Polar groups promoting in-situ polymerization phase separation for solid electrolytes enabling solid-state lithium batteries.

Plastic-crystal-embedded elastomer electrolytes (PCEEs), produced through polymerization-induced phase separation (PIPS), are gaining popularity as solid polymer electrolytes (SPEs). However, it remains to be investigated whether all monomer molecules can achieve polymerization-induced phase separation and the corresponding differences in lithium metal battery performance. Herein, we prepared PCEEs with different functional groups (OH, CN, F) through in situ polymerization. Research findings show that PCEE containing - CN or - F achieves the separation of the plastic crystalline phase and succinonitrile (SN) phase, whereas PCEE containing OH cannot due to hydrogen bonding with the SN phase. Notably, the PCEE synthesized with the F monomer (FBA-PCEE) exhibited exceptional interfacial stability with lithium metal anodes and lithium iron phosphate (LFP) cathodes, due to its unique coordination mechanism with lithium ions. The FBA-PCEE demonstrated a high ionic conductivity (2.02 × 10-3 S cm-1) and lithium-ion migration number ( [Formula: see text]  = 0.75). Moreover, lithium symmetric cells incorporating FBA-PCEE demonstrated stable cycling performance for more than 1000 h at a current density of 0.1 mA cm-2, resulting in the development of a solid electrolyte interphase (SEI) rich in LiF, Li3N, and Li2CO3 over time. Additionally, incorporating FBA-PCEE facilitated the stable cycling of LPF over 1000 cycles at 0.5C, maintaining a capacity retention of 77.38 % after 500 cycles. When coupled with high-voltage Nickel Cobalt Manganese Oxide (NCM-622) cathodes and lithium metal anodes, a discharge capacity of 119.70 mAh g-1 at 0.1C was sustained after 100 cycles, exhibiting a capacity retention of 78.95 %. This study elucidates the critical role of monomer design in achieving PIPS, offering valuable insights into developing high-performance polymer composite electrolytes for advanced lithium metal batteries.

The effect of charge screening for cationic surfactants on the rigidity of interfacial nanoparticle assemblies.

HYPOTHESIS: Functionalizing colloidal particles with oppositely charged surfactants is crucial for stabilizing emulsions, foams, all-liquid structures, and bijels. However, surfactants can reduce the attachment energy, the driving force for colloidal self-assembly at interfaces. An open question remains on how the inherent interfacial activity of cationic surfactants influences the interfacial rigidity of particle-laden interfaces. We hypothesize that charge screening among cationic surfactants regulates the rigidity of oil/water interfaces by reducing the attachment energy of nanoparticles. EXPERIMENTS: We investigate the interfacial rigidity of cetyltrimethylammonium bromide (CTAB) functionalized silica nanoparticles (Ludox® TMA) by analyzing the shape deformation of 1,4-butanediol diacrylate (BDA) droplets under varying salt and alcohol concentrations. The nanoparticle packing density is assessed using scanning electron microscopy. Attachment energy is characterized through interfacial tension measurements, three-phase contact angle analysis, and CTAB adsorption studies. We also examine the effects of interfacial rigidities on the structure of bijel films formed via roll-to-roll solvent transfer-induced phase separation (R2R-STrIPS) using confocal laser scanning microscopy. FINDINGS: Increasing salt and alcohol concentrations decrease the interfacial rigidity of CTAB-functionalized nanoparticle films by reducing the interfacial tension. The contact angle has a minor influence on the rigidity. These results indicate that CTAB charge screening weakens the nanoparticle attachment energy to the interface. Controlling the rigidity enables the mass production of bijel sheets with consistent flatness, which is crucial for their potential applications in catalysis, energy storage, tissue engineering, and filtration membranes.

Three-Dimensional Simulation of Whole-Genome Structuring Through the Transition from Anaphase to Interphase.

In order to analyze the three-dimensional genome architecture, it is important to simulate how the genome is structured through the cell cycle progression. In this chapter, we present the usage of our computation codes for simulating how the human genome is formed as the cell transforms from anaphase to interphase. We do not use the global Hi-C data as an input into the genome simulation but represent all chromosomes as linear polymers annotated by the neighboring region contact index (NCI), which classifies the A/B type of each local chromatin region. The simulated mitotic chromosomes heterogeneously expand upon entry to the G1 phase, which induces phase separation of A and B chromatin regions, establishing chromosome territories, compartments, and lamina and nucleolus associations in the interphase nucleus. When the appropriate one-dimensional chromosomal annotation is possible, using the protocol of this chapter, one can quantitatively simulate the three-dimensional genome structure and dynamics of human cells of interest.

DNA Sensor ABCF1 Phase Separates With cccDNA to Inhibit Hepatitis B Virus Replication.

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) contributes to viral persistence and recurrence, however, how the host innate immune system responds to cccDNA is still less known. Here, based on cccDNA-hepatic proteins interaction profiling, DNA sensor ATP-binding cassette subfamily F member 1 (ABCF1) is identified as a novel cccDNA-binding protein and host restriction factor for HBV replication. Mechanistically, ABCF1 recognizes cccDNA by KKx4 motif and forms phase-separated condensates by the poly-glutamine (PolyQ) region of the N-terminal intrinsically disordered low-complexity domain (LCD). Subsequently, ABCF1-cccDNA phase separation not only activates the type I/III interferon (IFN-I/III) pathway but also prevents Pol II accumulation on cccDNA to inhibit HBV transcription. In turn, to sustain viral replication, HBV reduces ABCF1 expression by HBx-mediated ubiquitination and degradation of SRY-box transcription factor 4（SOX4）, leading to defects in SOX4-mediated upregulation of ABCF1 transcription. Taken together, the study shows that ABCF1 interacts with cccDNA to form phase separation that dually drives innate immune signaling and HBV transcriptional inhibition. These findings shed new light on the understanding of host defense against cccDNA and provide a novel promising therapeutic strategy for HBV infection.

Non-hygroscopic ionogel-based humidity-insensitive iontronic sensor arrays for intra-articular pressure sensing.

Implanted pressure sensors can provide pressure information to assess localized health conditions of specific tissues or organs, such as the intra-articular pressure within knee joints. However, the prerequisites for implanted sensors pose greater challenges than those for wearables or for robots: aside from biocompatibility and tissue-like softness, they must also exhibit humidity insensitivity and high-pressure resolution across a broad pressure spectrum. Iontronic sensors can provide superior sensing properties, but they undergo property degradation in wet environments due to the hygroscopic nature of their active component: ionogels. Herein, we introduce a humidity-insensitive iontronic sensor array based on a hydrophobic and tough ionogel polymerized in a hydrophobicity transition yielding two hydrophobic phases: a soft liquid-rich phase that enhances ionic conductivity and ductility, and a stiff polymer-rich phase that contributes to superior toughness. We demonstrate the in vivo implantation of these sensor arrays to monitor real-time intra-articular pressure distribution in a sheep model, while assessing knee flexion with an angular resolution of 0.1° and a pressure resolution of 0.1%. We anticipate that this sensor array will find applications in various orthopedic surgeries and implantable medical devices.

Impact of Porosity and Stiffness of 3D Printed Polycaprolactone Scaffolds on Osteogenic Differentiation of Human Mesenchymal Stromal Cells and Activation of Dendritic Cells.

Despite the potential of extrusion-based printing of thermoplastic polymers in bone tissue engineering, the inherent nonporous stiff nature of the printed filaments may elicit immune responses that influence bone regeneration. In this study, bone scaffolds made of polycaprolactone (PCL) filaments with different internal microporosity and stiffness was 3D-printed. It was achieved by combining three fabrication techniques, salt leaching and 3D printing at either low or high temperatures (LT/HT) with or without nonsolvent induced phase separation (NIPS). Printing PCL at HT resulted in stiff scaffolds (modulus of elasticity (E): 403 ± 19 MPa and strain: 6.6 ± 0.1%), while NIPS-based printing at LT produced less stiff and highly flexible scaffolds (E: 53 ± 10 MPa and strain: 435 ± 105%). Moreover, the introduction of porosity by salt leaching in the printed filaments significantly changed the mechanical properties and degradation rate of the scaffolds. Furthermore, this study aimed to show how these variations influence proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBMSC) and the maturation and activation of human monocyte-derived dendritic cells (Mo-DC). The cytocompatibility of the printed scaffolds was confirmed by live-dead imaging, metabolic activity measurement, and the continuous proliferation of hBMSC over 14 days. While all scaffolds facilitated the expression of osteogenic markers (RUNX2 and Collagen I) from hBMSC as detected through immunofluorescence staining, the variation in porosity and stiffness notably influenced the early and late mineralization. Furthermore, the flexible LT scaffolds, with porosity induced by NIPS and salt leaching, stimulated Mo-DC to adopt a pro-inflammatory phenotype marked by a significant increase in the expression of IL1B and TNF genes, alongside decreased expression of anti-inflammatory markers, IL10 and TGF1B. Altogether, the results of the current study demonstrate the importance of tailoring porosity and stiffness of PCL scaffolds to direct their biological performance toward a more immune-mediated bone healing process.

PARP1 condensates differentially partition DNA repair proteins and enhance DNA ligation.

Poly(ADP-ribose) polymerase 1 (PARP1) is one of the first responders to DNA damage and plays crucial roles in recruiting DNA repair proteins through its activity - poly(ADP-ribosyl)ation (PARylation). The enrichment of DNA repair proteins at sites of DNA damage has been described as the formation of a biomolecular condensate. However, it remains unclear how exactly PARP1 and PARylation contribute to the formation and organization of DNA repair condensates. Using recombinant human single-strand repair proteins in vitro, we find that PARP1 readily forms viscous biomolecular condensates in a DNA-dependent manner and that this depends on its three zinc finger (ZnF) domains. PARylation enhances PARP1 condensation in a PAR chain length-dependent manner and increases the internal dynamics of PARP1 condensates. DNA and single-strand break repair proteins XRCC1, LigIII, Polß, and FUS partition in PARP1 condensates, although in different patterns. While Polß and FUS are both homogeneously mixed within PARP1 condensates, FUS enrichment is greatly enhanced upon PARylation whereas Polß partitioning is not. XRCC1 and LigIII display an inhomogeneous organization within PARP1 condensates; their enrichment in these multiphase condensates is enhanced by PARylation. Functionally, PARP1 condensates concentrate short DNA fragments, which correlates with PARP1 clusters compacting long DNA and bridging DNA ends. Furthermore, the presence of PARP1 condensates significantly promotes DNA ligation upon PARylation. These findings provide insight into how PARP1 condensation and PARylation regulate the assembly and biochemical activities of DNA repair factors, which may inform on how PARPs function in DNA repair foci and other PAR-driven condensates in cells.

Liquid-liquid phase separation-related signature predicts prognosis and therapeutic response in esophageal adenocarcinoma.

BACKGROUND: Esophageal adenocarcinoma is a leading cause of mortality worldwide. New evidence indicates that liquid-liquid phase separation is related to malignancies. The current study aims at exploring the functions of liquid-liquid phase separation within esophageal adenocarcinoma. Patients within the TCGA dataset were classified using liquid-liquid phase separation-related genes. Significantly differentially expressed genes and prognostic factors for overall survival have been screened by Cox regression. Based on the liquid-liquid phase separation score, the construction of a prognostic model and liquid-liquid phase separation signature was constructed. Tumor mutation burden and drug sensitivity were analyzed in two groups: high liquid-liquid phase separation scores, and low liquid-liquid phase separation scores. According to liquid-liquid phase separation, some small-molecule compounds targeting esophageal adenocarcinoma were screened. The results were verified in vitro with an external cohort. RESULTS: 87 samples are involved, and 61 liquid-liquid phase separation-related genes may influence esophageal adenocarcinoma by changing DNA conformation and metabolism. Meanwhile, based on a high liquid-liquid phase separation score and low score group including 43 patients, it is found that the result significantly lowered the 5-year overall survival to 32.6 %, compared to 64.8 % in the low-score group of 44 patients with p < 0.001. The high score group had an average TIDE score of 0.27 versus 0.14 in the low-score group, with p = 0.003. The median tumor mutation burden was 9.1 mutations/Mb in the high-score group versus 6.4 mutations/Mb in the low-score group, with p = 0.011. The predictive model worked very well, with area under the curve values of 0.82, 0.79, and 0.76 for 1-, 3-, and 5-year survival, respectively. Liquid-liquid phase separation has been validated as an effective prognostic biomarker and drug sensitivity predictor. SIGNIFICANCE: Liquid-liquid phase separation is potentially implicated in esophageal adenocarcinoma and works as a prognostic biomarker assessment of vulnerability to LLPS, which could help develop individualized therapies by showing how one is situated about various medications where responses vary across the body.

YTHDF2 phase separation promotes arsenic-induced keratinocyte transformation in a poly-m6A-dependent manner by inhibiting translational initiation of the key tumor suppressor PTEN.

The phase separation of N6-methyladenosine (m6A) binding protein YTHDF2 plays a vital role in arsenic-induced skin damage, and YTHDF2 can bind to m6A-methylated mRNA of tumor suppressor PTEN. However, whether and how YTHDF2 phase separation regulates PTEN involved in arsenic-induced malignant transformation of keratinocytes remains blank. Here, we established arsenite-induced transformation models with stable expression of wild-type YTHDF2 or mutant YTHDF2 protein in vitro and in vivo. We found that the YTHDF2 protein underwent phase separation during arsenite-induced malignant transformation of keratinocytes, and YTHDF2 phase separation promoted the malignant phenotype of keratinocytes. Mechanically, YTHDF2 phase separation reduced PTEN protein levels, which in turn activated the pro-survival AKT signal. The binding of YTHDF2 to multiple m6A sites on PTEN mRNA drove YTHDF2 phase separation, inhibiting PTEN translation initiation and thus reducing PTEN protein levels. YTHDF2 phase separation recruited translation-initiation-factor kinase EIF2AK1 to phosphorylate eIF2α, thereby inhibiting translation initiation of poly-m6A-methylated PTEN mRNA. Furthermore, arsenite-induced oxidative stress triggered YTHDF2 phase separation by increasing m6A levels of PTEN mRNA. Our results demonstrated that YTHDF2 phase separation promotes arsenite-induced malignant transformation by inhibiting PTEN translation in a poly-m6A-dependent manner. This study sheds light on arsenic carcinogenicity from the novel aspect of m6A-mediated YTHDF2 phase separation.

Temperature-Governed Microstructure of Poly(vinyl alcohol) Hydrogels Prepared through Mixed-Solvent-Induced Phase Separation.

The formation of phase-separated structures in hydrogels plays a crucial role in determining their optical and mechanical properties. Traditionally, phase-separated hydrogels are prepared through a two-step process involving initial hydrogel synthesis followed by post-treatment. In this study, we present an approach for temperature-governed phase separation microstructure modulation in hydrogels, harnessing the cononsolvency effect. This method allows the phase-separated structure to develop during hydrogel synthesis, significantly simplifying the preparation process. Importantly, we found that the preparation temperature has a substantial effect on the internal structure of the phase-separated hydrogel. We systematically investigated how the temperature influences the phase structure, optical properties, and mechanical performance of these hydrogels. The resulting hydrogels demonstrate excellent moisturizing and antifreezing capabilities. Additionally, the incorporation of sodium chloride imparts remarkable electrical conductivity to the hydrogels, making them suitable for strain sensing applications across a wide temperature range.

Kindlin-2 Phase Separation in Response to Flow Controls Vascular Stability.

BACKGROUND: Atheroprotective shear stress preserves endothelial barrier function, while atheroprone shear stress enhances endothelial permeability. Yet, the underlying mechanisms through which distinct flow patterns regulate EC integrity remain to be clarified. This study aimed to investigate the involvement of Kindlin-2, a key component of focal adhesion and endothelial adherens junctions crucial for regulating endothelial cell (EC) integrity and vascular stability. METHODS: Mouse models of atherosclerosis in EC-specific Kindlin-2 knockout mice (Kindlin-2iΔEC) were used to study the role of Kindlin-2 in atherogenesis. Pulsatile shear (2±4 dynes/cm2) or oscillatory shear (0.5±4 dynes/cm2) were applied to culture ECs. Live-cell imaging, fluorescence recovery after photobleaching assay, and optoDroplet assay were used to study the liquid-liquid phase separation (LLPS) of Kindlin-2. Co-immunoprecipitation, mutagenesis, proximity ligation assay, and transendothelial electrical resistance assay were used to explore the underlying mechanism of flow-regulated Kindlin-2 function. RESULTS: We found that Kindlin-2 localization is altered under different flow patterns. Kindlin-2iΔEC mice showed heightened vascular permeability. Kindlin-2iΔEC were bred onto ApoE-/- mice to generate Kindlin-2iΔEC; ApoE-/- mice, which displayed a significant increase in atherosclerosis lesions. In vitro data showed that in ECs, Kindlin-2 underwent LLPS, a critical process for proper focal adhesion assembly, maturation, and junction formation. Mass spectrometry analysis revealed that oscillatory shear increased arginine methylation of Kindlin-2, catalyzed by PRMT5 (protein arginine methyltransferase 5). Functionally, arginine hypermethylation inhibits Kindlin-2 LLPS, impairing focal adhesion assembly and junction maturation. Notably, we identified R290 of Kindlin-2 as a crucial residue for LLPS and a key site for arginine methylation. Finally, pharmacologically inhibiting arginine methylation reduces EC activation and plaque formation. CONCLUSIONS: Collectively, our study elucidates that mechanical force induces arginine methylation of Kindlin-2, thereby regulating vascular stability through its impact on Kindlin-2 LLPS. Targeting Kindlin-2 arginine methylation emerges as a promising hemodynamic-based strategy for treating vascular disorders and atherosclerosis. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02783300.

Self-stratification and phase separation in drying binary colloidal films.

HYPOTHESIS: Films that develop compositional heterogeneity during drying offer a promising approach for achieving tailored functionalities. These functionalities can be realized by strategically directing different components during the drying process. One approach to achieve this is through spontaneous size segregation of colloidal particles. Two variants thereof have previously been observed in binary suspensions: layer formation (self-stratification) due to kinetically driven concentration gradients, and micro-domain formation (phase separation) due to thermodynamic depletion interactions between the small and large species. Surprisingly, in the context of binary colloidal films, these phenomena have never been investigated concurrently during evaporation. EXPERIMENTS: We show how we can achieve both self-stratification and domain formation in a single step. Using real-time 3D confocal fluorescence microscopy, we quantitatively unravel the effects of various parameters on the emergence of compositional heterogeneity. FINDINGS: We reveal that beyond a certain size ratio, micro-phase separation becomes a prominent mechanism dictating the final morphology. The initial volume fraction minimally affects the final domain size but significantly impacts self-stratification. Reducing the evaporation rate increases the domain size while minimizing stratification. Finally, reducing the colloidal electrostatic interaction by a small increase in salt concentration enhances phase separation yet reverses stratification. These findings unveil a strategy for harnessing two distinct size segregation mechanisms in a single film, forming a foundation for customizable self-partitioning coatings.

Mechanical and Dimensional Stability of Gelatin-Based Hydrogels Through 3D Printing-Facilitated Confined Space Assembly.

Hydrogels have emerged as promising biomaterials for tissue regeneration; yet, their inherent swelling can cause deformation and reduced mechanical properties, posing challenges for practical applications in biomedical engineering. Traditional methods to reduce hydrogel swelling often involve complex synthesis procedures with limited flexibility. Inspired by nature's efficient designs, we present here the approach to improve hydrogel performance using 3D printing-assisted microstructure engineering. By utilizing polymerization-induced phase separation of hydrogel from copolymerization of gelatin methacrylate and hydroxyethyl methacrylate (poly(GelMA-co-HEMA)) in the confined space during vat photopolymerization (VPP) 3D printing, we replicate the cuttlebone-like microstructure of hydrogels with enhanced mechanical properties and swelling resistance. We demonstrate here a 4-fold increase in elastic modulus compared to bulk polymerization of poly(GelMA-co-HEMA), together with improved mechanical and dimensional stability. This method offers promising opportunities for practical biomedical and tissue engineering applications, overcoming previous limitations in the design and performance.

A two-task predictor for discovering phase separation proteins and their undergoing mechanism.

Liquid-liquid phase separation (LLPS) is one of the mechanisms mediating the compartmentalization of macromolecules (proteins and nucleic acids) in cells, forming biomolecular condensates or membraneless organelles. Consequently, the systematic identification of potential LLPS proteins is crucial for understanding the phase separation process and its biological mechanisms. A two-task predictor, Opt_PredLLPS, was developed to discover potential phase separation proteins and further evaluate their mechanism. The first task model of Opt_PredLLPS combines a convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM) through a fully connected layer, where the CNN utilizes evolutionary information features as input, and BiLSTM utilizes multimodal features as input. If a protein is predicted to be an LLPS protein, it is input into the second task model to predict whether this protein needs to interact with its partners to undergo LLPS. The second task model employs the XGBoost classification algorithm and 37 physicochemical properties following a three-step feature selection. The effectiveness of the model was validated on multiple benchmark datasets, and in silico saturation mutagenesis was used to identify regions that play a key role in phase separation. These findings may assist future research on the LLPS mechanism and the discovery of potential phase separation proteins.

JMJD1C forms condensates to facilitate a RUNX1-dependent gene expression program shared by multiple types of AML cells.

JMJD1C, a member of the lysine demethylase 3 (KDM3) family, is universally required for the survival of several types of acute myeloid leukemia (AML) cells with different genetic mutations, representing a therapeutic opportunity with broad application. Yet how JMJD1C regulates the leukemic programs of various AML cells is largely unexplored. Here we show that JMJD1C interacts with the master hematopoietic transcription factor RUNX1, which thereby recruits JMJD1C to the genome to facilitate a RUNX1-driven transcriptional program that supports leukemic cell survival. The underlying mechanism hinges on the long N-terminal disordered region of JMJD1C, which harbors two inseparable abilities: condensate formation and direct interaction with RUNX1. This dual capability of JMJD1C may influence enhancer-promoter contacts crucial for the expression of key leukemic genes regulated by RUNX1. Our findings demonstrate a previously unappreciated role for the non-catalytic function of JMJD1C in transcriptional regulation, underlying a mechanism shared by different types of leukemias.

Phase Separation Mediated Sub-Nuclear Compartmentalization of Androgen Receptors.

The androgen receptor (AR), a member of the nuclear steroid hormone receptor family of transcription factors, plays a crucial role not only in the development of the male phenotype but also in the development and growth of prostate cancer. While AR structure and AR interactions with coregulators and chromatin have been studied in detail, improving our understanding of AR function in gene transcription regulation, the spatio-temporal organization and the role of microscopically discernible AR foci in the nucleus are still underexplored. This review delves into the molecular mechanisms underlying AR foci formation, focusing on liquid-liquid phase separation and its role in spatially organizing ARs and their binding partners within the nucleus at transcription sites, as well as the influence of 3D-genome organization on AR-mediated gene transcription.

Nucleoporin Nsp1 surveils the phase state of FG-Nups.

Transport through the nuclear pore complex (NPC) relies on intrinsically disordered FG-nucleoporins (FG-Nups) forming a selective barrier. Away from the NPC, FG-Nups readily form condensates and aggregates, and we address how this behavior is surveilled in cells. FG-Nups, including Nsp1, together with the nuclear transport receptor Kap95, form a native daughter cell-specific cytosolic condensate in yeast. In aged cells, this condensate disappears as cytosolic Nsp1 levels decline. Biochemical assays and modeling show that Nsp1 is a modulator of FG-Nup condensates, promoting a liquid-like state. Nsp1's presence in the cytosol and condensates is critical, as a reduction of cytosolic levels in young cells induces NPC defects and a general decline in protein quality control that quantitatively mimics aging phenotypes. These phenotypes can be rescued by a cytosolic form of Nsp1. We conclude that Nsp1 is a phase state regulator that surveils FG-Nups and impacts general protein homeostasis.

Dissolution of copovidone-based amorphous solid dispersions: Influence of atomic layer coating, hydration kinetics, and formulation.

Atomic layer coating (ALC) is an emerging, solvent-free technique to coat amorphous solid dispersion (ASD) particles with a nanolayer ceramic coating that has been shown to improve powder characteristics and limit drug crystallization. Herein, we evaluate the impact of aluminum oxide coatings with varying thickness and conformality on the release behavior of ritonavir/copovidone ASDs. Release performance of powders, neat tablets, and formulated tablets was studied. Confocal fluorescence microscopy (CFM) was used to visualize particle hydration and phase separation during immersion of the ASD in aqueous media. CFM revealed particle hydration requires defects for solvent penetration, but coatings, regardless of thickness, had minor impacts on powder dissolution provided defects were present. In tablets where less surface area is exposed to the dissolution media due to gel formation, slowed hydration kinetics resulted in phase separation of the drug from the polymer in coated samples, limiting release. Formulation with two superdisintegrants, crospovidone and croscarmellose sodium, as well as lactose achieved ∼90% release in less than 10 minutes, matching the uncoated ASD particles of the same formulation. This study highlights the importance of hydration rate, as well as the utility of confocal fluorescence microscopy to provide insight into release and phase behavior of ASDs.

Light-induced cryptochrome 2 liquid-liquid phase separation and mRNA methylation.

Light is essential not only for photosynthesis but also for the regulation of various physiological and developmental processes in plants. While the mechanisms by which light regulates transcription and protein stability are well established, the effects of light on RNA methylation and their subsequent impact on plant growth and development are less understood. Upon exposure to blue light, the photoreceptor cryptochromes form nuclear speckles or nuclear bodies, termed CRY photobodies. The CRY2 photobodies undergo light-induced homo-oligomerization and liquid-liquid phase separation (LLPS), which are crucial for their physiological activity. Recent studies have proposed that blue light-induced CRY2 LLPS increases the local concentration or directly enhances the biochemical activities of RNA N6-methyladenosine (m6A) methyltransferases, thus, to regulate circadian clock and maintain Chl homeostasis through processes of RNA decay or translation. This review aimed to elucidate the functions of CRY2 and LLPS in RNA methylation, focusing on the light-controlled reversible phase transitions regulon and the outstanding questions that remain in RNA methylation.

RNA G-quadruplexes form scaffolds that promote neuropathological α-synuclein aggregation.

Synucleinopathies, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, are triggered by α-synuclein aggregation, triggering progressive neurodegeneration. However, the intracellular α-synuclein aggregation mechanism remains unclear. Herein, we demonstrate that RNA G-quadruplex assembly forms scaffolds for α-synuclein aggregation, contributing to neurodegeneration. Purified α-synuclein binds RNA G-quadruplexes directly through the N terminus. RNA G-quadruplexes undergo Ca2+-induced phase separation and assembly, accelerating α-synuclein sol-gel phase transition. In α-synuclein preformed fibril-treated neurons, RNA G-quadruplex assembly comprising synaptic mRNAs co-aggregates with α-synuclein upon excess cytoplasmic Ca2+ influx, eliciting synaptic dysfunction. Forced RNA G-quadruplex assembly using an optogenetic approach evokes α-synuclein aggregation, causing neuronal dysfunction and neurodegeneration. The administration of 5-aminolevulinic acid, a protoporphyrin IX prodrug, prevents RNA G-quadruplex phase separation, thereby attenuating α-synuclein aggregation, neurodegeneration, and progressive motor deficits in α-synuclein preformed fibril-injected synucleinopathic mice. Therefore, Ca2+ influx-induced RNA G-quadruplex assembly accelerates α-synuclein phase transition and aggregation, potentially contributing to synucleinopathies.