In Vivo Delivery Processes and Development Strategies of Lipid Nanoparticles.

Lipid nanoparticles (LNPs) represent an advanced and highly efficient delivery system for RNA molecules, demonstrating exceptional biocompatibility and remarkable delivery efficiency. This is evidenced by the clinical authorization of three LNP formulations: Patisiran, BNT162b2, and mRNA-1273. To further maximize the efficacy of RNA-based therapy, it is imperative to develop more potent LNP delivery systems that can effectively protect inherently unstable and negatively charged RNA molecules from degradation by nucleases, while facilitating their cellular uptake into target cells. Therefore, this review presents feasible strategies commonly employed for the development of efficient LNP delivery systems. The strategies encompass combinatorial chemistry for large-scale synthesis of ionizable lipids, rational design strategy of ionizable lipids, functional molecules-derived lipid molecules, the optimization of LNP formulations, and the adjustment of particle size and charge property of LNPs. Prior to introducing these developing strategies, in vivo delivery processes of LNPs, a crucial determinant influencing the clinical translation of LNP formulations, is described to better understand how to develop LNP delivery systems.

Prognostic Value of QRS Duration in Patients with Dilated Cardiomyopathy According to Left Ventricular Ejection Fraction.

Background: The prognostic significance of QRS duration (QRSd) in patients with dilated cardiomyopathy (DCM) and a left ventricular ejection fraction (LVEF) between 30% and 50% is unclear, resulting in questions regarding eligibility for cardiac resynchronisation therapy. This study aimed to explore the prognostic role of QRSd in patients with DCM and a LVEF 30-50% or LVEF < 30. Methods: Patients hospitalised at Fuwai hospital with DCM who had a LVEF ≤ 50% were prospectively included. The primary outcomes were a composite of death, heart transplantation, and rehospitalisation for worsening heart failure. Results: Among the 633 patients included, 302 (47.7%) had a LVEF of 30-50%. The multivariable hazard ratio (HR) for QRSd ≥ 120 ms was 1.65 (95% confidence interval [CI] 1.29-2.11, p < 0.001) for overall DCM patients, 2.8 (95% CI 1.82-4.30, p < 0.001) for patients with LVEF 30-50%, and 1.41 (95% CI 1.02-1.94, p = 0.036) for patients with LVEF < 30%. QRSd ≥ 120 ms tended to be more strongly associated with outcome in patients with LVEF 30-50% than in those with LVEF < 30% despite the non-significant interaction (p = 0.067). DCM patients with QRSd ≥ 120 ms and LVEF 30-50% did not experience a significantly better outcome than those with LVEF < 30% and QRSd < 120 ms after propensity-score matching (HR 0.91, 95% CI 0.61-1.36, p = 0.645). Conclusions: QRSd independently predicts prognosis in DCM patients irrespective of LVEF and identifies a group of high-risk patients who may benefit from device implantation despite the absence of severely reduced LVEF.

Photocatalytic synthesis of alkynylsulfones and alkenylsulfones using sulfonylhydrazides and alkynes.

An efficient and energy saving photocatalytic coupling reaction of benzenesulfonyl hydrazide with bromoacetylene has been reported. A series of alkynylsulfones were obtained in up to 98% yield. In addition, changing the base from KHCO3 to KOAc can give the alkenylsulfone product. In addition, we tested the biological activity of some alkynylsulfone compounds and found that they exhibited excellent in vitro antioxidant activity by activating the Nrf2/ARE pathway, up to 8 fold.

Comparison and application of SOFM, fuzzy c-means and k-means clustering algorithms for natural soil environment regionalization in China.

Soil attributes and their environmental drivers exhibit different patterns in different geographical directions, along with distinct regional characteristics, which may have important effects on substance migration and transformation such as organic matter and soil elements or the environmental impacts of pollutants. Therefore, regional soil characteristics should be considered in the process of regionalization for environmental management. However, no comprehensive evaluation or systematic classification of the natural soil environment has been established for China. Here, we established an index system for natural soil environmental regionalization (NSER) by combining literature data obtained based on bibliometrics with the analytic hierarchy process (AHP). Based on the index system, we collected spatial distribution data for 14 indexes at the national scale. In addition, three clustering algorithms-self-organizing feature mapping (SOFM), fuzzy c-means (FCM) and k-means (KM)-were used to classify and define the natural soil environment. We imported four cluster validity indexes (CVI) to evaluate different models: Davies-Bouldin index (DB), Silhouette index (Sil) and Calinski-Harabasz index (CH) for FCM and KM, clustering quality index (CQI) for SOFM. Analysis and comparison of the results showed that when the number of clusters was 13, the FCM clustering algorithm achieved the optimal clustering results (DB = 1.16, Sil = 0.78, CH = 6.77 × 106), allowing the natural soil environment of China to be divided into 12 regions with distinct characteristics. Our study provides a set of comprehensive scientific research methods for regionalization research based on spatial data, it has important reference value for improving soil environmental management based on local conditions in China.

Electroencephalography Signal Processing: A Comprehensive Review and Analysis of Methods and Techniques.

The electroencephalography (EEG) signal is a noninvasive and complex signal that has numerous applications in biomedical fields, including sleep and the brain-computer interface. Given its complexity, researchers have proposed several advanced preprocessing and feature extraction methods to analyze EEG signals. In this study, we analyze a comprehensive review of numerous articles related to EEG signal processing. We searched the major scientific and engineering databases and summarized the results of our findings. Our survey encompassed the entire process of EEG signal processing, from acquisition and pretreatment (denoising) to feature extraction, classification, and application. We present a detailed discussion and comparison of various methods and techniques used for EEG signal processing. Additionally, we identify the current limitations of these techniques and analyze their future development trends. We conclude by offering some suggestions for future research in the field of EEG signal processing.

Human health risk-based Generic Assessment Criteria for agricultural soil in Jiangsu and Zhejiang provinces, China.

Agricultural soil pollution in China poses a major threat to human health and food safety. There are no agricultural soil environmental standards based on human health in China, which prevents effective screening and assessment of risks. Jiangsu (JS) and Zhejiang (ZJ) provinces, located in the Yangtze River Delta (YRD) core region, have obvious differences in agricultural land conditions, which will result in differences in Generic Assessment Criteria (GAC). In this study, we derived and compared human health risk-based GAC using the Contaminated Land Exposure Assessment (CLEA) model for agricultural land scenarios in these two provinces. We found differences in the GAC between JS and ZJ due to differences in parameters. These differences are greatest for benzene, and cadmium (Cd). For Cd, the contribution of oral intake exceeds 90 %, and the vegetable consumption rate and mean daily intake (MDI) may be key parameters affecting GAC. For the volatile organic compound benzene, the inhalation of indoor vapor accounts for about 30 %, and the key parameters affecting the GAC for benzene may be the attenuation factor and soil organic matte (SOM). The derived GAC are generally lager (i.e., less stringent) than the GB15618-2018 and UK Suitable 4 Use Levels (S4ULs); however, the derived GAC for JS and ZJ were lower than the soil screening values (SSV) for residential land in China. This may be related to methods, land use types, and critical receptors. This work will contribute to the development of regional soil environmental standards in China.

Human health risk-based soil environmental criteria (SEC) for park soil in Beijing, China.

Urban parks are important places that allow urban residents to experience nature but are also associated with the risk of exposure to contaminated soil. Therefore, it is necessary to establish appropriate soil environment criteria (SEC) to manage park soil quality. Studies on the demographic characteristics and behavioral patterns of urban park visitors are helpful for the selection of sensitive receptors and the determination of parameters in the establishment of SEC. This study explored the park visitors' demographic characteristics and behavioral patterns, and applied the results to derive SEC. Eighty-six parks in Beijing were selected, and mobile phone data were obtained to analysis the demographic characteristics and residence time of the visitors. Kruskal-Wallis test, kernel density estimation and random forest model were used for data analysis. The CLEA model was used to derive SEC. The results showed that the demographic characteristics and behavioral patterns of visitors in different types of parks were quite different. Parks were mostly used by males and visitors aged 31-45. Most visitors stayed in the park for 1-2 h, and the distance from a given visitor's home to the park was the most important factor affecting stay time. Then, several parameters such as the parameters related to the receptors and occupation period were optimized, and the SEC of sensitive parks and non-sensitive parks were derived. Exposure frequency may be the main reason for the difference of SEC between the two types of parks. The SECs of sensitive parks were higher than the soil screening values (SSVs) for class 1 land in GB36600-2018, indicating that the current SSVs for some parks may be too conservative. This study provides a reference for the formulation and revision of soil environmental standards for park land, and suggests strengthening research on human behavioral patterns.

Is hand-to-mouth contact the main pathway of children's soil and dust intake?

Children (n = 240) between the ages of 2 and 17 years were randomly selected from three cities in China. The total amount of soil and dust (SD) on their hands was measured and ranged from 3.50-187.39 mg (median = 19.49 mg). We screened for seven elements (Ce, V, Y, Al, Ba, Sc, and Mn), and Ce levels were used to calculate hand SD by variability and soil elements. The main factors affecting SD amount were location and age group, as identified using a conditional inference tree. Hand SD and the hand SD intake rate were highest in Gansu Province, followed by Guangdong and Hubei provinces, respectively. Hand SD and the hand SD intake rate were highest among children in primary school, followed by kindergarten and secondary school, respectively. The hand SD intake rate of the three typical areas was 11.9 mg/d, which was about 26.6% of the children's soil intake rate (44.8 mg/d), indicating that hand-to-mouth contact is not the main route for children's soil intake in the three areas of China.

Selenium (Se) plays a key role in the biological effects of some viruses: Implications for COVID-19.

Host nutrition is an important factor affecting disease progression. Selenium (Se) is an essential trace element for the human body with anti-inflammatory, antioxidant, and immune effects, and Se deficiency increases RNA-virus replication and virulent mutations, which lead to more severe tissue damage and symptoms. Low Se status in the host may be an important cause of health complications induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this article, we describe the metabolic mechanisms by which Se is involved in anti-inflammatory, antioxidant, and immune effects, and review the role and clinical effects of Se in viral infection. We then discuss the potential relationship between Se and coronavirus disease 2019 (COVID-19). The association between soil Se level and the incidence of COVID-19 was observed in different cities of Hubei Province. The incidence of COVID-19 was more than 10 times lower in Se-enriched cities (Enshi, Shiyan, and Xiangyang) than in Se-deficient cities (Suizhou and Xiaogan). Although the relationship between soil Se levels and the incidence of COVID-19 in Hubei still needs further study, these findings provide baseline information demonstrating the effect of Se levels on SARS-CoV-2, which could contribute to the prevention and management of COVID-19.

Status of arsenic accumulation in agricultural soils across China (1985-2016).

Based on 1677 published studies, 1648 sites across China collected from 1985 to 2016 were used to research the concentrations of arsenic in agricultural soils. In order to understand the status of arsenic pollution in agricultural soils in China over the past three decades, and to learn about the arsenic stocks in agricultural soils in various regions, and compared the relationship with annual arsenic emissions in China, and finally evaluated the potential ecological risks and human health risks. The median arsenic concentration in the surface agricultural soils of China was 10.40 mg Kg-1, and it ranged from 0.4 mg Kg-1 to 175.8 mg Kg-1. The inventory of arsenic in Chinese agricultural surface soils was estimated to be 3.71 × 106 t. In this study, the arsenic concentrations were found to be higher in Central, South, and Southwest China than those in other regions. The trend of arsenic pollution in agricultural soils has gradually increased over the past three decades. However, the growth rate of arsenic concentrations pollution in farmlands agricultural in China slowed during 2012-2016. The ecological risk index and geoaccumulation index revealed that arsenic in Chinese agricultural soil poses a low risk to the ecosystem. For human health assessment, the dietary pathway was the main pathway of exposure to arsenic in farmland soil of China. However, children's soil intake also contributed 34.48% to the exposure to arsenic, owing to their behavior. This study can provide a reference for the management of arsenic agricultural pollution in farmland soils in China.

[Chemical constituents from roots of Viburnum setigerum].

This experiment was to study the constituents of the roots of Viburnum setigerum through various column chromatographic techniques. Thirteen compounds were obtained and their structures were identified using chemical and spectroscopic methods as (7αH, 8'αH)-4, 4', 8α-trihydroxy-3, 3', 9-trimethoxy-7, 9'-epoxylignan (1), (7αH, 8'αH)-4, 4', 8α, 9-tetrahydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan (2), alashinol G (3), alashinol F (4), (-)-secoisolariciresinol (5), (7R, 7'R, 8R, 8'S)-3, 3'-dimethoxy-7, 7'-epoxylignane -4, 4', 9, 9'-tetraol (6), (7αH, 8αH, 8'ßH)-4, 4', 7'α, 9-tetrahydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan (7), loganin (8), dihydroquercetin (9), protocatechuic acid (10), 4-hydroxy-3-methoxy-benzoic acid (11), adoxoside (12), and catechin (13). Compound 1 was a new compound. Compounds 3-7 and 11 were reported from the genus Viburnum for the first time. All compounds were separated from this plant for the first time.

Long Non-Coding RNAs in Hepatitis B Virus-Related Hepatocellular Carcinoma: Regulation, Functions, and Underlying Mechanisms.

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer death in the world. Hepatitis B virus (HBV) and its X gene-encoded protein (HBx) play important roles in the progression of HCC. Although long non-coding RNAs (lncRNAs) cannot encode proteins, growing evidence indicates that they play essential roles in HCC progression, and contribute to cell proliferation, invasion and metastasis, autophagy, and apoptosis by targeting a large number of pivotal protein-coding genes, miRNAs, and signaling pathways. In this review, we briefly outline recent findings of differentially expressed lncRNAs in HBV-related HCC, with particular focus on several key lncRNAs, and discuss their regulation by HBV/HBx, their functions, and their underlying molecular mechanisms in the progression of HCC.

[Research on Chemical Constituents and Anti-tumor Activity of Eupatorium chinense].

Objective: To study the chemical constituents and their anti-tumor activity of Eupatorium chinense. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Conclusion: Compounds 2 ~ 5 are isolated from the Eupatorium chinense for the first time,and compound 2 has significant cytotoxic activity against HGC-27 cell line.

[Effect of echinacoside on replication and antigen expression of hepatitis B virus].

To verify the effect of echinacoside on replication and antigen expression of hepatitis B virus (HBV) by using HBV-transfected HepG2. 2. 15 cells as the in vitro model. The ELISA method was used to determine HBeAg and HBsAg levels in cellular supernatants. The effect of echinacoside on HBV replication was studied by using HBV transgenic mice as the in vivo model. First of all, the HBV DNA level in hepatic tissues was quantified with PCR method. Meanwhile, the serum transaminase levels and hepatic pathological changes were also evaluated. Subsequently, HBV transgenic mice were divided into five groups: the control group, the lamivudine group (50 mg · kg(-1)) and echinacoside high, medium and low dose group (50, 25 and 12.5 mg · kg(-1)). The mice were orally administered with drugs once per day for 30 days. At the 31st day, the mice serum was separated to measure HBsAg, HBeAg and HBV DNA. Additionally, the liver HBV DNA level and histopathological change were detected. The results indicated that echinacoside at 50 and 100 mg · L(-1) suppressed significantly HBsAg and HBeAg expressions on the sixth day, with the maximum inhibition ratios of 42.68% and 46.29%; And echinacoside at 100 mg · L(-1) also showed an inhibitory effect on HBV DNA. Besides, echinacoside at 50 mg · kg(-1) inhibited significantly HBsAg and HBeAg expressions of HBV transgenic mice, with the inhibition ratios of 42.82% and 29.12%, and reduced markedly the serum HBV DNA level in HBV transgenic mice. In conclusion, the study suggested that echinacoside has a strong effect against HBV replication and antigen expression.

Evaluation of hepatocyteprotective and anti-hepatitis B virus properties of Cichoric acid from Cichorium intybus leaves in cell culture.

Hepatitis B is the most common serious liver infection in the world. To date, there is still no complete cure for chronic hepatitis B. Natural caffeic acid analogues possess prominent antiviral activity, especially anti-hepatitis B virus (HBV) and anti-human immunodeficiency virus effects. Cichoric acid is a caffeic acid derivative from Cichorium intybus. In the study, the anti-hepatitis B property of cichoric acid was evaluated by the D-galactosamine (D-GalN)-induced normal human HL-7702 hepatocyte injury model, the duck hepatitis B virus (DHBV)-infected duck fetal hepatocytes and the HBV-transfected cell line HepG2.2.15 cells, respectively. The results showed that cichoric acid attenuated significantly D-GalN-induced HL-7702 hepatocyte injury at 10-100 µg/mL and produced a maximum protection rate of 56.26%. Moreover, cichoric acid at 1-100 µg/mL inhibited markedly DHBV DNA replication in infected duck fetal hepatocytes. Also, cichoric acid at 10-100 µg/mL reduced significantly the hepatitis B surface and envelope antigen levels in HepG2.2.15 cells and produced the maximum inhibition rates of 79.94% and 76.41%, respectively. Meanwhile, test compound at 50-100 µg/mL inhibited markedly HBV DNA replication. In conclusion, this study verifies the anti-hepatitis B effect of cichoric acid from Cichorium intybus leaves. In addition, cichoric acid could be used to design the antiviral agents.

Vitamin D-Parathyroid Hormone-Fibroblast Growth Factor 23 Axis and Cardiac Remodeling.

Cardiac remodeling is a compensatory adaptive response to chronic heart failure (HF) altering the structure, function, and metabolism of the heart. Many nutritional and metabolic diseases can aggravate the pathophysiological development of cardiac remodeling. Vitamin D deficiency leads to cardiac remodeling by activating the renin-angiotensin-aldosterone system (RAAS), resulting in enhanced inflammation and directly promoting cardiac fibrosis and extracellular matrix deposition. Hyperparathyroidism upregulates protein kinase A or protein kinase C, enhances intracellular calcium influx, promotes oxidative stress, activates RAAS, and increases aldosterone levels, thereby aggravating cardiac remodeling. Besides, fibroblast growth factor 23 (FGF23) plays a direct role in the heart, resulting in ventricular hypertrophy and myocardial fibrosis. Vitamin D deficiency leads to hyperparathyroidism, which in turn increases the level of FGF23. Elevated levels of FGF23 further inhibit vitamin D synthesis. Evidence exists that vitamin D deficiency, hyperparathyroidism, and marked elevations in FGF23 concentration form a vicious cycle and are believed to contribute directly to cardiac remodeling. Therefore, the purpose of this article is to introduce the specific effects of the above substances on the heart and to explain the significance of understanding the vitamin D-parathyroid hormone-FGF23 axis in improving or even reversing cardiac remodeling, thus contributing to the treatment of patients with HF.

Association of point-of-care testing for sST2 with clinical outcomes in patients hospitalized with heart failure.

AIMS: This study aimed to investigate the association of soluble suppression of tumorigenicity-2 (sST2) measured by point-of-care testing assay with clinical outcomes in patients hospitalized with heart failure after adjusting for other predictors including N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT). METHODS: A total of 1726 consecutive patients hospitalized with heart failure from July 2015 to December 2021 were enrolled. Baseline serum sST2 concentrations were measured by immunofluorescence assay. Primary endpoint event was the composite of all-cause death, heart transplantation, or left ventricular assist device. RESULTS: During the median follow-up duration of 682 days, 434 patients (25.1%) suffered from primary endpoint events. Baseline sST2 remained an independent predictor of the primary endpoint event in patients hospitalized with heart failure after adjusting for other predictors including NT-proBNP and hs-cTnT [per log (unit) increase, adjusted hazard ratio (HR) (95% confidence interval) (CI): 1.20 (1.09, 1.32), P < 0.001]. And baseline sST2 had a better prognostic value for patients with chronic decompensated heart failure [per log (unit) increase, adjusted HR (95% CI): 1.19 (1.07, 1.31)] than for those with acute new onset heart failure [per log (unit) increase, adjusted HR (95% CI): 1.28 (0.94, 1.75), P value for interaction <0.001], as well as a better prognostic value for patients with New York Heart Association (NYHA) functional class I-II [per log (unit) increase, adjusted HR (95% CI): 1.67 (1.11, 2.52)] than for those with NYHA functional class III-IV [per log (unit) increase, adjusted HR (95% CI): 1.18 (1.07, 1.31), P value for interaction <0.001]. Baseline sST2 was also a good predictor of the primary endpoint event in patients hospitalized with heart failure at 1 month, 3 months, 1 year and 2 years (area under the curve: 0.789, 0.775, 0.736 and 0.733, respectively), and the best cut-off values were 27.2 ng/ml, 27.1 ng/ml, 27.1 ng/ml and 25.1 ng/ml, respectively. Furthermore, baseline sST2 could provide additional prognostic value when added to baseline NT-proBNP and hs-cTnT (all P values <0.05). According to the category of elevated biomarkers (including NT-proBNP, hs-cTnT, and sST2), patients with three elevated biomarkers had a higher risk of the primary endpoint event compared with those with one or two elevated biomarkers (all P values <0.05). CONCLUSIONS: Baseline sST2 remained an independent predictor of adverse events after adjusting for other predictors including NT-proBNP and hs-cTnT, particularly in patients with chronic decompensated heart failure and NYHA functional class I-II. And in the basis of baseline NT-proBNP and hs-cTnT, adding baseline sST2 could provide additional prognostic value for patients hospitalized with heart failure.

Combinatorial synthesis and high-throughput screening of alkyl amines for nonviral gene delivery.

Efficient delivery of plasmid DNA and siRNA into cells is essential for biological and biomedical research. Although significant efforts have been made to develop efficient nonviral vectors, such as cationic lipids and polymers, most of the vectors require multistep synthesis, which complicates both fast structural optimizations and combinatorial synthesis of such vectors. Here, we present a facile, single-step method based on an alkylation of amines, allowing for the fast parallel synthesis of libraries of cationic lipid-like molecules (lipidoids). We exploited the method to synthesize 200 lipidoids, which were screened for their transfection efficiency in HEK293T cells. The screen resulted in about 2% of new lipidoids capable of efficient cell transfection similar or higher than the efficiency of Lipofectamine 2000. In addition, we observed an enhancement of cellular transfection by combining single- with double-chain lipidoids, which was attributed to the different roles of the single- and double-tailed lipids in the mixed liposomes.

Switching the chemoselectivity of perakine reductase for selective reduction of α,ß-unsaturated ketones by Arg127 mutation.

The chemoselectivity of perakine reductase (PR) was engineered through rational design. We identified Arg127 as a control site of chemoselectivity. Mutation of Arg127 switched the chemoselectivity of PR between CO and CC or led to non-selectivity towards α,ß-unsaturated ketones, leading to the production of allylic alcohols, saturated ketones, or a mixture of both. This study provides an example for developing novel reductases for α,ß-unsaturated ketones.

Availability, Functionality, and Safety as well as Quality Control of Hepatocytes as Seeding Cells in Liver Regenerative Medicine: State of the Art and Challenges.

Hepatic disease is one of the most common causes of death worldwide and has become a global health problem. Liver transplantation is the only effective treatment strategy for patients with hepatic function failure, but the insufficient number of donated healthy livers is the main obstacle limiting this process. To alleviate the demand for donor's livers, alternative approaches are being actively explored using liver tissue engineering principles. Liver tissue engineering consists of three elements, including seeding cells, extracellular matrix, and bioreactors. Among them, seeding cell is the most key factor. In this regard, hepatocyte-based tissue engineering can overcome the above shortages for tissue repair and regeneration in hepatic disorders. Primary human hepatocytes in liver regenerative medicine are the most preferred seeding cells, although limited access to a sufficient number of functional hepatocytes are a major issue due to the difficulties in long-term function maintenance of hepatocyte as well as the lack of availability of healthy donors. Hepatocyte-like cells (HLCs), derived from various stem cells, including non-liver-derived stem cells and liver-derived stem cells, as well as trans-differentiation of other cell types, may provide adequate cell sources and could replace primary human hepatocytes as seeding cells. However, it is still a great difficulty that HLCs generated by stem cell differentiation meet the quality required for clinical therapy. Furthermore, none of the standardized protocols to generate high-quality HLCs is available. Whether primary hepatocytes or HLCs are from various sources, preventing the functional deterioration of hepatocytes or generating fully functional hepatocytes is also a big challenge, respectively. In addition, the adoptions of three-dimensional co-culture systems and some small-molecule compounds contribute to maintaining the hepatic functionality of primary hepatocytes and enhancing the liver-specific functions of HLCs. In short, hepatocyte-based liver regenerative medicine is an attractive alternative strategy for liver diseases, notwithstanding some challenges still exist from bench to bedside. This review summarizes the current status, issues, and challenges in availability, functionality, and safety, as well as quality control of seeding hepatocytes with regard to liver tissue engineering in regenerative medicine for the treatment of liver disorders.