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Green-Synthesized Nanoparticles as Potential Sensors for Health Hazardous Compounds
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Rachel Fanelwa Ajayi, Sphamandla Nqunqa, Yonela Mgwili, Siphokazi Tshoko, Nokwanda Ngema, Germana Lyimo, Tessia Rakgotho, Ndzumbululo Ndou, Razia Adam
Just like AuNPs, the synthesis of silver nanoparticles (AgNPs) is drawing more attention due to their applications in catalysis (Kumar et al., 2014): in antimicrobial application, in biomolecular detection and diagnostics, in microelectronics (Gittins et al., 2000), in sensing devices and towards the targeting of drugs (Sengupta et al., 2005). Some studies have also shown AgNPs in the medicinal field where they have been used as anti-inflammatory, antidiabetic and antioxidant agents as well as in cancer treatment and diagnosis (Chen et al., 2013). Several physical and chemical synthesis routes have been applied to produce AgNPs. However, there are drawbacks that come with these methods since they include the use of toxic precursor chemicals such as sodium borohydride, potassium nitrate, ethylene glycol, sodium dodecyl benzyl sulfate and polyvinyl pyrrolidone, thus generating toxic by-products (Roy et al., 2019). Since these nanoparticles are now applied to areas involving human contact, a need to develop environmentally friendly processes for nanoparticle synthesis is of great need. With the advancement of science, alternative synthesis routes which are eco-friendly, less costly, energy-efficient and non-toxic have been developed through green synthesis methods.
Application of Bioresponsive Polymers in Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Manisha Lalan, Deepti Jani, Pratiksha Trivedi, Deepa H. Patel
Another interesting study by Ke et al. was on microneedles filled pH-responsive poly(lactic-co-glycolic acid) (PLGA) hollow microspheres to deliver multiple drugs simultaneously to skin. The hollow PLGA micro-spheres had an aqueous core containing model drug along with sodium bicarbonate. Another drug was loaded into the polyvinylpyrrolidone based microneedles. The polyvinyl pyrrolidone dissolved rapidly in skin on application releasing the drug while sodium bicarbonate generated carbon dioxide bubbles in the acidic microenvironment of skin. These bubbles created micropores in the PLGA shell to release the drug incorporated inside microspheres [15–18].
Micronutrient Supplementation and Ergogenesis — Amino Acids
Published in Luke Bucci, Nutrients as Ergogenic Aids for Sports and Exercise, 2020
Arginine pyroglutamate (L-arginine-2-pyrrolidone-5-carboxylate) was combined with L-lysine hydrochloride (1200 mg of each) and administered orally to 15 healthy male volunteers aged 15 to 20 years.695 Biologically active growth hormone was greatly elevated in plasma from 30 to 120 min after the p.o. dose (two to eight times baseline value). Plasma somatomedin A levels were trebled at 8 h after administration. Plasma insulin levels were doubled at 30 min after oral dosing of the mixture. Administration of arginine pyroglutamate or lysine by themselves did not result in a significant increase of growth hormone over baseline levels. Nevertheless, although use of oral arginine supplementation to release somatotropin is possible, there is still much controversy over whether increased somatotropin levels (if indeed, levels are continually released) are of benefit to athletes.10
Advances in engineering and delivery strategies for cytokine immunotherapy
Published in Expert Opinion on Drug Delivery, 2023
Margaret Bohmer, Yonger Xue, Katarina Jankovic, Yizhou Dong
Another type of inorganic NP is a colloidal system, such as colloidal gold. Colloidal gold NPs were tagged with a peptide containing Asn-Gly-Arg (NGR), which targets a type of CD13 that is expressed in tumor vasculature [135]. This CD13-targeting mechanism allowed for the targeted delivery of a low, but active dose of TNF-α to fibrosarcomas in mice without toxicity. The head-to-tail cyclized NGR peptide chosen contained a free thiol that coupled with the~25 nm gold NPs, which then bound to the active site of CD13 [135]. Silver NPs may also be used for cytokine delivery. They were synthesized by the polyol method and coated with carboxylated vinyl pyrrolidone (PVP) to increase stability and reduce toxicity. With recombinant murine IL-10 conjugated to the surface, the NPs successfully produced an anti-inflammatory effect in lipopolysaccharide-stimulated macrophages [136].
Synthetic biodegradable polyesters for implantable controlled-release devices
Published in Expert Opinion on Drug Delivery, 2022
Jinal U. Pothupitiya, Christy Zheng, W. Mark Saltzman
Microparticle depots are often produced by solvent evaporation or spray-drying techniques and can entrap both hydrophilic and hydrophobic materials [68,69]. These well-known processes allow for the encapsulation of heat-sensitive drugs. Drawbacks of microparticle depots include poor encapsulation efficiencies, heterogeneity in particle size, toxic effects resulting from residual organic solvents left behind from the preparation process, and unpredictable burst release of drugs due to improper entrapment [20]. With in situ forming gels [70,71], the injected material (a solution or suspension) gels after injection into the local tissue environment. In one version of this approach, the polymer-drug solution is prepared by dissolving the two components – plus other additives to help control release – in a biocompatible, water-miscible solvent such as N-methyl-2-pyrrolidone [72]. When injected into the target area, the solvent disperses into the aqueous tissue environment, causing the polymer to precipitate, entrapping the drug within the polymer matrix. Although this method has the benefit of simplicity, it can suffer drawbacks due to the unpredictable release of drugs, owing to the heterogeneous distribution of drugs within the matrix and the delay between polymer-drug precipitation and injection [73–76].
The clinical toxicity of imidacloprid self-poisoning following the introduction of newer formulations
Published in Clinical Toxicology, 2021
Varan Perananthan, Fahim Mohamed, Seyed Shahmy, Indika Gawarammana, Andrew Dawson, Nicholas Buckley
Neonicotinoids are nicotinic acetylcholine receptor (nAChR) agonists, inducing neuromuscular paralysis. These agents are highly selective for insect nAChRs over vertebrate nAChRs, explaining its low human toxicity [3]. However, there are case reports of neuro-psychiatric sequelae, rhabdomyolysis resulting in acute kidney injury, ischemic and metabolic encephalopathy, ventricular fibrillation, multi-organ failure and even death after exposure to imidacloprid [4–16]. These features may not be due to nicotinic effects alone as the solvents in imidacloprid preparations such as N-methyl-2-pyrrolidone (NMP) and dimethylsulfoxide also contributes to its toxicity [2]. In Sri Lanka, several new formulations of Imidacloprid with unknown solvents have been introduced since we last reported on clinical outcomes [1]. We herein describe the clinical manifestations of these newer products, and compare these with our earlier observations.