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Gene Therapy in Tissue Engineering: Prospects and Challenges
Published in Rajesh K. Kesharwani, Raj K. Keservani, Anil K. Sharma, Tissue Engineering, 2022
The second most important challenge is in the expansion of genetically modified stem cells in culture before it is seeded into the scaffold for a desired duration of time. This may sounds simple; but it requires extensive studies for optimization. Postdelivery, there is a great deal of modalities that needs to be addressed regarding identification of promoter/control elements to ensure the production of the appropriate protein. This is basically achieved by introducing the “gene cassette” within the vector or the genome of the cells and by studying the vehicle properties in different tissue culture. If everything goes fine, then they are taken to the next level to be seeded into the scaffold for tissue engineering. This step may require further improvisation by adding new control elements to obtain results. Furthermore, introducing a bioengineered scaffold with desired genetically modified stem cells into humans needs much deliberation on understanding the immune responses; in some cases immune system needs to be boosted and in others suppressed.
Predicting algorithm of attC site based on combination optimization strategy
Published in Connection Science, 2022
Zhendong Liu, Xi Chen, Dongyan Li, Xinrong Lv, Mengying Qin, Ke Bai, Zhiqiang He, Yurong Yang, Xiaofeng Li, Qionghai Dai
In this paper, we study based on the bacterial integration subsystem. The bacterial integration system is an important application of site-specific recombination, which can capture and express foreign gene cassettes and convert them into functional gene expression units by site-specific recombination (Domingues et al., 2012). Through the recombination of DNA fragments between sites, bacteria can acquire properties that are beneficial to themselves, such as increasing bacterial resistance. Studies have shown that integron-promoted horizontal gene transfer enables bacteria to acquire foreign drug resistance genes as an important reason for accelerating the spread of clinically relevant Gram-negative pathogens(Mazel et al., 2015; Stalder et al., 2012). The function of the integron depends on the activity of the integrase (Nivina et al., 2016; Weiss et al., 2019), which is a site-specific tyrosine recombinase with the special ability to excise, integrate, reverse and translocate DNA fragments in organisms. Gene cassettes are usually mobile elements that carry a single gene and an associated recombination site (attC). Investigation shows that many gene cassettes often carry antibiotic resistance genes. Gene cassettes can exist independently in the form of a free ring, or they can be recognised and catalysed by integrases, and site-specific recombination becomes a part of the integron structure (Ghaly et al., 2021; Vit et al., 2020).
Aerosol partitioning potential of bacteria presenting antimicrobial resistance from different stages of a small decentralized septic treatment system
Published in Aerosol Science and Technology, 2023
Gabriela E. Ramos, Hyoungmook Pak, Ryan Gerlich, Anish Jantrania, Brooke L. Smith, Maria D. King
PCoA analysis indicates that under summer conditions the 16S genes from the bioaerosols are more related to each other than to the 16S genes of the water samples or to any other combination of 16S-based microbiome composition and conditions. The 16S microbiome composition of the winter aerosol above Tank 1 differed from the other aerosol samples depending on whether the lid was open or closed. In the winter the Tank 1 bioaerosol and water samples showed similarity. Compared to the winter samples, the 16S genes in the aerosolized microbiomes in the summer were more related to each other and less to the water microbiomes. The ozone treatment in Tank 2 affects the microbiome of both winter and summer samples. The microbiome composition also depended on the month of collection. From the PCoA, the summer water and the summer aerosol samples had similar 16S microbiome compositions, respectively. The summer aerosols were collectively related in microbiome composition, indicating possible quorum sensing to coordinate the behavior of the entire microbiome, between different species, to build resistance to environmental stresses. A study by Abisado et al. (2018), explains the significance of how mixed microbial communities interact and influence quorum sensing evolution. It is also known that antibiotic-resistance genes are transferred between bacteria by plasmids, gene transposons, and gene cassettes (Bennett 2008). Unlike the summer aerosols, the winter aerosol microbiomes were less comparable, except for the aerosols from open Tank 2 and closed Tank 4. The dissimilarity between the samples during the winter season may be related to the development of antibiotic resistance in the aerosolized bacteria triggered by unfavorable environmental factors such as low temperature and wind air movement.