Versatile Tool for the Analysis of Metal-Protein Interactions Reveals the Promiscuity of Metallodrug-Protein Interactions.

Metallodrug-protein interactions contribute to their therapeutic effect (even when DNA is the dominant target), side-effects and are implicit in drug resistance. Here, we provide mass spectrometric-based evidence to show that metallodrug interactions with proteins are considerably more complex than current literature would suggest. Using native-like incubation and electrospray conditions together with an automated tool we designed for exhaustive mass spectra matching, the promiscuity of binding of cisplatin to ubiquitin is revealed, with 14 different binding sites observed. There is a binding preference to negatively charged sites on the protein, consistent with the cationic nature of the cisplatin adduct following aquation. These results have implications in metallodrug development and beyond to the toxicological effects of metal ions more generally.

Biochemical and biophysical characterization of ruthenation of BRCA1 RING protein by RAPTA complexes and its E3 ubiquitin ligase activity.

RAPTA compounds, ([Ru(η6-arene)(PTA)Cl2], PTA = 1,3,5-triaza-7-phosphaadamantane), have been reported to overcome drug resistance in cisplatin resistant cells. However, the exact mechanism of these complexes is still largely unexplored. In this study, the interaction of some RAPTA compounds with the N-terminal fragment of the BRCA1 RING domain protein was investigated. The binding of the RAPTA compounds to the BRCA1 protein resulted in a release of Zn2+ ions in a dose and time dependent manner, as well as thermal alteration of ruthenated-BRCA1 proteins. Electron Transfer Dissociation (ETD) fragmentation mass spectrometry revealed the preferential binding sites of the RAPTA complexes on the BRCA1 zinc finger RING domain at a similar short peptide stretch, Cys24Lys25Phe26Cys27Met28Leu29 and Lys35 (residues 44-49 and 55 on full length BRCA1). Changes in the conformation and binding constants of ruthenium-BRCA1 adducts were established, resulting in inactivation of the RING heterodimer BRCA1/BARD1-mediated E3 ubiquitin ligase function. These findings could provide mechanistic insight into the mode of action of RAPTA complexes for on tested BRCA1 model protein.

The Differential Distribution of RAPTA-T in Non-Invasive and Invasive Breast Cancer Cells Correlates with Its Anti-Invasive and Anti-Metastatic Effects.

Nanoscale secondary ion mass spectrometry (NanoSIMS) combined with transmission electron microscopy (TEM) can be a powerful approach to visualize the exact distribution of drugs at the sub-cellular level. In this work, we exploit this approach to identify the distribution and localisation of the organometallic ruthenium(II)-arene drug Ru(η6-C6H5Me)(pta)Cl2, termed RAPTA-T, in MDA-MB-231 and MCF-7 human breast cancer cells. These cell lines have been chosen because the former cell lines are highly invasive and resistant to most chemotherapeutic agents and the latter ones are very sensitive to hormonal-based therapies. In the MDA-MB-231 cells, RAPTA-T was found to predominantly localise on the cell membrane and to a lesser extent in the nucleolus. These findings are consistent with the previously reported anti-metastatic properties of RAPTA-T and the observation that once internalized RAPTA-T is associated with chromatin. RAPTA-T shows a lack of membrane accumulation on the non-invasive MCF-7 cells, which correlates well with its selective anti-metastatic properties on invasive cell lines.

Work readiness of pharmacy graduates: An exploratory study.

Introduction: The recent global pandemic of Covid-19 caused various disruptions. Among them were face-to-face teaching and learning activities being switched to virtual sessions in accordance with health authorities recommendations. The impact of these changes on work readiness of pharmacy graduates is unknown. Aim: This study aims to determine the impact of pharmacy graduate's work readiness, particularly those that had their studies disrupted from the pandemic. Methods: Practicing pharmacists with supervisory experience were interviewed on their opinions on work readiness of early career and intern pharmacists. Specifically, they were asked to comment on work readiness of pharmacy graduates who had their later stage of pharmacy education impacted by the pandemic. Data was transcribed verbatim and thematically analysed. This was also supplemented with quantitative data from graduating students in 2020 and 2021 using the Work Readiness Scale. Results: Qualitative feedback showed four themes related to workforce readiness: work competence, social intelligence, personal characteristics, and organizational acumen. Preceptors interviewed noted differences in communication abilities when interacting with patients. However, this improved with time. Quantitative data collected from graduates via the validated Work-Readiness Scale also showed a more positive agreement towards perceived work readiness. These graduates were comfortable with using technology as they had used these extensively in their learning during the pandemic and thus was comfortable in adopting digital health tools in their practice. Conclusion: Although graduates reported to be work ready, there were gaps in communication skills and confidence levels when interacting with patients, as reported by supervising preceptors. Graduates also described this sense of 'missing out' from not having the opportunity to attend face-to-face activities like their originally planned hospital placements and how it impacted their choice of career. As pharmacists continue to play vital roles as members of the broader healthcare workforce, both in clinical and nonclinical settings, learnings from this study should be considered in designing educational activities to train and develop the workforce of the future.

Remote extemporaneous compounding lab practical for pharmacy students during the COVID-19 pandemic.

BACKGROUND AND PURPOSE: Due to COVID-19 movement restrictions, institutes of higher learning had to deliver pharmacy curricula remotely. One major challenge was teaching practical lab skills, such as extemporaneous compounding, remotely due to the need for hands-on learning and its associated logistical requirements. EDUCATIONAL ACTIVITY AND SETTING: We present the approach to remote extemporaneous compounding teaching taken by three pharmacy schools: Monash University Malaysia, University of Michigan, and University of Maryland. Prior to delivery, students were either supplied with or asked to procure a set of easily accessible ingredients and equipment to conduct the extemporaneous practicals from home. We conducted lessons remotely using both synchronous and asynchronous delivery, and demonstrated, taught, and assessed practical lab skills using video conferencing modalities. FINDINGS: We successfully conducted remote teaching of extemporaneous compounding, where similar learning outcomes to the face-to-face implementation were achieved. At Monash University Malaysia, > 90% of students responding to the post-activity surveys found the remote extemporaneous sessions useful for their learning, and qualitative comments supported these views. Mean scores from the remote extemporaneous labs in 2021 were similar to those when conducted physically in 2019, supporting the effectiveness of the approach. The different approaches attempted by the three institutions highlighted the flexibility in implementation that can be considered to achieve similar outcomes. SUMMARY: Combining technology-based approaches with synchronous and asynchronous teaching and learning methods can successfully deliver extemporaneous compounding skills remotely.

Cultural adaptation and validation of instruments for measuring the flipped classroom experience.

INTRODUCTION: In 2017, a revamped bachelor of pharmacy program was introduced at Monash University and incorporated a predominantly flipped classroom-based pedagogy. The attitudes and preferences of students towards this program had yet to be assessed using a reliable instrument. Since no instrument was readily available, the objective of this study was to identify, contextualize, and validate a suitable instrument. METHODS: We conducted a literature search to identify and adapt a validated instrument. Cognitive interviews were conducted to examine students' understanding of scales and definitions of items. The instrument was then evaluated by education experts for further refinement. The reliability of the final instrument was assessed in a cohort of students, and unsuitable items were removed. RESULTS: Students had issues understanding the scales and specific terms used in the original instrument, potentially due to differences in terminologies used in the university's context and variance in English proficiency levels and exposure. In the preference domain, wording of the instrument to present exclusively traditional classroom or exclusively flipped classroom statements greatly influenced its reliability. This could be due to exposure of students to a predominantly flipped classroom environment since inception. The final instrument optimized in this study had α = 0.85, 0.86, and 0.9 for the pre-activities, in-class lectures, and in-class workshops attitude domains, respectively, and α = 0.73 for the preference domain. CONCLUSIONS: Our study highlights the necessity of contextualizing instruments to fit the local context in which they are administered and provides key recommendations when conducting such adaptations.

Application of imaging mass spectrometry approaches to facilitate metal-based anticancer drug research.

Mass spectrometry imaging is being increasingly used in metal-based anticancer drug development to study elemental and/or molecular drug distributions in different biological systems. The main analytical tools employed are SIMS (especially nanoSIMS), LA-ICP-MSI and MALDI-MSI as well as a combination of complementary imaging techniques. Main challenges are appropriate sample preparation methods, reliable and validated quantification strategies and a trade-off between sensitivity and spatial resolution. So far, research has mostly focused on the development of analytical methods for imaging with the long term goal to study drug uptake into tumor tissue and toxicity affected organs and to identify cellular targets of metal-based drugs. In this review we cover the technological features of the mass spectrometry imaging methods used and give an overview of the applications in metal-based anticancer drug research as well as some future perspectives.

Differences in cisplatin distribution in sensitive and resistant ovarian cancer cells: a TEM/NanoSIMS study.

Cisplatin is a widely used anti-cancer drug, but its effect is often limited by acquired resistance to the compound during treatment. Here, we use a combination of transmission electron microscopy (TEM) and nanoscale-secondary ion mass spectrometry (NanoSIMS) to reveal differences between cisplatin uptake in human ovarian cancers cells, which are known to be susceptible to acquired resistance to cisplatin. Both cisplatin sensitive and resistant cell lines were studied, revealing markedly less cisplatin in the resistant cell line. In cisplatin sensitive cells, Pt was seen to distribute diffusely in the cells with hotspots in the nucleolus, mitochondria, and autophagosomes. Inductively coupled plasma mass spectrometry (ICP-MS) was used to validate the NanoSIMS results.

Expression proteomics study to determine metallodrug targets and optimal drug combinations.

The emerging technique termed functional identification of target by expression proteomics (FITExP) has been shown to identify the key protein targets of anti-cancer drugs. Here, we use this approach to elucidate the proteins involved in the mechanism of action of two ruthenium(II)-based anti-cancer compounds, RAPTA-T and RAPTA-EA in breast cancer cells, revealing significant differences in the proteins upregulated. RAPTA-T causes upregulation of multiple proteins suggesting a broad mechanism of action involving suppression of both metastasis and tumorigenicity. RAPTA-EA bearing a GST inhibiting ethacrynic acid moiety, causes upregulation of mainly oxidative stress related proteins. The approach used in this work could be applied to the prediction of effective drug combinations to test in cancer chemotherapy clinical trials.

Correction: NanoSIMS analysis of an isotopically labelled organometallic ruthenium(II) drug to probe its distribution and state in vitro.

Correction for 'NanoSIMS analysis of an isotopically labelled organometallic ruthenium(II) drug to probe its distribution and state in vitro' by Ronald F. S. Lee et al., Chem. Commun., 2015, DOI: 10.1039/c5cc06983a.

NanoSIMS analysis of an isotopically labelled organometallic ruthenium(II) drug to probe its distribution and state in vitro.

The in vitro inter- and intra-cellular distribution of an isotopically labelled ruthenium(II)-arene (RAPTA) anti-metastatic compound in human ovarian cancer cells was imaged using nano-scale secondary ion mass spectrometry (NanoSIMS). Ultra-high resolution isotopic images of (13)C, (15)N, and Ru indicate that the phosphine ligand remains coordinated to the ruthenium(II) ion whereas the arene detaches. The complex localizes mainly on the membrane or at the interface between cells which correlates with its anti-metastatic effects.

Lyophilization of cholesterol-free PEGylated liposomes and its impact on drug loading by passive equilibration.

The obstacles in translating liposome formulations into marketable products could be attributed to their physical instabilities upon long-term storage as aqueous dispersions. Lyophilization is the most commonly used technique to improve physical stability of liposomes. The development of stable, lyophilized liposomes is focused primarily on the cholesterol-containing liposomes or pure phosphatidylcholine-based liposomes, with minimal studies on cholesterol-free, pegylated (CF-PEG) liposomes which have emerged as an important class of liposome drug carriers. Hence, it is our interest to investigate the effect of lyophilization on CF-PEG liposomes, and specifically, on drug loading via the passive equilibration method. Three different sugar cryoprotectants were used at two different sugar-to-lipid molar ratios (S/L). Our results demonstrated that CF-PEG liposomes lyophilized with sucrose at S/L=5:1 yielded the best cryoprotective effect, as characterized by size, polydispersity indices, and microscopic examination upon liposome reconstitution. The lyophilized liposomes had low water content of 2.59 ± 0.18%. Of note, lyophilized CF-PEG liposomes exhibited two-fold increase in drug content when carboplatin was loaded via the passive equilibration method, and the in vitro drug release profile of these liposomes were not different from that of the non-lyophilized counterparts. Taken together, we envisioned that a stable, lyophilized empty CF-PEG liposome system could be coupled to hydrophilic drug loading via the passive equilibration method to produce a liposomal drug kit product.