The subacute toxicity and underlying mechanisms of biomimetic mesoporous polydopamine nanoparticles.

Recently, mesoporous nanomaterials with widespread applications have attracted great interest in the field of drug delivery due to their unique structure and good physiochemical properties. As a biomimetic nanomaterial, mesoporous polydopamine (MPDA) possesses both a superior nature and good compatibility, endowing it with good clinical transformation prospects compared with other inorganic mesoporous nanocarriers. However, the subacute toxicity and underlying mechanisms of biomimetic mesoporous polydopamine nanoparticles remain uncertain. Herein, we prepared MPDAs by a soft template method and evaluated their primary physiochemical properties and metabolite toxicity, as well as potential mechanisms. The results demonstrated that MPDA injection at low (3.61 mg/kg) and medium doses (10.87 mg/kg) did not significantly change the body weight, organ index or routine blood parameters. In contrast, high-dose MPDA injection (78.57 mg/kg) is associated with disturbances in the gut microbiota, activation of inflammatory pathways through the abnormal metabolism of bile acids and unsaturated fatty acids, and potential oxidative stress injury. In sum, the MPDA dose applied should be controlled during the treatment. This study first provides a systematic evaluation of metabolite toxicity and related mechanisms for MPDA-based nanoparticles, filling the gap between their research and clinical transformation as a drug delivery nanoplatform.

Collagen changes in rabbit conjunctiva after conjunctival crosslinking.

This study aims to determine the ultrastructural changes in collagen fibrils in rabbit conjunctiva after conjunctival crosslinking using riboflavin and ultraviolet A (UVA) light at an irradiation intensity of 45 mW/cm2. Conjunctival crosslinking may increase conjunctival stiffness. The supertemporal quadrants of the right eyes of 24 adult rabbits were treated with a topical riboflavin solution (0.25%) before irradiation with UVA light at 45 mW/cm2 for 4 min. After 3 weeks, the collagen fibrils in fibril bundles were examined by electron microscopy. Immunohistochemical staining was used to detect the expression levels of collagen I and collagen III in the rabbits' conjunctiva. The diameter of the collagen fibrils in the fibril bundles varied slightly, ranging from 30 to 60 nm in the conjunctival stroma of the control group. In the treatment group, the diameter of collagen fibrils ranged from 60 to 90 nm. The thickest collagen fibrils were observed in the treatment group (up to 90 nm in diameter). In contrast, those in the conjunctival stroma of the control group were considerably smaller (up to 60 nm in diameter). However, thicknesses of collagen fibrils displayed a unimodal distribution. Both collagen I and collagen III increased after treatment with riboflavin and UVA light irradiation at 45 mW/cm2. The data indicate that in rabbits, conjunctival crosslinking with riboflavin and UVA light at 45 mW/cm2 for 4 min is safe and does not induce ultrastructural alterations of the conjunctival cells. The conjunctival crosslinking with riboflavin and UVA light at 45 mW/cm2 can increase the diameter of collagen fibrils, but the average densities of collagen I and collagen III have no statistical significance.

Dynamic structural evolution of lignin macromolecules and hemicelluloses during Chinese pine growth.

To comprehend the biosynthesis processes of conifers, it is essential to investigate the disparity between the cell wall shape and the interior chemical structures of polymers throughout the development of Chinese pine. In this study, branches of mature Chinese pine were separated according to their growth time (2, 4, 6, 8 and 10 years). The variation of cell wall morphology and lignin distribution was comprehensively monitored by scanning electron microscopy (SEM) and confocal Raman microscopy (CRM), respectively. Moreover, the chemical structures of lignin and alkali-extracted hemicelluloses were extensively characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The thickness of latewood cell walls increased steadily from 1.29 µm to 3.38 µm, and the structure of the cell wall components became more complicated as the growth time increased. Based on the structural analysis, it was found that the content of ß-O-4 (39.88-45.44/100 Ar), ß-ß (3.20-10.02/100 Ar) and ß-5 (8.09-15.35/100 Ar) linkages as well as the degree of polymerization of lignin increased with the growth time. The complication propensity increased significantly over 6 years before slowing to a trickle over 8 and 10 years. Furthermore, alkali-extracted hemicelluloses of Chinese pine mainly consist of galactoglucomannans and arabinoglucuronxylan, in which the relative content of galactoglucomannans increased with the growth of the pine, especially from 6 to 10 years.

The design of small-molecule prodrugs and activatable phototherapeutics for cancer therapy.

Cancer remains as one of the most significant health problems, with approximately 19 million people diagnosed worldwide each year. Chemotherapy is a routinely used method to treat cancer patients. However, current treatment options lack the appropriate selectivity for cancer cells, are prone to resistance mechanisms, and are plagued with dose-limiting toxicities. As such, researchers have devoted their attention to developing prodrug-based strategies that have the potential to overcome these limitations. This tutorial review highlights recently developed prodrug strategies for cancer therapy. Prodrug examples that provide an integrated diagnostic (fluorescent, photoacoustic, and magnetic resonance imaging) response, which are referred to as theranostics, are also discussed. Owing to the non-invasive nature of light (and X-rays), we have discussed external excitation prodrug strategies as well as examples of activatable photosensitizers that enhance the precision of photodynamic therapy/photothermal therapy. Activatable photosensitizers/photothermal agents can be seen as analogous to prodrugs, with their phototherapeutic properties at a specific wavelength activated in the presence of disease-related biomarkers. We discuss each design strategy and illustrate the importance of targeting biomarkers specific to the tumour microenvironment and biomarkers that are known to be overexpressed within cancer cells. Moreover, we discuss the advantages of each approach and highlight their inherent limitations. We hope in doing so, the reader will appreciate the current challenges and available opportunities in the field and inspire subsequent generations to pursue this crucial area of cancer research.

Using patient-derived organoids to predict locally advanced or metastatic lung cancer tumor response: A real-world study.

Predicting the clinical response to chemotherapeutic or targeted treatment in patients with locally advanced or metastatic lung cancer requires an accurate and affordable tool. Tumor organoids are a potential approach in precision medicine for predicting the clinical response to treatment. However, their clinical application in lung cancer has rarely been reported because of the difficulty in generating pure tumor organoids. In this study, we have generated 214 cancer organoids from 107 patients, of which 212 are lung cancer organoids (LCOs), primarily derived from malignant serous effusions. LCO-based drug sensitivity tests (LCO-DSTs) for chemotherapy and targeted therapy have been performed in a real-world study to predict the clinical response to the respective treatment. LCO-DSTs accurately predict the clinical response to treatment in this cohort of patients with advanced lung cancer. In conclusion, LCO-DST is a promising precision medicine tool in treating of advanced lung cancer.

Structure regulated 3D flower-like lignin-based anode material for lithium-ion batteries and its storage kinetics.

As a green sustainable material, lignin-derived porous carbon (LPC) exhibits great application potential when used as the anode material in lithium-ion batteries (LIBs), but the applications are limited by the heterogeneity of the lignin precursor. Therefore, it is crucial to reveal the relationship among lignin properties, porous carbon structure and the kinetics of lithium-ion storage. Herein, LPCs from fractionated lignin have been prepared by an eco-friendly and recyclable activator. The structure of the LPCs was regulated by adjusting the molecular weight, linkage abundance and glass transition temperature (Tg) of lignin macromolecules. As the anode material of LIBs, the prepared 3D flower-like LPCE70 could achieve a reversible capacity of 528 mAh g-1 at a current density of 0.2 A g-1 after 200 cycles, 63 % higher than that of commercial graphite. Furthermore, kinetic calculations of lithium-ion storage behavior of LPCs were firstly used to confirm the contribution ratio of diffusion-controlled behavior and capacitive effect. Lignin with a high linkage abundance could yield LPCE70 with the largest interlayer spacing and specific surface area to maximize lithium-ion storage from both diffusion-controlled and capacitive contributions of specific capacities. This work provides a green, facile and effective pathway for value-added utilization of lignin in LIBs.

Fractionation of technical lignin and its application on the lignin/poly-(butylene adipate-co-terephthalate) bio-composites.

Complex and heterogeneous structures of lignin impede its further conversion and valorization. Herein, three technical lignins (from softwood, hardwood, and grass) were fractionated with acetone solvent to reduce their structural heterogeneity, which were then blended with poly-(butylene adipate-co-terephthalate) (PBAT) to fabricate biodegradable bio-composites. Macromolecular structures of lignins and their effects on the properties of lignin/PBAT composites were thoroughly investigated. Results showed that all fractionated lignin composites displayed better properties. Particularly, the raw and fractionated softwood lignin-based composites exhibited superior performance compared with others. Benefiting from the lower molecular weight, hydroxyl groups, and condensation, acetone fractionated softwood lignin presented the lowest Tg (115.7 °C), achieving ideal melt miscibility and interfacial interaction between lignin and PBAT. The decreased Tg of lignin facilitated the lignin dispersion in the matrix and increase the mechanical strength of the composites. Overall, the fractionated technical lignin possessed desirable physical and chemical structure features, conferring composites good miscibility and mechanical properties.

Clinical outcomes of EGFR+/METamp+ vs. EGFR+/METamp- untreated patients with advanced non-small cell lung cancer.

BACKGROUND: MET dysregulation has been implicated in the development of primary and secondary resistance to EGFR tyrosine kinase inhibitor (TKI) therapy. However, the clinicopathological characteristics and outcomes of patients harboring EGFR-sensitive mutations and de novo MET amplifications still need to be explored. METHODS: A total of 54 patients from our hospital with non-small cell lung cancer harboring EGFR-sensitive mutations and/or de novo MET amplifications were included in this study. Survival rates were estimated by the Kaplan-Meier method with log-rank statistics. Lung cancer organoids (LCOs) were generated from patient-derived malignant pleural effusion to perform drug sensitivity assays. RESULTS: Fifty-four patients with the appropriate clinicopathological characteristics were enrolled. MET FISH was performed in 40 patients who were stratified accordingly into two groups: EGFR+/METamp- (n = 22) and EGFR+/METamp + (n = 18). Survival rates for EGFR+/METamp- and EGFR+/METamp + patients respectively, were as follows: the median progression-free survival (PFS) was 12.1 and 1.9 months (p<0.001); the median post-progression overall survival (pOS) was 25.6 and 11.6 months (p = 0.023); the median overall survival (OS) was 33.2 and 12.7 months (p = 0.013). Drug testing conducted in LCOs derived from malignant pleural effusion from EGFR+/METamp + patients showed that dual targeted therapy was more effective than TKI monotherapy. CONCLUSION: EGFR+/METamp + patients treated with first-line TKI monotherapy had poor clinical outcomes. Dual targeted therapy showed potent anticancer activity in the LCO drug testing assay, suggesting that it is a promising first-line treatment for EGFR+/METamp + patients. Randomized controlled trials are needed to further validate these results.

Dual-Channel Fluorescent Probe for the Simultaneous Monitoring of Peroxynitrite and Adenosine-5'-triphosphate in Cellular Applications.

Changes in adenosine triphosphate (ATP) and peroxynitrite (ONOO-) concentrations have been correlated in a number of diseases including ischemia-reperfusion injury and drug-induced liver injury. Herein, we report the development of a fluorescent probe ATP-LW, which enables the simultaneous detection of ONOO- and ATP. ONOO- selectively oxidizes the boronate pinacol ester of ATP-LW to afford the fluorescent 4-hydroxy-1,8-naphthalimide product NA-OH (λex = 450 nm, λem = 562 nm or λex = 488 nm, λem = 568 nm). In contrast, the binding of ATP to ATP-LW induces the spirolactam ring opening of rhodamine to afford a highly emissive product (λex = 520 nm, λem = 587 nm). Due to the differences in emission between the ONOO- and ATP products, ATP-LW allows ONOO- levels to be monitored in the green channel (λex = 488 nm, λem = 500-575 nm) and ATP concentrations in the red channel (λex = 514 nm, λem = 575-650 nm). The use of ATP-LW as a combined ONOO- and ATP probe was demonstrated using hepatocytes (HL-7702 cells) in cellular imaging experiments. Treatment of HL-7702 cells with oligomycin A (an inhibitor of ATP synthase) resulted in a reduction of signal intensity in the red channel and an increase in that of the green channel as expected for a reduction in ATP concentrations. Similar fluorescence changes were seen in the presence of SIN-1 (an exogenous ONOO- donor).

Discovery of a Potential Liver Fibrosis Inhibitor from a Mushroom Endophytic Fungus by Genome Mining of a Silent Biosynthetic Gene Cluster.

Liver fibrosis has accounted for liver diseases and overall mortality, but no relevant drug has been developed. Filamentous fungi are important resources of natural products for pharmaceutical development. Calcarisporium arbuscula is a mushroom endophytic fungus, which primarily produces aurovertins. Here, in an aurovertin null-production mutant, one silent gene cluster (mca17) was activated by overexpression of a pathway-specific zinc finger transcriptional regulator, and a tetramic acid-type compound (1, MCA17-1) was identified. Along with detailed structural characterization, its biosynthesis was proposed to be produced from the core PKS-NRPS hybrid enzyme. Moreover, 1 suppressed the activation of LX-2 upon transforming growth factor-ß (TGF-ß) challenge and had stronger bioactivity than the positive control obeticholic acid (OCA) against liver fibrosis. Our work suggested that this engineered fungus could be a producer of 1 for promising pharmaceutical development, and alternatively, it would be developed as a mushroom ingredient in dietary therapy to prevent liver fibrosis.

Selectivity Comparison of Tumor-Imaging Probes Designed Based on Various Tumor-Targeting Strategies: A Proof of Concept Study.

Fluorescence probes are emerging as appealing tools for tumor imaging, although the discovery of ideal probes with high tumor selectivity and desirable tumor-to-normal contrast remains challenging. There are currently two strategies used for designing tumor-targeted probes. One is employing tumor-targeting agents and the other is tumor-microenvironment-activatable probes. Although these two strategies have been widely explored, there are few reports on the comparison of probe performance designed based on the two strategies. Herein, by targeting somatostatin receptors (SSTR) overexpressed in neuroendocrine tumors with octreotide (OCT), we have designed two probes, with probe P5 being tumor-microenvironment-activatable and P5cc3 having fluorescence always on. A comparison of their selectivity toward tumor cells over SSTR-expressing normal cells demonstrated that these two probes showed a similar degree of tumor selectivity, whereas the activatable probe P5 showed enhanced tumor-to-normal imaging contrast due to its tumor-microenvironment-activatable fluorescence. Our results consolidate the rationality of either strategy for designing tumor-targeted imaging agents, and highlight the activatable strategy as a feasible way of enhancing tumor-to-normal imaging contrast.

Effect of integrated treatment on improving the enzymatic digestibility of poplar and the structural features of isolated hemicelluloses.

Herein, a two-step hydrothermal pretreatment combined with alkali extraction method was applied to deconstruct the poplar cell walls for enzymatic hydrolysis. Results revealed that 88.1 % of hemicelluloses and 77.6 % of lignin were removed during the integrated treatment performed at 180 °C and a maximum enzymatic hydrolysis efficiency of 96.1 % was achieved. Confocal Raman microscopy suggested that the removal of hemicelluloses from cell walls was inhomogeneous, and most hemicelluloses were released from the secondary wall. In addition, 35.2-56.8 % of hemicelluloses were isolated from the integrated treatment. Detailed structural analysis revealed that the water-soluble hemicelluloses possessed more branched structure than the alkali-soluble hemicelluloses and the hemicelluloses isolated from the poplar were mainly composed of a linear backbone of (1→4)-ß-d-Xylp with 4-O-Me-α-d-GlcpA attached as side chains. This work provides an efficient pathway to transform poplar into fermentable sugars and hemicelluloses with considerable yield.

Structural elucidation of lignin macromolecule from abaca during alkaline hydrogen peroxide delignification.

To maximize the utilization of Abaca lignin in the current biorefinery, structural characteristics of native lignin from Abaca were firstly comprehensively investigated. Parallelly, effective delignification of Abaca was achieved by alkaline hydrogen peroxide (AHP) process, which facilitated the production of specialty paper in industry. The structural changes of lignin macromolecules during the AHP delignification were illustrated by comparing the structural differences of the released lignin fraction and corresponding native lignin, which were analyzed via the advanced analytical methods, such as 2D-HSQC NMR, 31P NMR, pyrolysis-GC/MS, and GPC techniques. It was found that Abaca lignin is a HGS-type lignin, which is overwhelmingly composed of ß-O-4 linkages and abundant hydroxycinnamic acids (mainly p-coumaric acid). In addition, partial cleavage of ß-O-4 linkages and p-coumarate in lignin occurred during the AHP delignification process. Meanwhile, AHP process also led to the elevation of H-type lignin units in AHPL. Considering that ß-O-4 bond is vulnerable in the catalytic degradation process of lignin, the lignin with abundant ß-O-4 linkages is beneficial to the downstream conversion of lignin into aromatic chemicals.

Comparative study of hemicelluloses from Hybrid Pennisetum via a green and clean integrated process.

In this study, a green and clean integrated process based on microwave-assisted hydrothermal pretreatment (MHTP) and subsequent alkali post-treatment was performed to isolate and characterize water- and alkali-soluble hemicelluloses (SHs and AHs) from Hybrid Pennisetum (HP) as well as to improve the enzymatic digestibility of HP. Meanwhile, part of hemicelluloses was degraded into the value-added xylo-oligosaccharides (XOS) during the MHTP process, which would be applied to the food and pharmaceuticals industries. State-of-the-art analytical techniques (e.g., HPLC, HPAEC, GPC, and 2D-HSQC) were used to investigate the main component streams (SHs, AHs, XOS, and glucose). Results showed that the structural characteristic of SHs and AHs was mainly composed of ß-(1→4)-linked xylans. Additionally, the enzymatic digestibility of the cellulose-rich substrate (A190(10)) was 92.8%, which was 3.4 times higher than that of raw material (27.4%). In short, the proposed integrated process was considered as a promising biorefinery strategy for both hemicellulose-based products and bioethanol.

Amination of biorefinery technical lignins using Mannich reaction synergy with subcritical ethanol depolymerization.

The alcoholic depolymerization and Mannich reaction were conducted to improve the chemical activity of biorefinery technical lignins and introduce amino groups into lignins, respectively. To understand the chemical structural transformations and examine the reaction mechanism, GPC and solution-state NMR techniques were performed. Element analysis was also used to quantify the amount of amine groups. The NMR characterization the depolymerized lignins indicated of the depolymerization, demethoxylation, and bond cleavage of linkages occurred during the depolymerization process. Results showed that the depolymerization temperature instead of the addition of capping reagents was the main factor for improving the reactivity of lignin under the given conditions. The Mannich reaction was very selective, primarily occurred at H3,5 and G5 positions, and the H units present a higher chemical reactivity. It is believed that the understanding of the fundamental chemistry of lignin during depolymerization and Mannich reaction process will contribute to the extension of high value-added applications of biorefinery lignin.

Assessment of integrated process based on autohydrolysis and robust delignification process for enzymatic saccharification of bamboo.

In this study, bamboo (Phyllostachys pubescens) was successfully deconstructed using an integrated process (autohydrolysis and subsequent delignification). Xylooligosaccharides, high-purity lignin, and digestible substrates for producing glucose can be consecutively collected during the integrated process. The structural change and fate of lignin during autohydrolysis process was deeply investigated. Additionally, the structural characteristics and active functional groups of the lignin fractions obtained by these delignification processes were thoroughly investigated by NMR (2D-HSQC and 31P NMR) and GPC techniques. The chemical compositions (S, G, and H) and major linkages (ß-O-4, ß-ß, ß-5, etc.) were thoroughly assigned and the frequencies of the major lignin linkages were quantitatively compared. Considering the structural characteristics and molecular weights of the lignin as well as enzymatic saccharification ratio of the substrate, the combination of autohydrolysis and organic base-catalyzed ethanol pretreatment was deemed as a promising biorefinery mode in the future based on bamboo feedstock.

Expressions of matrix metalloproteinases 1 and 3 and their tissue inhibitors in the conjunctival tissue and fibroblasts cultured from conjunctivochalasis.

AIM: To investigate the expression of matrix metalloproteinases 1 and 3 (MMP-1 and MMP-3) and their tissue inhibitors of metalloproteinases 1 and 3 (TIMP-1 and TIMP-3) in the conjunctiva of eyes with conjunctivochalasis (CCh). METHODS: The conjunctival tissue was obtained from the CCh patients and controls, the MMPs/TIMPs expression concentration was determined by enzyme-linked immuno-sorbent assay (ELISA) and immunofluorescence staining. The expression levels of MMPs/TIMPs in the CCh fibro-blasts were determined by analyzing its concentration in the cellular supernatant that was abstracted from the in vitro cultured CCh fibroblasts. RESULTS: MMP-1 and MMP-3 levels determined by ELISA were both significantly higher in the CCh group than that in the control group (P=0.042, 0.022, respectively), so was the levels of TIMP-1 (P=0.010). No significant difference in the expression of TIMP-3 in conjunctiva was found between the two groups (P=0.298). The expression of MMP-1 and MMP-3 were both up-regulated significantly in the CCh group (P=0.040, 0.001, respectively) on immuno-fluorescence staining. MMP-1 and MMP-3 expression in the fibroblasts were both significantly higher in the CCh group than that in the control group (P=0.027, 0.001, respectively), while neither the TIMP-1 nor TIMP-3 expression was significantly different between the two groups (P=0.421, 0.237, respectively). CONCLUSION: The overexpression of MMP-1 and MMP-3 in conjunctival tissue and fibroblasts may play an important role in the pathogenesis and development of CCh.

Lower eyelid tension in young adults determined by a simple lid tensiometer.

PURPOSE: Eyelid tension seems to be related to corneal astigmatism and to affect the ocular surface. The aim of this study is to determine the lower eyelid tension in young adults with a simple lid tensiometer. METHODS: A commercially available precision digital pressure gauge that was connected to a pressure-guided tube full of water with a sensor at its end being placed between the lower eyelid and ocular surface was used as the lid tensiometer to measure the lower eyelid pressure at the central lid in 8 male and 12 female subjects aged between 20 and 39 years with normal healthy eyes. Measurements were respectively performed by 2 operators under the same conditions to test possible interoperator variation. RESULTS: The lower eyelid pressures of the 20 subjects measured by 2 operators at the central lid were 445.28 ± 121.17 and 458.65 ± 127.15 Pa, respectively. The test of interoperator variation demonstrated that there was good agreement between 2 operators (intraclass correlation coefficient = 0.965, F = 56.09, P < 0.001). CONCLUSIONS: Our simple lid tensiometer is a viable option for measuring eyelid pressure with good repeatability.

Comparison study of two diagnostic and grading systems for conjunctivochalasis.

BACKGROUND: Different diagnostic and grading systems of conjunctivochalasis have resulted in apparent disparity between the prevalence rates of recent population-based studies. This study aimed to investigate the disparity between 4-level system cited from Meller and Tseng in 1998 (abbreviated here as Meller's system) and 5-level system modified from Meller's system cited from Zhang and associates (abbreviated here as Zhang's system) regarding the diagnosis and the patients' preferences for the treatment of conjunctivochalasis in the general population. METHODS: A total of 546 senile residents living in the Guiyangyuan community of Shanghai, China, participated in the study. The diagnostic criteria for conjunctivochalasis were based on two diagnostic grading systems: Meller's system and Zhang's system, which was modified from Meller's system. The participants' preference regarding medical treatment for conjunctivochalasis was determined according to the response to a question. One year later, a follow-up interview determines whether the patient had undergone surgery for conjunctivochalasis. RESULTS: With Meller's system, 398 participants were confirmed as having conjunctivochalasis, and the prevalence rate was 72.89%. According to Zhang's system, only 213 participants were diagnosed as having conjunctivochalasis, and the prevalence rate was 39.01%. A total of 109 eyes underwent medical treatment or surgery for conjunctivochalasis in the following year, including eight eyes that were diagnosed as grade II and 101 eyes that were diagnosed as grade III according to Meller's system and five eyes that were diagnosed as grade I, 55 eyes that were diagnosed as grade II, 31 eyes that were diagnosed as grade III, and 18 eyes that were diagnosed as grade IV according to Zhang' system. CONCLUSION: Diagnoses of conjunctivochalasis using Zhang's system are more consistent with patient requests and the medical treatment strategies used than diagnoses made using Meller's system.