Vesicle fusion has long provided an easy and reliable method to form supported lipid bilayers (SLBs) from simple, zwitterionic vesicles on siliceous substrates. However, for complex compositions, such as vesicles with high cholesterol content and multiple lipid types, the energy barrier for the vesicle-to-bilayer transition is increased or the required vesicle-vesicle and vesicle-substrate interactions are insufficient for vesicle fusion. Thus, for vesicle compositions that more accurately mimic native membranes, vesicle fusion often fails to form SLBs. In this paper, we review three approaches to overcome these barriers to form complex, biomimetic SLBs via vesicle fusion: (i) optimization of experimental conditions (e.g., temperature, buffer ionic strength, osmotic stress, cation valency, and buffer pH), (ii) α-helical (AH) peptide-induced vesicle fusion, and (iii) bilayer edge-induced vesicle fusion. AH peptide-induced vesicle fusion can form complex SLBs on multiple substrate types without the use of additional equipment. Bilayer edge-induced vesicle fusion uses microfluidics to form SLBs from vesicles with complex composition, including vesicles derived from native cell membranes. Collectively, this review introduces vesicle fusion techniques that can be generalized for many biomimetic vesicle compositions and many substrate types, and thus will aid efforts to reliably create complex SLB platforms on a range of substrates.

In this study, we present a technique to create a complex, high cholesterol-containing supported lipid bilayers (SLBs) using α-helical (AH) peptide-induced vesicle fusion. Vesicles consisting of POPC : POPE : POPS : SM : Chol (9.35 : 19.25 : 8.25 : 18.15 : 45.00) were used to form a SLB that models the native composition of the human immunodeficiency virus-1 (HIV-1) lipid envelope. In the absence of AH peptides, these biomimetic vesicles fail to form a complete SLB. We verified and characterized AH peptide-induced vesicle fusion by quartz crystal microbalance with dissipation monitoring, neutron reflectivity, and atomic force microscopy. Successful SLB formation entailed a characteristic frequency shift of −35.4 ± 2.0 Hz and a change in dissipation energy of 1.91 ± 0.52 × 10−6. Neutron reflectivity measurements determined the SLB thickness to be 49.9 +1.9−1.5 Å, and showed the SLB to be 100 +0.0−0.1% complete and void of residual AH peptide after washing. Atomic force microscopy imaging confirmed complete SLB formation and revealed three distinct domains with no visible defects. This vesicle fusion technique gives researchers access to a complex SLB composition with high cholesterol content and thus the ability to better recapitulate the native HIV-1 lipid membrane.

Financial toxicity describes the financial burden and distress that can arise for patients, and their family members, as a result of cancer treatment. It includes direct out-of-pocket costs for treatment and indirect costs such as travel, time, and changes to employment that can increase the burden of cancer. While high costs of cancer care have threatened the sustainability of access to care for decades, it is only in the past 10 years that the term “financial toxicity” has been popularized to recognize that the financial burdens of care can be just as important as the physical toxicities traditionally associated with cancer therapy. The past decade has seen a rapid growth in research identifying the prevalence and impact of financial toxicity. Research is now beginning to focus on innovations in screening and care delivery that can mitigate this risk. There is a need to determine the optimal strategy for clinicians and cancer centers to address costs of care in order to minimize financial toxicity, promote access to high value care, and reduce health disparities. We review the evolution of concerns over costs of cancer care, the impact of financial burdens on patients, methods to screen for financial toxicity, proposed solutions, and priorities for future research to identify and address costs that threaten the health and quality of life for many patients with cancer.

Background There is significant debate over whether written consent is necessary for low-risk, pragmatic randomized controlled trials (RCT). Objective To assess the U.S. public’s views regarding alternatives to written consent for low-risk pragmatic RCTs. Design National experimental survey (2-by-2 factorial design) examining support for written consent versus general notification or verbal consent in two research scenarios. Setting Web-based survey conducted in December 2014. Participants 2130 U.S. adults sampled from a nationally representative probability-based online panel (response rate, 64%). Measurements Respondent’s recommendation to an ethics review board and personal preference as a potential participant for how to obtain consent/notification in the two research scenarios. Results A majority in each of the four arms (ranging from 60.3% to 71.5%) recommended written informed consent. Personal preferences generally tracked that advice. Most (78.9%) believed the pragmatic RCTs did not pose additional risks but 62.5% of these respondents would still recommend written consent. In contrast, a substantial minority in all arms (28.5% to 39.7%) recommended the alternative option (general notification or verbal consent) over written consent. Limitations Framing effects could impact respondents’ attitudes and non-respondents may differ in levels of trust towards research or healthcare institutions. Conclusions A majority of the public endorsed written informed consent over the most widely considered alternatives for low-risk pragmatic RCTs; however, a substantial minority endorsed general notification or verbal consent. Primary Funding Source Time-sharing Experiments in the Social Sciences and Intramural Research Program of the National Institutes of Health, Clinical Center.