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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
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].
When an obscurity becomes trend: social-media descriptions of tianeptine use and associated atypical drug use
Published in The American Journal of Drug and Alcohol Abuse, 2021
Kirsten E. Smith, Jeffery M. Rogers, Justin C. Strickland, David H. Epstein
Across posts, a prominent theme was “polydrug use that included tianeptine” (n = 210). This included polydrug use in which tianeptine was being used on the same occasions as other substances or as part of the same longer-term pattern of use (within weeks or months) with myriad licit and illicit substances. This also included research chemicals and supplements with varying degrees of legality. The breadth of substances discussed in posts was substantial and not all were psychoactive (see Table 2). Although there were mentions of substances we expected to find, there were also many we had not anticipated (e.g., memantine, Vortioxetine) or that were heretofore unknown to us (e.g., HRX-1074, GLYX-1). Substances frequently discussed as being co-used with tianeptine were typically referred to as “nootropics” (or “noots”, or “cognitive enhancers”). The most frequently mentioned nootropic drug was phenibut (n = 35; 4-amino-3-phenul-butyric acid), a GABAB agonist with anxiolytic and putative cognitive-enhancing effects sold online as a dietary supplement, and clinically prescribed only in Russia (31–35). The second most frequently mentioned nootropic drug (n = 25) were racetams (e.g., piracetam, phenylpiracetam, levetiracetam), a drug class with a shared pyrrolidone nucleus that is also purported by vendors to have cognitive enhancing effects (36,37).
Safety considerations selecting antiseizure medications for the treatment of individuals with Dravet syndrome
Published in Expert Opinion on Drug Safety, 2021
Rima Nabbout, N Chemaly, C Chiron, M. Kuchenbuch
Levetiracetam (LEV) is a derivative of pyrrolidone. Its main anti-seizure – mechanism is due to a binding to the synaptic protein of the SV2A vesicle which causes a reduction in the release of vesicles from the excitatory synapses [115]. However, LEV also has anti-seizure properties though an inhibition of AMPA receptors, N‐type voltage‐sensitive potassic and calcium potassic channels, calcium release, an increased GABAA, and glycine receptor-mediated currents [116] (Figure 2). The bioavailability of the oral formulation of LEV is 96% with a plasma peak at 1 h after administration. Peak plasma levels could be reduced by 20% through concomitant food intake. LEV protein binding in plasma compartment is ~10%. Only ~25% of LEV is metabolized; the rest is excreted in the urine in unchanged form. However, the clearance of LEV could be increased by 60% in children under 10 years of age compared to adults [117]. The half-time of LEV is 7 h in adults. Few drug–drug interactions have been reported for LEV.