Facile generation of heterotelechelic poly(2-oxazoline)s towards accelerated exploration of poly(2-oxazoline)-based nanomedicine

Controlling the end-groups of biocompatible polymers is crucial for enabling polymer-based therapeutics and nanomedicine. Typically, end-group diversification is a challenging and time-consuming endeavor, especially for polymers pre-pared via ionic polymerization mechanisms with limited functional group tolerance. In this study, we present a facile end-group diversification approach for poly(2-oxazoline)s (POx), enabling quick and reliable production of hetero-telechelic polymers to facilitate POxylation. The approach relies on the careful tuning of reaction parameters to establish differential reactivity of a pentafluorobenzyl initiator fragment and the living oxazolinium chain-end, allowing the selective introduction of N-, S-, O-nucleophiles via the termination of the polymerization, and a consecutive nucleophilic para-fluoro substitution. The value of this approach for the accelerated development of nanomedicine is demonstrated through the synthesis of well-defined lipid-polymer conjugates and POx-polypeptide block-copolymers, which are well-suited for drug and gene delivery. Furthermore, we investigated the application of a lipid-POx conjugate for the formulation and delivery of mRNA-loaded lipid nanoparticles for immunization against the SARS-COV-2 virus, underscoring the value of POx as a biocompatible polymer platform.

Carrier-free mRNA vaccine induces robust immunity against SARS-CoV-2 in mice and non-human primates without systemic reactogenicity

Carrier-free naked mRNA vaccines may reduce the reactogenicity associated with delivery carriers; however, their effectiveness against infectious diseases has been suboptimal. To boost efficacy, we targeted the skin layer rich in antigen-presenting cells (APCs) and utilized a jet injector. The jet injection efficiently introduced naked mRNA into skin cells, including APCs in mice. Further analyses indicated that APCs, after taking up antigen mRNA in the skin, migrated to the lymph nodes (LNs) for antigen presentation. Additionally, the jet injection provoked localized lymphocyte infiltration in the skin, serving as a physical adjuvant for vaccination. Without a delivery carrier, our approach confined mRNA distribution to the injection site, preventing systemic mRNA leakage and associated systemic proinflammatory reactions. In mouse vaccination, the naked mRNA jet injection elicited robust antigen-specific antibody production over 6 months, along with germinal center formation in LNs and the induction of both CD4- and CD8-positive T cells. By targeting the SARS-CoV-2 spike protein, this approach provided protection against viral challenge. Furthermore, our approach generated neutralizing antibodies against SARS-CoV-2 in non-human primates at levels comparable to those observed in mice. In conclusion, our approach offers a safe and effective option for mRNA vaccines targeting infectious diseases.

Hydrophobicity Tuning of Cationic Polyaspartamide Derivatives for Enhanced Antisense Oligonucleotide Delivery

Various cationic polymers are used to deliver polyplex-mediated antisense oligonucleotides (ASOs). However, few studies have investigated the structural determinants of polyplex functionalities in polymers. This study focused on the polymer hydrophobicity. A series of amphiphilic polyaspartamide derivatives possessing various hydrophobic (R) moieties together with cationic diethylenetriamine (DET) moieties in the side chain (PAsp(DET/R)s) were synthesized to optimize the R moieties (or hydrophobicity) for locked nucleic acid (LNA) gapmer ASO delivery. The gene knockdown efficiencies of PAsp(DET/R) polyplexes were plotted against a hydrophobicity parameter, logD7.3, of PAsp(DET/R), revealing that the gene knockdown efficiency was substantially improved by PAsp(DET/R) with logD7.3 higher than -2.4. This was explained by the increased polyplex stability and improved cellular uptake of ASO payloads. After intratracheal administration, the polyplex samples with a higher logD7.3 than -2.4 induced a significantly higher gene knockdown in the lung tissue compared with counterparts with lower hydrophobicity and naked ASO. These results demonstrate that the hydrophobicity of PAsp(DET/R) is crucial for efficient ASO delivery in vitro and in vivo.

Ionizable Polymeric Micelles with Phenylalanine Moieties Enhance Intracellular Delivery of Self-Replicating RNA for Long-Lasting Protein Expression In Vivo

mRNA-based therapeutics are revolutionizing the landscape of medical interventions. However, the short half-life of mRNA and transient protein expression often limits its therapeutic potential, demanding high treatment doses or repeated administrations. Self-replicating RNA (RepRNA)-based treatments could offer enhanced protein production and reduce the required dosage. Here, we developed polymeric micelles based on flexible poly(ethylene glycol)-poly(glycerol) (PEG-PG) block copolymers modified with phenylalanine (Phe) moieties via biodegradable ester bonds for the efficient delivery of RepRNA. These polymers successfully encapsulated RepRNA into sub-100 nm micelles assisted by the hydrophobicity of the Phe moieties and their ability to π-π stack with the bases in RepRNA. The micelles made from Phe-modified PEG-PG (PEG-PG(Phe)) effectively maintained the integrity of the loaded RepRNA in RNase-rich serum conditions. Once taken up by cells, the micelles triggered a pH-responsive membrane disruption, promoted by the strong protonation of the amino groups at endosomal pH, thereby delivering the RepRNA to the cytosol. The system induced strong protein expression in vitro and outperformed commercial transfecting reagents in vivo, where it resulted in enhanced and long-lasting protein expression.

Oligosarcosine Conjugation of Arginine-Rich Peptides Improves the Intracellular Delivery of Peptide/pDNA Complexes

Cell-penetrating peptides (CPPs), for example, arginine (Arg) rich peptides, are used for the intracellular delivery of nucleic acids. In this study, oligosarcosine-conjugated Arg-rich peptides were designed as plasmid DNA (pDNA) carriers, and the physicochemical parameters and transfection efficiency of the peptide/pDNA complexes were evaluated. Oligosarcosine with different lengths were conjugated to a base sequence composed of arginine and α-aminoisobutyric acid (Aib) [(Aib-Arg-Arg)3]. Oligosarcosine conjugation inhibited the aggregation of the complexes after mixing with pDNA, shielded the positive charge of the complexes, and provided efficient pDNA transfection in cultured cells. The efficiency of the pDNA transfection was improved by varying the length of the oligosarcosine moiety (10-15 units were optimal). The cellular uptake efficiency and intracellular distribution of pDNA were the same regardless of oligosarcosine conjugation. These results implied that intracellular processes, including the decondensation of pDNA, contributed to the efficiency of the protein expression from pDNA. This study demonstrated the advantages of oligosarcosine conjugation to Arg-rich CPPs and provided valuable insight into the future design of CPPs.

Spectral Splitting Solar Cells Consisting of a Mesoscopic Wide-Bandgap Perovskite Solar Cell and an Inverted Narrow-Bandgap Perovskite Solar Cell

In comparison to monolithic perovskite/perovskite double-junction solar cells, a four-terminal spectrum-splitting system is a simple method to obtain a higher power conversion efficiency (PCE) because it has no constraints of unifying the structures of the top and bottom cells. In this work, utilizing the fact that low-bandgap Sn-Pb bottom cells work the best in p-i-n while Pb-based wide-bandgap top cells work better in an n-i-p architecture, a wide-bandgap (Eg = 1.61 eV) perovskite solar cell with a mesoscopic structure and a narrow-bandgap (Eg = 1.27 eV) perovskite solar cell with an inverted structure were combined to fabricate a double-junction four-terminal spectral splitting solar cell. The double-junction solar cell with the 801 nm spectral splitting with an active area of 0.18 cm2 was found to work with a PCE of 25.3%, which is the highest reported so far for a 4-T all-perovskite double-junction spectral splitting solar cell.

mRNA vaccine designs for optimal adjuvanticity and delivery

Adjuvanticity and delivery are crucial facets of mRNA vaccine design. In modern mRNA vaccines, adjuvant functions are integrated into mRNA vaccine nanoparticles, allowing the co-delivery of antigen mRNA and adjuvants in a unified, all-in-one formulation. In this formulation, many mRNA vaccines utilize the immunostimulating properties of mRNA and vaccine carrier components, including lipids and polymers, as adjuvants. However, careful design is necessary, as excessive adjuvanticity and activation of improper innate immune signalling can conversely hinder vaccination efficacy and trigger adverse effects. mRNA vaccines also require delivery systems to achieve antigen expression in antigen-presenting cells (APCs) within lymphoid organs. Some vaccines directly target APCs in the lymphoid organs, while others rely on APCs migration to the draining lymph nodes after taking up mRNA vaccines. This review explores the current mechanistic understanding of these processes and the ongoing efforts to improve vaccine safety and efficacy based on this understanding.

Effect of Chloride Incorporation on the Intermediate Phase and Film Morphology of Methylammonium Lead Halide Perovskites

The influence of chloride integration on perovskite film deposition, encompassing both the structures of intermediate phases and the properties of the final films, was explored. Our methodology involved the fabrication of perovskite intermediate-phase films with varying concentrations of methylammonium chloride (MACl). Subsequently, we conducted an analysis employing X-ray diffraction and Rietveld refinement, incorporating the March-Dollase correction, to gain insights into how chloride-induced intermediate phases impact film morphology. Remarkably, a distinct preferred orientation was observed in the (020) lattice plane perpendicular to the substrate surface, and this orientation was found to be directly correlated to the MACl concentration. This distinctive arrangement of chloride-induced intermediate-phase complexes facilitated controlled crystallization, leading to highly oriented crystals and an improved film morphology. As a consequence, perovskite solar cell devices incorporating chloride-containing methylammonium lead iodide achieved a power conversion efficiency exceeding 20%. These findings suggest a crucial link between the preferred orientation observed in the final chlorine-derived perovskite films and the intermediate-phase structure formed during the initial stages of perovskite formation. These results suggest a profound impact of intermediate phase compositions and crystal structures on perovskite formation, emphasizing the importance of a comprehensive understanding of these factors to enable precise control over ideal structures and the subsequent transformation into high-quality perovskite films.

Impact of compact TiO2 interface modification on the crystallinity of perovskite solar cells

The effect of TiO2 interfacial morphology on perovskite crystallinity was investigated by modifying the micro and nanoscale surface roughness of compact TiO2. While surface treatments of the compact TiO2 layer are recognized as effective strategies to enhance the photovoltaic performance of perovskite solar cells, the discussion regarding the crystallinity of perovskite atop TiO2 has been limited. In this study, we explored the impact of micro and nano scale interface morphology on perovskite crystal formation and its subsequent effects on device performance. Surprisingly, despite the absence of noticeable voids at the interface between the compact TiO2 and perovskite layers, the perovskite crystal morphology exhibited significant improvement following either micro or nanoscale interfacial modification. This enhancement ultimately led to improved photoconversion efficiency and reduced I-V hysteresis. These results emphasize the importance of underlayer surface morphology in the perovskite crystallization and suggest that the presence of grain boundaries within the perovskite layer may also contribute to I-V hysteresis in perovskite solar cells.

Molecular dynamics simulation to reveal the transport mechanism of LiPF6 in ethylene carbonate + dimethylcarbonate binary solvent

This paper presents the molecular dynamics simulation of 1 mol kg-1 LiPF6 in a binary solvent of ethylene carbonate (EC) and dimethylcarbonate, which is a representative electrolyte solution for lithium-ion batteries. The simulation successfully reproduced the diffusion coefficient, ionic conductivity, and shear viscosity as functions of EC content at 300 K, which had been experimentally determined in our previous study. The Yukawa potential was adopted to model intercharge interactions to reduce computational costs, which consequently allowed us to precisely calculate the conductivity and viscosity by directly integrating time-correlation functions without explicitly modeling the molecular polarization. Breaking down microscopic current correlation functions into components revealed that, whereas the cation-anion attractive interaction dominantly impedes the conduction when the EC content is low, it is the cation-cation and anion-anion repulsive interactions that reduce the conductivity at a high EC content. An analysis of the pressure correlations revealed that all components positively contribute to the viscosity in the binary solvent without the electrolyte. On the other hand, negative terms are observed in five out of six cross correlations in the presence of the electrolyte, implying that these correlations negatively contribute to the shear stress and entropy production, both of which are net positive.

Polyplex designs for improving the stability and safety of RNA therapeutics

Nanoparticle-based delivery systems have contributed to the recent clinical success of RNA therapeutics, including siRNA and mRNA. RNA delivery using polymers has several distinct properties, such as enabling RNA delivery into extra-hepatic organs, modulation of immune responses to RNA, and regulation of intracellular RNA release. However, delivery systems should overcome safety and stability issues to achieve widespread therapeutic applications. Safety concerns include direct damage to cellular components, innate and adaptive immune responses, complement activation, and interaction with surrounding molecules and cells in the blood circulation. The stability of the delivery systems should balance extracellular RNA protection and controlled intracellular RNA release, which requires optimization for each RNA species. Further, polymer designs for improving safety and stability often conflict with each other. This review covers advances in polymer-based approaches to address these issues over several years, focusing on biological understanding and design concepts for delivery systems rather than material chemistry.

Comb-structured mRNA vaccine tethered with short double-stranded RNA adjuvants maximizes cellular immunity for cancer treatment

Integrating antigen-encoding mRNA (Messenger RNA) and immunostimulatory adjuvant into a single formulation is a promising approach to potentiating the efficacy of mRNA vaccines. Here, we developed a scheme based on RNA engineering to integrate adjuvancy directly into antigen-encoding mRNA strands without hampering the ability to express antigen proteins. Short double-stranded RNA (dsRNA) was designed to target retinoic acid-inducible gene-I (RIG-I), an innate immune receptor, for effective cancer vaccination and then tethered onto the mRNA strand via hybridization. Tuning the dsRNA structure and microenvironment by changing its length and sequence enabled the determination of the structure of dsRNA-tethered mRNA efficiently stimulating RIG-I. Eventually, the formulation loaded with dsRNA-tethered mRNA of the optimal structure effectively activated mouse and human dendritic cells and drove them to secrete a broad spectrum of proinflammatory cytokines without increasing the secretion of anti-inflammatory cytokines. Notably, the immunostimulating intensity was tunable by modulating the number of dsRNA along the mRNA strand, which prevents excessive immunostimulation. Versatility in the applicable formulation is a practical advantage of the dsRNA-tethered mRNA. Its formulation with three existing systems, i.e., anionic lipoplex, ionizable lipid-based lipid nanoparticles, and polyplex micelles, induced appreciable cellular immunity in the mice model. Of particular interest, dsRNA-tethered mRNA encoding ovalbumin (OVA) formulated in anionic lipoplex used in clinical trials exerted a significant therapeutic effect in the mouse lymphoma (E.G7-OVA) model. In conclusion, the system developed here provides a simple and robust platform to supply the desired intensity of immunostimulation in various formulations of mRNA cancer vaccines.

Acute coronary syndrome due to left main coronary trunk compression 2 months after left atrial auricle clipping: a case report

BACKGROUND

Left atrial auricle (LAA) clipping is a common method of preventing cardiogenic thromboembolism. However, acute coronary syndrome (ACS) has been reported as a fatal complication of LAA clipping. We describe a case of ACS 2 months after LAA clipping.

CASE PRESENTATION

A 33-year-old male with atrial fibrillation was scheduled LAA clipping during aortic valve replacement for congenital aortic bicuspid valve. The surgery went smoothly with no postoperative complications, but he suddenly went into cardiac arrest 2 months later. Emergency coronary angiography and intravascular ultrasonography revealed that compression by the clip of the left main coronary trunk had caused the ACS. Percutaneous coronary intervention with stents was performed, and the clip was removed under general anesthesia.

CONCLUSION

Even in the remote timepoint of LAA clipping, compression of the coronary artery by the clip should be differentiated as a cause of ACS.

Correlation between Mechanical Properties and Collagen Degeneration in Fibrous Tissue

Fibrosis is a disease that causes abnormal accumulation of collagen and other extracellular matrix components. It can lead to organ failure and is responsible for one-third of all deaths worldwide. However, there is no cure for this disease, and the development of minimally invasive therapies is urgently needed. We have previously reported techniques for adjusting the shape and flexibility of fibrous tissue by traction while denaturing it with heat. However, studies comparing heat and traction on fibrous tissue are limited, so this paper examined that. Applying heat and traction to bovine Achilles tendon tissue has been shown to cause the denaturation of collagen molecules to accumulate in the tissue in response to these loads. Heat-induced collagen denaturation was nondirectional and omnidirectional, whereas mechanical stress-induced collagen denaturation was concentrated in the direction of traction. When both heat and traction were applied, collagen denaturation increased more than under a single load, indicating a synergistic effect.

Cap analogs with a hydrophobic photocleavable tag enable facile purification of fully capped mRNA with various cap structures

Starting with the clinical application of two vaccines in 2020, mRNA therapeutics are currently being investigated for a variety of applications. Removing immunogenic uncapped mRNA from transcribed mRNA is critical in mRNA research and clinical applications. Commonly used capping methods provide maximum capping efficiency of around 80-90% for widely used Cap-0- and Cap-1-type mRNAs. However, uncapped and capped mRNA possesses almost identical physicochemical properties, posing challenges to their physical separation. In this work, we develop hydrophobic photocaged tag-modified cap analogs, which separate capped mRNA from uncapped mRNA by reversed-phase high-performance liquid chromatography. Subsequent photo-irradiation recovers footprint-free native capped mRNA. This approach provides 100% capping efficiency even in Cap-2-type mRNA with versatility applicable to 650 nt and 4,247 nt mRNA. We find that the Cap-2-type mRNA shows up to 3- to 4-fold higher translation activity in cultured cells and animals than the Cap-1-type mRNA prepared by the standard capping method.

Phase Control of Organometal Halide Perovskites for Development of Highly Efficient Solar Cells

To develop a highly efficient solar cell using organometal halide perovskites, its microscale structure control is one of the most important factors because the microstructural defects inside the organometal halide perovskite are harmful to charge carrier flow and, thus, degrade device performance. In this study, we confirmed the existence of large physical gaps at the grain boundary in a methylammonium iodide (MAPbI₃, MA = CH₃NH₃) perovskite with transmission electron microscopy (TEM) analysis and revealed that the physical gap prevents charge carrier flow in the MAPbI₃ perovskite. To minimize the physical gap and its negative influences, the grain size of the MAPbI₃ perovskite was optimized by increasing the portion of the cubic phase via microstructural phase control using liquid nitrogen (LN₂). Through microstructural phase control of the MAPbI₃ perovskite, its grain boundaries and physical gap were significantly decreased, and 20.23% power conversion efficiency (PCE) was achieved with a single cation MAPbI₃ perovskite solar cell.

Amide-to-ester substitution as a stable alternative to N-methylation for increasing membrane permeability in cyclic peptides

Naturally occurring peptides with high membrane permeability often have ester bonds on their backbones. However, the impact of amide-to-ester substitutions on the membrane permeability of peptides has not been directly evaluated. Here we report the effect of amide-to-ester substitutions on the membrane permeability and conformational ensemble of cyclic peptides related to membrane permeation. Amide-to-ester substitutions are shown to improve the membrane permeability of dipeptides and a model cyclic hexapeptide. NMR-based conformational analysis and enhanced sampling molecular dynamics simulations suggest that the conformational transition of the cyclic hexapeptide upon membrane permeation is differently influenced by an amide-to-ester substitution and an amide N-methylation. The effect of amide-to-ester substitution on membrane permeability of other cyclic hexapeptides, cyclic octapeptides, and a cyclic nonapeptide is also investigated to examine the scope of the substitution. Appropriate utilization of amide-to-ester substitution based on our results will facilitate the development of membrane-permeable peptides.

Block catiomers with flanking hydrolyzable tyrosinate groups enhance in vivo mRNA delivery via π-π stacking-assisted micellar assembly

Messenger RNA (mRNA) therapeutics have recently demonstrated high clinical potential with the accelerated approval of SARS-CoV-2 vaccines. To fulfill the promise of unprecedented mRNA-based treatments, the development of safe and efficient carriers is still necessary to achieve effective delivery of mRNA. Herein, we prepared mRNA-loaded nanocarriers for enhanced in vivo delivery using biocompatible block copolymers having functional amino acid moieties for tunable interaction with mRNA. The block copolymers were based on flexible poly(ethylene glycol)-poly(glycerol) (PEG-PG) modified with glycine (Gly), leucine (Leu) or tyrosine (Tyr) via ester bonds to generate block catiomers. Moreover, the amino acids can be gradually detached from the block copolymers after ester bond hydrolyzation, avoiding cytotoxic effects. When mixed with mRNA, the block catiomers formed narrowly distributed polymeric micelles with high stability and enhanced delivery efficiency. Particularly, the micelles based on tyrosine-modified PEG-PG (PEG-PGTyr), which formed a polyion complex (PIC) and π-π stacking with mRNA, displayed excellent stability against polyanions and promoted mRNA integrity in serum. PEG-PGTyr-based micelles also increased the cellular uptake and the endosomal escape, promoting high protein expression both in vitro and in vivo. Furthermore, the PEG-PGTyr-based micelles significantly extended the half-life of the loaded mRNA after intravenous injection. Our results highlight the potential of PEG-PGTyr-based micelles as safe and effective carriers for mRNA, expediting the rational design of polymeric materials for enhanced mRNA delivery.

An Amphipathic Structure of a Dipropylglycine-Containing Helical Peptide with Sufficient Length Enables Safe and Effective Intracellular siRNA Delivery

Amphipathic peptides composed of cationic amino acids and hydrophobic amino acids have cell-penetrating ability and are often used as a delivery tool for membrane-impermeable compounds. Small interfering RNA (siRNAs) are one of the delivery targets for such cell-penetrating peptides (CPPs). Cationic CPPs can associate with anionic siRNAs by electrostatic interactions resulting in the formation of nano-sized complexes, which can deliver siRNAs intracellularly. CPPs containing unnatural amino acids offer promising tools to siRNA delivery. However, the detailed structure-activity relationship in siRNA delivery has been rarely studied. In the current study, we designed peptides containing dipropylglycine (Dpg) and explored the cellular uptake and cytotoxicity of peptide/siRNA complexes. The amphipathic structure of the peptides played a key role in complexation with siRNAs and intracellular siRNA delivery. In the amphipathic peptides, cellular uptake of siRNA increased with increasing peptide length, but cytotoxicity was reduced. A peptide containing four Dpg exhibited an effective gene-silencing effect with small amounts of peptides without cytotoxicity in medium containing serum. These findings will be helpful for the design of novel CPPs for siRNA delivery.

Anesthetic management with remimazolam in a patient with Child-Pugh C liver cirrhosis: a case report

BACKGROUND

Remimazolam is a new ultra-short-acting benzodiazepine, and its sedative effect is prolonged in patients with hepatic impairment. This is the first report of remimazolam anesthesia in a patient with Child-Pugh C liver cirrhosis.

CASE PRESENTATION

A 52-year-old female was diagnosed with tongue cancer and scheduled for partial glossectomy. Preoperative examinations revealed Child-Pugh C liver cirrhosis, but the pathogenesis was unknown. We scheduled remimazolam anesthesia because it would stabilize her intraoperative circulation. We managed with a much lower-than-normal dose of remimazolam; even so, the patient required flumazenil to regain consciousness. She was admitted to the intensive care unit, but her consciousness remained clear even after the effect of flumazenil had worn off.

CONCLUSION

We experienced anesthetic management with remimazolam in a patient with Child-Pugh C liver cirrhosis. Even conservative use of remimazolam in patients with severe hepatic dysfunction may result in emergence times that are delayed longer than expected.

Anesthetic management of a patient with subclinical myasthenia gravis who underwent a thymectomy: a case report

Background

Some individuals with subclinical myasthenia gravis (MG) are positive for serum anti-acetylcholine receptor antibodies, without neurological symptoms. There are no anesthetic management guidelines for subclinical MG. We report the anesthetic management of a patient with subclinical MG who underwent a thymectomy.

Case presentation

A 57-year-old female with subclinical MG was scheduled for an extended thymectomy. Anesthesia was induced and maintained with mainly propofol and remifentanil. We administrated the minimum amount of rocuronium with reference to train-of-four (TOF) monitoring when a neuromuscular relaxant is needed. Although the prolonged effect of rocuronium was observed, the TOF ratio had already recovered to 100% before the tracheal extubation. Postoperative analgesia was performed by a continuous epidural infusion of levobupivacaine.

Conclusion

We reported the anesthetic management of a patient with subclinical MG who underwent a thymectomy. Further research is necessary to clarify subclinical MG patients' sensitivity to rocuronium.

Successful management of a patient with preoperative respiratory failure due to a solid giant retroperitoneal tumor: a case report

BACKGROUND

We report the successful preoperative management of respiratory failure in a patient with a solid giant retroperitoneal tumor with a hemodynamic monitoring system and nasal high-flow therapy (NHFT).

CASE PRESENTATION

Twenty days before his scheduled resection of a giant retroperitoneal liposarcoma, a 64-year-old man presented with dyspnea. After admission to our intensive care unit, he received NHFT and hemodynamic therapy using a LiDCOrapid V3™ monitor (Masimo Japan, Tokyo). NHFT and intense diuresis improved his respiratory condition. The tumor resection was performed on the 5th day. He was discharged to the general ward with an oxygen nasal cannula on the second postoperative day. Although preoperative transthoracic echography showed mild aortic regurgitation and moderate mitral regurgitation, the degree of regurgitation had become trivial about 1-month post-surgery.

CONCLUSIONS

A cause of preoperative respiratory failure associated with a giant retroperitoneal tumor might be not only diaphragmatic compression but also heart failure and excess fluid volume.

Trends and outcomes of early rehabilitation in intensive care unit for patients with cardiovascular disease – a cohort study with propensity score-matched analysis

Background

Early rehabilitation in the intensive care unit (ICU), including early mobility therapy, is known to improve the clinical outcomes in patients with critically ill. However, the effectiveness of acute-phase cardiovascular rehabilitation (CR) during ICU treatment have not been thoroughly evaluated in patients with cardiovascular disease (CVD).

Purpose

We aimed to investigate the trends and outcomes of acute-phase CR in the ICU for patients with CVD, including in-hospital and long-term clinical outcomes.

Methods

We reviewed 1948 consecutive patients with CVD admitted to tertiary academic ICU at a university hospital. Patients were arbitrarily assessed by an ICU team consisting of medical and surgical doctors, nurses and physiotherapists within 24 hours after admission to ICU to discover whether their rehabilitation could be initiated according to the specific clinical trial and statement. As clinical characteristics, disease aetiology, comorbid conditions, and ICU treatment were obtained from an electronic database. We evaluated the probability of return to walking independence and return to home as in-hospital clinical outcomes. All patients were followed for five years and investigated all-cause and cardiovascular events after hospital discharge as long-term clinical outcomes. The associations between the implementation of CR during ICU treatment (ICU-CR) and clinical outcomes were evaluated using propensity score-matched analysis with adjustment for clinical characteristics in all matched patients and various subgroups, including aged >65 years, surgical patients, emergency, and length of ICU stay ≥48 hours.

Results

Out of studied patients, 1092 patients received ICU-CR, the number of which positively correlated with year-trend (r=0.986, P<0.001). After propensity score matching with adjustment for clinical characteristics including calendar years, 758 patients were included for analysis (pairs of n=379 ICU-CR and non-ICU-CR). The ICU-CR was significantly associated with a higher probability of return to walking independence (incident rate ratio [IRR], 2.04; 95% confidence interval [CI], 1.77–2.36) and return to home (IRR, 1.22 95% CI, 1.05–1.41). These associations were consistently observed in various subgroups regarding CVD conditions (Figure 1). During the median follow-up periods of 2.6 years, all-cause clinical events and cardiovascular events occurred in 289 patients (38.1%) and 153 patients (20.2%), respectively. The ICU-CR showed significantly lower rates of five-year all-cause and cardiovascular events than non-ICU-CR (hazard ratio [95% CI] for all-cause events and cardiovascular events, 0.71 [0.56–0.89] and 0.69 [0.50–0.95], respectively, Figure 2).

Conclusions

The implementation of acute-phase CR in the ICU increased with year-trend, considered beneficial to improve in-hospital and long-term clinical outcomes in patients with CVD and various subgroups of relatively severe disease conditions.

Funding Acknowledgement

Type of funding sources: None.

Perme ICU Mobility Score as a comprehensive assessment tool of acute-phase rehabilitation is correlated with clinical outcomes in patients after cardiovascular surgery

Background

Early mobility therapy in the intensive care unit (ICU) is widely employed to improve the physical function and prognosis of patients with critically ill. On the other hand, patients who undergo cardiovascular surgery frequently suffer from disabilities after ICU care due to their cardiopulmonary conditions and treatments. However, few studies have reported the procedures and assessments of acute-phase rehabilitation in these patients. Recently, the Perme ICU Mobility Score (Perme Score) was developed as a reliable tool to assess comprehensive mobility status of patients in the ICU. We hypothesised that the Perme Score is a useful tool for assessing the mobility levels in the ICU and predicting clinical outcomes in patients undergoing acute-phase rehabilitation after cardiovascular surgery.

Purpose

To investigate the associations between the Perme Score within the second days after cardiovascular surgery and the patients' clinical outcomes, including physical function and the incidence of clinical events.

Methods

We studied 224 consecutive patients (34.4% female; aged 65±13 years) who were admitted to the ICU of a tertiary academic hospital after cardiac and/or major vascular surgery. Clinical characteristics including patient profiles, comorbidities, surgical details and APACHE II and SOFA scores were evaluated on ICU admission. The Perme Score contains categories on mental status, potential mobility barriers, muscle strength and mobility level, with higher scores indicating greater activity levels in the ICU. We assessed the Perme Score within the second days after the surgery. As a physical function at hospital discharge, we measured the six-minute walk distance (6MWD). The primary endpoint was a composite outcome of the number of all-cause mortality and/or all-cause unplanned readmission. We analysed the associations of the Perme Score with the 6MWD and the incidence of clinical events using multiple regression analysis and multivariate Poisson regression analysis, respectively.

Results

After adjusting for clinical confounding factors, a higher Perme Score was an independent factor of a higher 6MWD (Table 1). During the median follow-up period of 1.3 years, 51 cases of all-cause mortality/readmission occurred in 37 (16.5%) patients, with an incidence rate of 18.6/100 person-years. In the multivariate Poisson regression analysis, even after adjusting for the severity score in the ICU, a higher Perme Score was significantly and independently associated with lower rates of all-cause clinical events (adjusted incident rate ratio: 0.96, 95% confidence interval: 0.93–0.99, P=0.008, Figure 1).

Conclusions

The Perme Score within the second days after cardiovascular surgery is correlated with physical function at hospital discharge and the incidence of clinical events after discharge. Thus, a comprehensive assessment of acute-phase rehabilitation after cardiovascular surgery may be useful in predicting clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.

Cancer as a risk factor for physical dysfunction and poor prognosis in patients with cardiovascular disease

Introduction

The emerging interdisciplinary field of cardio-oncology is of interest to clinicians because a history of cancer or cancer treatment is considered a severe risk factor for cardiovascular disease (CVD). Both cancer and CVD can reduce skeletal muscle mass; together, they can lead to a poorer prognosis. However, it is unclear whether a patient's cancer history can lower physical function and lead to a poor prognosis with the coexistence of cancer history and physical dysfunction in patients with CVD. This study aimed to identify the relationship between cancer history and physical function, as well as the prognostic value of their combination, in patients with CVD.

Methods

We reviewed 3,640 patients with CVD (mean age, 67.9±13.5 years) who underwent physical-function tests (gait speed and 6-min walking distance [6MWD]). We performed multivariate linear regression analysis to assess potential associations between cancer history and physical-function tests in patients with CVD. Additionally, we used the Kaplan–Meier curve and Cox regression analyses to assess survival and prognostic significance for patients divided into four groups according to the presence or absence of cancer history and high or low physical function.

Results

In multivariate linear regression analysis, cancer history was independently associated with lower gait speed and 6MWD (gait speed, P=0.048 and 6MWD, P=0.040). A total of 581 deaths occurred over a median follow-up period of 3.08 years (interquartile range: 1.36–5.27). For all-cause mortality, patients with a history of cancer and reduced physical function were found to have a significantly higher mortality risk even after adjusting for several covariates (gait speed, HR: 1.66, P=0.003 and 6MWD, HR: 1.71, P=0.003).

Conclusion

Cancer history was correlated with physical dysfunction in patients with CVD. Moreover, the coexistence of cancer history and physical dysfunction resulted in poorer prognosis in patients with CVD.

Funding Acknowledgement

Type of funding sources: None.

Sex differences in frequency of instrumental activities of daily living after cardiac rehabilitation and its impact on long-term mortality in patients with heart failure

Introduction

While the major outcome of cardiac rehabilitation for heart failure (HF) is the improvement of exercise tolerance, prognosis, and quality of life, instrumental activities of daily living (IADL) has also been focused on as one of the its outcomes. IADL has been reported to be associated with all-cause mortality and quality of life in community-dwelling people and in patients with stable heart disease, but no report has examined the relationship between IADL after cardiac rehabilitation for HF and prognosis. In addition, it is assumed that sex differences may affect the frequency of performing each component of IADL, but there are no reports examining the association with prognosis by sex.

Purpose

The present study aimed to investigate the sex differences in frequency of IADL and its impact on outcomes.

Methods

We retrospectively studied 490 consecutive patients who were admitted due to acute decompensated HF and participated in outpatient cardiac rehabilitation after discharge. The study was performed in accordance with the tenets of the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of our institution. IADL frequency was assessed using the questionnaire-based Frenchay Activities Index (FAI). The primary endpoint was all-cause death and secondary endpoint was combined events (all-cause death and/or readmission due to HF). We performed the Kaplan–Meier and log-rank tests and multivariable Cox regression analysis to evaluate the prognostic predictive capability of the FAI.

Results

The study population had a median age of 69 (interquartile range [IQR]: 58–76) years, and 33.9% of patients were females. The median FAI score was 24 (IQR: 16–29) points. According to the Youden index based on the area under the curve calculated by the receiver operating characteristics curve, the cut-off values of FAI for all-cause death in all-over, females, and males were 23, 22, and 23 points, respectively. Over a median follow-up period of 4.8 years (IQR: 2.3–6.6 years), all-cause death and combined events were occurred in 95 (19.4%) and 213 (43.5%), respectively. After adjustment for several pre-existing prognostic factors, IADL assessed by the FAI was independently associated with all-cause mortality (hazard ratio [HR]: 0.961, 95% confidence interval [CI]:0.937–0.986) and combined events (HR: 0.968, 95% CI: 0.952–0.985), respectively. In addition, there was no interaction between sex in prognostic capability (P=0.664).

Conclusion

Lower IADL frequency assessed by FAI at the end of outpatient cardiac rehabilitation was shown to be associated with poorer prognosis in patients with HF, regardless of sex. The IADL level is generally higher in females than in males but seems to be a useful marker for risk stratification at the end of cardiac rehabilitation in both females and males.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid [JSPS KAKENHI Grant Number JP 19K19884]

Impact of small-airway disease on exercise intolerance and long-term outcomes in patients with heart failure and reduced or preserved ejection fraction

Introduction

Exercise intolerance in patients with heart failure (HF) is a strong indicator of a poor prognosis. As the respiratory impairment in HF patients, the small airway is reportedly more susceptible than central airways, which results in increased airway resistance and may cause poor outcomes. However, the impact of small-airway disease (SAD) on exercise intolerance and prognosis in patients with HF is still unclear.

Purpose

We investigated the associations between SAD and exercise intolerance in patients with HF, and the clinical significance of SAD for long-term clinical events with a reduced or preserved ejection fraction.

Methods

We reviewed 1015 patients with HF (mean age, 66.9±14.6 years; male, 64.5%) admitted for medical treatment. Patients with a prior history of chronic respiratory disease or an obstructive lung pattern – defined as the forced expiratory volume (%) in 1 s relative to <70% forced vital capacity using spirometry – were excluded. Characteristics including HF aetiology, comorbidities conditions, medications, blood parameters, and echocardiographic variables were obtained from clinical records. All patients underwent spirometry at hospital discharge, and SAD was defined as the maximum mid-expiratory flow (%) relative to a <60% predicted value. At hospital discharge, we measured 6-min walk distance (6MWD), and <300 m was considered as exercise intolerance. The primary endpoint was a composite clinical event of all-cause death and/or unplanned readmission for HF. Multivariate logistic regression analysis was used to assess the association between SAD and exercise intolerance. The multivariate Cox proportional hazard model was used to clarify whether SAD was an independent predictor for the incidence of clinical events. We also performed subgroup analyses in each multivariate analysis based on a left ventricular ejection fraction (LVEF) of 40%.

Result

SAD was observed in 479 (47.2%) patients. LVEF subgroups included 458 (45.1%) and 518 (51.0%) patients with LVEF <40% and ≥40%, respectively. After adjusting for clinical characteristics, SAD was independently associated with 6MWD <300 m (Figure 1). Moreover, this association was consistently observed in the LVEF <40% and ≥40% (Figure 1). During the median follow-up period of 1.5 years, all-cause death/readmission occurred in 431 patients (42.5%), and the incidence rate was 17.5/100 person-years. In the multivariate Cox proportional hazard model, SAD was independently associated with lower event-free survival rates in all patients and the LVEF <40% subgroup, but not LVEF ≥40% subgroup (Figure 2A, B, and C, respectively).

Conclusion

This study is the first to reveal that SAD is associated with exercise intolerance in patients with HF regardless of LVEF. Moreover, SAD may have a predictive significance for long-term outcomes in patients with HF and subgroups with reduced, but not preserved ejection fraction.

Funding Acknowledgement

Type of funding sources: None.

Bedside insertion of a peripherally inserted central catheter into a patient with BMI of 84.8 kg/m2 using a magnetic tracking and electrocardiogram-based tip confirmation system: a case report

Background

Peripherally inserted central catheters (PICCs) are typically placed under fluoroscopy. We used a magnetic tracking and electrocardiogram-based tip confirmation system for insertion of a PICC insertion in a morbidly obese patient at the bedside.

Case presentation

A 53-year-old female with severe obesity (height, 160 cm; weight, 217 kg; BMI, 84.8 kg/m2) was admitted to the intensive care unit. Both bilateral, inguinal, and cervical regions were covered with an excess of adipose tissue, making it difficult to place a central venous line. Since transferring her to fluoroscopy seemed dangerous, a PICC was inserted using Sherlock 3CG® TCS at the bedside. Magnetic sensor guidance failed due to the thick subcutaneous tissue her precordium, but intracavity electrocardiography could direct the tip to an appropriate position.

Conclusion

We experienced bedside insertion of a PICC into a patient with BMI of 84.8 kg/m2 patient using a Sherlock 3CG® TCS. Since the interaction between Sherlock 3CG® TCS and body habitus has not been investigated, further reports are needed.

Acute normovolemic hemodilution reduced the frequency and amount of perioperative allogeneic blood transfusion in pediatric and adolescent scoliosis surgery: a retrospective observational study

PURPOSE

The aim of the present study is to investigate whether acute normovolemic hemodilution (ANH) can reduce the frequency and amount of perioperative allogeneic blood transfusion (ABT) (intraoperative ABT and postoperative ABT until discharge from the hospital) in pediatric and adolescent scoliosis surgery.

METHODS

This single-center, retrospective, observational study included the perioperative data of 147 patients who were 18 years old or younger and underwent scoliosis surgery. Patients were divided into groups according to whether they received ANH: i.e., an ANH group and control group. Propensity-score-adjusted multivariable logistic regression analysis was performed to determine whether ANH can reduce the frequency of perioperative ABT.

RESULTS

A total of 125 patients were analyzed, 95 and 30 in the ANH and control group, respectively. The intraoperative/postoperative ABT frequency was significantly lower in the ANH group than in the control group (17.9% vs. 36.7%, p = 0.044). The amount of ABT [median (IQR): 0 (0, 0) mL/kg vs. 0 (0, 16.3) mL/kg, p = 0.033] was also significantly lower in the ANH group than in the control group. Propensity-score-adjusted multivariable logistic regression analysis indicated that ANH use [odds ratio: 0.15; 95% confidence interval: 0.03, 0.77; p = 0.023)] was associated with a lower risk of ABT after adjusting for intraoperative blood loss and duration of surgery.

CONCLUSION

ANH use can reduce the frequency and amount of perioperative ABT in pediatric and adolescent scoliosis surgery.

Complete Chemical Synthesis of Minimal Messenger RNA by Efficient Chemical Capping Reaction

Site-specific chemical modification of mRNA can improve its translational efficiency and stability. For this purpose, it is desirable to develop a complete chemical synthesis method for chemically modified mRNA. The key is a chemical reaction that introduces a cap structure into the chemically synthesized RNA. In this study, we developed a fast and quantitative chemical capping reaction between 5'-phosphorylated RNA and N⁷-methylated GDP imidazolide in the presence of 1-methylimidazole in the organic solvent dimethyl sulfoxide. It enabled quantitative preparation of capping RNA within 3 h. We prepared chemically modified 107-nucleotide mRNAs, including N⁶-methyladenosine, insertion of non-nucleotide linkers, and 2'-O-methylated nucleotides at the 5' end and evaluated their effects on translational activity in cultured HeLa cells. The results showed that mRNAs with non-nucleotide linkers in the untranslated regions were sufficiently tolerant to translation and that mRNAs with the Cap_2 structure had higher translational activity than those with the Cap_0 structure.

Relationship between the spread of coronavirus disease 2019, social frailty and depressive symptoms in patients with heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the Japan Society for the Promotion of Science (JSPS) KAKENHI

Background

Owing to the spread of coronavirus disease 2019 (COVID-19), people have refrained from going out unnecessarily and have been maintaining social distance. These new lifestyle approaches have affected people physically, psychologically, and socially. Patients with heart failure (HF) are more likely to have social frailty, physical frailty, cognitive impairment, and depressive symptoms, and an overlap of these conditions leads to adverse events. Therefore, multi-domain assessment and understanding of the condition of patients with HF are important for disease management. The spread of COVID-19 is a predicted risk factor for these events, but its impact in patients with HF has not been investigated.

Purpose

We investigated whether the spread of COVID-19 is associated with the development of the multi-domain of frailty in patients with HF.

Methods

Patients who were independent in their daily activities before admission were included in the study. The presence of social frailty (Makizako’s five items), physical frailty (Fried phenotype model), cognitive impairment (Mini-Cog), and depressive symptoms (the Patient Health Questionnaire-2) in patients with HF were assessed at hospital discharge. Logistic regression analyses were used to examine the impact of the spread of COVID-19 on the development of the multi-domain of frailty in patients with HF.

Results

We included 482 patients in this study. Median patient age was 74 years, and 64.5% were male. In multivariate logistic regression analyses, the spread of COVID-19 was significantly associated with the development of social frailty (odds ratio [OR]: 1.15, 95% confidence interval [CI]: 1.02–1.30) and depressive symptoms (OR: 1.14, 95% CI: 1.02–1.27) but not with the development of physical frailty (OR: 1.24, 95% CI: 0.51–3.02) and cognitive impairment (OR: 1.72, 95% CI: 0.80–3.73).

Conclusion

The spread of COVID-19 was associated with the development of social frailty and depressive symptoms in patients with HF. Evaluation of social frailty and depressive symptoms during hospitalization would support disease management and understand their social and psychological conditions specific to the spread of COVID-19.

Prevalence of metabolic dysfunction-associated fatty liver disease and its association with physical function in patients with acute coronary syndrome

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI

Background

It is widely known that patients with acute coronary syndrome (ACS) are at increased risk of nonalcoholic fatty liver disease (NAFLD), which is linked to sarcopenia and physical dysfunction. However, the relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and physical dysfunction remains unclear.

Purpose

The purpose of this study was to investigate the prevalence of MAFLD in patients with ACS to assess the relationship between MAFLD and muscle strength, walking speed, and 6-minute walking distance (6 MWD).

Methods

We reviewed patients with ACS who were assessed for hepatic steatosis using the fatty liver index, and the results were further assessed to determine the presence of MAFLD. Multiple regression analysis was used to examine the association between MAFLD and physical function.

Results

Among 479 enrolled hospitalized patients, MAFLD was identified in 234 (48.9%) patients. We conducted a multiple regression analysis in which MAFLD was independently associated with lower leg strength, gait speed, and 6 MWD (leg strength, P = 0.023; gait speed, P = 0.002 and 6 MWD, P = 0.017). Furthermore, having more metabolic impairment was still associated with lower physical function decline (leg strength, P for trend = 0.002; gait speed, P for trend = 0.019 and 6 MWD, P for trend = 0.003).

Conclusions

MAFLD is common in hospitalized patients with ACS, and most patients with MAFLD have many overlapping metabolic abnormalities. MAFLD is associated with impaired physical function, and the greater the number of overlapping metabolic abnormalities, the worse the motor function.

Skeletal muscle mass metrics as factors in the prognosis of heart failure patients

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI Grant

Background

Sarcopenia is a chronic condition that is characterized by the loss of skeletal muscle mass with declining muscle strength and/or performance that occurs gradually with aging. It has been reported that sarcopenia is highly prevalent in patients with heart failure (HF) and is a poor prognostic factor. Therefore, it is important to accurately assess skeletal muscle mass in patients with HF. However, there are no reports that have simultaneously examined different skeletal muscle mass metrics as factors in the prognosis of HF patients.

Purpose

The purpose of this study is to examine if the different skeletal muscle mass metrics are associated with the prognosis of HF patients.

Methods

We examined a total of 869 patients with HF, aged ≥20 years (73 [63, 80] years; 537 males), who were admitted to our hospital and participated in an inpatient cardiac rehabilitation program. We used skeletal muscle mass index (SMI) as measured by bioelectrical impedance analysis (BIA), mid-upper arm circumference (MUAC), arm muscle circumference (AMC), and calf circumference (CC) as metrics of skeletal muscle mass. The primary outcome was all-cause deaths, and secondary outcome was HF readmission. To investigate the association between each skeletal muscle mass metric and prognosis, patients were divided into three groups according to the tertiles of SMI, MUAC, AMC, and CC. In addition, cumulative event rates of survival curves, Gray test, and Fine & Gray test were performed to evaluate the prognostic predictive capability.

Results

Over a median follow-up period of 0.9 years (interquartile 0.4–1.9) years, a total of 80 deaths and 195 HF readmissions occurred in the patients. Cumulative event rates of survival curves and Gray test showed that there was a significant decrease in all-cause mortality and HF readmission in the high MUAC group and high AMC group compared to their respective low groups (P < 0.05). Fine & Gray test after multivariate adjustment showed significantly better prognosis in the high MUAC group and high AMC group compared to their respective low groups (All-cause mortality: high MUAC group, subdistribution hazard ratio [sHR] = 0.42, 95% confidence interval [CI] = 0.20-0.88, P < 0.05; high AMC group, sHR = 0.34, 95%CI = 0.16-0.72 P < 0.05, HF readmission: high MUAC group, sHR = 0.69, 95%CI = 0.47-1.00, P < 0.05; high AMC group, sHR = 0.63, 95%CI = 0.43-0.93, P < 0.05).

Conclusion

Patients with HF who maintained high MUAC and high AMC had a good prognosis. CC and SMI were not associated with the prognosis of HF patients. This suggests the importance of evaluating MUAC and AMC in HF patients.

Bridging mRNA and Polycation Using RNA Oligonucleotide Derivatives Improves the Robustness of Polyplex Micelles for Efficient mRNA Delivery

Polyplex for messenger RNA (mRNA) delivery requires strong yet reversible association between mRNA and polycation for extracellular robustness and selective intracellular disintegration. Herein, RNA oligonucleotide (OligoRNA) derivatives that bridge mRNA and polycation are developed to stabilize polyplex micelles (PMs). A set of the OligoRNAs introduced with a polyol moiety in their 5' end is designed to hybridize to fixed positions along mRNA strand. After PM preparation from the hybridized mRNA and poly(ethylene glycol)-polycation block copolymer derived with phenylboronic acid (PBA) moieties in its cationic segment, PBA moieties form reversible phenylboronate ester linkages with a polyol moiety at 5' end of OligoRNAs and a diol moiety at their 3' end ribose, in the PM core. The OligoRNAs work as a node to bridge ionically complexed mRNA and polycation, thereby improving PM stability against polyion exchange reaction and ribonuclease attack in extracellular environment. After cellular uptake, intracellular high concentration of adenosine triphosphate triggers the cleavage of phenylboronate ester linkages, resulting in mRNA release from PM. Ultimately, the PM provides efficient mRNA introduction in cultured cells and mouse lungs after intratracheal administration, demonstrating the potential of the bridging strategy in polyplex-based mRNA delivery.

Delivery Systems of Plasmid DNA and Messenger RNA for Advanced Therapies

The vast potential of non-viral delivery systems of messenger RNA (mRNA) and plasmid DNA (pDNA) has been demonstrated in the vaccines against coronavirus disease 2019 (COVID-19) [...]

Effective mRNA Protection by Poly(l-ornithine) Synergizes with Endosomal Escape Functionality of a Charge-Conversion Polymer toward Maximizing mRNA Introduction Efficiency

For efficient delivery of messenger (m)RNA, delivery carriers need two major functions: protecting mRNA from nucleases and translocating mRNA from endolysosomes to the cytoplasm. Herein, these two complementary functionalities are integrated into a single polyplex by fine-tuning the catiomer chemical structure and incorporating the endosomal escape modality. The effect of the methylene spacer length on the catiomer side chain is evaluated by comparing poly(l-lysine) (PLL) with a tetramethylene spacer and poly(L-ornithine) (PLO) with a trimethylene spacer. Noteworthily, the nuclease stability of the mRNA/catiomer polyplexes is largely affected by the difference in one methylene group, with PLO/mRNA polyplex showing enhanced stability compared to PLL/mRNA polyplex. To introduce the endosomal escape function, the PLO/mRNA polyplex is wrapped with a charge-conversion polymer (CCP), which is negatively charged at extracellular pH but turns positive at endosomal acidic pH to disrupt the endosomal membrane. Compared to the parent PLO/mRNA polyplex, CCP facilitated the endosomal escape of the polyplex in cultured cells to improve the protein expression efficiency from mRNA by approximately 80-fold. Collectively, this system synergizes the protective effect of PLO against nucleases and the endosomal escape capability of CCP in mRNA delivery.

Two cases of circulatory collapse due to suspected remimazolam anaphylaxis

Background

Remimazolam was approved in Japan in January 2020. We report two cases of circulatory collapse due to suspected remimazolam anaphylaxis during anesthetic induction.

Case presentation

Case 1: A 74-year-old male was scheduled for debridement and skin grafting for a severe burn injury. We induced anesthesia with 4 mg of remimazolam and 20 mg of ketamine. The patient subsequently developed treatment-resistant severe hypotension.

Case 2: A 59-year-old male was scheduled for laparoscopic-assisted sigmoid colectomy. We induced anesthesia with 9 mg of remimazolam. Within a few minutes, the patient developed treatment-resistant severe hypotension.

As serum tryptase was elevated in both cases and only intravenous administration of adrenaline was effective, we considered the circulatory collapse might be due to anaphylaxis.

Conclusion

We experienced two cases of circulatory collapse due to suspected remimazolam anaphylaxis during anesthetic induction. The prevalence of remimazolam anaphylaxis is not yet known, and further research is needed.

Microglial Immunoregulation by Apoptotic Cellular Membrane Mimetic Polymeric Particles

Phosphatidylserine (PtdSer), one of the phospholipids that the apoptotic cell exposes, has emerged for anti-inflammatory therapy via polarizing inflammatory microglia (Mi1) to anti-inflammatory phenotype (Mi2). In this study, we report microglia polarization effect of PtdSer-exposing polymeric particles (PSPs). PSPs upregulated Mi2 microglia and suppressed Mi1 microglia through peroxisome proliferator-activated receptor gamma upregulation in vitro and in vivo. This study highlights the potential of PSPs for anti-inflammatory therapy.

Increased plasma drug concentration and decreased additional insulin secretion following oral administration of glimepiride in Spontaneously Diabetic Torii rats

We aimed to evaluate the pharmacokinetics and pharmacological effects of glimepiride in the Spontaneously Diabetic Torii (SDT) rat, which is a non-obese model of type 2 diabetes. After oral administration of glimepiride (10 mg/kg), the maximum plasma concentrations and the area under the curve from 0 to 6 h of glimepiride in SDT rats were significantly higher than those in age-matched Sprague-Dawley rats. Whereas, additional insulin secretion following glimepiride treatment was markedly reduced in SDT rats. Thus, the SDT rat can be regarded as a model that reflects type 2 diabetes with reduced insulin secretory capacity. Our findings suggested that glimepiride could be ineffective in sever type 2 diabetic patients.

Cell-Penetrating Peptides: Emerging Tools for mRNA Delivery

Messenger RNAs (mRNAs) were previously shown to have great potential for preventive vaccination against infectious diseases and therapeutic applications in the treatment of cancers and genetic diseases. Delivery systems for mRNAs, including lipid- and polymer-based carriers, are being developed for improving mRNA bioavailability. Among these systems, cell-penetrating peptides (CPPs) of 4–40 amino acids have emerged as powerful tools for mRNA delivery, which were originally developed to deliver membrane-impermeable drugs, peptides, proteins, and nucleic acids to cells and tissues. Various functionalities can be integrated into CPPs by tuning the composition and sequence of natural and non-natural amino acids for mRNA delivery. With the employment of CPPs, improved endosomal escape efficiencies, selective targeting of dendritic cells (DCs), modulation of endosomal pathways for efficient antigen presentation by DCs, and effective mRNA delivery to the lungs by dry powder inhalation have been reported; additionally, they have been found to prolong protein expression by intracellular stabilization of mRNA. This review highlights the distinctive features of CPP-based mRNA delivery systems.

Enzymatically Transformable Polymersome-Based Nanotherapeutics to Eliminate Minimal Relapsable Cancer

Prevention of metastatic and local-regional recurrence of cancer after surgery remains difficult. Targeting postsurgical premetastatic niche and microresiduals presents an excellent prospective opportunity but is often challenged by poor therapeutic delivery into minimal residual tumors. Here, an enzymatically transformable polymer-based nanotherapeutic approach is presented that exploits matrix metalloproteinase (MMP) overactivation in tumor-associated tissues to guide the codelivery of colchicine (microtubule-disrupting and anti-inflammatory agent) and marimastat (MMP inhibitor). The dePEGylation of polymersomes catalyzed by MMPs not only exposes the guanidine moiety to improve tissue/cell-targeting/retention to increase bioavailability, but also differentially releases marimastat and colchicine to engage their extracellular (MMPs) and intracellular (microtubules) targets of action, respectively. In primary tumors/overt metastases, the vasculature-specific targeting of nanotherapeutics can function synchronously with the enhanced permeability and retention effect to deter malignant progression of metastatic breast cancer. After the surgical removal of large primary tumors, nanotherapeutic agents are localized in the premetastatic niche and at the site of the postsurgical wound, disrupting the premetastatic microenvironment and eliminating microresiduals, which radically reduces metastatic and local-regional recurrence. The findings suggest that nanotherapeutics can safely widen the therapeutic window to resuscitate colchicine and MMP inhibitors for other inflammatory disorders.

A helix foldamer oligopeptide improves intracellular stability and prolongs protein expression of the delivered mRNA

Prolonging the duration of protein expression from mRNA is a major challenge in the development of mRNA nanomedicines. mRNA complexed with helix foldamer oligopeptides consisting of arginine and α-aminoisobutyric acids showed higher intracellular stability than that complexed with oligoarginines, thereby maintaining efficient protein translation for three days.

Hybridization of Bogoliubov Quasiparticles between Adjacent CuO_{2} Layers in the Triple-Layer Cuprate Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{10+δ} Studied by Angle-Resolved Photoemission Spectroscopy

Hybridization of Bogoliubov quasiparticles (BQPs) between the CuO_{2} layers in the triple-layer cuprate high-temperature superconductor Bi_{2}Sr_{2}Cu_{2}Cu_{3}O_{10+δ} is studied by angle-resolved photoemission spectroscopy (ARPES). In the superconducting state, an anticrossing gap opens between the outer- and inner-BQP bands, which we attribute primarily to interlayer single-particle hopping with possible contributions from interlayer Cooper pairing. We find that the d-wave superconducting gap of both BQP bands smoothly develops with momentum without an abrupt jump in contrast to a previous ARPES study. Hybridization between the BQPs also gradually increases in going from the off nodal to the antinodal region, which is explained by the momentum dependence of the interlayer single-particle hopping. As possible mechanisms for the enhancement of the superconducting transition temperature, the hybridization between the BQPs as well as the combination of phonon modes of the triple CuO_{2} layers and spin fluctuations represented by a four-well model are discussed.

Bioinspired Silicification of mRNA-Loaded Polyion Complexes for Macrophage-Targeted mRNA Delivery

In vitro transcribed messenger RNA (mRNA) delivery to macrophages is a promising therapeutic modality for inflammatory diseases because it can modulate the immunological activity of macrophages. However, efficient macrophage-targeted mRNA delivery remains challenging. Herein, we fabricated silica-coated polyion complexes (PICs), termed SilPICs, via bioinspired silicification for stable encapsulation of mRNA and scavenger receptor (SR)-mediated macrophage targeting. Silica coating was readily performed by simply mixing mRNA-loaded PICs with tetramethyl orthosilicate in aqueous media at 25 °C. The silica shell formation was verified by a slight increase in size (∼18 nm), a conversion of ζ-potential from positive (+22 mV) to negative (-23 mV), the peak appearance derived from silanol groups and siloxane bonds in the IR spectra, and elemental analyses by scanning transmission electron microscopy-energy-dispersive X-ray spectrometry (STEM-EDS). The silica shell efficiently protected the mRNA payload from enzymatic degradation in a fetal bovine serum-containing medium. Meanwhile, the reversibility of the silica shell allowed mRNA release from SilPICs after silica dissolution into silicic acids under diluted conditions. Furthermore, SilPICs elicited 20-fold higher mRNA transfection efficiency in the macrophage cell line RAW264.7 compared to noncoated PICs, presumably due to the facilitated cellular internalization by the silica shell. These enhancements were compromised in the RAW264.7 cells incubated with dextran sulfate and poly(inosinic acid) as inhibitors of SR type A1 and were not observed in cultured CT26 colon cancer cells, which are SR-negative cells. Collectively, SilPIC is a promising mRNA delivery vehicle with both mRNA protectability and macrophage targetability.