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Role of Enzymes in Bioremediation of Organic Pollutants
Published in M.H. Fulekar, Bhawana Pathak, Bioremediation Technology, 2020
Smita Chaudhry, Rashmi Paliwal
Phosphatases catalyze the transformation of organophosphate compounds by hydrolyzing the ester and anhydride bonds resulting in the production of phosphoric acid. On the basis of pH optima, the enzymes can be classified as alkaline phosphatase (EC 3.1.3.1) and acid phosphatase (EC 3.1.3.2), whereas on the basis of the structure of the substrate, the phosphatase enzyme can further be classified into three groups that include phosphoric monoester hydrolases (EC 3.1.3), phosphoric diester hydrolases (EC 3.1.4), and triphosphoric monoester hydrolases (EC 3.1.5). Alkaline phosphatase catalyzes the hydrolysis of a variety of organophosphorus substrates and need Zn2+ or Cr2+ for their activity. The enzyme has been purified and characterized in halotolerant bacterium Halomonaselongata (Bylund et al., 1990). Acid phosphatases are classified as monophosphoric-monoester-phosphohydrolases and catalyze the hydrolysis of C─O─P bonds. Phosphatases of plant and microbial origin are particularly gaining attention due to their capacity to hydrolyze the di- and triphosphate ester bond that is present in organophosphorus pesticides. The hydrolysis of an organophosphorus pesticide (methyl paraoxon) by acid phosphatase leading to the production of p-nitrophenol is presented in Figure 6.6.
The response of bone cells to titanium surfaces modified by simvastatin-loaded multilayered films
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Min Lai, Xufeng Yan, Ziyang Jin
To investigate the effect of multilayered simvastatin films-modified titanium substrate on osteoclast differentiation, osteoclastic differentiation of RAW264.7 cells was activated by the presence of RANKL and M-CSF on different substrate sufaces. Multinucleated cells (osteoclasts) were observed on Ti and nano-Ti substrates rather than LBL coated Ti and SV-LBL coated Ti substrates (Figure 7A). tartrate-resistant acid phosphatase (TRAP) activity as an osteoclastic marker was used to evaluate the osteoclasts [38]. The TRAP activity of osteoclasts on LBL coated Ti and SV-LBL coated Ti substrates was significantly lower (p < 0.01 and p < 0.05) than that on Ti and nano-Ti substrates, especially on SV-LBL coated Ti substrate (Figure 7B). These results indicate that SV-LBL coated Ti substrate inhibited osteoclast activity.
Analysis of stress and stabilization in adolescent with osteoporotic idiopathic scoliosis: finite element method
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Qiaolin Zhang, Yan Zhang, Teo. Ee Chon, Julien S. Baker, Yaodong Gu
In this study, the FE model was established by using the CT image of a normal person and the lumbar CT image of an AIS patient with frontal Cobb and lumbar lordosis angles of 43°and 45°. This study is different from previous studies in that lumbar scoliosis in this study is serious, and previous studies have not involved such serious scoliosis. Secondly, previous spinal FE studies are often limited to the biomechanical analysis of scoliosis or OP. Young's modulus of cancellous bone and endplate is used to simulate OP, and combined with AIS to explore the biomechanical characteristics of adolescents with osteoporotic idiopathic scoliosis. A significant relationship between severity of scoliosis and bone mineral density has been reported (Cheng et al. 1999), nearly one-third of all women and one-sixth of all men over age 65 have OP, and this condition is often accompanied by lumbar scoliosis (Routh et al. 2005; Íñiguez-Macedo et al. 2019). Previous studies have investigated bone mineral density and bone metabolism in AIS patients using the bone metabolism markers, bone alkaline phosphatase, and tartrate-resistant acid phosphatase serum band 5. Sixty-five percent of AIS patients had osteopenia or OP and 59% of AIS patients had high values for tartrate-resistant acid phosphatase serum band 5. The AIS patients with high values of Tartrate-resistant acid phosphatase serum band 5 had lower Z scores than those with normal values of Tartrate-resistant acid phosphatase serum band 5. Higher rates of bone resorption are associated with low bone density in AIS patients. Osteopenia or OP accounts for a large proportion of patients with AIS.
Microstructured titanium functionalized by naringin inserted multilayers for promoting osteogenesis and inhibiting osteoclastogenesis
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Ke Shen, Xiaojing Zhang, Qiang Tang, Xingtang Fang, Chunlei Zhang, Zhaojing Zhu, Yanhua Hou, Min Lai
Macrophages were seeded on the materials at a concentration of 2 × 104 cells/cm2 and cultured in 24-well plates in osteoclast culture medium (containing 50 ng/mL ligands of recombinant nuclear transcription factor Kappa -B (RANKL) and 20 ng/mL macrophage colony stimulating factor (M-CSF)) for 7 and 9 days. 1% Triton X-100 was used to lyse the cells. Cell lysates were collected and used for further experiments. Tartrate resistant acid phosphatase assay and total protein content of cells were measured by spectrophotometric microplate reader at 405 nm and 562 nm respectively using Tartrate resistant acid phosphatase assay kit and BCA protein detection kit. Tartrate resistant acid phosphatase activity was expressed as enzyme activity unit.