Alloyed Trimetallic Nanocomposite as an Efficient and Recyclable Solid Matrix for Ideonella sakaiensis Lipase Immobilization.

In this work, a trimetallic (Ni/Co/Zn) organic framework (tMOF), synthesized by a solvothermal method, was calcinated at 400 and 600 °C and the final products were used as a support for lipase immobilization. The material annealed at 400 °C (Ni-Co-Zn@400) had an improved surface area (66.01 m2/g) and pore volume (0.194 cm3/g), which showed the highest enzyme loading capacity (301 mg/g) with a specific activity of 0.196 U/mg, and could protect the enzyme against thermal denaturation at 65 °C. The optimal pH and temperature for the lipase were 8.0 and 45 °C but could tolerate pH levels 7.0-8.0 and temperatures 40-60 °C. Moreover, the immobilized enzyme (Ni-Co-Zn@Lipase, Ni-Co-Zn@400@Lipase, or Ni-Co-Zn@600@Lipase) could be recovered and reused for over seven cycles maintaining 80, 90, and 11% of its original activity and maintained a residual activity >90% after 40 storage days. The remarkable thermostability and storage stability of the immobilized lipase suggest that the rigid structure of the support acted as a protective shield against denaturation, while the improved pH tolerance toward the alkaline range indicates a shift in the ionization state attributed to unequal partitioning of hydroxyl and hydrogen ions within the microenvironment of the active site, suggesting that acidic residues may have been involved in forming an enzyme-support bond. The high enzyme loading capacity, specific activity, encouraging stability, and high recoverability of the tMOF@Lipase indicate that a multimetallic MOF could be a better platform for efficient enzyme immobilization.

Amorphous-crystalline phase transition and intrinsic magnetic property of nickel organic framework for easy immobilization and recycling of ß-Galactosidase.

This work describes the synthesis of fibrous nickel-based metal organic framework (Ni-ZIF) via simple solvothermal method. The material formed was calcinated at 400, 600, 800 °C to improve its surface area, porosity and enzyme binding capacity. Changes in X-ray diffraction pattern after calcination revealed the Ni-ZIF transitioned from amorphous to crystalline structure. The surface area, pore volume and pore size for Ni-ZIF@600 were found to be 312.15 m2/g, 0.88 cm3/g and 10.28 nm, with an enzyme loading capacity of 593.85 mg/g after 30 h The free (ß-Gal-LEH) and immobilized ß-Galactosidase were stable at pH 7.5, temperature 50 °C, and yielded 70.70 and 63.95 mM glucose after milk lactose hydrolysis, respectively. The Ni-ZIF@600@ß-Gal-LEH exhibited high enzyme retention capacity, maintaining 59.44 % of its original activity after 6-cycles. The enhanced magnetic property, enzyme binding capacity and easy recoverability of the calcinated Ni-ZIF could guarantee its industrial significance as immobilization module for enzyme-mediated catalysis.

Analysis of cell-free fetal DNA in 16,843 pregnant women from a single center in China using targeted sequencing approach.

INTRODUCTION: Non-invasive prenatal testing (NIPT) using cell-free fetal DNA (cffDNA) has been widely accepted for detecting common fetal chromosome aneuploidies, but few large-scale studies have reported the kinetics of cffDNA concentration during gestation. This study examines cffDNA kinetics spanning gestational periods. METHODS: In this retrospective cohort study, cffDNA concentration from maternal plasma of 16,843 pregnant women between 4 and 39 weeks of pregnancy were determined by SNP-based targeted deep sequencing. RESULTS: Maternal plasma cffDNA could be detected as early as the fourth gestational week. After detection, cffDNA concentration begun to increase to the 39th week showing three conspicuous inflection points characterized by growth and stabilization phases. The rapid increase in cffDNA (∼1.19% per week) from the 4th to 9th week represents the first growth stage. The first plateau phase spanned from the 10th to 19th week (∼0.03% increase per week). cffDNA begun to rise dramatically (∼0.85% per week) from the 19th to 29th week, stabilizing at week 30 and onwards with only 0.27% increase per week representing the second plateau period. The proportion of cases with cffDNA ≥4% increased rapidly before the 10th gestational week with no significant increase from the 10th week onwards. About 92.00% of all the maternal plasma had a cffDNA greater than 4% from 10 weeks. DISCUSSION: We indicate that cffDNA had 3 inflection points at the 10th, 19th and 30th week of gestation, an observation not yet reported. Moreover, we show that cffDNA concentration has met the NIPT requirements after 9 weeks gestational age.

Development of chimeric antigen receptor-modified T cells for the treatment of esophageal cancer.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is an overexpressed antigen in esophageal squamous cell carcinomas (ESCCs) but with limited expression levels in normal esophageal tissues. Therefore, employing the adoptive transfer of T cells genetically modified to express chimeric antigen receptor (CAR) targeting HER2 could be a promising therapeutic strategy against ESCC. METHODS: Two different second-generation CAR-T cells expressing antibodies for HER2 and CD19 antigens were developed using retroviral vector transduction. The expression of HER2 antigen in ESCC tissue and cell lines was examined by immunohistochemistry and flow cytometry, respectively. The tumor killing efficacy of the CAR-T cells in mice model and ESCC cell lines and its potential for the treatment of ESCC was evaluated by determining tumor size in mice xenograft, and by crystal violet staining, MTS assay, and cytokine release. RESULTS: In vitro, HER2.CAR-T cells efficiently recognized and killed HER2-positive tumor cells as evidenced by the secretion of proinflammatory cytokines, interferon-γ, and interleukin 2 and by cytotoxicity assays. In vivo, intratumor injection of HER2.CAR-T cells resulted in a significant suppression of established ESCCs in a subcutaneous xenograft BALB/c nude mouse model. In contrast, the injection of CD19.CAR-T cells did not affect the tumor growth pattern. CONCLUSIONS: An effective HER2 CAR targeting ESCC was developed successfully. The HER2.CAR-T cell showed promising immunotherapeutic potential for the treatment of HER2-positive esophageal cancer.

Technical integrative approaches to cheese whey valorization towards sustainable environment.

Whey, a byproduct of cheese production, is often treated as an industrial dairy waste. A large volume of this product is disposed of annually due to inadequate bioconversion approaches. With its high pollutant load, disposal without pretreatment has raised a lot of environmental concerns alerting the need to seek optimal methods for adequately extracting and utilizing its organic content. In recent years, several techniques for whey valorization have emerged which may serve as interventionary measures against its environmental effects after disposal. In this review, we discuss five major approaches, by which whey can be converted into eco-friendly products, to significantly cut whey wastage. The approaches to whey valorization are therefore examined under the following perspectives: whey as a raw material for the production of bioethanol and prebiotic oligosaccharides via ß-galactosidase and microbe catalyzed reactions, for the production of refined lactose as an excipient for pharmaceutical purposes, and the clinical significance of whey hydrolysates and their antifungal activity in food processing.