Buried-Interface Engineering Enables Efficient and 1960-Hour ISOS-L-2I Stable Inverted Perovskite Solar Cells.

High-performance perovskite solar cells (PSCs) typically require interfacial passivation, yet this is challenging for the buried interface, owing to the dissolution of passivation agents during the deposition of perovskites. Here, this limitation is overcome with in situ buried-interface passivation-achieved via directly adding a cyanoacrylic-acid-based molecular additive, namely BT-T, into the perovskite precursor solution. Classical and ab initio molecular dynamics simulations reveal that BT-T spontaneously may self-assemble at the buried interface during the formation of the perovskite layer on a nickel oxide hole-transporting layer. The preferential buried-interface passivation results in facilitated hole transfer and suppressed charge recombination. In addition, residual BT-T molecules in the perovskite layer enhance its stability and homogeneity. A power-conversion efficiency (PCE) of 23.48% for 1.0 cm2 inverted-structure PSCs is reported. The encapsulated PSC retains 95.4% of its initial PCE following 1960 h maximum-power-point tracking under continuous light illumination at 65 °C (i.e., ISOS-L-2I protocol). The demonstration of operating-stable PSCs under accelerated ageing conditions represents a step closer to the commercialization of this emerging technology.

Indoor Self-Powered Perovskite Optoelectronics with Ultraflexible Monochromatic Light Source.

Self-powered skin optoelectronics fabricated on ultrathin polymer films is emerging as one of the most promising components for the next-generation Internet of Things (IoT) technology. However, a longstanding challenge is the device underperformance owing to the low process temperature of polymer substrates. In addition, broadband electroluminescence (EL) based on organic or polymer semiconductors inevitably suffers from periodic spectral distortion due to Fabry-Pérot (FP) interference upon substrate bending, preventing advanced applications. Here, ultraflexible skin optoelectronics integrating high-performance solar cells and monochromatic light-emitting diodes using solution-processed perovskite semiconductors is presented. n-i-p perovskite solar cells and perovskite nanocrystal light-emitting diodes (PNC-LEDs), with power-conversion and current efficiencies of 18.2% and 15.2 cd A-1 , respectively, are demonstrated on ultrathin polymer substrates with high thermal stability, which is a record-high efficiency for ultraflexible perovskite solar cell. The narrowband EL with a full width at half-maximum of 23 nm successfully eliminates FP interference, yielding bending-insensitive spectra even under 50% of mechanical compression. Photo-plethysmography using the skin optoelectronic device demonstrates a signal selectivity of 98.2% at 87 bpm pulse. The results presented here pave the way to inexpensive and high-performance ultrathin optoelectronics for self-powered applications such as wearable displays and indoor IoT sensors.

Role of Nanoscale Inhomogeneities in Co2FeO4 Catalysts during the Oxygen Evolution Reaction.

Spinel-type catalysts are promising anode materials for the alkaline oxygen evolution reaction (OER), exhibiting low overpotentials and providing long-term stability. In this study, we compared two structurally equal Co2FeO4 spinels with nominally identical stoichiometry and substantially different OER activities. In particular, one of the samples, characterized by a metastable precatalyst state, was found to quickly achieve its steady-state optimum operation, while the other, which was initially closer to the ideal crystallographic spinel structure, never reached such a state and required 168 mV higher potential to achieve 1 mA/cm2. In addition, the enhanced OER activity was accompanied by a larger resistance to corrosion. More specifically, using various ex situ, quasi in situ, and operando methods, we could identify a correlation between the catalytic activity and compositional inhomogeneities resulting in an X-ray amorphous Co2+-rich minority phase linking the crystalline spinel domains in the as-prepared state. Operando X-ray absorption spectroscopy revealed that these Co2+-rich domains transform during OER to structurally different Co3+-rich domains. These domains appear to be crucial for enhancing OER kinetics while exhibiting distinctly different redox properties. Our work emphasizes the necessity of the operando methodology to gain fundamental insight into the activity-determining properties of OER catalysts and presents a promising catalyst concept in which a stable, crystalline structure hosts the disordered and active catalyst phase.

Multimodal host-guest complexation for efficient and stable perovskite photovoltaics.

Formamidinium lead iodide perovskites are promising light-harvesting materials, yet stabilizing them under operating conditions without compromising optimal optoelectronic properties remains challenging. We report a multimodal host-guest complexation strategy to overcome this challenge using a crown ether, dibenzo-21-crown-7, which acts as a vehicle that assembles at the interface and delivers Cs+ ions into the interior while modulating the material. This provides a local gradient of doping at the nanoscale that assists in photoinduced charge separation while passivating surface and bulk defects, stabilizing the perovskite phase through a synergistic effect of the host, guest, and host-guest complex. The resulting solar cells show power conversion efficiencies exceeding 24% and enhanced operational stability, maintaining over 95% of their performance without encapsulation for 500 h under continuous operation. Moreover, the host contributes to binding lead ions, reducing their environmental impact. This supramolecular strategy illustrates the broad implications of host-guest chemistry in photovoltaics.

Crown Ether Modulation Enables over 23% Efficient Formamidinium-Based Perovskite Solar Cells.

The use of molecular modulators to reduce the defect density at the surface and grain boundaries of perovskite materials has been demonstrated to be an effective approach to enhance the photovoltaic performance and device stability of perovskite solar cells. Herein, we employ crown ethers to modulate perovskite films, affording passivation of undercoordinated surface defects. This interaction has been elucidated by solid-state nuclear magnetic resonance and density functional theory calculations. The crown ether hosts induce the formation of host-guest complexes on the surface of the perovskite films, which reduces the concentration of surface electronic defects and suppresses nonradiative recombination by 40%, while minimizing moisture permeation. As a result, we achieved substantially improved photovoltaic performance with power conversion efficiencies exceeding 23%, accompanied by enhanced stability under ambient and operational conditions. This work opens a new avenue to improve the performance and stability of perovskite-based optoelectronic devices through supramolecular chemistry.

Author Correction: Downstream Products are Potent Inhibitors of the Heparan Sulfate 2-O-Sulfotransferase.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Current state of biologic pharmacovigilance in the European Union: improvements are needed.

INTRODUCTION: Pharmacovigilance is essential to monitoring the safety profiles of authorized medicines. Compared with small-molecule drugs, biological drugs are more complex, more susceptible to structural variability due to manufacturing processes, and have the potential to induce immune-related reactions, underscoring the importance of safety monitoring for these products. Although highly similar to reference products, biosimilars are not expected to be structurally identical. For these reasons, proper reporting of potential adverse drug reactions (ADRs) using distinguishable names and batch numbers is essential for accurate tracing of all biological drugs. To address the need for robust pharmacovigilance, the European Parliament and Council of the European Union provided legislation regarding pharmacovigilance of biologics in 2010. AREAS COVERED: This narrative review examines the current state of pharmacovigilance for biologics in the European Union (EU) and discusses relevant information on pharmacovigilance of biosimilars, the current EU pharmacovigilance system, and areas that could be improved. EXPERT OPINION: Although steps have been taken to improve pharmacovigilance of biologics in the EU, several enhancements can still be made, including additional training for healthcare professionals on ADR reporting, the use of 2D barcodes that enhance traceability, and an open discussion of potentially missed opportunities in the pharmacovigilance of biosimilars.

Managing the Risks of Medicines: An Examination of FDA's Application of Criteria for Requiring a REMS.

BACKGROUND: In September 2016, the Food and Drug Administration (FDA) published a draft guidance for industry, FDA's Application of Statutory Factors in Determining When a REMS Is Necessary, that detailed the factors the Agency considers in determining when a Risk Evaluation and Mitigation Strategy (REMS) is necessary. The objective of this study was to determine how the FDA has applied these criteria for newly approved drugs. METHODS: For the 3-year period, 2015-2017, which included a full year of FDA approvals both before and after the issuance of the draft guidance, publicly available FDA reviews were analyzed for all 113 approved products using the criteria outlined in the guidance. RESULTS: Of the 113 products approved, 5 required a REMS. The most cited reasons for not requiring a REMS for the remaining 108 drugs were that risks could be managed via professional labeling (87%), physicians (primarily specialists) were familiar with the management of the risks (76%), the risk profile was similar to other non-REMS marketed products (45%), products were used in a controlled setting (inpatient, infusion center) (30%), and/or safety concerns would be further evaluated by a postmarket study (14%). CONCLUSIONS: A review of Agency risk evaluations indicate that whether physicians are sufficiently familiar with and capable of managing a risk and that the health care setting where the product is administered is conducive to such management are leading factors in determining whether or not to require a REMS.

Downstream Products are Potent Inhibitors of the Heparan Sulfate 2-O-Sulfotransferase.

Heparan Sulfate (HS) is a cell signaling molecule linked to pathological processes ranging from cancer to viral entry, yet fundamental aspects of its biosynthesis remain incompletely understood. Here, the binding preferences of the uronyl 2-O-sulfotransferase (HS2ST) are examined with variably-sulfated hexasaccharides. Surprisingly, heavily sulfated oligosaccharides formed by later-acting sulfotransferases bind more tightly to HS2ST than those corresponding to its natural substrate or product. Inhibition assays also indicate that the IC50 values correlate simply with degree of oligosaccharide sulfation. Structural analysis predicts a mode of inhibition in which 6-O-sulfate groups located on glucosamine residues present in highly-sulfated oligosaccharides occupy the canonical binding site of the nucleotide cofactor. The unexpected finding that oligosaccharides associated with later stages in HS biosynthesis inhibit HS2ST indicates that the enzyme must be separated temporally and/or spatially from downstream products during biosynthesis in vivo, and highlights a challenge for the enzymatic synthesis of lengthy HS chains in vitro.

A Survey of Adverse Event Reporting Practices Among US Healthcare Professionals.

INTRODUCTION: The under-reporting of adverse drug events (ADEs) is an international health concern. A number of studies have assessed the root causes but, to our knowledge, little information exists relating under-reporting to practices and systems used for the recording and tracking of drug-related adverse event observations in ambulatory settings, institutional settings, and retail pharmacies. OBJECTIVES: Our objective was to explore the process for reporting ADEs in US hospitals, ambulatory settings, and retail pharmacies; to explore gaps and inconsistencies in the reporting process; and to identify the causes of under-reporting ADEs in these settings. METHODS: The Tufts Center for the Study of Drug Development (Tufts CSDD) interviewed 11 thought leaders and conducted a survey between May and August 2014 among US-based healthcare providers (HCPs) in diverse settings to assess their experiences with, and processes for, reporting ADEs. RESULTS: A total of 123 individuals completed the survey (42 % were pharmacists; 27 % were nurses; 15 % were physicians; and 16 % were classified as 'other'). HCPs indicated that the main reasons for under-reporting were difficulty in determining the cause of the ADE, given that most patients receive multiple therapies simultaneously (66 % of respondents); that HCPs lack sufficient time to report ADEs (63 % of respondents); poor integration of ADE-reporting systems (53 % of respondents); and uncertainty about reporting procedures (52 % of respondents). DISCUSSION: The results of this pilot study identify that key factors contributing to the under-reporting of ADEs relate to a lack of standardized process, a lack of training and education, and a lack of integrated health information technologies.

Pharmacovigilance Considerations for Biosimilars in the USA.

In 2015, five or more biosimilars may be approved in the USA. Because no two biologic medicines are identical, postapproval safety monitoring will be critical to detect potential differences in safety signals between a biosimilar, its reference product, and other biosimilars. Postapproval safety monitoring in the USA uses two signal detection systems: spontaneous reporting systems (SRSs) and active surveillance (AS) systems. Both depend on accurate identification of the specific product(s) dispensed or administered to patients, which may be compromised when products from multiple manufacturers share common drug nomenclature or coding. Product identification can present challenges across different healthcare settings, including inpatient and ambulatory care. Common oral-dosage drugs are predominantly dispensed directly to patients by pharmacists, whereas most injectable drugs, including biologics, are administered to patients by healthcare professionals in outpatient clinics or hospitals. Thus, the effectiveness of SRS and AS mechanisms in both pharmacy and medical channels must be given greater consideration as biotechnology matures. In this article, we describe these systems and their limitations. We identify challenges and opportunities for product-specific safety surveillance of biologics in both the pharmacy and medical settings and provide recommendations to improve biologic safety surveillance under the current and future systems envisioned in the Drug Quality and Security Act. As biosimilars are integrated into existing pharmacovigilance systems, distinguishable nonproprietary names and codes for all biologics, as well as other opportunities to improve traceability (e.g., increased use of barcodes), must be considered to ensure patient safety and confidence in this new class of drugs.

Active and passive surveillance of enoxaparin generics: a case study relevant to biosimilars.

OBJECTIVE: This retrospective analysis assessed the capability of active and passive safety surveillance systems to track product-specific safety events in the USA for branded and generic enoxaparin, a complex injectable subject to immune-related and other adverse events (AEs). METHODS: Analysis of heparin-induced thrombocytopenia (HIT) incidence was performed on benefit claims for commercial and Medicare supplemental-insured individuals newly treated with enoxaparin under pharmacy benefit (1 January 2009 - 30 June 2012). Additionally, spontaneous reports from the FDA AE Reporting System were reviewed to identify incidence and attribution of enoxaparin-related reports to specific manufacturers. RESULTS: Specific, dispensed products were identifiable from National Drug Codes only in pharmacy-benefit databases, permitting sensitive comparison of HIT incidence in nearly a third of patients treated with brand or generic enoxaparin. After originator medicine's loss of exclusivity, only 5% of spontaneous reports were processed by generic manufacturers; reports attributable to specific generics were approximately ninefold lower than expected based on market share. CONCLUSIONS: Claims data were useful for active surveillance of enoxaparin generics dispensed under pharmacy benefits but not for products administered under medical benefits. These findings suggest that the current spontaneous reporting system will not distinguish product-specific safety signals for products distributed by multiple manufacturers, including biosimilars.

Identifying and Quantifying the Accuracy of Product Name Attribution of US-Sourced Adverse Event Reports in MedWatch of Somatropins and Insulins.

BACKGROUND: As of 2014, the US FDA was considering policy options to promote accurate attribution of adverse events for biosimilars. In order to assess the identification and traceability of biologics from multiple sources, Tufts University's Center for the Study of Drug Development conducted a study reviewing the current FDA Adverse Event Reporting System (FAERS) for reports related to insulin and growth hormone products. METHODS: For this study, all primary suspect reports that were received by FAERS for human growth hormone (hGH) and human insulin between the fourth quarter of 2005 and the third quarter of 2013 were extracted and analyzed. RESULTS: The rates of "accurate" brand (ie, identifiable) drug names were generally high, with a higher incidence for hGH drugs than for insulin drugs (92% of hGH primary suspect reports vs 84% of insulin primary suspect reports). Lot number completion rates were generally low, with a higher incidence for insulin drugs than for hGH drugs (37% of insulin primary suspect reports vs 13% of hGH primary suspect reports). There were 13.5% of insulin reports that could not be linked to manufacturers, while 7.5% of hGH reports could not be linked to a manufacturer. CONCLUSIONS: The completion and accuracy rates of FAERS data on biologics observed in this study are consistent with those observed in earlier studies and suggest that traceability in adverse event reports can be improved through more consistent use of brand names or other product specific identifiers and through more frequent inclusion of lot numbers.

Similar names for similar biologics.

Approval of the first biosimilar in the USA may occur by the end of 2014, yet a naming approach for biosimilars has not been determined. Biosimilars are highly similar to their biologic reference product but are not identical to it, because of their structural complexity and variations in manufacturing processes among companies. There is a need for a naming approach that can distinguish a biosimilar from its reference product and other biosimilars and ensure accurate tracing of adverse events (AEs) to the administered product. In contrast, generic small-molecule drugs are identical to their reference product and, therefore, share the same nonproprietary name. Clinical trials required to demonstrate biosimilarity for approval may not detect rare AEs or those occurring after prolonged use, and the incidence of such events may differ between a biosimilar and its reference product. The need for precise biologic identification is further underscored by the possibility of biosimilar interchangeability, a US designation that will allow substitution without prescriber intervention. For several biologics, the US Food and Drug Administration (FDA) has used a naming approach that adds a prefix to a common root nonproprietary name, enabling healthcare providers to distinguish between products, avoid medication errors, and facilitate pharmacovigilance. We recommend that the FDA implement a biosimilars naming policy that likewise would add a distinguishable prefix or suffix to the root nonproprietary name of the reference product. This approach would ensure that a biosimilar could be distinguished from its reference product and other biosimilars in patient records and pharmacovigilance databases/reports, facilitating accurate attribution of AEs.

Pharmacovigilance and biosimilars: considerations, needs and challenges.

INTRODUCTION: Biosimilars are biologic medicines that are highly similar to approved biologics, notwithstanding minor differences in clinically inactive components. Since 2007, biosimilars have been approved for use in patients in the European Union (EU) and other regions. European experience provides several lessons as the United States (US) healthcare system prepares for biosimilar approvals. These lessons emphasize the need for adequate efficacy and safety studies, post-marketing surveys and a robust pharmacovigilance system that can accurately track and trace biologics, including biosimilars and their reference products, from the patient to the manufacturer. AREAS COVERED: We review the EU experience with biosimilar pharmacovigilance and discuss the implications for biosimilar pharmacovigilance in the USA. Furthermore, we review several aspects of biosimilar pharmacovigilance, including cohort event monitoring, traceability, biosimilar interchangeability, pharmacovigilance system development, nomenclature and counterfeit tracking. EXPERT OPINION: The availability of biosimilars as lower-cost biologics must carefully consider issues of safety, efficacy and traceability. Stringent pharmacovigilance procedures are required to detect potential differences in safety signals between biosimilars and their reference products. Pharmacovigilance of biologics should include processes that are easily used by prescribing practitioners to ensure that data are consistent and new safety signals are properly reported and assigned to the correct product.