Complex Surface Research Articles

Facile Preparation of Magnetic Chitosan Carbon Based on Recycling of Iron Sludge for Sb(III) Removal

In this study, following the concept of “treating waste with waste”, magnetic chitosan carbon (MCC) was developed through the pyrolysis of chitosan/iron sludge (CHS) beads created using an embedding method in a closed environment for antimony removal. The results indicate MCC has a good magnetic recovery rate and that its magnetic saturation strength can reach 33.243 emu/g. The iron proportion and acid resistance of MCC were all better than those of CHS, and at 25 °C, its adsorption saturation capacity improved from 24.956 mg/g to 38.234 mg/g. MCC has a quick adsorption equilibrium time, and in about 20 min, 90% of the final equilibrium capacity can be achieved. The primary mechanism of Sb adsorption by MCC is the formation of an inner sphere complex between Fe-O and Sb, while surface complexation, hydrogen bonding, and interaction also play a function. Thus, MCC, a lower-cost and greener adsorbent for Sb removal, has been made using iron sludge. This enabled it to utilize iron sludge as a resource and served as a reference for the sustainable management of water treatment residuals.

Highly stretchable and strain sensitive MXene/MXene:MWCNTs@TPU fiber with hierarchical conductive layers and porous elastic core structure

Fiber flexible strain sensors have the characteristics of small volume, light weight, good flexibility, easy deformation/recovery, and easy weaving. They can conform to various complex surfaces and endure various deformations, such as twisting and bending. Furthermore, the simple preparation process of fiber sensors lowers the production cost significantly. These features make them promising candidates for applications in motion monitoring, human-machine interface, and flexible intelligent products. However, the low sensitivity and narrow sensing range of existing sensors are still major challenges for their further development. To address these challenges, this paper proposes a MXene/MXene:MWCNTs@TPU fiber sensor, which adopts a two-step pre-stretching strategy to modify the porous TPU fiber surface with MXene and MWCNTs. The graded porous TPU fibers obtained by wet spinning can achieve 805 % stretching, providing a reliable substrate support for the fiber sensor, the combination of multi-dimensional conductive materials and the introduction of cracks and wrinkles enhance the sensitivity 277 and sensing range 510 % of the fiber sensor. The fiber sensor can detect various human motions and gestures by directly attaching to the skin or weaving into textiles, and can also be applied to information encryption transmission, demonstrating its huge potential in human health monitoring, intelligent flexible electronic products and encrypted communication.

The Stabilizing Effect of Chitosan‐Modified Biochar (β‐CD/C‐BC) on Agricultural Soil Contaminated by the Cd‐Pyr Complex

AbstractThe composite pollution of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in agricultural soil is increasingly severe. HMs can undergo surface adsorption, complexation, or chemical reactions to transform from bioavailable species to residual species, achieving chemical morphological stability. However, these processes have no effect on PAHs. Biochar (BC), due to its inherent characteristics, can significantly enhance the stability of PAHs and is recommended as a potential co‐stabilizing material for both heavy metals and PAHs. In this study, rice husk biochar modified with β‐cyclodextrin and chitosan (β‐CD/C‐BC) was utilized to stabilize agricultural soil contaminated by Cd and Pyrene (Pyr). One‐way tests were conducted on the dosage and curing time of biochar after a complete cycle of treatment. The results demonstrated that the optimal effect was achieved when the dosage of β‐CD/C‐BC was 7.5 % or the curing time was 21 days. The removal efficiencies for Cd and Pyr were found to be 84.62 %, 64.22 % or 85.90 %, 65.78 %, respectively. Additionally, BCR testing revealed that β‐CD/C‐BC could convert HMs in soil into a residual state (from 32 % to 82 %) with the highest stabilization rate, thereby reducing their migration ability and ecological risk.

Effects of Fe(II) and humic acid on U(VI) mobilization onto oxidized carbon nanofibers derived from the pyrolysis of bacterial cellulose

The effects of Fe(II) and humic acid on U(VI) immobilization onto oxidized carbon nanofibers (Ox-CNFs, pyrolysis of bacterial cellulose) were investigated by batch, spectroscopic and modeling techniques, with results suggesting that, Ox-CNFs exhibited fast adsorption rate (adsorption equilibrium within 3 h), high adsorption performance (maximum adsorption capacity of 208.4 mg/g), good recyclability (no notable change after five regenerations) in the presence of Fe(II) towards U(VI) from aqueous solutions (e.g., 40 % reduction and 10 % adsorption at pH 8.0), which was attributed to the various oxygen-containing functional groups, excellent chemical stability, large specific surface area and high redox effect. U(VI) adsorption increased with increasing pH from 2.0 to 5.0, then high-level plateau and remarkable decrease were observed at 5.0–6.0 and at pH > 6.0, respectively. According to FT-IR and XPS analysis, a negative correlation between U(VI) reduction and organic in the presence of Fe(II) implied that U(VI) reduction was driven by Fe(II) while inhibited by humic acid. The interaction mechanism of U(VI) on Ox-CNFs was demonstrated to be adsorption and ion exchange at low pH and reduction at high pH according to XPS and surface complexation modeling. These findings filled the knowledge gaps pertaining to the effect of Fe(II) on the transformation and fate of U(VI) in the actual environment. This carbon material with distinctive performance and unique topology offers a potential platform for actual application in environmental remediation.

Monitoring of copper adsorption on biochar using spectral induced polarization method

Copper contaminant generated from mining and industrial smelting poses potential risks to human health. Biochar, as a low-energy and cost-effective biomaterial, holds value in Cu remediation. Spectral Induced Polarization (SIP) technique is employed in this study to monitor the Cu remediation processes of by biochar in column experiments. Cation exchange at low Cu2+ concentrations and surface complexation at high Cu2+ concentrations are identified as the major mechanisms for copper retention on biochar. The normalized chargeability (mn) from SIP signals linearly decreased (R2 = 0.776) with copper retention under 60 mg/L Cu influent; while mn linearly increases (R2 = 0.907, 0.852) under high 300 and 700 mg/L Cu influents. The characteristic polarizing unit sizes (primarily the pores adsorbing Cu2+) calculated from Schwartz equation match well with experimental results by mercury intrusion porosimetry (MIP). It is revealed that Cu2+ was driven to small pores (∼3 μm) given high concentration gradient (influent Cu2+ concentration of 700 mg/L). Comparing to activated carbon, biochar is identified as an ideal adsorbent for Cu remediation, given its high adsorption capacity, cost-effectiveness, carbon-sink ability, and high sensitivity to SIP responses – the latter facilitates its performance assessment.

Towards greener water remediation: Ca-impregnated pyro-hydrochar of spent mushroom substrate for enhanced adsorption of acridine red and methylene blue

Sustainable solutions for environmental remediation are of great interest due to the escalated release of toxic substances into the ecosystem. Here, Ca-impregnated pyro-hydrocarbon (Ca-SMS) was synthesized from spent mushroom substrate (SMS) via hydrothermal carbonization at a relatively low process temperature, followed by subsequent physicochemical activation. Ca-SMS underwent characterization using various analytical techniques, and its efficacy in removing acridine red (AR) and methylene blue (MB) was assessed through batch experiments. The results suggested that Ca-SMS is an effective adsorbent for AR and MB, visiting a removal capacity of 33.82 and 81.98 mg g−1 at 35 °C, respectively. The kinetic investigation uncovered that the dye removal process mostly agreed with the pseudo-second-order (PSO), while the Langmuir and Freundlich models were the most suitable to describe the removal of dyes. Thermodynamic analyses showed that the remediation process is spontaneous and endothermic. Adsorption mechanisms among dyes and Ca-SMS were multiple: physical adsorption, surface complexation, electrostatic, and π-π interaction. The feasibility of the proposed method for real sample treatment was demonstrated. These findings indicate that Ca-SMS is an effective alternative sorbent for the remediation of textile wastewater and is a viable solution for waste reduction in the rising mushroom cultivation sector.

Investigating the electron-scale adsorption mechanisms using DFT calculations and experimental studies in self-assembly magnetic biochar gel incorporated with graphene nanosheets for enhanced Sb(III) removal

Environmental contamination posed by trivalent antimony [Sb(III)] in water has been globally recognized as a complex challenge, garnering considerable public concern. To enhance the adsorption efficiency of pristine biochar (BC) for Sb(III), a novel Fe/graphene-loaded biochar (FeGB) gel was synthesized through a facile in-situ self-assembly method. This study aimed to investigate the adsorption performance and elucidate the electron-scale adsorption mechanism for Sb(III) by the FeGB-gel. The Sb(III) adsorption isotherm data fitted well with the Langmuir model, and the maximum Sb(III) adsorption capacity of FeGB-gel (113.1 mg g−1) was significantly higher compared to that of BC (28.6 mg g−1). Spectroscopic investigations revealed that surface complexation and π–π stacking were the key mechanisms for Sb(III) adsorption. Electrochemical analyses confirmed an enhanced electron-accepting capacity (0.815 mmol e- g−1) of FeGB-gel, linked to the formation of Fe-related functional groups (Fe–O and Fe–O–OH), which contributed to a stronger Sb(III) oxidation capacity than BC (78.5% v.s. 49.3%). Density functional theory calculations highlighted that the presence of defects on graphene nanosheets enhanced the anchoring of FeOx on biochar, thereby elevating the Sb(III) adsorption energy of FeGB-gel to −1.96 eV. Additionally, the projected density of states profile suggested that the enhanced adsorption of FeGB-gel could be attributable to the orbital hybridization of Sb-p, O-p, and Fe-p/d orbitals (i.e., Fe–O–Sb bonding), which strengthened the electron transfer and chemical interaction during the Sb(III) removal process. The functionalization of biochar surface characteristics with Fe/graphene offers possibilities for a diverse range of biochar-based adsorbents and their application in addressing numerous environmental concerns.

Application of flame-formed carbon nanoparticle films for ethanol sensing

Carbon nanoparticles (CNPs) have received considerable attention due to their exceptional qualities and adaptability. Their unique physical and chemical characteristics make them extremely intriguing as materials for numerous high-potential applications, such as electronics and gas sensing. This study focused on producing carbon-based nanomaterial devices by deposition of flame-formed carbon nanoparticles on a suitable substrate and investigating their gas-sensing properties. CNPs were produced in a fuel-rich laminar premixed ethylene/air flame and the collected CNP film was morphologically and electrically characterized. The electrical conductivity of the film was investigated as a function of ethanol concentration and amount of deposited material. Notably, CNP films exhibited high sensitivity to ambient ethanol gas concentrations, and rapid recovery times at room temperature, and showed a sensitivity increasing with the amount of deposited material and the surface complexity. Our findings demonstrate the high potential of combustion-generated CNPs as building materials for low-cost and portable ethanol sensors.

Research on efficient removal of ciprofloxacin through sequential rice straw biochar modification via alkali activation and manganese oxides

Biochar is considered an environmentally friendly and cost-effective option for removing antibiotics from aqueous solutions. In this study, biochar derived from rice straw (RBC) was sequentially modified by KMnO4 and NaOH (Mn/Na-RBC) to achieve ciprofloxacin (CIP) removal. To explore the adsorption mechanisms between Mn/Na-RBC and CIP, the characterization analyses, adsorption isotherms, thermodynamics, and kinetics were investigated. The results revealed that Mn/Na-RBC significantly increased the specific surface area (154.12 m2·g–1), carbonization, and the number of oxygen-containing functional groups compared with pristine biochar, thereby substantially enhancing the CIP adsorption capacity. Through fitting of the adsorption model, it was found that the highest adsorption capacity was 32.25 mg·g–1 under acidic conditions (pH=3), and the pseudo-second-order and Freundlich model fit the adsorption behavior well. The main mechanisms of the adsorption process were pore filling, electrostatic interaction, H-bonding, π–π conjugation, n–π interaction and surface complexation. Moreover, the Mn/Na-RBC still exhibited a remarkable capacity to selectively adsorb CIP even in the presence of high ionic strengths. Thus, Mn/Na-RBC is a promising adsorbent for removing emerging contaminants from aquatic environments.

Enhanced adsorption of polystyrene nanoplastics by cetyltrimethylammonium bromide surface-modified magnetic rice straw biochar: Efficient performance and adsorption mechanisms

Nanoplastics, characterized by their small size, high diffusion, and stability, have attracted wide attention worldwide as a new potentially threatening pollutant. In this study, magnetic rice straw biochar modified with cetyltrimethylammonium bromide (CTAB) was prepared and utilized for the adsorption removal of polystyrene nanoparticles (PSNPs, <100 nm). The characteristics and adsorption performance of CTAB modified magnetic biochar (MBC-CTAB) were systematically investigated using characterization techniques and batch adsorption experiments. The grafting of alkyl chains onto the biochar surface through surfactant modification improved the surface activity and adsorption capacity of the magnetic biochar towards nanoplastics. Moreover, the application of an external magnetic field facilitated the rapid separation and recovery of MBC-CTAB. MBC-CTAB exhibited a removal efficiency of 99.56 % for 20 mg/L PSNPs, with a maximal adsorption capacity of 54.07 mg/g at 298 K. The presence of anions such as HPO42− and CO32− as well as dissolved organic compounds like humic acid creates significant competition between PSNPs, thereby inhibiting the adsorption capacity of MBC-CTAB towards PSNPs. The mechanism of MBC-CTAB for nanoplastics adsorption can be attributed to electrostatic interaction, hydrophobic interactions, pore filling, and surface complexation. This study demonstrates the feasibility of using surfactant-modified biochar for the adsorption of nanoplastics, providing a promising option for the development of new pollutant treatment technologies and the mitigation of the adverse impacts of nanoplastics on the environment and ecosystems.

Speciation controls on Ni adsorption to birnessite and organo-birnessite

Nickel (Ni) is an essential micronutrient for phytoplankton. Its importance to both the modern and ancient Earth system has encouraged development of Ni and its isotopes as biogeochemical tracers. To interpret these signatures however, understanding of how Ni and its isotopes are recorded in marine archives is required. Here we simulate different inorganic and organic Ni species in seawater and investigate their adsorption behaviours to variably crystalline phyllomanganates and organo-mineral phyllomanganate. We conduct pH adsorption edge experiments to determine the binding affinity of the different Ni species to the minerals and then perform desorption experiments to operationally define Ni bonding strength. We also use thermodynamic surface complexation modelling to constrain Ni adsorption mechanisms. From the adsorption edges and stability constants generated from our modelling, the binding affinity increases in the order of Ni-formate+ (aq) < NiCl+ (aq) < Ni2+ (aq). From the desorption experiments, desorption at pH 8 is non quantitative and increases in the opposite order of Ni-formate+ (aq) > NiCl+ (aq) ∼ Ni2+ (aq). For the organo-mineral however, Ni desorption at pH 8 is non quantitative and similar for all three experiments, and is significantly higher compared to the variably crystalline phyllomanganates. Although both our adsorption and desorption experiments were performed over 48 h, it is possible that desorption is somewhat slower than adsorption such that a longer desorption period may result in further Ni loss to solution and thus greater adsorption reversibility. Taken together however, the Ni-formate+ (aq) and Ni organo-birnessite desorption experiments suggest that Ni bonding strength is decreased by the presence of organic carbon, compared to NiCl+ (aq) and Ni2+ (aq). Because bonding strength governs equilibrium stable isotope fractionation, we use our experimental findings to suggest how Ni speciation in seawater might influence Ni isotope behaviour during adsorption to phyllomanganate. We find that our suggestions are consistent with isotopic measurements from natural sediments. Although the balance of Ni adsorption versus incorporation during uptake to phyllomanganates may play a greater part in explaining the variation in the Ni isotope composition in Mn-rich sediments, Ni speciation and the presence of organics might increase the range of δ60Ni values measured in natural settings.

Feature Separation and Fusion to Optimise the Migration Model of Mural Painting Style in Tombs

Tomb murals are different from cave temple murals and temple murals, as they are underground cultural relics, their painting style is unique, solemn, and austere, and the performance image is characterised by simple colours, low contrast, and fewer survivors. During the digital restoration process, it is important to have sufficient reference samples to ensure the accuracy of the restoration. In addition, the style of mural paintings in the tombs varies greatly from other styles of murals and types of word paintings. Therefore, learning the unique artistic style of tomb murals, providing stylistically consistent training samples for digital restoration, and overcoming the problems of dim lighting and complex surface granularity of tomb murals are all necessary for research. This paper proposes a generative adversarial network algorithm that separates and fuses style features to enhance the generative network’s ability to acquire image information. The algorithm extracts underlying and surface style feature details of the image to be tested and conducts fusion generation experiments. The generative network’s parsing layer modifies the input noise tensor and optimises the corresponding weights to prevent misalignment between drawing lines and fresco cracks. Finally, to optimise the fresco generation effect, we add the corresponding loss function in the discriminator. The tomb murals dataset was established for experiments and tests, and quantitatively and qualitatively analysed with other style migration models, and SSIM, FID, LPIPS and NIQE were used as evaluation indexes. The results were 0.97, 269.579, 0.425 and 3.250, respectively, and the effect of style migration of this paper’s method was significantly higher than that of the control group model.

Mechanism of Asymmetric Homologation of Alkenylboronic Acids with CF3-Diazomethane via Borotropic Rearrangement.

Density functional theory calculations have been performed to investigate the mechanism for the BINOL-catalyzed asymmetric homologation of alkenylboronic acids with CF3-diazomethane. The reaction proceeds via a chiral BINOL ester of the alkenylboronic acid substrate. The calculations reveal a complex scenario for the formation of the chiral BINOL-alkenylboronate species, which is the key intermediate in the catalytic process. The aliphatic alcohol additive plays an important role in the reaction. This study provides a rationalization of the stereoinduction step of the reaction, and the enantioselectivity is mainly attributed to the steric repulsion between the CF3 group of the diazomethane reagent and the γ-substituent of the BINOL catalyst. The complex potential energy surface obtained by the calculations is analyzed by means of microkinetic simulations.

1.2 kW, 20 kHz Nanosecond Nd:YAG Slab Laser System

In this paper, we develop a kW-level high-repetition-rate nanosecond master oscillator power amplifier (MOPA) laser system, employing a structure of fiber, Nd:YVO4, and Nd:YAG hybrid amplification. A tunable fiber seed source is used for adjustable pulse repetition frequency and pulse width. The Nd:YVO4 pre-amplifier, which is dual-end-pumped, achieves high gain while maintaining good beam quality, and the high-power side-pumped Nd:YAG slab main-amplifier enables efficient power amplification. The repetition rate of the output laser can be adjusted within the range of 1~20 kHz, and the pulse width can be tuned within the range of 10~300 ns. The seed output is 6 mW at a repetition frequency of 20 kHz; we achieve an average output power of 1240 W with a total power extraction efficiency of 39.1% and single-pulse energy of 62 mJ at a pulse width of 301 ns. This parameter-controllable high-power laser holds promise for applications in the laser cleaning of complex surface contaminants.

Fine Structure-Aware Sampling: A New Sampling Training Scheme for Pixel-Aligned Implicit Models in Single-View Human Reconstruction

Pixel-aligned implicit models, such as PIFu, PIFuHD, and ICON, are used for single-view clothed human reconstruction. These models need to be trained using a sampling training scheme. Existing sampling training schemes either fail to capture thin surfaces (e.g. ears, fingers) or cause noisy artefacts in reconstructed meshes. To address these problems, we introduce Fine Structured-Aware Sampling (FSS), a new sampling training scheme to train pixel-aligned implicit models for single-view human reconstruction. FSS resolves the aforementioned problems by proactively adapting to the thickness and complexity of surfaces. In addition, unlike existing sampling training schemes, FSS shows how normals of sample points can be capitalized in the training process to improve results. Lastly, to further improve the training process, FSS proposes a mesh thickness loss signal for pixel-aligned implicit models. It becomes computationally feasible to introduce this loss once a slight reworking of the pixel-aligned implicit function framework is carried out. Our results show that our methods significantly outperform SOTA methods qualitatively and quantitatively. Our code is publicly available at https://github.com/kcyt/FSS.

GSO-Net: Grid Surface Optimization via Learning Geometric Constraints

In the context of surface representations, we find a natural structural similarity between grid surface and image data. Motivated by this inspiration, we propose a novel approach: encoding grid surfaces as geometric images and using image processing methods to address surface optimization-related problems. As a result, we have created the first dataset for grid surface optimization and devised a learning-based grid surface optimization network specifically tailored to geometric images, addressing the surface optimization problem through a data-driven learning of geometric constraints paradigm. We conduct extensive experiments on developable surface optimization, surface flattening, and surface denoising tasks using the designed network and datasets. The results demonstrate that our proposed method not only addresses the surface optimization problem better than traditional numerical optimization methods, especially for complex surfaces, but also boosts the optimization speed by multiple orders of magnitude. This pioneering study successfully applies deep learning methods to the field of surface optimization and provides a new solution paradigm for similar tasks, which will provide inspiration and guidance for future developments in the field of discrete surface optimization. The code and dataset are available at https://github.com/chaoyunwang/GSO-Net.

Electric Field-Driven Jetting and Water-Assisted Transfer Printing for High-Resolution Electronics on Complex Curved Surfaces

High-resolution electronics on complex curved surfaces have wide applications in fields such as biometric health monitoring, intelligent aircraft skins, conformal displays, and biomimetics. However, current manufacturing processes can only adapt to limited curvature, posing a significant challenge for achieving high-resolution fabrication of electronics on complex curved surfaces. In this study, we propose a novel fabrication strategy that combines electric field-driven jetting and water-assisted transfer printing techniques to achieve the fabrication of high-resolution electronics on complex curved surfaces. The electric field-driven jetting enables the fabrication of high-resolution 2D electronics on sacrificial layer substrates. After dissolving the sacrificial layer, it is observed that the 2D electronics form a self-supporting structure with a certain rigidity and flexibility. During the water-assisted transfer printing process, this self-supporting structure undergoes stretching deformation with excellent conformity of the electronics to curved surfaces while effectively minimizing wrinkles. Finally, we successfully demonstrate the manufacture of 25 μm high-resolution electronics on highly curved surfaces (nautilus shell) and complex (scallop shell, stone) surfaces. The integrity of transferred circuit patterns and consistency of conductors are verified through infrared thermography analysis, confirming the feasibility of this manufacturing strategy. In addition, a protective film with strong adhesive properties is sprayed onto the transferred curved circuits to enhance their adhesion and resistance to extreme environments such as acids and alkalis. Our proposed technique provides a simple and effective new strategy for the fabrication of high-resolution electronics on complex curved surfaces.

Path Optimization of Aircraft-Gear-Tooth-Surface Detection Based on Improved Genetic Algorithm

Aiming at the problems of low detection efficiency and complexity of aircraft gear tooth surfaces, a path optimization algorithm based on an improved genetic algorithm is proposed. The detection area of the tooth surface is planned, the sampling points of the tooth surface are determined based on the digital technology of the tooth surface, and the sampling mesh is obtained by the truncated plane method to reduce the sampling distortion of the shape and improve the sampling efficiency. Adaptive crossover and mutation probability are used to improve the convergence speed and accuracy of the genetic algorithm. The selected individuals of the binary tournament are used to guide the global optimal search by a simulated annealing algorithm, and the local optimal is avoided by the Metropolis criterion. In the simulation experiment, the proposed method and other algorithms are used to optimize the detection path. The optimized tooth-surface-detection path has the shortest distance and the shortest time, that is, the tooth-surface-detection path efficiency is improved, verifying the practicability of the algorithm.

Enhanced removal of phosphate from aqueous solutions by oxygen vacancy-rich MgO microspheres: Performance and mechanism

The efficient removal of phosphate from water environments was extremely significant to control eutrophication of water bodies and prevent further deterioration of water quality. In this study, oxygen vacancy-rich magnesium oxide (OV–MgO) microspheres were synthesized by a simple solvothermal method coupling high-temperature calcination. The effects of adsorbent dosage, contact time, initial pH and coexisting components on phosphate adsorption performance were examined. The physicochemical properties of OV-MgO microspheres and the phosphate removal mechanisms were analyzed by various characterization techniques. The maximum adsorption capacity predicted by the Sips isotherm model was 379.7 mg P/g for OV-MgO microspheres. The phosphate adsorption in this study had a fast adsorption kinetics and a high selectivity. OV-MgO microspheres had a good acid resistance for phosphate adsorption, but their adsorption capacity decreased under alkaline conditions. The electrostatic attraction, ligand exchange, surface precipitation, inner-sphere surface complexation and oxygen vacancy capture were mainly responsible for efficient removal of phosphate from aqueous solutions. This study probably promoted the development of oxygen vacancy-rich metal (hydr)oxides with potential application prospects.

Abstract 3205: MicroRNA-peptide polyelectrolyte complex nanoparticle-hydrogel composite attenuates mesothelioma growth

Abstract Diffuse pleural mesothelioma (DPM) is a biologically unusual, aggressive asbestos-associated cancer affecting the entire pleura surface. DPM defies current standard multimodal therapies due to intrinsic chemoresistance and inability to achieve negative-margin resection of complex surface anatomy. Hence, current non-specific drug regimens ultimately fail because the biology of this tumor is poorly understood and even if surgically resected, tumor inevitably recurs from residual microscopic tumor foci. These various clinical challenges led us to develop a therapeutic platform delivering microRNA (miRNA), a novel anti-cancer agent therapeutic regimen, with the goal of eradicating residual microscopic tumor foci thereby improving the efficacy of multimodal therapy. We engineered a peptide-based biodegradable hydrogel that can be injected or sprayed directly to coat anatomic surfaces (surface-fill hydrogel; SFH), functioning as a therapeutic depot. Properties of SFH allow us to specify critical composition parameters such as biopersistence time, therapeutic payload, cell-specific targeting etc. In the first step of SFH formulation, miRNA complexed with different amphiphilic cationic peptides varying in length (19-26 amino acids) and amines (9-17), to form stable nanoparticles. Flash nanocomplexation (FNC) were used to produce highly scalable and kinetically controlled assembly of miRNA-peptide polyelectrolyte complex (PEC) nanoparticles (NPs), which utilizes a confined impinging jet (CIJ) mixer to achieve turbulent micromixing of the NPs components, yielding highly uniform and stable NPs. Next, NPs were encapsulated into another peptide hydrogel, formed via self-assembly of amphiphilic cationic peptide HLT2, thus forming a surface-fill hydrogel NPs composite. The SFH-NPs composite was not toxic to DPM cells and demonstrated efficient release of miRNA-peptide NPs from the SFH matrix in-vitro. The uptake of FAM-labeled miRNA-peptide NPs was confirmed by flowcytometry. Biodistribution analysis of NPs in mice bearing luciferase-positive DPM xenografts treated locally with Cy3-miRNA-SFH composite showed that Cy3-miRNA was concentrated in tumor cells but not in other organs. Furthermore, miR-215 exhibiting potent anti-tumor activity in DPM was used to study the therapeutic efficacy of SFH miRNA-nanoparticle composites. Subcutaneous DPM xenografts treated locally with miR-215 SFH composite shrank tumor significantly. Thus, delivery of specific miRNA-peptide PEC nanoparticles via SFH therapeutic platform in preclinical models of DPM displayed potent anti-cancer effects. Together, this new generation microRNA-peptide polyelectrolyte complex nanoparticles-SFH composite is a very promising delivery platform that could be extended for a diverse array of locoregional therapies. Citation Format: Anand Singh, Anderson Caleb, Joel P. Schneider, Chuong D. Hoang. MicroRNA-peptide polyelectrolyte complex nanoparticle-hydrogel composite attenuates mesothelioma growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3205.