Loss of idealism or realistic optimism? A cross-sectional analysis of dental hygiene students' and registered dental hygienists' professional identity perceptions.

OBJECTIVES: The dental hygiene profession in the U.S. is in the process of establishing a direct access model of care and contributing to the creation of the profession of a dental therapist. The objectives were to analyse the professional role perceptions of dental hygiene students and registered dental hygienists in these times of change. Specifically, it was explored whether dental hygiene students' current professional identities differ (i) from their expected future identities, and (ii) from dental hygienists' current and (iii) past identities. METHODS: Survey data were collected from 215 dental hygiene students concerning their present and future role perceptions, and from 352 registered dental hygienists concerning their present and past professional identity perceptions. RESULTS: Students' future professional identity perceptions were even more positive than their very positive current perceptions of their professional role components. Students' current perceptions of professional pride, professional ambition, work ethic and patient relations were more positive than dental hygienists' current perceptions of these professional role components. A comparison of students' current perceptions with dental hygienists' current and retrospective descriptions showed that students were more positive than dental hygienists in each case. CONCLUSIONS: The fact that dental hygienists had less positive role perceptions than dental hygiene students might lead to the conclusion that a loss of idealism occurs over the course of a professional lifespan. However, dental hygienists actually improved their role perceptions over time and students' future descriptions were more positive than their current descriptions, supporting the interpretation that realistic optimism dominates professional role perceptions in these times of change.

Thermo-targeted drug delivery of geldanamycin to hyperthermic tumor margins with diblock elastin-based biopolymers.

The tumor margins are the barrier to hepatocellular carcinoma (HCC) eradication for tumors>3 cm. Indeed, inadequately treated tumor margins commonly result in local and regional HCC recurrence with increased size and mass. Tumor recurrence is a common problem with chemotherapy, radiotherapy, thermal ablation, and/or surgical resection, by the inability to properly treat the tumor core and the tumor margins. Here we present novel thermosensitive biopolymer-drug conjugates for thermo-targeted chemotherapy at hyperthermic isotherms produced by focal, locoregional thermal ablation. The chemotherapeutic target is heat shock protein 90 (HSP90), a key molecular chaperone of several, and potent pro-oncogenic pathways including Akt, Raf-1, and mutated p53 that is upregulated in HCC. To inhibit HSP90, we have chosen geldanamycin (GA), a potent HSP90 inhibitor. GA has gained significant attention for its low IC50 ~ 1 nM and inhibition of Akt and Raf-1, amongst other critical pro-oncogenic pathways. Despite such evidence, clinical trials of GA have not shown promise due to off-target toxicity and poor formulation design. Here, we propose using diblock elastin-based biopolymers as a Ringsdorf macromolecular GA solubilizer--a new generation containing functional poly(Asp)/(Glu) blocks for facile drug conjugation and an ELP block for thermo-targeting of hyperthermic ablative margins. GA release is controlled by pH-sensitive, covalent hydrazone bonds with the biopolymer backbone to avoid systemic toxicity and off-target effects. The resultant biopolymer-conjugates form stable nanoconstructs and display tunable, acute phase transitions at high temperatures. Drug release kinetics are favorable with or without the presence of serum. Thermo-targeted chemotherapy and synchronous thermal ablation provide a unique opportunity for simultaneous destruction of the HCC ablative margins and tumor core for focal, locoregional control of HCC.

Folate-PEG-folate-graft-polyethylenimine-based gene delivery.

Folate-polyethylene glycol-folate-grafted-polyethylenimine (FPF-g-PEI) was synthesized by linking folic acid to both ends of a mono-functional PEG and then grafting to PEI. The graft ratio was determined using Beer's law by measuring the UV absorbance at 363 nm. The pH profile, diameter and shape of the carriers were determined. Transfection efficiencies were optimized in normal smooth muscle cells (SMC) and CT-26 colon adenocarcinoma cells using plasmid DNA encoding luciferase reporter gene. Free folic acid was shown to inhibit transfection with FPF-2.3 g-PEI at neutral charge ratio. Relative toxicity between PEI and the modified carrier was measured using MTT colorimetric assay. Therapeutic potential of pmIFN-gamma complexed with these polymeric carriers in terms of gene expression was determined at protein and mRNA levels using ELISA and RT-PCR. FPF-g-PEI was determined to have 2.3 folate-PEG-folate (FPF) linear polymers grafted to each PEI molecule. The average molecular weight was measured to be approximately 33,500 Mw and the pH profile was characteristic of endosomal disruption capacity. Atomic Force Microscopy (AFM) and Dynamic Laser Light Scattering (DLLS) indicated FPF-2.3 g-PEI and PEI (at 2 w/w ratio) efficiently condensed plasmid DNA resulting in oblique spheroid polyplexes with a mean diameter of approximately 150 nm. FPF-2.3 g-PEI was superior to PEI in terms of cytotoxicity and transfection efficiency in cancer cells. Smooth muscle cells showed no specificity for folate tethered complexes, where PEI/pLuc complexes yielded higher efficiencies.