Microplastic-induced NAFLD: Hepatoprotective effects of nanosized selenium.

Polystyrene microplastics (MPs) are persistent environmental pollutants commonly encountered in daily human life. Numerous studies have demonstrated their ability to induce liver damage, including oxidative stress, inflammation, and lipid accumulation. However, limited information exists regarding preventive measures against this issue. In our study, we investigated the potential preventive role of selenium nanoparticles (YC-3-SeNPs) derived from Yak-derived Bacillus cereus, a novel nanobiomaterial known for its antioxidant properties and lipid metabolism regulation. Using transcriptomic and metabolomic analyses, we identified key genes and metabolites associated with oxidative stress and lipid metabolism imbalance induced by MPs. Upregulated genes (Scd1, Fasn, Irs2, and Lpin) and elevated levels of arachidonic and palmitic acid accumulation were observed in MP-exposed mice, but not in those exposed to SeNPs. Further experiments confirmed that SeNPs significantly attenuated liver lipid accumulation and degeneration caused by MPs. Histological results and pathway screening validated our findings, revealing that MPs suppressed the Pparα pathway and Nrf2 pathway, whereas SeNPs activated both pathways. These findings suggest that MPs may contribute to the development of nonalcoholic fatty liver disease (NAFLD), while SeNPs hold promise as a future nanobio-product for its prevention.

Functionalized DNA-Origami-Protein Nanopores Generate Large Transmembrane Channels with Programmable Size-Selectivity.

The DNA-origami technique has enabled the engineering of transmembrane nanopores with programmable size and functionality, showing promise in building biosensors and synthetic cells. However, it remains challenging to build large (>10 nm), functionalizable nanopores that spontaneously perforate lipid membranes. Here, we take advantage of pneumolysin (PLY), a bacterial toxin that potently forms wide ring-like channels on cell membranes, to construct hybrid DNA-protein nanopores. This PLY-DNA-origami complex, in which a DNA-origami ring corrals up to 48 copies of PLY, targets the cholesterol-rich membranes of liposomes and red blood cells, readily forming uniformly sized pores with an average inner diameter of ∼22 nm. Such hybrid nanopores facilitate the exchange of macromolecules between perforated liposomes and their environment, with the exchange rate negatively correlating with the macromolecule size (diameters of gyration: 8-22 nm). Additionally, the DNA ring can be decorated with intrinsically disordered nucleoporins to further restrict the diffusion of traversing molecules, highlighting the programmability of the hybrid nanopores. PLY-DNA pores provide an enabling biophysical tool for studying the cross-membrane translocation of ultralarge molecules and open new opportunities for analytical chemistry, synthetic biology, and nanomedicine.

Conductive polyethersulfone membrane facilely prepared by simultaneous phase inversion method for enhanced anti-fouling and separation under low driven-pressure.

Electrically conductive membranes have been regarded as a new alternative to overcome the crucial drawbacks of membranes, including permeability-selectivity trade-off and fouling. It is still challenging to prepare conductive membranes with good mechanical strength, high conductivity and stable separation performance by reliable materials and methods. This work developed a facile method of simultaneous phase inversion to prepare electrically conductive polyethersulfone (PES) membranes with carboxylic multiwalled carbon nanotubes (MWCNT) and graphene (Gr). The resultant MWCNT/Gr/PES nanocomposite membranes are composed of the upper MWCNT/Gr layer with good conductivity and the base PES layer providing mechanical support. MWCNT as nanofillers effectively turns the insulting PES layers to be electrically conductive. With the dispersing and bridging functions of Gr, the MWCNT/Gr layer shows an enhanced electric conductivity of 0.10 S/cm. This MWCNT/Gr/PES membrane in an electro-filtration cell achieves excellent retention of Cu(II) ions up to 98 % and a high flux of 94.5 L m-2∙h-1∙bar-1 under a low driven-pressure of 0.1 MPa. The conductive membrane also shows improved anti-fouling capability during protein filtration, due mainly to the electrostatic repulsion and hydrogen evolution reaction on the electrode. This facile strategy has excellent potential in electro-assistant membrane filtration for fouling control and effective separation.

The safety and tolerability of alkaloids from Alstonia scholaris leaves in healthy Chinese volunteers: a single-centre, randomized, double-blind, placebo-controlled phase I clinical trial.

CONTEXT: Capsule of alkaloids from the leaf of Alstonia scholaris (L.) R.Br. (Apocynaceae) (CALAS) is a new investigational botanical drug (No. 2011L01436) for bronchitis, post-infectious cough and asthma. OBJECTIVE: To observe the clinical safety and tolerability of CALAS. MATERIALS AND METHODS: Subjects were assigned to eight cohorts, and each received randomly CALAS or placebo in one of single ascending dose (SAD) of 8, 40, 120, 240, 360, 480, or in one of multiple ascending dose (MAD) of 40 or 120 mg, three times daily for 7 days. Each cohort contained two placebo subjects. RESULTS: Sixty-two enrolled volunteers completed the study and no serious adverse events and clinically significant changes in vital signs, electrocardiography, and upper abdominal Doppler ultrasonography were observed. The ratios of treatment-emergent adverse events (TEAEs) were reported in 11/46 (23.91%) of CALAS groups and 3/16 (18.75%) of the placebo group (p > 0.05), respectively, based on the results of SAD and MAD. All TEAEs were mild, transient, and disappeared without any intervention. The TEAEs possibly related to CALAS treatment were as followings: hiccups (4/46: 8%), dry mouth and nausea (3/46: 6%), increased sleep (2/46: 4%), abdominal distension (1/46: 2%), bilirubin elevated (1/46: 2%). DISCUSSION AND CONCLUSIONS: CALAS is safe and well-tolerated with no unexpected or clinically relevant safety concerns up to a single dose of 360 mg and three times daily for 7 days up to 120 mg in healthy Chinese volunteers, supporting further Phase II studies.

DNA Thioaptamer with Homing Specificity to Lymphoma Bone Marrow Involvement.

Selective drug accumulation in the malignant tissue is a prerequisite for effective cancer treatment. However, most drug molecules and their formulated particles are blocked en route to the destiny tissue due to the existence of multiple biological and physical barriers including the tumor microvessel endothelium. Since the endothelial cells on the surface of the microvessel wall can be modulated by inflammatory cytokines and chemokines secreted by the tumor or stromal cells, an effective drug delivery approach is to enhance interaction between the drug particles and the unique spectrum of surface proteins on the tumor endothelium. In this study, we performed in vivo screening for thioaptamers that bind to the bone marrow endothelium with specificity in a murine model of lymphoma with bone marrow involvement (BMI). The R1 thioaptamer was isolated based on its high homing potency to bones with BMI, and 40-60% less efficiency in accumulation to healthy bones. In cell culture, R1 binds to human umbilical vein endothelial cells (HUVEC) with a high affinity ( Kd ≈ 3 nM), and the binding affinity can be further enhanced when cells were treated with a mixture of lymphoma cell and bone marrow cell conditioned media. Cellular uptake of R1 is through clathrin-mediated endocytosis. Conjugating R1 on to the surface of liposomal doxorubicin nanoparticles resulted in 2-3-fold increase in drug accumulation in lymphoma BMI. Taking together, we have successfully identified a thioaptamer that preferentially binds to the endothelium of lymphoma BMI. It can serve as an affinity moiety for targeted delivery of drug particles to the disease organ.

Multifunctional Nanoparticles Loading with Docetaxel and GDC0941 for Reversing Multidrug Resistance Mediated by PI3K/Akt Signal Pathway.

The polylactic-co-glycolic acid polyethylene glycol conjugated with cell penetrating peptide R7 (PLGA-PEG-R7)/polysulfadimethoxine-folate nanoparticles loaded with docetaxel (DTX) and GDC0941 (R7/PSD-Fol NPs) were prepared to overcome multidrug resistance (MDR) and enhance the antitumor activity. First, polysulfadimethoxine-folate was synthesized to construct the R7/PSD-Fol NPs. The R7/PSD-Fol NPs were prepared with the abilities of effective entrapment and drug loading. Due to the pH-sensitive effect of PSD-folate, the releasing of DTX and GDC0941 from the R7/PSD-Fol NPs was lower in pH 7.4 buffer solution than that in pH 5.0 buffer solution. The half maximal inhibitory concentration (IC50) of MCF-7 and resistant to doxorubicin (MCF-7/Adr) cells illustrated the cytotoxicity of R7/PSD-Fol nanoparticles by using the MTT method. The uptake of R7/PSD-Fol NPs was visualized by using the fluorescence of Rh-123 to detect the targeting effect of folate on the surface of R7/PSD-Fol NPs. The results of the cell apoptosis and the depolarization of mitochondrial membrane potential (MMP) were adopted to show the cytotoxicity of the R7/PSD-Fol NPs on MCF-7/Adr cells. The Western blot revealed the inhibition of PI3K/Akt pathway in MCF-7/Adr cells induced by R7/PSD-Fol NPs. Finally, both in vivo distribution and in vivo antitumor showed the R7/PSD-Fol NPs displayed the better distribution at tumor site and the stronger suppression of tumor growth in the tumor bearing nude mice compared with control group. It was concluded that R7/PSD-Fol NPs loaded with DTX and GDC0941 could overcome MDR and enhance the antitumor effect further.

Co-administration with cell penetrating peptide enhances the oral bioavailability of docetaxel-loaded nanoparticles.

This study proposes a novel docetaxel (DTX) cyclodextrin inclusion-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (D-CNPs) system with cell penetrating peptide (CPP), and evaluates its potential for oral administration of DTX. Heptaarginine (R7) was used as the CPP. D-CNPs were prepared by the double-emulsification method. The mean particle size and zeta potential of the resulting D-CNPs were 198.7 ± 12.56 nm and -27.25 ± 4.62 mV, respectively, and their mean encapsulation efficiency and drug loading were 80.35 ± 6.37% and 1.02 ± 0.15%, respectively. The morphology of the D-CNPs was observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The release behavior of the D-CNPs was studied by using the dialysis method. The relative bioavailability of D-CNPs and D-CNPs co-administered with R7 was enhanced about 5.57- and 9.43-fold, respectively, compared with the free DTX suspension. Furthermore, D-CNPs with R7 displayed maximum cytotoxicity against MCF-7 cells in MTT assay. D-CNPs co-administered with R7 showed markedly higher fluorescence intensity than D-CNPs without CPP. The results suggest that the D-CNPs co-administered with R7 could be a potential delivery system with excellent therapeutic efficacy for targeting the drugs to cancer cells.

Multifunctional nanoparticles as nanocarrier for vincristine sulfate delivery to overcome tumor multidrug resistance.

Multifunctional nanoparticles, Fol/R7 NPs, based on pH-sensitive PLGA-PEG-folate and cell penetrating peptide R7-conjugated PLGA-PEG, were constructed for targeting vincristine sulfate (VCR) to tumor and overcoming multidrug resistance (MDR). In this study, the pH-triggered VCR release was 65.6% during 8 h in pH 5.0, but only 35.8% in pH 7.4, demonstrating that a large amount of VCR released rapidly at weak acidic environment. The VCR-Fol/R7 NPs could significantly enhance cellular uptake and cytotoxicity in MCF-7 and MCF-7/Adr cells when compared to the nanoparticles solely modified by folate or R7. With folate receptor-mediated endocytosis and strong intracellular penetration, VCR-Fol/R7 NPs increased drug accumulation in resistant tumor cells by escaping P-glycoprotein mediated drug efflux. In vivo imaging suggested the active targeting attributed to pH sensitivity and folate receptor-mediated effect could improve tumor targeting efficacy. Indeed, VCR-Fol/R7 NPs exhibited the stongest antitumor efficacy in vivo. Therefore, Fol/R7 NPs are an effective nanocarrier for delivering antitumor drug and overcoming multidrug resistance.

Biomimetic Nanoarchitectonics with Chitosan Nanogels for Collaborative Induction of Ferroptosis and Anticancer Immunity for Cancer Therapy.

Immunogenic cell death (ICD) shows promising therapeutic potential for tumor regression. However, the low sensitivity and immunosuppressive state of current cell death manners seriously impede tumor immunogenicity. Ferroptosis characterized by excessive lipid peroxidation, has emerged as a potential strategy to induce ICD and activate antitumor immune responses. However, the effectiveness of ferroptosis is limited by antioxidant regulatory networks, including the glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) pathways, presenting challenges for its induction. Herein, they propose a novel approach that involves utilizing functionalized chitosan-ferrocene-sodium alginate (CFA) crosslinked nanogels, which are modified to pravastatin (PRV) and M1 macrophage membrane (MM) (designing as CFA/PRV@MM). Specifically, ferrocene boots intracellular reactive oxygen species levels for efficient glutathione (GSH) depletion through Fenton reaction, thus disrupting the GPX4/GSH axis, while PRV intervenes in the mevalonate pathway to inhibit the FSP1/CoQ10 antioxidant axis, thereby synergistically causing pronounced ferroptotic damage and promoting ICD. The CFA/PRV@MM nanogels demonstrate superior therapeutic efficacy in a mouse breast model, resulting in effective tumor ablation and immune response with minimal side effects. RNA transcription analysis reveals that nanogels can significantly affect metabolic progress, as well as immune activation. This research provides valuable insights into the design of ferroptosis induction for cancer immunotherapy.

Sensing, Imaging, and Therapeutic Strategies Endowing by Conjugate Polymers for Precision Medicine.

Conjugated polymers (CPs) have promising applications in biomedical fields, such as disease monitoring, real-time imaging diagnosis, and disease treatment. As a promising luminescent material with tunable emission, high brightness and excellent stability, CPs are widely used as fluorescent probes in biological detection and imaging. Rational molecular design and structural optimization have broadened absorption/emission range of CPs, which are more conductive for disease diagnosis and precision therapy. This review provides a comprehensive overview of recent advances in the application of CPs, aiming to elucidate their structural and functional relationships. The fluorescence properties of CPs and the mechanism of detection signal amplification are first discussed, followed by an elucidation of their emerging applications in biological detection. Subsequently, CPs-based imaging systems and therapeutic strategies are illustrated systematically. Finally, recent advancements in utilizing CPs as electroactive materials for bioelectronic devices are also investigated. Moreover, the challenges and outlooks of CPs for precision medicine are discussed. Through this systematic review, it is hoped to highlight the frontier progress of CPs and promote new breakthroughs in fundamental research and clinical transformation.

Preparation of hyaluronic acid-loaded Harmine polymeric micelles and in vitro effect anti-breast cancer.

AIMS: To prepare hyaluronic acid-loaded Harmine polymeric micelles with CD44 targeting properties and to investigate their anti-breast cancer effects in vitro. METHODS: The carboxyl group on hyaluronic acid is coupled to the amino group on 3,5-bis(trifluoromethyl)benzylamine by an amidation reaction. And the polymeric micelles self-assemble to encapsulate the Harmine in a hydrophobic core, characterized the polymer micelles by IR, 19F-NMR, Malvern particle sizing, release, hemolysis, and other experiments. Used CD44-positive MDA-MB-231 cells and CD44-negative MCF-7 cells as tumor models. The effect of polymer micelles on breast cancer cells in vitro by cytotoxicity assay, confocal, and flow cytometry. RESULTS: The prepared polymer micelles had a uniform particle size of about 200 nm, good dispersion, PDI < 0.3, encapsulation rate up to 87%, drug loading of 4.12±0.03%, and negative charge. Hyaluronidase has a good enzymatic effect on polymeric micelles, with a hemolysis rate of less than 1%. It showed some dose-dependent toxicity to both MDA-MB-231 and MCF-7, with increased uptake of polymer micelles by CD44-positive MDA-MB-231 compared to CD44-negative MCF-7 cells and significant effects of polymer micelles on apoptosis and cycling in both cell types. These results suggest that the hyaluronic acid-loaded Harmine polymer micelles designed in this study are effective in killing breast cancer cells while at the same time reducing the toxicity of Harmine and improving its slow-release targeting.

CLASP2 recognizes tubulins exposed at the microtubule plus-end in a nucleotide state-sensitive manner.

CLASPs (cytoplasmic linker-associated proteins) are ubiquitous stabilizers of microtubule dynamics, but their molecular targets at the microtubule plus-end are not understood. Using DNA origami-based reconstructions, we show that clusters of human CLASP2 form a load-bearing bond with terminal non-GTP tubulins at the stabilized microtubule tip. This activity relies on the unconventional TOG2 domain of CLASP2, which releases its high-affinity bond with non-GTP dimers upon their conversion into polymerization-competent GTP-tubulins. The ability of CLASP2 to recognize nucleotide-specific tubulin conformation and stabilize the catastrophe-promoting non-GTP tubulins intertwines with the previously underappreciated exchange between GDP and GTP at terminal tubulins. We propose that TOG2-dependent stabilization of sporadically occurring non-GTP tubulins represents a distinct molecular mechanism to suppress catastrophe at the freely assembling microtubule ends and to promote persistent tubulin assembly at the load-bearing tethered ends, such as at the kinetochores in dividing cells.

A biophotonic device based on a conjugated polymer and a macrophage-laden hydrogel for triggering immunotherapy.

A biophotonic device is fabricated by a 3D printing technique for tumor immunotherapy utilizing a flexible organic light-emitting diode (OLED) with deep blue emission and a gelatin-alginate hydrogel that contains a poly(phenylene vinylene) (PPV) derivative and live immune cells of macrophages (M0-RAW264.7). PPV is excited by the OLED to generate reactive oxygen species (ROS), enabling the macrophages to polarize to the M1 phenotype and secrete cytotoxic cytokines to induce the apoptosis of tumor cells. This strategy provides a new method for fabricating cell-involved biophotonic devices for immunotherapy.

In situ-formable, dynamic crosslinked poly(ethylene glycol) carrier for localized adeno-associated virus infection and reduced off-target effects.

The adeno-associated virus (AAV) is a potent vector for in vivo gene transduction and local therapeutic applications of AAVs, such as for skin ulcers, are expected. Localization of gene expression is important for the safety and efficiency of genetic therapies. We hypothesized that gene expression could be localized by designing biomaterials using poly(ethylene glycol) (PEG) as a carrier. Here we show one of the designed PEG carriers effectively localized gene expression on the ulcer surface and reduced off-target effects in the deep skin layer and the liver, as a representative organ to assess distant off-target effects, using a mouse skin ulcer model. The dissolution dynamics resulted in localization of the AAV gene transduction. The designed PEG carrier may be useful for in vivo gene therapies using AAVs, especially for localized expression.

Sensitive detection of single-nucleotide polymorphisms by conjugated polymers for personalized treatment of hypertension.

Genetic variants among individuals have been associated with ineffective control of hypertension. Previous work has shown that hypertension has a polygenic nature, and interactions between these loci have been associated with variations in drug response. Rapid detection of multiple genetic loci with high sensitivity and specificity is needed for the effective implementation of personalized medicine for the treatment of hypertension. Here, we used a cationic conjugated polymer (CCP)-based multistep fluorescence resonance energy transfer (MS-FRET) technique to qualitatively analyze DNA genotypes associated with hypertension in the Chinese population. Assessment of 10 genetic loci using this technique successfully identified known hypertensive risk alleles in a retrospective study of whole-blood samples from 150 patients hospitalized with hypertension. We then applied our detection method in a prospective clinical trial of 100 patients with essential hypertension and found that personalized treatment of patients with hypertension based on results from the MS-FRET technique could effectively improve blood pressure control rate (94.0% versus 54.0%) and shorten the time duration to controlling blood pressure (4.06 ± 2.10 versus 5.82 ± 1.84 days) as compared with conventional treatment. These results suggest that CCP-based MS-FRET genetic variant detection may assist clinicians in rapid and accurate classification of risk in patients with hypertension and improve treatment outcomes.

Light-induced facile and efficient synthesis of color-variable lignin-based gold nanoparticles and its application as Pb2+ sensor.

The sustainable synthesis of gold nanoparticles (AuNPs) is widely exploited. However, the preparation of color-variable AuNPs based on renewable energy had not been reported. Here, a facile approach to synthesis color-variable lignin-based AuNPs was presented for the first time, using UV-induced decomposition of Au2O3 as the gold precursor and lignin as the stabilizer for AuNPs in dimethyl sulfoxide solvent. UV radiation technology could effectively convert Au3+ into Au0. In addition, the reaction behavior was systematically studied, and the conversion rate and reaction rate of Au2O3 could be further enhanced by changing the temperature. More interestingly, the aggregation degree of AuNPs could be adjusted by changing the amount of lignin, and the color-variable AuNPs from wine red to purple was realized. At the same time, the lignin-functionalized AuNPs showed high selectivity as the colorimetric detector towards Pb2+ ions. Our work displayed a facile, nontoxic and efficient method to prepare color-variable AuNPs, which might provide a realizable perspective to the colorimetric and sensing of AuNPs.

Straw waste promotes microbial functional diversity and lignocellulose degradation during the aerobic process of pig manure in an ectopic fermentation system via metagenomic analysis.

This study compares the physicochemical properties, lignocellulose degradation, microbial community composition, and carbohydrate-active enzymes (CAZymes) in ectopic fermentation systems (EFS) of pig manure mixed with either conventional padding (C) or straw waste (A). The degradation rates of cellulose, hemicellulose, and lignin were found to be significantly higher in A (27.72%, 22.72%, and 18.80%, respectively) than in C (21.05%, 16.17%, and 11.69%, respectively) owing to the activities of lignocellulolytic enzymes. Metagenomics revealed that straw addition had a stronger effect on the bacterial community succession than fungi. The abundances of Sphingobacterium, Pseudomonas, and CAZymes were higher in A than in C, as well as the auxiliary activity enzymes, which are crucial for lignocellulose degradation. Redundancy analysis indicates a positive correlation between lignocellulose degradation and Sphingobacterium, Pseudomonas, Bacillus, and Actinobacteria contents. A structural equation model was applied to further verify that the increased microbial functional diversity was the primary driver of lignocellulosic degradation, which could be effectively regulated by the enhanced temperature with straw addition. Replacing traditional padding with straw can thus accelerate lignocellulosic degradation, promote microbial functional diversity, and improve the EFS efficiency.

Conjugated polymers for biomedical applications.

Conjugated polymers (CPs) are a series of organic semiconductor materials with large π-conjugated backbones and delocalized electronic structures. Due to their specific photophysical properties and photoelectric effects, plenty of CPs with varied chemical structures and functions are quickly evolving in the diverse biomedical field, such as fluorescence imaging, photodynamic therapy, photothermal therapy, etc. In addition, the functionalized side chains of CPs could contribute to the expected water-solubility, biocompatibility, biological response, etc. CPs can also be prepared into nanoparticles for acquiring controllable particle size and dispersion through the common synthesis procedure. In this review, we focus on the latest developments of CPs in biotherapy, biological regulation, biological response and bioprinting applications. The major challenges and outlooks of CPs for applications in the biomedical field are also discussed.

Effect of microstructure-scale features on lignin fluorescence for preparation of high fluorescence efficiency lignin-based nanomaterials.

As a natural fluorescent material, the practical application of lignin fluorescence was hindered due to the low fluorescence quantum yield (QY). Inspired by its aggregation fluorescence behavior, the effect of microstructure-scale on lignin fluorescence was studied from two levels, the molecular weight and colloidal sphere. It was demonstrated that with the decrease of lignin microstructure-scale, the non-radiative dissipation and reabsorption effect of lignin fluorescence would be weak, resulting in high emission efficiency. On this basis, hydrogenolysis was used to obtain small molecular fragments and reduce content of reabsorbing groups of lignin, of which the QY was greatly increased by 35 times to about 12%. In addition, the emission peak of lignin was the fluorescence addition of its main structural units. The long-wavelength emission peak was often the illusion from the reabsorption effect but not duo to the formation of conjugated structure. This work provided a potential method for the preparation of high QY lignin and an in-depth understanding of lignin fluorescence.

Multiple fluorescence labeling and two dimensional FTIR-13C NMR heterospectral correlation spectroscopy to characterize extracellular polymeric substances in biofilms produced during composting.

Knowledge on the structure and function of extracellular polymeric substances (EPS) in biofilms is essential for understanding biodegradation processes. Herein, a novel method based on multiple fluorescence labeling and two-dimensional (2D) FTIR-(13)C NMR heterospectral correlation spectroscopy was developed to gain insight on the composition, architecture, and function of EPS in biofilms during composting. Compared to other environmental biofilms, biofilms in the thermophilic (>55 °C) and cooling (mature) stage of composting have distinct characteristics. The results of multiple fluorescence labeling demonstrated that biofilms were distributed in clusters during the thermophilic stage (day 14), and dead cells were detected. In the mature stage (day 26), the biofilm formed a continuous layer with a thickness of approximately 20-100 µm around the compost, and recolonization of cells at the surface of the compost was easily observed. Through 2D FTIR-(13)C NMR correlation heterospectral spectroscopy, the following trend in the ease of the degradation of organic compounds was observed: heteropolysaccharides > cellulose > amide I in proteins. And proteins and cellulose showed significantly more degradation than heteropolysaccharides. In summary, the combination of multiple fluorescence labeling and 2D correlation spectroscopy is a promising approach for the characterization of EPS in biofilms.