Multifunctional siRNA/ferrocene/cyclodextrin nanoparticles for enhanced chemodynamic cancer therapy.

The therapeutic outcome of chemodynamic therapy (CDT) is greatly hindered by the presence of oxidative damage repair proteins (MTH1) inside cancer cells. These oxidative damage repair proteins detoxify the action of radicals generated by Fenton or Fenton-like reactions. Hence, it is extremely important to develop a simple strategy for the downregulation of MTH1 protein inside cancer cells along with the delivery of metal ions into cancer cells. A one-pot host-guest supramolecular approach for the codelivery of MTH1 siRNA and metal ions into a cancer cell is reported. Our approach involves the fabrication of an inclusion complex between cationic ß-cyclodextrin and a ferrocene prodrug, which spontaneously undergoes amphiphilicity-driven self-assembly to form spherical nanoparticles (NPs) having a positively charged surface. The cationic surface of the NPs was then explored for the loading of MTH1 siRNA through electrostatic interactions. Using HeLa cells as a representative example, efficient uptake of the NPs, delivery of MTH1 siRNA and the enhanced CDT of the nanoformulation are demonstrated. This work highlights the potential of the supramolecular approach as a simple yet efficient method for the delivery of siRNA across the cell membrane for enhanced chemodynamic therapy.

A comparative evaluation of preheat treatment, postcure heat treatment, and combined heat treatment on degree of conversion of a bulk-fill composite: An in vitro study.

Aims: The aim of this study was to evaluate the effect on the degree of conversion of Tetric N-Ceram Bulk Fill Composite subjected to preheat treatment, postcure heat treatment, and combined heat treatment. Materials and Methods: A total of 90 samples were prepared from Tetric N-Ceram Bulk Fill using customized stainless steel molds and divided into six groups of 15 samples each based on the heat treatment. Group I (control group): no heat treatment, Group II: preheat treatment at 60°C, Group III: postcure heat treatment at 100°C, Group IV: postcure heat treatment at 200°C, Group V: combined preheat treatment at 60°C and postcure heat treatment at 100°C, and Group VI: combined preheat treatment at 60°C and postcure heat treatment at 200°C. The degree of conversion was analyzed using Raman spectrometer. Statistical Analysis Used: Data were analyzed using analysis of variance followed by the Scheffé test using Statistical Package for the Social Sciences 20.0 version. Results: The order of values of degree of conversion from maximum to minimum for the groups are as follows: Group VI (98.77 ± 0.52) > Group V (97.11 ± 0.78) > Group IV (95.00 ± 0.86) > Group III (93.00 ± 1.22) > Group II (86.88 ± 1.36) > Group I (76.55 ± 1.42). The statistical analysis revealed a statistically significant difference between the groups (P < 0.05). Conclusions: Combined heat treatment samples showed better values of degree of conversion.

A comparative evaluation of cyclic fatigue resistance of FlexiCON (Edge Endo) files in rotary versus reciprocating motion at various curvatures - An in vitro study.

AIM: The aim of the study to compare the cyclic fatigue resistance of FlexiCON (Edge Endo) files in rotary versus reciprocating motion in coronal, middle, and apical curvature of the simulated artificial canal. MATERIALS AND METHODS: A total number of 36 new files, 25 mm length of ISO size 25 at the tip and a taper of 0.06, were used for the study and divided into two groups of 18 files each. Group I: FlexiCON X3, was used in a rotary motion and Group II: FlexiCON X1 was used in a reciprocating motion. Cyclic fatigue testing was conducted in a custom-made device that allowed for a reproducible simulation of a curved canal. The canal system, which comprised two adjustable stainless steel blocks, had a 60° angle of curvature and 3 mm width. The groups were further divided into three subgroups with six files in each, representing apical curvature (Group Ia/IIa), middle curvature (Group Ib/IIb), and Coronal curvature (Group Ic/IIc). Using X-Smart plus motor, files were used in rotary and reciprocating mode and the number of cycles to failure was recorded. STATISTICAL ANALYSIS: Data were analyzed using ANOVA and Post hoc followed by Dunnett's test and unpaired t-test using Statistical Package for the Social Sciences 16 version. RESULTS: FlexiCON X1 reciprocating files showed the maximum cyclic fatigue resistance at coronal curvature (1936.50 ± 1.09) followed by middle (1514.50 ± 1.07) and apical curvature (1487.50 ± 6.75), while FlexiCON X3 rotary files showed the maximum cyclic fatigue at the middle curvature (1106.00 ± 4.21), followed by coronal (920.00 ± 1.16) and apical curvature (757.00 ± 5.34). The statistical analysis revealed a statistically significant difference (P = 0.001) between the two groups. CONCLUSION: FlexiCON X1 reciprocating files showed better cyclic fatigue resistance at coronal, middle, and apical curvature compared to FlexiCON X3 rotary files.

Students' perceptions of a flipped classroom approach to paramedic theory.

INTRODUCTION: The flipped classroom is a pedagogical model in which the typical lecture and homework/self-study elements of a course are reversed or _flipped'. The flipped model differs from distance and online learning, since students still have face-to-face contact with tutors. Studies have shown that the flipped classroom approach can be effective with clinical skills learning by paramedics, but it is not clear whether anatomy, physiology, pathophysiology and pharmacology can effectively be taught using a flipped approach. METHODS: A flipped classroom approach was taken for a three-hour theory session on the Diploma of Higher Education in Paramedic Practice that would usually have been taught by traditional lecture. Participants, 20 student paramedics already employed by the Ambulance Service as Emergency Care Assistants, completed a two-part questionnaire after the session. Part one comprised 22 Likert style questions, with part two allowing qualitative data with five open ended questions. RESULTS: All students preferred the traditional lecture over a flipped approach. Time constraints and preparation were seen as major disadvantages of the flipped classroom, as was being unable to ask questions in real time. Flexibility was seen to be an advantage of online lectures, and a blended/combination approach of online resources and traditional lecture was seen as valuable. CONCLUSION: The demographic of students may have had an impact upon the results of the study and the lack of popularity of the flipped approach. Employed students have the added pressure of full-time work, and further research is needed into whether different methods should be employed when choosing how to educate employed paramedic students versus those who enter via the undergraduate route and study full time.

The effect of three different antioxidants on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin: An in vitro study.

OBJECTIVE: The effect of 10% ascorbic acid, 10% tannic acid, and 10% gallic acid on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin was evaluated. MATERIALS AND METHODS: Fifty human premolars were decoronated to attain 14-mm root length and divided into five groups of 10 teeth each. Biomechanical preparation was done with rotary instruments. Group I specimens were irrigated with saline and 17% ethylenediaminetetraacetic acid (EDTA). Specimens from groups II, III, IV, and V were irrigated with 5.25% sodium hypochlorite and 17% EDTA. Specimens from groups III, IV, and V underwent additional irrigation with antioxidants-10% ascorbic acid, 10% tannic acid, and 10% gallic acid, respectively. Following obturation with Resilon and Real Seal SE, scanning electron microscope (SEM) analysis was done to note the maximum dentinal tubular penetration at the cervical, middle, and apical thirds of each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA), Post hoc and Dunnett's test. RESULTS: Maximum dentinal tubular penetration of Resilon and Real Seal SE was obtained following irrigation with 10% gallic acid. CONCLUSION: 10% gallic acid was superior among the antioxidant irrigants that enabled the increased dentinal tubular penetration of Resilon and Real Seal SE.

Are they really refusing to travel? A qualitative study of prehospital records.

BACKGROUND: Refusal by the patient to travel after calling an emergency ambulance may lead to a preventable waste of scarce resources if it can be shown that an alternative more appropriate response could be employed. A greater understanding is required of the reasons behind 'refusal to travel' (RTT) in order to find appropriate solutions to address this issue. We sought to investigate the reasons why patients refuse to travel following emergency call-out in a rural county. METHODS: Written records made by ambulance crews for patients (n = 397) who were not transported to hospital following an emergency call-out during October 2004 were retrospectively analysed. RESULTS: Twelve main themes emerged for RTT which included non injury or minor injury, falls and recovery after treatment on scene; other themes included alternative supervision, follow-up and treatment arrangements or patients arranging their own transport. Importantly, only 8% of the sample was recorded by ambulance crews as truly refusing to travel against advice. CONCLUSION: A system that facilitates standardised recording of RTT information including social reasons for non-transportation needs to be designed. 'Refused to travel' disclaimers need to reflect instances when crew and patient are satisfied that not going to hospital is the right outcome. These recommendations should be considered within the context of the plans for widening the role of ambulance services.