferior (PICOH). A smaller angle means more EAC overhang. Angles >180° counted as 180° since they are non-obstructing. Analysis was performed between angular measurements and clinical and demographic data. RESULTS: 86 patients (88 ears total) were studied. Mean age was 8.3 years. Only obstructing angles were analyzed statistically (<180°). The ICOH was most severe and occurred in 72/88 (81.8%) ears with a mean of 145.9 ±â€¯12.8SD° (range 102-171°). ACOH occurred in 60/88 (68.2%) ears with a mean of 148.3 ±â€¯10.9SD° (range 120-169°). PICOH occurred in 59/88 (67%) ears with a mean of 150.4 ±â€¯9.2SD° (range 124-169°). Overall, ICOH was significantly more severe than PICOH (P = 0.026). ICOH had more Severe (142-102°) overhangs (27/88, 30.7%) than ACOH (17/88, 19.3%) or PICOH (11/88, 12.5%), but these were not significantly different. Analysis of clinical data showed that as the ICOH overhang became more severe, there was a history of significantly more (p = 0.039, r = -0.209) tympanostomy tubes placed. CONCLUSIONS: The greatest prevalence and severity of EAC overhang was the ICOH with a mean angle of 145.9°, compared with 148.3° and 150.4° for the ACOH and PICOH, respectively. This anatomic study demonstrates that ICOH and PICOH are prevalent anatomic variants and may possibly cause similar difficulties in otoscopic diagnosis and surgical TM and middle ear exposure as the well-known ACOH.

Novel Superparamagnetic Microdevices Based on Magnetized PLGA/PLA Microparticles Obtained by Supercritical Fluid Emulsion and Coating by Carboxybetaine-Functionalized Chitosan Allowing the Tuneable Release of Therapeutics.

When superparamagnetic nanoparticles (MAG) are loaded within microcarriers of thermosensitive and injectable biopolymers, "smart" microdevices are obtained: they respond to an external magnetic field through the release of any co-encapsulated molecules with a remote on-off control. Creating reliable and effective fabrication technologies for the production of these smart nano/microdevices remains a challenge. In this work, supercritical emulsion extraction technology is proposed for the fabrication of microcapsules with a core of poly-lactic-co-glycolic acid (PLGA) or polylactic acid (PLA) covered by carboxybetaine-functionalized chitosan (f-chi) and loaded with MAG (mean size of 6.5 ± 3.0 nm) and water-soluble fluorescein (Fluo). Fluo is co-encapsulated as a fluorescent marker for the release study. Microcarriers showed a mean size of 800 ± 60 nm with an encapsulation efficiency of up to 90%. The inversion of surface charge, after the f-chi coating, suggested the presence of a uniform functionalized surface available for further chemical linkage. The external chitosan layer had a thickness of 200 ± 50 nm. An excellent MAG dispersion was confirmed within the biopolymer matrix that was shown to be responsive to external magnetic field; indeed, Fluo was released over 3 or 5 days from PLGA or f-chi-PLGA microdevices into phosphate-buffered saline medium at 37°C, whereas remote on-off controlled release was achieved when an alternating magnetic field was applied.

Carboxybetaine-modified succinylated chitosan-based beads encourage pancreatic ß-cells (Min-6) to form islet-like spheroids under in vitro conditions.

In vitro, pancreatic ß-cells tend to reduce their ability to aggregate into islets and lose insulin-producing ability, likely due to insufficient cell-cell and cell-matrix interactions that are essential for ß-cell retention, viability and functionality. In response to these needs, surfaces of succinylated chitosan-based beads (NSC) were modified with zwitterionic carboxy-betaine (CB) moieties, a compatible osmolyte known to regulate cellular hydration state, and used to promote the formation of ß-cell spheroids using a conventional 2D cell culture technique. The NSC were synthesised by ionic gelation and surface-functionalised with CB using carbodiimide chemistry. Scanning electron microscopy (SEM), dynamic laser scattering (DLS) and Fourier transform infrared spectroscopy (FTIR) were employed as characterisation tools to confirm the successful modification of the succinylated chitosan material into spherical beads with rough surfaces and a diameter of 0.4 µm. NSC with and without CB were re-suspended at concentrations of 0.1, 0.3 and 0.6 mg/mL in saline medium and tested in vitro with MIN6 murine pancreatic ß-cell line. Results showed that a concentration of 0.3 mg/mL, NSC-CB encouraged pancreatic MIN6 cells to proliferate and form spheroids via E-cadherin and Pdx-1 activation within 48 h in culture. These spheroids, with a size of approximately 80 µm, exhibited high cell viability and enhanced insulin protein expression and secretion when compared to cells organised by the non-modified beads.

Osteopathic manipulative treatment for self-reported fatigue, stress, and depression in first-year osteopathic medical students.

CONTEXT: During medical education, many students experience psychological distress, including symptoms such as fatigue, stress, and depression. OBJECTIVE: To evaluate the effect of osteopathic manipulative treatment (OMT) on self-perceived fatigue, stress, and depression in first-year osteopathic medical students. METHODS: This randomized controlled pilot study with repeated measures was conducted at the Lake Erie College of Osteopathic Medicine-Bradenton in Florida during the fall 2012 semester. First-year osteopathic medical students voluntarily enrolled in the study and were randomly assigned to directed OMT (D-OMT), nondirected OMT (ND-OMT), or control groups. The D-OMT and ND-OMT groups received treatment by osteopathic physicians weekly for 4 weeks. The control group received no treatment. All groups completed the Epworth Sleepiness Scale (ESS), the Self-Perceived Stress Scale (SPSS), and the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire 9 (PHQ-9) depression scale before treatment (pretest), after 2 treatments (midtest), and after 4 treatments (posttest). RESULTS: All participants self-reported as white and single, with both sexes equally represented, and had an mean age of 24 years. Analysis of ESS scores revealed a statistically significant decrease in the D-OMT group from pretest and posttest scores and a statistically significant increase in the ND-OMT group from pretest to midtest but not from pretest to posttest scores. No statistically significant differences were noted in the control group scores on this measure. No statistically significant differences were seen in the SPSS or PHQ-9 scores from pretest to midtest or pretest to posttest in any of the 3 groups. CONCLUSION: The D-OMT regimen used in the current study produced a statistically significant decrease in self-perceived fatigue in first-year osteopathic medical students. Osteopathic manipulative treatment represents a potential modality to reduce self-perceived distress in medical students. Further research is warranted.

A service learning program in providing nutrition education to children.

OBJECTIVE: To implement a service learning program in nutrition and assess its impact on pharmacy students' communication skills and professionalism and elementary school children's knowledge of nutrition concepts. DESIGN: First-year pharmacy students completed 4 nutrition education sessions led by a registered dietitian and then presented the material to pre-selected classes of at-risk elementary school children in kindergarten through third grade. ASSESSMENT: Ninety-six pharmacy students completed the pre- and post-experience survey and more than 90% rated achievement of course objectives as strongly agree or agree. Four hundred sixty-eight elementary students completed a pre- and posttest on nutrition knowledge. Significant improvement was found in all grade levels on the knowledge test. CONCLUSION: This service learning experience was beneficial for the elementary school children and pharmacy students, enhancing the knowledge of both groups and establishing a positive relationship between the pharmacy school and the community.