Browse Articles

Frequency‐Adaptive Elastomers Through Cooperative Dynamics of Liquid‐Crystalline Domains and a Rubber Matrix

ABSTRACT Elastomers are highly suitable for components requiring conformal deformation under load, but their low modulus sensitivity to frequency limits the material's ability to resist dynamic damage. Here we report a phase‐separated elastomer that remains compliant at low loading frequency and stiffens strongly at high frequency, while preserving elastic recovery. The elastomer comprises a carboxylated nitrile rubber (XNBR) matrix and dispersed liquid‐crystalline (LC) domains. Under slow loading, the dispersed phase can relax local stress through mesogen reorientation. In contrast, the same domains become increasingly load‐bearing under faster loading as this motion is constrained. As a result, the modulus of the phase‐separated elastomer increases by 6.2‐fold from 0.01 to 100 Hz, compared with about 2.2‐fold for the neat XNBR. In addition to rate stiffening, the materials retain resilience, low hysteresis, and long‐term dimensional stability, leading to significantly improved resistance to abrasive wear (77.4% reduction in mass loss), repeated impact (83.7% reduction in damaged ratio), and notch propagation (over 30 000 cycles) upon high‐frequency loading, compared with the neat XNBR. These results show that cooperative dynamics between a recoverable rubber matrix and LC domains can provide a useful route to elastomers that combine compliance with adaptive mechanical protection.

Macrocycle‐Based Charge‐Transfer Cocrystals: From Host–Guest Recognition to Multifunctional Solid‐State Materials

ABSTRACT Macrocycle‐based charge‐transfer (CT) cocrystals have recently emerged as a distinctive class of adaptive supramolecular solids that bridge molecular recognition and solid‐state functional materials. Unlike conventional CT assemblies, these systems combine host–guest chemistry with intermolecular donor–acceptor interactions, enabling simultaneous regulation of molecular packing, electronic coupling, and excited‐state processes. The coexistence of cavity‐confined complexation and exo‐wall CT assembly, together with the dynamic nature of host–guest interactions, provides unique opportunities for constructing stimuli‐responsive materials whose structures and functions can be continuously modulated by external inputs. In this Review, we discuss the fundamental principles underlying the design and construction of macrocycle‐based CT cocrystals and highlight how adaptive host–guest recognition governs CT interactions and emergent solid‐state properties. Recent advances in vapochromic sensing, molecular separation, photothermal conversion, luminescence modulation, and multifunctional integrated systems are systematically summarized, with particular emphasis on competitive and cooperative structural regulation mechanisms. Finally, we outline current challenges and future directions toward programmable, multicomponent, and application‐oriented CT materials. By establishing connections between supramolecular structure, CT behavior, and functional output, this Review aims to provide a conceptual framework for the development of next‐generation adaptive molecular solids.

Wafer‐Scale Ultrafine Wrinkle Architectures of TMDCs for Multifunctionality

ABSTRACT Intensely applied strain from wrinkled architecture mitigates intrinsic limitations of 2D materials while enhancing their capabilities through spatially modulated electronic and catalytic properties. Here, this study introduces a deterministic wafer‐scale fabrication strategy that enables densely distributed ultrafine wrinkled architectures in atomically thin molybdenum disulfide (MoS 2 ) crystals, achieving tensile strains up to 3.29% over 50% of the scan area. The wrinkle structures are obtained by modulating the parameters of a wet transfer method, including transfer liquid media, thermal energy, and polystyrene (PS) solution concentrations. Collectively, these results demonstrate a practical route to wafer‐scale fabrication of ultrafine wrinkle structures. The wrinkled MoS 2 (w‐MoS 2 ) exhibits optimal multifunctional device performance in electronics and as a hydrogen evolution catalyst. In a hydrogen evolution reaction (HER), the lowest Tafel slope (52.3 mV dec −1 ) is observed, comparable to that of metallic TMDC catalysts. Furthermore, our w‐MoS 2 memory device displays an on/off ratio of 5 × 10 7 with a large memory window corresponding to 65% of the total gate voltage ( V GS ) sweep range. This simple and innovative morphology engineering offers a viable and reproducible pathway toward high‐performance electronic and catalytic functionalities in highly strained 2D materials.

Anisotropy‐Driven Discovery of Rare‐Earth‐Free Magnets in Mo ₂ FeB ₂ ‐Type Borides

ABSTRACT Multifunctional materials are critically important for modern technologies. Magnets, especially those relevant to spintronic applications, are essential for energy‐efficient data processing and advanced magnetic devices, while high‐strength materials provide excellent mechanical and thermal stability. Mo 2 FeB 2 ‐type materials are well established for their superior strength and thermal properties, yet their magnetic behavior has remained largely theoretical, dominated by antiferromagnets and, more recently, predicted altermagnets. Building on our recent report of spin‐glass phases exhibiting large anisotropy, we have discovered Mo 2 FeB 2 ‐type high‐temperature ferromagnets: Mn‐rich MoMn 2 B 2 and WMn 2 B 2 . These compounds exhibit magnetic ordering above room temperature, with Curie temperatures (and Weiss constants) of 400 K ( θ  = 229 K) and 380 K ( θ  = +154 K), respectively. Notably, rare‐earth‐free WMn 2 B 2 displays enhanced coercivity with an intrinsic coercivity of 67.6 kA m −1 at 5 K, supported by DFT calculations revealing a large in‐plane magnetocrystalline anisotropy energy of +0.27 meV/f.u., driven by the strong spin‐orbit coupling of tungsten. These findings show that Mn‐rich Mo 2 FeB 2 ‐type borides are promising rare‐earth‐free permanent magnet candidates that combine high‐temperature ferromagnetism, enhanced magnetic anisotropy, and excellent structural stability.

Redox‐Ligand‐Coupled Chemical Reprogramming of Battery Waste Into Metal–Organic Electrodes for Closed‐Loop Energy Storage

ABSTRACT Sustainable battery waste management requires moving beyond element recovery toward full‐component reutilization. Here, we report a redox‐ligand‐coupled chemical reprogramming strategy that transforms chemically distinct components of battery waste into functional energy storage materials. Using LiCoO 2 and polyethylene terephthalate (PET) as a model system, terephthalate and ethylene glycol generated from PET depolymerization act synergistically as coordinating ligands, proton sources, and reductants, enabling the dissolution of cathode materials and their in situ reconstruction into a redox‐active metal–organic framework (cobalt terephthalate, CoTPA) under hydrothermal conditions without external leaching agents or reductants. This self‐reinforcing reaction network couples polymer depolymerization with cathode deconstruction, eliminating external reagents and complex separation processes. The resulting CoTPA anode delivers a reversible capacity of ≈1170 mAh g −1 at 0.1 A g −1 , and retains 92.1% of its initial capacity after 500 cycles at 1 A g −1 . When integrated with regenerated graphite (RG), CoTPA enables a battery‐level closed‐loop dual‐ion battery (DIB) with an energy density of 304 Wh kg −1 (based on total active material mass). The strategy is extended to layered oxide cathodes and diverse PET sources. Beyond conventional recycling, this work establishes a chemistry‐driven paradigm that reprograms waste components into value‐added functional materials, offering a scalable pathway toward circular energy storage.

Evolutionary, Functional and Mechanistic Characterisation of Microbial Terpene Synthase‐Like Genes From Springtails

ABSTRACT Despite previous doubts about the origin of terpenes in springtails, a deep bioinformatic analysis of the genomes of 26 springtails surprisingly revealed the presence of many genes coding for microbial‐type terpene synthases. Five candidate enzymes from Sinella curviseta representing different branches of a phylogenetic tree were selected for investigation, four of which were active in in vitro incubations with an enzyme‐dependent substrate selectivity ranging from farnesyl (FPP) to geranylfarnesyl pyrophosphate (GFPP), with formation of multiple products in all cases. The obtained enzyme products included the new macrocycle sestersinellene, the enantiomer of a sesterterpene produced by a terpene synthase from Leucosceptrum canum and the unusual diterpene sinellene ether representing a novel skeleton, reinforcing springtails as an interesting source of terpenes. Extensive isotopic labelling experiments revealed several unusual mechanistic aspects such as the formation of a series of enantiomerically pure products besides one scalemic compound (germacrene D), as well as an unexpected stereochemical course for a reprotonation step in sinellene ether biosynthesis by ScTC2. Taken together, this study lays the foundation for future research on terpene biosynthesis in Collembola, an ancient lineage of arthropods.

Conjugated Thiophene Linker Design of the Self‐Assembled Monolayer Toward Highly Efficient and Stable Organic Solar Cells

ABSTRACT Achieving high power conversion efficiency (PCE) and operational stability remains a critical challenge of organic solar cells (OSCs). While the 2PACz self‐assembled monolayer (SAM) offers suppressed parasitic absorption and facilitated charge collection over the routinely‐used PEDOT:PSS hole‐transport layer (HTL), their operational stability is often limited by the vulnerable chemical structure under high‐energy photon illumination. In this work, we design and synthesize two SAMs, PhPACz and ThPACz, whose flexible alkyl linker between phosphonic acid and carbazole of 2PACz is substituted by rigid phenyl or thiophene to manipulate the HOMO and LUMO orbitals and further mediate the electron density distribution of SAM, thereby promoting charge delocalization at the interface and enhancing photochemical stability. The ThPACz SAM delivers suppressed oxygen defects on the ITO surface and largely enhanced the bond dissociation energy at the vulnerable C‐N bond (from 72.2 kcal/mol in 2PACz to 97.3 kcal/mol in ThPACz), translating to a champion efficiency of 20.5% in D18:L8‐BO binary OSCs, alongside a significantly extended T 80 lifetime (over 7 times) under either visible or 365 nm UV light, outperforming the 2PACz based benchmark. This study underscores the critical role of conjugated linkers in designing high‐performance, stable SAMs for next‐generation OSCs.

Direct Synthesis of Well‐Defined Epoxide‐Terminated Telechelic Polymers via an Alcohol‐Mediated Self‐Switching Strategy

ABSTRACT The one‐step synthesis of well‐defined telechelic polymers represents a highly attractive approach, providing an efficient alternative to conventional stepwise synthetic protocols. However, achieving such control remains challenging due to the competitive nature of chain propagation and end‐group functionalization, which often leads to uncontrolled chain‐end structures and broad dispersities. Here, we report an alcohol‐mediated self‐switching strategy, in which the dominant chain‐end reaction shifts from propagation to end‐group functionalization upon consumption of one monomer component within a single reaction system. Using epichlorohydrin, a multisite monomer, as a model for the ring‐opening alternating copolymerization with cyclic anhydrides, we obtained well‐defined epoxide‐terminated telechelic polyesters with narrow dispersities ( Đ ∼ 1.1), high end‐group fidelity (>99%), and controllable linear, three‐arm, and four‐arm architectures under alcohol‐mediated conditions. Mechanistic studies reveal that monomer activation and stabilization of the living species through hydrogen‐bonding interactions, combined with the zero‐order kinetics of cyclic anhydride, facilitate rapid propagation while suppressing premature functionalization. Subsequent intramolecular cyclization of β‐chlorohydrin living chain ends, along with proton‐transfer‐induced dehydrochlorination of β‐chlorohydrin dormant chain ends, collectively ensure quantitative epoxide end‐group formation. These results elucidate the catalyst‐like roles of alcohol and establish self‐switching of competing chain‐end reactions as a practical strategy for the direct synthesis of well‐defined telechelic polymers.

Porous COF@cMOF Heterojunction‐Assisted Laser Desorption/Ionization Mass Spectrometry for Enhanced Breast‐Cancer Serum Metabolomic Screening

ABSTRACT Early breast‐cancer (BC) screening requires reliable molecular information from minimally invasive samples, yet sensitive detection of small‐molecule metabolites in complex biofluids remains challenging. Herein, a structurally well‐defined porous heterojunction matrix, COF316@CuHHTP, is developed through an in situ epitaxial‐growth strategy for serum metabolomic screening. Porous and chemically robust COF316 serves as the core scaffold, while conductive CuHHTP forms a coherent shell for interfacial charge mediation. The resulting heterojunction enables efficient small‐molecule capture and directional transport through the channels, while enhanced photothermal conversion and optimized charge transport collectively improve desorption/ionization efficiency and sensitivity for small‐molecule metabolites. Consequently, COF316@CuHHTP enables sensitive and robust laser desorption/ionization mass spectrometry (LDI‐MS) analysis, with the maximum signal‐to‐noise (S/N) enhancement reaching ∼194‐fold, ultralow limits of detection (LODs) down to the pmol level, and strong tolerance to high‐salt and protein‐rich conditions. Applied to serum analysis, this platform enables BC diagnosis with excellent discriminatory performance (AUC = 0.996) and identifies 20 disease‐associated metabolic signatures.

Goutam Ghosh

Vertically Oriented Calixarene Self‐Assembled Monolayers Enable Efficient Tin‐Based Perovskite Solar Cells

ABSTRACT Self‐assembled monolayers (SAMs) represent an effective strategy for optimizing buried interfacial quality in tin‐based perovskite solar cells (TPSCs). Nevertheless, conventional SAMs often suffer from severe molecular agglomeration, deteriorating interface quality, and tend to adopt a “lying‐down” configuration on hole transport layers, leading to a reduced vertical dipole component and limited ability to tune mismatched energy level alignment. Herein, a multifunctional SAM, 4‐sulfocalix[6]arene (SC6A), is introduced to simultaneously regulate the buried interface and optimize band alignment in TPSCs. Owing to six anchoring sulfonate groups, SC6A forms robust multidentate interactions with NiO x , enabling homogeneous interfacial coverage and improved perovskite film growth. Meanwhile, SC6A possesses a large intrinsic molecular dipole and preferentially adopts a vertical orientation, which maximizes the effective dipole component normal to the interface, induces favorable band alignment, and accelerates charge extraction. As a result, TPSCs with SC6A exhibit a power conversion efficiency (PCE) of 16.46%. TPSCs with SC6A maintain 98% of their initial PCE after 980 h of shelf storage. Furthermore, the TPSC with SC6A maintains 90% of its initial PCE after 300 h of continuous operation under 1‐sun illumination, whereas the control device reaches the same retention level after only 146 h, demonstrating enhanced long‐term operational stability.

Moisture‐Responsive Ion‐Coupling Networks in Molecularly Engineered MoS ₂ Channels for Enhanced Ion Transport

ABSTRACT Classical nanofluidic ion transport predominantly relies on fixed surface charges for selectivity. However, such static‐charge systems are fundamentally limited by an “immobilization effect”; the deep energy wells required for ion recruitment inevitably hinder subsequent release, stifling continuous transport kinetics. Herein, we report a paradigm‐shifting dynamic ion‐coupling mechanism mediated by surface‐anchored counter‐ions that establish transient, moisture‐responsive coordination with mobile species. By decorating angstrom‐scale 2D molybdenum disulfide (MoS 2 ) channels with single‐site Pb 2+ , we create a molecularly engineered interface that facilitates rapid ion hopping. This strategy flattens the migration energy landscape and decouples ion entry from release, circumventing the inherent trade‐off in traditional fixed‐charge membranes. Our biomimetic approach achieves an extraordinary 30‐fold enhancement in ionic current compared to pristine channels. Leveraging these dynamic interactions, we demonstrate a humidity‐driven energy generator delivering a record‐high power density of 532.8 µW cm − 2  at ∼75% RH, significantly surpassing state‐of‐the‐art technologies. These findings establish dynamic ion coupling as a powerful blueprint for advancing molecular iontronics, self‐powered sensing, and next‐generation energy conversion.

Intracellular Delivery of Hydrophilic Glycans Using Superchaotropic Clusters

ABSTRACT The intracellular delivery of glycans is a significant challenge. Glycan delivery is typically achieved by per‐acetylation necessitating the use of the cytotoxic carrier solvent DMSO, or complex nanoscale delivery devices, to transit across the cell membrane. Here we deploy superchaotropic boron clusters to unlock solvent‐free intracellular delivery of azido‐glycans, as well as trehalose. The cluster B 12 Br 12 2– delivered glycans into suspension and adherent cells, enabling successful metabolic oligosaccharide labelling and bioconjugation of glycoproteins, cell surface glycans, and also glycosylated‐RNA. This approach offers a practical and operationally simple solution to the challenge of glycan intracellular delivery and removes the cytotoxic impact of solvents.

Decoupling Ion Transport and Desolvation via Spatially Heterogeneous Solvation Structure for Wide‐Temperature Sodium‐Ion Batteries

ABSTRACT Despite competitive room‐temperature performance, sodium‐ion batteries suffer from sluggish kinetics and unstable interphases at ultralow temperatures. Herein, a single‐ether (diethylene glycol dibutyl ether, DGDE)‐based electrolyte featuring a spatially heterogeneous solvation structure across both the bulk and interfacial regions is successfully constructed by introducing a strongly polar sulfonate ester additive, 2,2,2‑trifluoroethyl trifluoromethanesulfonate (TTMS). In the bulk, DGDE chelates Na + via its multiple coordination sites to form a solvent‑separated ion pair dominated solvation structure, thereby enhancing ion dissociation and ionic conductivity. At the electrode–electrolyte interface, TTMS preferentially adsorbs onto the cathode surface, reconstructing the electric double layer into a compact, anion‐rich configuration dominated by contact ion pairs and aggregates. Meanwhile, TTMS in the inner Helmholtz plane provides desolvation‐active sites, lowering the charge‐transfer barrier and enabling the formation of a robust, inorganic‐rich interphase. This spatially heterogeneous solvation structure enables the decoupling of fast bulk ion transport and rapid interface desolvation. Consequently, at −40°C, the Na||NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cell with the optimized electrolyte delivers an initial specific capacity of 109.9 mAh g −1 and sustains reversible cycling for 140 cycles with a capacity retention of 87.3%. Moreover, the cell demonstrates reliable electrochemical operation over a wide‐temperature range from −60°C to 55°C.

Dopant‐Tailored Matrices: A Crystal Engineering Strategy for Organic Room‐Temperature Phosphorescent Host–Guest Systems and Beyond

ABSTRACT Host–guest doping of molecular crystals is a powerful strategy to tune optoelectronic properties, yet achieving precise host–dopant compatibility and beneficial synergy without introducing detrimental effects caused by dopant‐induced disorders remains challenging. Here, a new crystal engineering strategy is introduced in which host matrices are rationally designed to accommodate a predefined class of dopants and promote favorable host–guest interactions. This tailored‐dopant matrix concept is demonstrated for dopant‐induced organic room‐temperature phosphorescence (RTP) using carbazole‐based matrices and benzoindole‐based dopants, a prototypical RTP system. Guided by the hypothesis that a herringbone packing of carbazole units promotes synergistic structural interactions with the dopant, a multiscale theoretical methodology is first developed to elucidate the intermolecular interactions stabilizing this motif in pristine carbazole‐based crystals. These insights enable the design and synthesis of new host architectures exhibiting the targeted packing arrangement. Ultimately, the resulting single‐crystalline host–guest materials exhibit long‐lived organic RTP, with phosphorescence lifetimes of several hundred milliseconds. This work could establish dopant‐tailored crystal engineering as a potential new paradigm for designing functional doped organic semiconductor crystals with tailored optoelectronic properties.

Epitaxial Oxide Interfaces Create Poison‐Resistant CuO Sites for Environmental Catalysis

ABSTRACT Real exhaust streams rarely contain a single pollutant: NO x coexists with volatile organic compounds (VOCs) in flue gas from petrochemical production, chemical manufacturing, and waste incineration, yet catalysts that couple NH 3 ‐SCR with VOC oxidation typically suffer competitive adsorption, sulfur poisoning, and HCN byproduct formation. Here we engineer an epitaxially stabilized CuO overlayer on Ti 1‐x In x O 2 that breaks the activity–selectivity–stability constraint by creating electron‐poor, high‐symmetry Cu–O sites and activating lattice‐oxygen redox at the oxide–oxide interface. Interfacial strain and charge transfer increase Cu–O covalency and Lewis acidity, accelerating NO x reduction via an Eley–Rideal pathway while diverting sulfate deposition away from Cu. Concurrently, interface‐activated lattice oxygen sustains deep oxidation of CH 3 SH (a representative S‐VOC) through a Mars–van Krevelen cycle, suppressing HCN. Epitaxial interfaces thus offer a general route to poison‐resistant multipollutant catalysis.

An In Vivo Single‐Vesicle Electrochemistry Enables Monitoring Vesicular Dopamine Dynamics and Pharmacological Rescue

ABSTRACT Direct single vesicle‐resolved quantification of neurotransmitter storage and exocytotic dynamics in an intact living vertebrate nervous system has remained elusive. Here, we establish an in vivo single‐vesicle electrochemistry platform in anesthetized living zebrafish larvae, enabling quantification of vesicular dopamine (DA) loading and quantal release dynamics in the intact neural system. By combining intracellular vesicle impact electrochemical cytometry and single‐cell amperometry, we directly measure vesicular cargo and exocytotic release in dopaminergic neuron soma of the ventral diencephalon at single‐vesicle resolution. Pharmacological validation with a DA elevation drug confirmed the sensitivity and robustness of the approach. Application of this platform to a chemical‐induced Parkinsonian model revealed pronounced reductions in vesicular DA content, altered release patterns, and impaired exocytotic dynamics. Rasagiline treatment partially restored vesicular DA storage and release dynamics toward physiological levels, suggesting a protective modulation of vesicle function. This in vivo electrochemical method offers a single vesicle‐resolved analytical platform for dissecting vesicular heterogeneity and dysfunction directly in intact neural systems, thereby bridging single‐vesicle chemistry with in vivo neurobiology and opening new avenues for mechanistic studies of neurodegeneration and therapeutic intervention.

Polyfluorinated‐Regulator‐Assisted Scaffold‐Directed Tilted 1D/3D Heterointerfaces for High‐Voltage and Stable Perovskite Solar Cells

ABSTRACT Protective low‐dimensional interphases can improve perovskite solar‐cell stability, but they often compromise charge extraction because of unfavorable interfacial packing and transport barriers. Herein, we report a scaffold‐directed strategy to construct an interwoven tilted 1D/3D heterointerface on inverted perovskite absorbers. By depositing PbI 2 onto a tilt‐oriented 3D perovskite scaffold and inducing solvent‐assisted reconstruction, a compact near‐surface interphase composed of edge‐sharing 1D PbI 2 and face‐sharing 1D δ ‐FAPbI 3 is formed with an oblique orientation guided by the crystallographic texture of the underlying 3D framework. Unlike conventional laterally aligned low‐dimensional overlayers, this tilted 1D interphase preserves out‐of‐plane interfacial connectivity while providing a robust barrier against defect propagation and ion migration. We further identify 7F‐EA‐HI, a flexible polyfluorinated ammonium iodide, as an effective crystallization regulator that suppresses reconstruction‐induced defects and favorably modulates interfacial energetics through its large molecular dipole. As a result, the optimized inverted PSCs deliver a power conversion efficiency (PCE) of 24.94%, with an open‐circuit voltage ( V OC ) of 1.188 V, a short‐circuit current density ( J SC ) of 24.67 mA cm −2 , and a fill factor (FF) of 85.11%, along with markedly improved ambient and thermal stability. This work demonstrates tilted 1D/3D interfacial engineering as a viable route toward high‐voltage and durable perovskite optoelectronics.

Chloride‐Driven Interfacial Confinement Facilitates Adaptive Directional Electron Transfer in Hypersaline Environments

ABSTRACT Chloride ions (Cl − ) are conventionally regarded as inhibitory species in hypersaline wastewater treatment, where they cause active‐site shielding, radical scavenging, and catalyst deactivation. Contrary to this established view, we demonstrate that Cl − can transform from a passive inhibitor into an active interfacial regulatory species. We show that rather than suppressing reactivity, Cl − can reconfigure the confined solid‐liquid interface to modulate charge‐transfer kinetics and facilitate mass transport, establishing a new catalytic pathway. Herein, we report a Cl − ‐driven directional coordination strategy that combines the Cl − species with the catalyst interface and oxidant to construct an adaptive electron transfer channel (AETC). Multi‐scale experiments, density functional theory (DFT) calculations, and molecular dynamics simulations reveal that the Cl − ‐driven coordination changes internal electronic interactions, modulates orbital hybridization with the oxidant, and adjusts the interfacial hydrogen‐bonding network. This AETC alleviates mass‐transfer constraints and suppresses catalytic deactivation, enabling accelerated degradation kinetics alongside long‐term stability. Overall, this work challenges the traditional perception of Cl − , demonstrating that Cl − can drive constructive interfacial functions in extreme ionic environments.

Retinoic‐Acid‐Derived Ionizable Lipids Enable Spleen‐Selective Antigen Expression for mRNA Cancer Vaccination

ABSTRACT Effective mRNA cancer vaccination requires productive antigen expression in lymphoid antigen‐presenting cells rather than high total antigen output. Here, we report a retinoic‐acid‐inspired ionizable lipid platform for spleen‐selective functional mRNA expression. Systematic variation of the ionizable scaffold, linker architecture, and retinoid‐derived hydrophobic domain generated a modular 40‐member library of retinoic‐acid‐derived ionizable lipids (RAILs). Paired in vitro and in vivo screening identified AT4‐13CRA LNPs as the lead formulation, with the highest spleen‐to‐liver reporter‐expression ratio and approximately 15.1‐fold higher splenic expression than the tested Dlin‐MC3/18PA selective organ targeting (SORT) formulation. Enhanced reporter expression was not explained by total cellular uptake alone and was accompanied by reduced lysosomal mRNA retention and attenuated TNF‐α/NF‐κB‐associated activation. Serum‐corona proteomics revealed an immunoglobulin heavy‐chain‐ and J‐chain‐associated profile distinct from the apolipoprotein‐associated profile of 18PA‐containing SORT LNPs. In Ai9 reporter mice and an OVA mRNA vaccination model, AT4‐13CRA LNPs promoted functional expression in splenic macrophages and dendritic cells, enhanced antigen‐specific CD8 + T‐cell and antibody responses, and improved prophylactic protection against B16F10‐OVA tumor challenge. These findings establish retinoid‐derived hydrophobic‐domain engineering as a chemically defined route to spleen‐selective, inflammation‐restrained, antigen‐presenting‐cell‐centered mRNA cancer vaccination.