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Surface Engineered Graphene Oxide and Its Derivatives
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Zaira Zaman Chowdhury, Abu Nasser Faisal, Shahjalal Mohammad Shibly, Devarajan Thangadurai, Saher Islam, Jeyabalan Sangeetha
Polymer-based functionalization and conjugation techniques significantly improve the in vivo circulation period and biocompatibility of GO (Nurunnabi et al. 2015). Polyethylene glycol (PEG) has received considerable interest in biomedicine. By grafting GO sheets with highly branched and biocompatible PEG, an effective drug-delivery platform using functionalized Gr was first developed. PEGylated GO was found to be nontoxic and extremely stable in biochemical fluid, including protein serum (Mao et al. 2013; Nurunnabi et al. 2015). However, PEG is a bulky and complex molecule that, due to its limited bioavailability, may substantially enhance the biomagnification of GO (Li et al. 2014a). Hydrophilic polyacrylic acid–Gr nano-sheets (PAA-GrNs) have shown excellent solubility in water and persistence in physiological system. PAA-GrNs have the capacity to adsorb aromatic compounds, water-insoluble medicines, and exhibit a significant pH dependence and effective regulated discharge (Chen et al. 2013).
Bowel disorders
Published in Henry J. Woodford, Essential Geriatrics, 2022
Polyethylene glycol (PG) is a mixture of polymers that increase stool water content due to an osmotic effect. Molecules with a molecular weight of 3,350 or above are used because they cannot be absorbed by the gut (macrogol 3,350).12 PG has been shown to be effective in the treatment of faecal impaction (see page 286). It comes as a powder that is added to water, which removes the risk of dehydration. It is not metabolised by bowel bacteria and is not absorbed. Each sachet is usually mixed with 125 ml of water and up to eight sachets can be taken per day. This can require swallowing a significant volume of liquid and may be unsuitable for people with reduced oral intake or an impaired swallow. Starch-based thickening agents cannot be added to these solutions.
Orders Norzivirales and Timlovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
In connection with the biocompatible polymers, the Nicole F. Steinmetz team raised a critical question of the bioinspired shielding strategies for nanoparticle drug delivery applications (Gulati et al. 2018). Since nanoparticle surface camouflage was often required to reduce immune clearance and thereby increase circulation times allowing the carriers to reach their target site, the origin of the coating remained highly important, whether of synthetic or biologic origin. To this end, polyethylene glycol has long been used, with several PEGylated products reaching clinical use. Unfortunately, the growing use of PEG in consumer products has led to an increasing prevalence of PEG-specific antibodies in the human population, which in turn has fueled the search for alternative coating strategies. Gulati et al. (2018) highlighted alternative bioinspired nanoparticle shielding strategies that may be more beneficial moving forward than PEG and other synthetic polymer coatings.
Managing women of childbearing age with chronic myeloid leukemia: safety and treatment considerations
Published in Expert Review of Hematology, 2023
HF Robertson, MJ Buckton, JF Apperley
Whilst undoubtedly safe to use in pregnancy, it is important to appreciate the expected efficacy and tolerability of IFN-α. When used first line, the rates of complete hematological remission ranged between 31% and 73% [13,14], and the time to hematological response was slower than we observe with the TKIs. In the German CML III study, the median time to first response in the 133 patients randomized to IFN-α was approximately 2.5 months for the 110 responders, and to complete remission (41 patients) approximately 6.5 months [13]. Complete cytogenetic responses occur in 7–18% of patients [13,14]. This discrepancy in response may be due in part to genetic polymorphisms, rendering certain individuals more or less sensitized to the drug [15,16]. The unpredictability of IFN-α to induce cytogenetic responses is particularly troubling in women who are diagnosed with CML in pregnancy and have had no prior TKI therapy to control the disease. Even for those who have achieved good responses with TKI therapy and have discontinued due to pregnancy, the ability of IFN-α to regain these responses is uncertain at best. As well as the doubt surrounding its efficacy, IFN-α requires sub-cutaneous injections and can be poorly tolerated with some patients forced to discontinue the drug due to hematological toxicity and/or unpleasant systemic side effects [17,18]. This has been partially overcome by the advent of the polyethylene glycol vector (PEG), which is also safe for use throughout pregnancy and requires less frequent administration [19].
Application of titanium dioxide (TiO2) nanoparticles in cancer therapies
Published in Journal of Drug Targeting, 2019
Selin Çeşmeli, Cigir Biray Avci
Harada et al. (2013) [20] at Osaka Prefecture University, used titanium dioxide nanoparticles in the form of encapsulated inside micelle. Polyethylene glycol, a polymer which is commonly used in medical applications, was used for the stabilisation of micelles and for improving the biocompatibility also decreasing the cytotoxicity of micelles. As the far-red light used in photodynamic therapy cannot penetrate into deeper part of tissues, researchers in this study preferred ultrasound. Because ultrasound does not harm the cells and also could able to go to the further sides inside cancer cells. They found that both healthy cells and HeLa cells, an immortal cell line took up these micelles and after the ultrasound was applied to the micelles; TiO2 nanoparticles generated reactive oxygen species (ROS) that are cytotoxic agents. As a result, ultrasound energy could be used in clinic with this application in order to target and kill the only tumour.
Phenylketonuria in the adult patient
Published in Expert Opinion on Orphan Drugs, 2019
Leticia Ceberio, Álvaro Hermida, Eva Venegas, Francisco Arrieta, Montserrat Morales, Maria Forga, Montserrat Gonzalo
A promising alternative is based on the enzyme replacement therapy. The enzyme phenylalanine ammonia lyase (PAL), obtained from a recombinant mutant of Anabaena variabilis, converts Phe to ammonia and trans-cinnamic acid, sub-products that are metabolized by the liver and excreted in the urine (Figure 2). Pegvaliase is a pegylated PAL that can be provided daily by subcutaneous self-administration. The formulation with polyethylene glycol (PGE) reduces the immune response against the exogenous enzyme and the associated adverse events. PGE also improves the pharmacodynamic stability of PAL, increasing the enzymatic activity. Pegvaliase has been recently approved by FDA for the treatment of adult patients with PKU who have blood Phe concentrations > 600 µmol/L [54]. To date, results from 7 clinical trials and >350 patients have proved the efficacy and safety of this novel therapy in reducing the plasma Phe levels in adults with PKU. A relatively high risk of anaphylaxis was detected during clinical trials. The reported AEs were mild or moderate and the most common AEs were arthralgia, injection-site reaction and erythema and headache [55]. Long-term clinical trials as well as a phase III trial in Europe are currently ongoing.