High-Performance Biscrolled MXene/Carbon Nanotube Yarn Supercapacitors.

Yarn-shaped supercapacitors (YSCs) once integrated into fabrics provide promising energy storage solutions to the increasing demand of wearable and portable electronics. In such device format, however, it is a challenge to achieve outstanding electrochemical performance without compromising flexibility. Here, MXene-based YSCs that exhibit both flexibility and superior energy storage performance by employing a biscrolling approach to create flexible yarns from highly delaminated and pseudocapacitive MXene sheets that are trapped within helical yarn corridors are reported. With specific capacitance and energy and power densities values exceeding those reported for any YSCs, this work illustrates that biscrolled MXene yarns can potentially provide the conformal energy solution for powering electronics beyond just the form factor of flexible YSCs.

Thermoacoustic sound projector: exceeding the fundamental efficiency of carbon nanotubes.

The combination of smooth, continuous sound spectra produced by a sound source having no vibrating parts, a nanoscale thickness of a flexible active layer and the feasibility of creating large, conformal projectors provoke interest in thermoacoustic phenomena. However, at low frequencies, the sound pressure level (SPL) and the sound generation efficiency of an open carbon nanotube sheet (CNTS) is low. In addition, the nanoscale thickness of fragile heating elements, their high sensitivity to the environment and the high surface temperatures practical for thermoacoustic sound generation necessitate protective encapsulation of a freestanding CNTS in inert gases. Encapsulation provides the desired increase of sound pressure towards low frequencies. However, the protective enclosure restricts heat dissipation from the resistively heated CNTS and the interior of the encapsulated device. Here, the heat dissipation issue is addressed by short pulse excitations of the CNTS. An overall increase of energy conversion efficiency by more than four orders (from 10-5 to 0.1) and the SPL of 120 dB re 20 µPa @ 1 m in air and 170 dB re 1 µPa @ 1 m in water were demonstrated. The short pulse excitation provides a stable linear increase of output sound pressure with substantially increased input power density (>2.5 W cm-2). We provide an extensive experimental study of pulse excitations in different thermodynamic regimes for freestanding CNTSs with varying thermal inertias (single-walled and multiwalled with varying diameters and numbers of superimposed sheet layers) in vacuum and in air. The acoustical and geometrical parameters providing further enhancement of energy conversion efficiency are discussed.

Flexible and Compressible Temperature Sensors Based on Hierarchically Buckled Carbon Nanotube/Rubber Bi-Sheath-Core Fibers.

Flexible and compressible temperature sensors are highly desired for artificial skin and epidermal electronics. Here we demonstrated a flexible and compressible resistive temperature sensor using hierarchically buckled carbon nanotube/rubber bi-sheath-core structure (a buckled carbon nanotube outer sheath and a buckled rubber inner sheath wrapped around a rubber fiber core). When heated, lateral contacts of the adjacent buckles increase, resulting in electrical resistance decrease and serving as highly sensitive temperature sensors. This bi-sheath-core fiber temperature sensor showed high linearity, good repeatability, large negative temperature coefficient of resistance (NTC = -54.7/°C), and insensitivity to compressive deformations (up to -20% strain). The NTC and temperature dependence of percent resistance change can be easily tuned by modulating the buckling bi-sheath-core structures such as varying the number of nanotube layers and the rubber sheath stiffness.

Superior rechargeability and efficiency of lithium-oxygen batteries: hierarchical air electrode architecture combined with a soluble catalyst.

The lithium-oxygen battery has the potential to deliver extremely high energy densities; however, the practical use of Li-O2 batteries has been restricted because of their poor cyclability and low energy efficiency. In this work, we report a novel Li-O2 battery with high reversibility and good energy efficiency using a soluble catalyst combined with a hierarchical nanoporous air electrode. Through the porous three-dimensional network of the air electrode, not only lithium ions and oxygen but also soluble catalysts can be rapidly transported, enabling ultra-efficient electrode reactions and significantly enhanced catalytic activity. The novel Li-O2 battery, combining an ideal air electrode and a soluble catalyst, can deliver a high reversible capacity (1000 mAh g(-1) ) up to 900 cycles with reduced polarization (about 0.25 V).

Improved sample introduction approach in hydrophilic interaction liquid chromatography to avoid breakthrough of proteins.

When therapeutic proteins are analysed under hydrophilic interaction liquid chromatography (HILIC) conditions, there is an inherent mismatch between the sample diluent (proteins must be solubilised in aqueous media) and the mobile phase, which is mostly composed of aprotic solvent (acetonitrile). This difference in eluent strength between sample diluent and mobile phase is responsible for severe analyte breakthrough and peak distortion. As demonstrated with therapeutic proteins of different sizes (insulin of 6 kDa, anakinra of 17 kDa and rituximab subunits of 25 and 50 kDa), only very small volumes of 0.1-0.2 µL can be injected without breakthrough effects, when performing rapid analysis on short HILIC columns of 20-50 mm, leading to poor sensitivity. In order to avoid the undesired effect of the strong sample diluent, a special injection program should be preferred. This consists in the addition and automatic injection of a defined volume of weak solvent (acetonitrile) along with the sample to increase retention factors during sample loading. Various injection programs were tested, including the addition of a pre-injection or post-injection or both (bracketed injection) of acetonitrile plugs. Several weak to strong injection solvent ratios of 1:1, 1:2, 1:4 and 1:10 were tested. Our work proves that the addition of a pre-plug solvent with a weak vs. strong injection solvent ratio of 1:10 is a valuable strategy to inject relatively large volumes of proteins in HILIC, regardless of column dimensions, thus maximising sensitivity. No peak deformation or breakthrough was observed under these conditions. However, it is important to note that peak broadening (40 % larger peaks) was observed when the injection program increased the injection solvent ratio from 1:1 to 1:10. Finally, this strategy was applied to a wide range of therapeutic mAb products with different physico-chemical properties. In all cases, relatively large volumes can be successfully injected onto small volume HILIC columns using a purely aqueous sample diluent, as long as an appropriate (weak) solvent pre-injection is applied.

Practical study on the impact of injection conditions in gradient elution mode for the analysis of therapeutic proteins when using very short columns.

The impact of injected sample volume on apparent efficiency has been studied for very short columns in a systematic way. For large molecules such as therapeutic proteins, it was found that relatively large volumes can be injected onto ultra-short RPLC and IEX columns (i.e. L < 50 mm) without significantly affecting the quality of the separation. This favourable behavior is due to the on-off elution mechanism of large molecules and to the fact that therapeutic protein samples are formulated in aqueous-based media, which is the weakest solvent in RPLC and IEX. Therefore, their peak is strongly focused at the column inlet even when large volume is injected, and pre-column peak dispersion is compensated. However, ultra-short HILIC columns do not seem to be favorable, as they require for very low injection volume to avoid detrimental peak splitting and breakthrough effects. Such peak distortion is related to the inherent solvent mismatch between sample diluent (aqueous) and mobile phase strength (highly organic in HILIC). When studying mass load, the ranking of the elution modes was the same, and the largest relative mass could be injected onto IEX columns (as large as 10% sample to sorbent mass), without affecting the separation quality.

Analysing the In-Use Stability of mRNA-LNP COVID-19 Vaccines Comirnaty™ (Pfizer) and Spikevax™ (Moderna): A Comparative Study of the Particulate.

Comirnaty™ and Spikevax™ were the first vaccines approved for human use based on modified non-replicating mRNA lipophilic nanoparticle (mRNA-LNP) technology, with great success in the treatment of COVID-19. They have been used massively worldwide. One of the major inconveniences of these vaccines is related to pharmaceutical stability issues. Proper transportation, storage, and in-use handling before administration to patients are critical steps since failures can potentially reduce potency. In this research, the in-use stability of Comirnaty™ and Spikevax™ clinical samples was analysed and the results were compared. As changes in the size of the mRNA-LNPs are related to potency, these modifications were analysed by qualitative Dynamic Light Scattering (DLS) as a stability-indicating method for control and stressed vaccine samples. Strong stress factors (accelerated light irradiation, manual shaking, and vortex vibration) and conditions that mimic in-use handling (exposure to natural light and room temperature, repeated cycles of injections, and 24 h storage in syringes) were checked. The morphology of the mRNA-LNPs was analysed by Transmission Electron Microscopy (TEM) to better interpret and support the DLS results. Although the two vaccines are based on the same mRNA-LNP technology, the results demonstrate that they are characterised by very different particle size profiles and behaviours against different handling/stress conditions.

Comprehensive physicochemical characterization of a peptide-based medicine: Teduglutide (Revestive®) structural description and stress testing.

Teduglutide (Revestive®) is a glucagon-like peptide-2 analogue used for the treatment of short bowel syndrome, a rare life-threatening condition in which the amount of functional gut is too short to enable proper absorption of nutrients and fluids. During handling prior to administration to the patient in hospital, it is possible that peptide-based medicines may be exposed to environmental stress conditions that could affect their quality. It is therefore essential to carry out stress testing studies to evaluate how such medicines respond to these stresses. For this reason, in this paper we present a strategy for a comprehensive analytical characterization of a peptide and a stress testing study in which it was subjected to various stress conditions: heating at 40 °C and 60 °C, light exposure and shaking. Several complementary analytical techniques were used throughout this study: Far UV circular dichroism, intrinsic protein fluorescence spectroscopy, dynamic light scattering, size-exclusion chromatography and intact and peptide mapping reverse-phase chromatography coupled to mass spectrometry. To the best of our knowledge, this is the first study to offer an in-depth description of the chemical structure of teduglutide peptide and its physicochemical characteristics after stress stimuli were applied to the reconstituted medicine Revestive®.

A reel-wound carbon nanotube polarizer for terahertz frequencies.

Utilizing highly oriented multiwalled carbon nanotube aerogel sheets, we fabricated micrometer-thick freestanding carbon nanotube (CNT) polarizers. Simple winding of nanotube sheets on a U-shaped polyethylene reel enabled rapid and reliable polarizer fabrication, bypassing lithography or chemical etching processes. With the remarkable extinction ratio reaching ∼37 dB in the broad spectral range from 0.1 to 2.0 THz, combined with the extraordinary gravimetric mechanical strength of CNTs, and the dispersionless character of freestanding sheets, the commercialization prospects for our CNT terahertz polarizers appear attractive.

Degradation and in-use stability study of five marketed therapeutic monoclonal antibodies by generic weak cation exchange liquid chromatographic method ((WCX)HPLC/DAD).

Therapeutic monoclonal antibodies (mAbs) represent a very important class of the current biopharmaceutics. The great complexity of their structure made necessary the use of different analytical approaches for assessing different physico-chemical properties. In this work, weak cation exchange (WCX) high performance liquid chromatography with diode array detection ((WCX)HPLC/DAD) is used to assess the charge variant profile. The method here developed combined the effect of ionic strength and controlled pH gradient and allows for the charge variants analysis of the five mAbs studied, namely bevacizumab (BVZ), cetuximab (CTX) infliximab (INF), rituximab (RTX) and trastuzumab (TTZ), which are among the most used mAbs worldwide. The differences in the charge variants in the natural isoforms of the mAbs promoted characteristic WCX chromatograms for each of mAbs that can be also useful for identification purposes. These chromatograms have provided to be suitable for tracking changes in the charge variants of each mAb analyzed both in controlled degraded and in stabilities study along time of in-use samples solutions at 2 mg/mL in 0.9% NaCl stored refrigerated (at 4 °C) and frozen (-20 °C) for two months. The results obtained indicated different stabilities of these mAbs, all IgG1, against degradation by different stressed environmental conditions and in-use stability along two months.

Method for identification and quantification of intact teduglutide peptide using (RP)UHPLC-UV-(HESI/ORBITRAP)MS.

Teduglutide (Revestive®, 10 mg mL-1) is a recombinant human glucagon-like peptide 2 analogue, used in the treatment of short bowel syndrome, a serious and highly disabling condition which results from either too small a length of intestine or loss of critical intestinal function. The determination of therapeutic compounds of protein-nature is always challenging due to their complex structure. In this work, we present a fast, straightforward reversed phase (RP)UHPLC-UV-(HESI/ORBITRAP)MS method for the identification and quantification of the intact teduglutide peptide. The method has been developed and validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines; therefore, linearity, limits of detection and quantification, accuracy (precision and trueness), robustness, system suitability and specificity using the signal from the UV and MS, have been evaluated. The validation performance parameters obtained from the UV and MS signals were compared throughout the work, to select the most suitable. To study the specificity of the method and the impact of medicine mishandling under hospital conditions, force degradation studies were performed, i.e. thermal (40 °C and 60 °C), shaking (mechanical) and light (accelerated exposition) effects. Identification by the exact mass of teduglutide was achieved and it was confirmed that the peptide does not undergo any post-translational modifications (PTMs). To the best of our knowledge, the present work reports the first method developed for the simultaneous identification, structural characterization, and quantification of the therapeutic teduglutide peptide. Finally, the proposed method is able to indicate stability when quantifying the intact teduglutide since detects and characterises the exact mass of the degradation/modification products.

Tracking the physicochemical stability of teduglutide (Revestive®) clinical solutions over time in different storage containers.

Teduglutide, the active ingredient of the medicine Revestive® (5 mg), is a recombinant therapeutic peptide that mimics the effects of the endogenous glucagon-like peptide 2 (GLP-2). It stimulates intestinal growth, adaptation and function in patients with Short Bowel Syndrome who are dependent on parenteral nutrition. The Summary of Product Characteristics recommends immediate use of the reconstituted solutions and the discarding of any subsequent surplus. This study aims to carry out a long-term stability study that reproduces hospital conditions of use which provide sound evidence regarding the use of teduglutide surplus beyond the Summary Product Characteristics recommendations. We conducted a stability study of teduglutide solutions prepared from a 5 mg vial of Revestive®. Some of the solutions were stored in their original vial after reconstitution, while others were repackaged in plastic syringes to evaluate their physicochemical stability over time. For this purpose, we applied a set of previously validated analytical methodologies to evaluate the main critical quality attributes of teduglutide, i.e., primary (including post-tralational modifications), secondary and tertiary structures, aggregates, particulate, concentration and pH. The results indicate that the solutions maintain high physicochemical stability over time, regardless of the storage temperature (4ºC or -20ºC) or the storage container (vials or syringes). This research provides new data on the stability of Revestive® that will be of great value to hospital pharmacists. This comprehensive assessment of the physicochemical long-term stability of TGT has demonstrated that under the storage conditions and over the period studied here, the medicine maintains its quality, efficacy and safety profiles.

Aligned, isotropic and patterned carbon nanotube substrates that control the growth and alignment of Chinese hamster ovary cells.

Here we culture Chinese hamster ovary cells on isotropic, aligned and patterned substrates based on multiwall carbon nanotubes. The nanotubes provide the substrate with nanoscale topography. The cells adhere to and grow on all substrates, and on the aligned substrate, the cells align strongly with the axis of the bundles of the multiwall nanotubes. This control over cell alignment is required for tissue engineering; almost all tissues consist of oriented cells. The aligned substrates are made using straightforward physical chemistry techniques from forests of multiwall nanotubes; no lithography is required to make inexpensive large-scale substrates with highly aligned nanoscale grooves. Interestingly, although the cells strongly align with the nanoscale grooves, only a few also elongate along this axis: alignment of the cells does not require a pronounced change in morphology of the cell. We also pattern the nanotube bundles over length scales comparable to the cell size and show that the cells follow this pattern.

Stability study over time of clinical solutions of ziv-aflibercept prepared in infusion bags using a proper combination of physicochemical and functional strategies.

A range of biopharmaceutical products are used to target Vascular Endothelial Growth Factor (VEGF), including Eylea® (aflibercept, AFL) and Zaltrap® (ziv-aflibercept, ziv-AFL). The first is indicated for ophthalmological diseases such as neovascular (wet) age-related macular degeneration, while the second is used in the treatment of metastatic colorectal cancer. The stability of AFL in prefilled syringes has been widely studied; however, no research has yet been done on the stability of ziv-AFL in polyolefin infusion bags. Therefore, the purpose of the present research is to evaluate the stability of ziv-AFL (Zaltrap®) clinical solutions prepared under aseptic conditions in polyolefin infusion bags at two different concentrations, i.e. 4.0 and 0.6 mg/mL, and stored refrigerated in darkness at 2-8 °C for 14 days. With that aim, the ziv-AFL clinical solutions were assessed by analysing changes in its physicochemical and functional properties. The distribution of the particulates was studied over a range of 0.001-10 µm by Dynamic Light Scattering (DLS); oligomers were analysed by Size-Exclusion High-Performance Chromatography with Diode Array Detection (SE/HLPC-DAD); the secondary structure of the protein was studied by far UV Circular Dichroism (CD) and the tertiary structure by Intrinsic Tryptophan Fluorescence (IT-F) and Intrinsic Protein Fluorescence (IP-F); charge variants were assessed by Strong Cation Exchange Ultra-High-Performance Chromatography with UV detection (SCX/UHPLC-UV); functionality was evaluated by ELISA by measuring the biological activity as manifested in the extension of the immunological reaction of the ziv-AFL with its antigen (VEGF). Neither aggregation nor oligomerization were detected by the techniques mentioned above. Secondary and tertiary structures remained unchanged over the 14-day period, as did charge variants. The functionality observed initially was maintained along time. Therefore, it could be proposed that the ziv-AFL clinical solutions studied showed great physicochemical and functional stability over a period of two weeks, regardless of the concentration, i.e. 4 or 0.6 mg/mL.

Intact charge variant analysis of ziv-aflibercept by cationic exchange liquid chromatography as a proof of concept: Comparison between volatile and non-volatile salts in the mobile phase.

Ziv-aflibercept (ziv-AFL) is a complex fusion protein which is widely used in hospitals for the treatment of colorectal metastatic cancer. Charge variants are critical attributes for assessing post-transitional modifications (PMTs) that have to be controlled during the development and manufacture of these proteins and until their administration to patients. Cation exchange (CEX) chromatography is a charge-sensitive analytical method that is well suited for analysing charge variants in proteins. The aim of this paper is to analyse the charge variants of ziv-AFL in the medicine (Zaltrap®) when fresh and when degraded. Two CEX chromatographic methods were compared for this purpose. The former was an adaptation of the method used in the first published study in which charge variants were analysed via pH gradient elution using volatile, low ionic strength buffers with direct coupling to high-resolution Orbitrap mass spectrometry. The second method was developed and optimized during our research using the salt-mediated pH gradient mode and classical non-volatile, high ionic strength buffers which were incompatible with direct coupling with mass detection. Fresh and controlled degraded samples of ziv-AFL were used to evaluate the capacity of both CEX chromatographic strategies for detecting charge variants in ziv-AFL. In the controlled degradation study the samples of the medicine were subjected to three stress factors: temperature of 60 °C for three hours, freeze/thaw process -two cycles-, and exposure to light for twelve hours. The CEX chromatographic method with non-volatile salts in the mobile phase enabled better detection of charge variants degraded ziv-AFL samples than the method using volatile salts with lower ionic strength. In addition, the complexity of the mass spectra data generated made it impossible to identify the multicharge variant species of ziv-AFL. Although charge variants were not separated in ziv-AFL fresh sample, our results indicate that the method with non-volatile salts in the mobile phase could be used to characterize and track changes in the charge variant UV chromatographic profile of ziv-AFL in fresh and degraded samples, even though it cannot be coupled to a mass detector and there is therefore no information about mass. The increase of basic protein degraded compounds were the most important degradation pattern detected in ziv-AFL (Zaltrap®).

Use of subcutaneous tocilizumab to prepare intravenous solutions for COVID-19 emergency shortage: Comparative analytical study of physicochemical quality attributes.

COVID-19, a disease caused by the novel coronavirus SARS-CoV-2, has produced a serious emergency for global public health, placing enormous stress on national health systems in many countries. Several studies suggest that cytokine storms (interleukins) may play an important role in severe cases of COVID-19. Neutralizing key inflammatory factors in cytokine release syndrome (CRS) could therefore be of great value in reducing the mortality rate. Tocilizumab (TCZ) in its intravenous (IV) form of administration -RoActemra® 20 mg/mL (Roche)-is indicated for treatment of severe CRS patients. Preliminary investigations have concluded that inhibition of IL-6 with TCZ appears to be efficacious and safe, with several ongoing clinical trials. This has led to a huge increase in demand for IV TCZ for treating severe COVID-19 patients in hospitals, which has resulted in drug shortages. Here, we present a comparability study assessing the main critical physicochemical attributes of TCZ solutions used for infusion, at 6 mg/mL and 4 mg/mL, prepared from RoActemra® 20 mg/mL (IV form) and from RoActemra® 162 mg (0.9 mL solution pre-filled syringe, subcutaneous(SC) form), to evaluate the use of the latter for preparing clinical solutions required for IV administration, so that in a situation of shortage of the IV medicine, the SC form could be used to prepare the solutions for IV delivery of TCZ. It is important to remember that during the current pandemic all the medicines are used off-label, since none of them has yet been approved for the treatment of COVID-19.

Comparing different domains of analysis for the characterisation of N-glycans on monoclonal antibodies.

With the size of the biopharmaceutical market exponentially increasing, there is an aligned growth in the importance of data-rich analyses, not only to assess drug product safety but also to assist drug development driven by the deeper understanding of structure/function relationships. In monoclonal antibodies, many functions are regulated by N-glycans present in the constant region of the heavy chains and their mechanisms of action are not completely known. The importance of their function focuses analytical research efforts on the development of robust, accurate and fast methods to support drug development and quality control. Released N-glycan analysis is considered as the gold standard for glycosylation characterisation; however, it is not the only method for quantitative analysis of glycoform heterogeneity. In this study, ten different analytical workflows for N-glycan analysis were compared using four monoclonal antibodies. While observing good comparability between the quantitative results generated, it was possible to appreciate the advantages and disadvantages of each technique and to summarise all the observations to guide the choice of the most appropriate analytical workflow according to application and the desired depth of data generated.

Comprehensive biophysical and functional study of ziv-aflibercept: characterization and forced degradation.

Aflibercept (AFL) is an Fc fusion protein used in the treatment of colorectal cancers and different ophthalmological diseases. There are two medicines in which AFL is the active substance: Zaltrap and Eylea, referred as ziv-AFL and AFL respectively. No proper accelerated degradation studies were published on either AFL or ziv-AFL. These studies are essential during research, development and manufacturing stages. Here, we characterized ziv-AFL and submitted it to different stress conditions: light, 60 °C, freeze-thaw cycles, changes in pH, high hypertonic solution and strong denaturing conditions. We used an array of techniques to detect aggregation (SE-HPLC/DAD and DLS), changes in secondary structure (Far-UV circular dichroism), changes in conformation or tertiary structure (Intrinsic tryptophan fluorescence) and alterations in functionality (ELISA). Results indicate that aggregation is common degradation pathway. Two different types of aggregates were detected: dimers and high molecular weight aggregates attributed to ß-amyloid-like structures. Secondary structure was maintained in most of the stress tests, while conformation was altered by almost all the tests except for the freeze-thaw cycles. Functionality, evaluated by its immunochemical reaction with VEGF, was found to be stable but with decrease when exposed to light and with likely partial inactivation of the drug when pH was altered.

Comparative Stability Studies of Different Infliximab and Biosimilar CT-P13 Clinical Solutions by Combined Use of Physicochemical Analytical Techniques and Enzyme-Linked Immunosorbent Assay (ELISA).

BACKGROUND: There are two products in which infliximab is the active pharmaceutical ingredient. These are Remicade® (INF; reference product) and Remsima™/Inflectra™ (CT-P13; infliximab biosimilar). Remsima™/Inflectra™ are bioidentical products. Different recommendations have been made for the clinical solutions of each brand (Remicade® or Remsima™/Inflectra™) despite the manufacturer of the biosimilar claiming high levels of similarity to the innovator. OBJECTIVE: The objective of this study was to assess and compare stability against degradation and over time of different clinical infliximab solutions prepared from Remicade® and from Remsima™/Inflectra™ using a suitable set of characterization methods in line with the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) recommendations. METHODS: Reconstituted solutions of INF and CT-P13 and dilutions as used in hospital were stored in glass vials (10 and 2 mg/mL) or in polyolefin infusion bags (0.4 mg/mL) refrigerated between 2 and 8 °C for 2 weeks. Regarding the physicochemical properties, the distribution of the particulates were studied over a range of 0.001-1 µm by dynamic light scattering (DLS) and oligomers up to 8 monomer were analyzed by native size-exclusion ultra-high-performance liquid chromatography with ultraviolet (UV)-visible detection coupled to (native) mass spectrometry (SE/UHPLC-UV-(native) MS); mass spectrometry was also used to evaluate natural aggregates and isoform profile; DLS was also employed to detect gross conformational changes by tracking the hydrodynamic radius (HR). The secondary structure of the proteins was studied by far UV circular dichroism (CD). The tertiary structure was investigated by intrinsic tryptophan fluorescence (IT-F). Reverse-phase ultra-high-performance liquid chromatography with UV detection (RP/UHPLC-UV) was used to analyze intact INF and CT-P13 for quantification purposes. Functionality was evaluated via the biological activity measured by the extension of the immunological reaction of the INF and the CT-P13 with its antigen, i.e., the tumor necrosis factor-α by enzyme-linked immunosorbent assay (ELISA). RESULTS: The stress applied to INF and CT-P13 solutions showed similar levels of aggregate formation, structural variation, and chemical modifications. The only noteworthy difference between INF and CT-P13 was detected in their behavior to freeze-thaw cycles, in which CT-P13 showed slightly more robustness. INF and CT-P13 showed identical CD spectra, similar to those reported for IgG1 in which there is dominance in ß sheet secondary structures; this typical conformation remained unmodified over time in INF and CT-P13. No significant changes were detected in the tertiary structure and no aggregates process was noticed over the time studied. Polydispersity slightly increased for the most concentrated solutions, while there were no meaningful differences in the HR in the solutions over time. The concentration of INF and CT-P13 also remained constant. Differences in the native isoform MS profile were detected, as expected by the different glycosylation pattern, with no important modification over time. Functionality was maintained over the test period (60 days) and was similar in all the solutions tested, with no differences between INF and biosimilar solutions. CONCLUSIONS: High levels of similarity were noticed in the behavior of INF and CT-P13 when subjected to stress. When stored refrigerated at between 2 and 8 °C and prepared as normally used in the hospital pharmacy, all solutions showed physicochemical and functional stability for all the concentrations tested and all containers, at least for the 14-day test period.

Controllable Preparation of Ordered and Hierarchically Buckled Structures for Inflatable Tumor Ablation, Volumetric Strain Sensor, and Communication via Inflatable Antenna.

Inflatable conducting devices providing improved properties and functionalities are needed for diverse applications. However, the difficult part in making high-performance inflatable devices is the enabling of two-dimensional (2D) buckles with controlled structures on inflatable catheters. Here, we report the fabrication of highly inflatable devices with controllable structures by wrapping the super-aligned carbon nanotube sheet (SACNS) on the pre-inflated catheter. The resulting structure exhibits unique 2D buckled structures including quasi-parallel buckles, crisscrossed buckles, and hierarchically buckled structures, which enables reversible structural changes of 7470% volumetric strain. The 2D SACNS buckled structures show stable electrical conductance and surface wettability during large strain inflation/deflation cycles. Inflatable devices including inflatable tumor ablation, capacitive volumetric strain sensor, and communication via inflatable radio frequency antenna based on these structures are demonstrated.