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How Much Diagnosis Can We Afford?
Published in Pat Croskerry, Karen S. Cosby, Mark L. Graber, Hardeep Singh, Diagnosis, 2017
Since the completion of the Human Genome Project (HGP) in 2001, a rapid explosion in accessible technology has helped characterize genomes associated with disease, making it possible to detect many conditions before they even manifest symptoms. Potential parents can be screened before conception to determine the risk for hereditary disease in their offspring. In assisted reproduction, selected embryos can be tested for a number of genetic conditions before implantation; a few examples are shown in Table 13.4 [34]. Prenatal genetic screening is widely available using both invasive and noninvasive methods. Newborns are now routinely screened at birth for dozens of genetic disorders, typically including inborn errors of metabolism, cystic fibrosis, and hemoglobinopathies [34,35].
Conjugated Poly/Oligo-Electrolytes for Cancer Diagnosis and Therapy
Published in John R. Reynolds, Barry C. Thompson, Terje A. Skotheim, Conjugated Polymers, 2019
Lingyun Zhou, Guillermo C. Bazan, Shu Wang
Gene therapy is under rapid development. A wide variety of diseases can be treated using gene therapy, including cancer, neurodegenerative, antiviral, hematological, and hereditary genetic disorders, with promising success.130–133 Along with viral vectors, nanohydrogels, silica nanoparticles and polyethyleneimine (PEI) or other liposomes, CPs/COs and their nanoparticles are potential candidates for gene delivery.134 Due to the negative charges of DNA and RNA, cationic conjugated molecules can interact and thus be used to load the gene cargo. Additionally, owing to the biocompatibility of CPs/COs, when serve as drug delivery vectors, CPs/COs exhibit little immune response.
Dendrimers and Gene Delivery
Published in Zahoor Ahmad Parry, Rajesh Pandey, Dendrimers in Medical Science, 2017
Zahoor Ahmad Parry, Rajesh Pandey
Gene therapy is a proven tool to tackle many suitable selected stubborn diseases such as cancer and genetic/hereditary disorders in which conventional treatments may be ineffective. In addition to DNA transfer, RNA interference (RNAi) has emerged as another approach for gene therapy or gene manipulation. Since its initial report in 1998, RNAi quickly became a powerful tool in basic research as well as to develop novel therapeutics 1–3. In the general RNAi process, a dsRNA is introduced into a target cell. One strand of the dsRNA is designed to be an antisense RNA because its sequence is complementary to the RNA transcript of the gene selected for silencing. Inside the cell, an ATP-dependent RNAase III called ‘dicer,’ catalyzes the cleavage of both strands to produce a double stranded small interfering RNA (ds-siRNA), 21–23 nucleotides long and having 2-nucleotides long 3’-overhangs on each strand. The ds-siRNA is passed on to another protein complex called RNA-induced silencing complex (RISC). In an ATP-dependent manner, RISC unwinds the ds-siRNA and selects the antisense strand, now called the ‘guide strand.’ The other strand called the ‘passenger strand’ is discarded. RISC pairs the single guide strand with a complementary region on the target gene transcript (mRNA). The RNase H activity of RISC performs its ‘slicer’ function by cleaving the RNA transcript so that it can no longer be translated by ribosomes. The guide strand remains associated with RISC, hence it can be used for multiple cycles of mRNA cleavage, i.e., post-transcriptional gene silencing [4]. This process is also called post-transcriptional gene silencing and is highly efficient and specific. This is because a single nucleotide mismatch between the target mRNA and the siRNA would prevent the recognition/pairing and thereby the silencing process.
Preparation, properties, applications and outlook of graphene-based materials in biomedical field: a comprehensive review
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Luyang Yao, Anqi Chen, Li Li, Yu Liu
Gene therapy is an advanced approach to treat diseases at the molecular level of genes that deliver exogenous therapeutic gene into target cells, usually in hereditary diseases and tumors. The unique structure and chemical properties of graphene nanoparticles provide a high volume of gene loading. To improve biocompatibility, biostability, cellular uptake and increase in gene loading capacity and transfection efficiency, the surfaces of graphene and its derivatives have been modified with various polymers or ligands [146]. Polyamidoamine (PAMAM) dendritic macromolecules are commonly used as gene carriers. Liu et al. [139] covalently coupled with PAMAM on the GO plane and functionalized PAMAM through glycyrrhetinic acid (GA). Through GA functionalization, the gene transfection capacity of GO-PAMAM was increased by approximately 50% and showed targeting to SMMC-7721 compared to human embryonic kidney cells (HEK-293). On the other hand, the biocompatibility of SMMC-7721 greatly improved, when the GO-PAMAM-GA-0.5 concentration reached 200 μg/ml, and the viability of SMMC-7721 cells remained at about 98%. Lin and his team [140] further coated with polyethylene glycol: branched polyethylene imine to form P@N-GQDs on the basis of nitrogen-doped GQDs. PcDNA3-EGFP treated P@N-GQDs and then was applied to BE (2)-M17 cells, the result shows obvious superposition of BE (2)-M17 with EGFP signal. In addition, under 465 nm excitation wavelength, the signal intensity of P@N-GQDs was 1.83 times that of N-GQDs in vivo, and P@N-GQDs with the anti-GD2 antibody (Ab-GD2@P@N-GQDs) was accumulated in cancer cells (the maximum fluorescence intensity was 6.72 × 107 in the excised tumors from in vivo imaging system). The results show that the Ab-GD2@P@N-GQDs successfully targets neuroblastoma and has great potential as a gene carrier with excellent imaging capability.