Longitudinal Study of Cirrhosis Development in STAM and carbon tetrachloride Mouse Models Using Fourier Transform Infrared Spectral Imaging

Animal models of cirrhosis are of great interest to investigate the pathological process leading to the final stage of cirrhosis. The aim of this study was to analyze the different steps involved in the progressive development of cirrhosis using Fourier transform infrared spectral histology in 2 mouse models of cirrhosis, the STAM model of metabolic cirrhosis, and the carbon tetrachloride-induced cirrhosis model. Formalin-fixed, paraffin-embedded liver samples were obtained from 3 mice at 5 time points in each model to analyze the course of hepatic lesions up to the formation of cirrhosis. For each time point, adjacent 3-μm-thick liver sections were obtained for histologic stains and spectral histology. Fourier transform infrared acquisitions of liver sections were performed at projected pixel sizes of 25 μm × 25 μm and 6.25 μm × 6.25 μm. Spectral images were then preprocessed with an extended multiplicative signal correction and analyzed with common k-means clustering, including all stages in each model. In both models, the 2- and 4-class common k-means clustering in the 1000 to 1350 cm-1 range showed that spectral classes characterized by higher absorbance peaks of glycogen were predominant at baseline, then decreased markedly in early stages of hepatic damage, and almost disappeared in cirrhotic tissues. Concomitantly, spectral classes characterized by higher absorbance peaks of nucleic acids became progressively predominant during the course of hepatic lesions. These results were confirmed using k-means clustering on the peaks of interest identified for glycogen and nucleic acid content. Our study showed that the glycogen depletion previously described at the stage of cirrhosis is an early event in the pathological process, independently of the cause of cirrhosis. In addition, there was a progressive increase in the nucleic acid content, which may be linked to increased proliferation and polyploidy in response to cellular lesions.

Infrared spectroscopy and flow cytometry studies on the apoptotic effect of nano-chrysin in HeLa cells

Mapping the structural changes in membrane lipids, proteins, polysaccharides and nucleic acids has opened new channels for understanding the mode of action of anticancer natural products. Earlier, we synthesized chrysin nanoparticles (NChr) with good bioavailability, and characterized its size, surface charge, entrapment efficiency, and drug release pattern using PLGA polymer. NChr induced concentration dependent cytotoxicity in HeLa cells with an IC₅₀ of 61.54 ± 1.2 µM in comparison with free chrysin with IC₅₀ of 86.51 ± 2.9 µM. Since nanoparticles interact dynamically with cell membranes, organelles, proteins and DNA, it is necessary to understand the interplay of nanodrug induced macromolecular changes in cancer cells. In this work, we obtained signatures of NChr-induced biochemical changes in HeLa cells by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy technique coupled with flow cytometry. NChr induced cell membrane disruption, G1 phase cell cycle arrest, and increased externalization of phosphatidylserine leading to apoptosis indicating the biochemical perturbations in membrane lipids and DNA of HeLa cells in comparison with untreated cells. The 1300-1000 cm^-1 spectral region indicated NChr interaction with the ribose sugar backbone and DNA denaturation. Spectral range 1800-1400 cm^-1 indicated a concentration dependent decrease in α helical and β sheet structures which may lead to protein degradation during apoptosis. The spectral range 3000-2800 cm^-1 indicated the lipid peroxidation in response to NChr treatment. This is the first study describing the bio-macromolecular changes induced by a nano encapsulated drug and can pave the way to investigate unconventional modes of action for bioactive formulations.

UV/Fe(II) synergistically activated S(IV) per-treatment on HA-enhanced Ca2+ scaling in NF filtration: Fouling mitigation, mechanisms and correlation analysis of membrane resistance in different filtration stage

The aim of this study was to investigate the feasibility and fouling mitigation mechanisms of UV/Fe(II) synergistically activated sulfite (S(IV)) (UFS) pretreatment to alleviate membrane fouling caused by HA-enhanced Ca²⁺ scaling. After UFS treatment, hydrophobic substances and carboxyl groups structure were destroyed by the in-situ-generated SO•-4, resulted in a significant reduction of hydrophobic substances ratio and carboxyl group concentration. Due to the formation of more electropositive in-situ-generated Fe(III), the complexation between Ca²⁺ and carboxyl groups was weakened so that the bulk crystallization size on the membrane surface was greatly reduced. The filter cake enhanced osmotic pressure effect (CEOP) and concentration polarization effect were hence alleviated, as well as the surface roughness. At the microcosmic perspective, as the energy barrier between the membrane and foulants was increased significantly after pretreatment, the anti-foulants adsorption ability of the membrane was enhanced. Correlation analysis showed that the carboxyl concentration and density, HPO ratio, larger particle size (>100 nm) ratio, the Ca²⁺ concentration in the scaling layer and energy barrier all had a good correlation with the membrane resistance. This research not only provides an advanced oxidation technology that can effectively alleviate the synergistically-fouling effect of HA and Ca²⁺ of nanofiltration process, but also proposes a guidance for the UV/Fe(II) synergistically activated sulfite.

Effects of UV/Fe(II)/sulfite pre-treatment on NOM-enhanced Ca2+ scaling during nanofiltration treatment: Fouling mitigation, mechanisms, and correlation analysis of membrane resistance

This study was aimed to evaluate the effects of a pre-treatment involving sulfite (S(IV)) synergistically activated by ultraviolet (UV)/Fe(II) on natural organic matter (NOM)-enhanced Ca²⁺ scaling during nanofiltration treatment. Based on the variations in the physicochemical properties and correlation analyses of irreversible resistance, the intrinsic fouling mechanisms were revealed from two aspects: bulk crystallization (interaction between NOM and inorganic ions) and surface crystallization (morphology of surface crystallization and a change in the Ca²⁺ concentration in the scaling layer). Furthermore, the degradation contribution rates of different free radicals during the UV/Fe(II)/S(IV) (UFS) treatment process were evaluated. During the reactions in the UFS, three free radicals (SO·-4, OH^·- and e- aq) were generated, and in-situ Fe(III) was formed in-situ. The carboxyl groups of the NOM were attacked by the free radicals, resulting in decreased of carboxyl concentration and density. In addition, the bond between Ca²⁺ and NOM weakened, and hydrophobic (HPO) substances were mineralized. However, the Fe(III) formed in-situ was active and electropositive, competing with Ca²⁺ for the complexation active sites on the NOM. The synergy effect of bulk crystallization and surface crystallization led to a significant decrease in the particle size of feed solution. The crystal size and roughness of membrane surface also decreased, which was conducive to reducing the membrane irreversible resistance. Correlation analysis revealed that the HPO ratio, carboxyl density and particle size (> 100 nm) ratio were effective characterization parameters for predicting irreversible resistance. This study not only provides guidance for alleviating membrane fouling caused by NOM-enhanced Ca²⁺ scaling during the nanofiltration process, but also presents the rationality of irreversible resistance during nanofiltration process and various indicators with strong linear correlation.

Usnic acid induced changes in biomolecules and their association with apoptosis in squamous carcinoma (A-431) cells: A flow cytometry, FTIR and DLS spectroscopic study

Many natural products induce apoptotic cell death in cancer cells, though studies on their interactions with macromolecules are limited. For the first time, this study demonstrated the cytotoxic potential of usnic acid (UA) against squamous carcinoma (A-431) cells and the associated changes in cell surface proteins, lipids and DNA by attenuated total reflection- fourier transform infrared spectroscopy (ATR-FTIR) and dynamic light scattering (DLS) spectroscopic studies. The IC₅₀ for UA was 98.9 µM after treatment of A-431 cells for 48 h, while the IC₅₀ reduced to 39.2 µM after 72 h of incubation time. UA induced oxidative stress in treated cells as confirmed by DCFHDA flow cytometry assay, depletion in reduced glutathione and increase in lipid peroxidation. The oxidative stress resulted in conformation change in amide I, amide II protein bands and DNA as observed by ATR-FTIR in UA treated A-431 cells. Shift in secondary structures of proteins from α helix to β sheets and structural changes in DNA was observed in UA treated A-431 cells. An increase in the band intensity of phospholipids, increased distribution of lipid and change in membrane potential was noted in UA treated cells, which was confirmed by externalization of phosphatidylserine to the outer membrane by annexin V-FITC/PI assay. Increase in mitochondrial membrane potential, cell cycle arrest at G0/G1 phase by flow cytometry and activation of caspase-3/7 dependent proteins confirmed the UA induced apoptosis in treated A-431 cells. FTIR and DLS spectroscopy confirmed the changes in biomolecules after UA treatment, which were associated with apoptosis, as observed by flow cytometry.

Therapeutic Prospects of Polysaccharides for Ovarian Cancer

Ovarian cancer (OC) is ranked as the leading cause of death among cancers of the female reproductive tract. First-line platinum treatment faces the severe challenges associated with the patient relapse and poor prognosis. Thus, it is imperative to develop natural antitumor drugs for OC with high efficacy. Natural polysaccharides have significant biological activities and antitumor effects. Our work has demonstrated that polysaccharides play key roles by inhibiting the cell proliferation and growth, regulating the tumor cell cycle, inducing apoptosis, suppressing the tumor cell migration and invasion, improving the immunomodulatory activities, and enhancing the efficacy of chemotherapy (cisplatin) in OC, which provide powerful evidence for the application of polysaccharides as novel anticancer agents, supplementary remedies, and adjunct therapeutic agents alone or in combination with cisplatin for preventing and treating the OC.

Synergistic effects of silver nanoparticles and cisplatin in combating inflammation and hyperplasia of airway stents

Anti-inflammatory and antihyperplasia activities are essential requirements for the successful use of airway stents. In this work, silver nanoparticles (AgNPs) and cisplatin (DDP) were combined in a synergistic modification strategy to improve the surface function of airway stents. Using polycaprolactone (PCL) as a drug carrier, a dual-functional PCL-AgNPs-DDP fiber film-coated airway stent was fabricated by electrospinning. The physicochemical and biological properties of the obtained fiber films were examined. The ATR-FTIR, XPS, SEM-EDS and TEM results suggested that AgNPs and DDP could be successfully immobilized onto the airway stent surface. The drug release and surface degradation results revealed that AgNPs and DDP can undergo sustained release from films for 30 d, and the weight loss was approximately 50% after 35 d. In addition, the dual-functional fiber film suppressed human embryonic lung fibroblast growth and exhibited excellent antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Furthermore, the effectiveness of the dual-functional fiber film-coated airway stent was evaluated by application to the trachea of New Zealand rabbits. The in vivo results indicated that PCL-AgNPs-DDP fiber film-coated airway stent can significantly inhibit granulation tissue formation and collagen deposition, reduced the expression of IL-8, TNF-α, IL-1α, PCNA, α-SMA and CD68, and ultimately achieved anti-inflammatory and antihyperplasia effects. Hence, this study provides a dual-functional surface-coated airway stent to address the clinical complications associated with respiratory tract inflammation and granulation tissue hyperplasia, thus inhibiting tracheal stenosis.

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This study provides a dual-functional PCL-AgNPs-DDP nanofiber film-coated airway stent.

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The airway stent processes antibacterial activity and suppress CCC-HPF-1 growth.

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The stent inhibits tracheal stenosis by antiinflammatory and antihyperplasia treatment.

Fourier Transform Infrared Spectroscopy: An Innovative Method for the Diagnosis of Ovarian Cancer

Ovarian cancer is the most lethal gynecologic malignancy due to the late diagnoses at advanced stages, drug resistance and the high recurrence rate. Thus, there is an urgent need to develop new techniques to diagnose and monitor ovarian cancer patients. Fourier transform infrared (FTIR) spectroscopy has great potential in the diagnosis of this disease, as well as the real-time monitoring of cancer development and chemoresistance. As a noninvasive, simple and convenient technique, it can not only distinguish the molecular differences between normal and malignant tissues, but also be used to identify the characteristics of different types of ovarian cancer. FTIR spectroscopy is also widely used in monitoring cancer cells in response to antitumor drugs, distinguishing cells in different growth states, and identifying new synthetic drugs. In this paper, the applications of FTIR spectroscopy for ovarian cancer diagnosis and other works carried out so far are described in detail.

Diverse and unexpected outcomes from oxidation of the platinum(II) anticancer agent [Pt{(p-BrC6F4)NCH2CH2NEt2}Cl(py)] by hydrogen peroxide

Oxidation of the anti-tumour agent [Pt{(p-BrC₆F₄)NCH₂CH₂NEt₂}Cl(py)], 1 (py = pyridine) with hydrogen peroxide under a variety of conditions yields a range of organoenamineamidoplatinum(II) compounds [Pt{(p-BrC₆F₄)NCH=C(X)NEt₂}Cl(py)] (X = H, Cl, Br) as well as species with shared occupancy involving H, Cl and Br. Thus, oxidation of the -CH₂-CH₂- backbone (dehydrogenation) occurs, often accompanied by substitution. Oxidation of 1 with H₂O₂ in acetone yielded 1:1 co-crystallized [Pt{(p-BrC₆F₄)NCH=CHNEt₂}Cl(py)], 1H and [Pt{(p-BrC₆F₄)NCH=C(Cl)NEt₂}Cl(py)], 1Cl. The former was obtained pure in low yield from the oxidation of 1 with (NH₄)₂[Ce(NO₃)₆] in acetone, and the latter was obtained from 1 and H₂O₂ in CH₂Cl₂ at near reflux. From the latter reaction under vigorous refluxing [Pt{(p-BrC₆F₄)NCH=C(Br)NEt₂}Cl(py)], 1Br was isolated. In refluxing acetonitrile, oxidation of 1 with H₂O₂ yielded [Pt{(p-BrC₆F₄)NCH=C(H₀.₂₅Br_0.75)NEt₂}Cl(py)], 1H_0.25Br_0.75, in which the alkene is mainly substituted by Br in a dual occupancy. Treatment of 1 with H₂O₂ and tetrabutylammonium hydroxide in acetone at room temperature formed [Pt{(p-HC₆F₄)NCH₂CH₂NEt₂}Cl(py)], 2. Oxidation of [Pt{(p-HC₆F₄)NCH₂CH₂NEt₂}Br(py)], 3 with H₂O₂ in boiling acetonitrile gave the ligand oxidation product [Pt{(p-HC₆F₄)NCH=C(Br)NEt₂}Br(py)], 3Br. All major products were identified by X-ray crystallography as well as by ¹H and ¹⁹F NMR spectra. In cases of mixed crystals or dual occupancy compounds, the ¹⁹F and ¹H NMR spectra showed dissociation into the components in the solution in the same proportions as in isolated crystalline material.

Detection of macromolecular inversion-induced structural changes in osteosarcoma cells by FTIR microspectroscopy

Fourier transform infrared (FTIR) microspectroscopy provides a biochemical fingerprint of the cells. In this study, chemical changes in 143B osteosarcoma cells were investigated using FTIR analysis of cancer cells after their treatment with polymeric invertible micellar assemblies (IMAs) and curcumin-loaded IMAs and compared with untreated osteosarcoma cells. A comprehensive principal component analysis (PCA) was applied to analyze the FTIR results and confirm noticeable changes in cell surface chemical structures in the fingerprint regions of 1480-900 cm^-1. The performed clustering shows visible differences for all investigated groups of cancer cells. It is demonstrated that a combination of FTIR microspectroscopy with PCA can be an efficient approach in determining interactions of osteosarcoma cells and drug-loaded polymer micellar assemblies. Graphical abstract.

Carbon doped Fe3O4 peroxidase-like nanozyme for mitigating the membrane fouling by NOM at neutral pH

Oxidation is a widely used method in drinking water treatment to mitigate the membrane fouling caused by the natural organic matters (NOM) from the surface water during ultra-filtration (UF) and nano-filtration (NF) processes, and H₂O₂ is one of the common oxidants for it. However, the oxidation capability of H₂O₂ at neutral pH is lower, compared to the acidic and alkaline conditions. In order to improve the efficiency of NOM oxidation at neutral pH, a carbon-doped Fe₃O₄ peroxidase-like nanozyme (CFPN) was synthesized in this study and used as a high-performance catalyst for H₂O₂ to generate hydroxyl radical. The oxygen-containing groups on the carbon structure of CFPN can form an acidic microenvironment, allowing H₂O₂ to produce hydroxyl radical by catalysis in neutral conditions. The results of hydrophilicity analysis, zeta potential, high-performance liquid size exclusion chromatography (HPSEC), Fourier transform infrared spectrum (FTIR) and flux indicated that the hydroxyl radical can oxidize the hydrophobic matters of humic acid (HA) into hydrophilic matters by Fenton reaction or electrophilic addition reaction, which can mitigate the fouling of NF membranes. The results of the same test for the bovine serum albumin (BSA) indicated that the hydroxyl radical can mitigate the fouling of UF membranes by degrading the tertiary and secondary structures of BSA and partly oxidizing the side chain groups. In addition, two types of surface water samples were used to verify the above mechanism, and the results indicated that the hydroxyl radical treatment at neutral pH is a new viable and effective strategy to significantly mitigate the NOM fouling of UF and NF membranes.

Detection of human brain tumours via evaluation of their biochemical composition using ATR-FTIR spectroscopy

The biochemical composition of normal human brain tissue in comparison with that of brain-tumour tissue was studied and diagnosed by means of the attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy technique. IR spectroscopy is a potential histopathological tool for detecting and diagnosing cancer and other diseases. In the study, the amounts of lipids, protein, and water in different brain-tissue specimens from patients of various ages were determined from their ATR-FTIR spectra upon analysing a combination of the pure-component spectra. A higher level of biocomponents was observed in the normal tissue, and in particular, more fluid (water) was contained in benign tumours. The age of patients was found to play an important role; patient age exhibited a direct correlation with the concentration of biocomponents, with increasing age corresponding to a reduction in lipids and proteins. These results demonstrate the diagnostic potential of ATR-FTIR spectroscopy for evaluating brain tumours in terms of its ability to distinguish between normal tissue and tumours in vivo and afford real-time intraoperative diagnosis.

The Application of ATR-FTIR Spectroscopy and the Reversible DNA Conformation as a Sensor to Test the Effectiveness of Platinum(II) Anticancer Drugs

Platinum(II) complexes have been found to be effective against cancer cells. Cisplatin curbs cell replication by interacting with the deoxyribonucleic acid (DNA), reducing cell proliferation and eventually leading to cell death. In order to investigate the ability of platinum complexes to affect cancer cells, two examples from the class of polyfluorophenylorganoamidoplatinum(II) complexes were synthesised and tested on isolated DNA. The two compounds trans-[N,N′-bis(2,3,5,6-tetrafluorophenyl)ethane-1,2-diaminato(1-)](2,3,4,5,6-pentafluorobenzoato)(pyridine)platinum(II) (PFB) and trans-[N,N′-bis(2,3,5,6-tetrafluorophenyl)ethane-1,2-diaminato(1-)](2,4,6-trimethylbenzoato)(pyridine)platinum(II) (TMB) were compared with cisplatin through their reaction with DNA. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy was applied to analyse the interaction of the Pt^(II) complexes with DNA in the hydrated, dehydrated and rehydrated states. These were compared with control DNA in acetone/water (PFB, TMB) and isotonic saline (cisplatin) under the same conditions. Principle Component Analysis (PCA) was applied to compare the ATR-FTIR spectra of the untreated control DNA with spectra of PFB and TMB treated DNA samples. Disruptions in the conformation of DNA treated with the Pt^(II) complexes upon rehydration were mainly observed by monitoring the position of the IR-band around 1711 cm⁻¹ assigned to the DNA base-stacking vibration. Furthermore, other intensity changes in the phosphodiester bands of DNA at ~1234 cm⁻¹ and 1225 cm⁻¹ and shifts in the dianionic phosphodiester vibration at 966 cm⁻¹ were observed. The isolated double stranded DNA (dsDNA) or single stranded DNA (ssDNA) showed different structural changes when incubated with the studied compounds. PCA confirmed PFB had the most dramatic effect by denaturing both dsDNA and ssDNA. Both compounds, along with cisplatin, induced changes in DNA bands at 1711, 1088, 1051 and 966 cm⁻¹ indicative of DNA conformation changes. The ability to monitor conformational change with infrared spectroscopy paves the way for a sensor to screen for new anticancer therapeutic agents.