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Nanocarrier Technologies for Enhancing the Solubility and Dissolution Rate of Api
Published in Debarshi Kar Mahapatra, Sanjay Kumar Bharti, Medicinal Chemistry with Pharmaceutical Product Development, 2019
Ashwini Deshpande, Tulshidas S. Patil
Chitosan (CS) containing myricetin (Myr)/HP-β-CD inclusion complex was incorporated into nanogel. 1.73 fold enhancement in the maximum plasma concentration (Cmax) of Myr-loaded nanogels group as compared to that of the plain Myr group. The area under curve (AUC) value for nanogel formulation was found to be higher as compared to plain drug, also the relative bioavailability of Myr-loaded nanogels was found to be 220.66%, which demonstrated an improved performance of myricetin after an oral nanogel delivery system. This nanogel system mainly governed by erosion with Fickian mechanism, which provided sustained release system for drug delivery [207].
Medication: Nanoparticles for Imaging and Drug Delivery
Published in Harry F. Tibbals, Medical Nanotechnology and Nanomedicine, 2017
Nanoparticle hydrogels can be prepared by emulsion or precipitation polymerization to form a stable colloidal dispersion. By use of free radical scavenging metals to slow the polymerization process, nanogel particles can be prepared with highly controlled uniform polymer chain lengths and cross-linkages, in a process called atom transfer radical polymerization (ATRP), also known as “living polymerization” because the polymerization chain reactions are not terminated as randomly as in an uncontrolled process [214,215]. Under special conditions, certain drugs with affinity for absorption onto the nanogel polymer chains can be loaded spontaneously into the nanogels, displacing absorbed water and resulting in the reduction of the solvent volume, leading to gel collapse and formation of dense drug-laden nanoparticles [216].
Engineered Nanoparticles for Drug Delivery in Cancer Therapy *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Tianmeng Sun, Yu Shrike Zhang, Pang Bo, Dong Choon Hyun, Miaoxin Yang, Younan Xia
Wang and coworkers have developed charge-converting nanogels that could be activated for drug delivery applications by the acidity in tumors [308]. They first fabricated the parent nanogel based on poly(2-aminoethyl methacrylate hydrochloride) (PAMA) with PEG-diacrylate (PEGDA) as a cross-linker. The nanogel exhibited a uniform size of 100 nm in water and a positive zeta potential of + 30 mV. The positive charges on the surface of nanogels were advantageous for cell uptake because they interacted strongly with the negatively charged cell membranes. However, such charges also induce strong interactions with serum proteins, causing them to aggregate and become rapidly cleared from circulation. To solve this issue, the authors devised a similar method to the example we showed for liposomes: they added a layer of 2,3-dimethylmaleic anhydride (DMMA) to the surface of the nanogels, which changed the zeta potential of the gels to 17 mV. After incubation in an acidic environment (pH 6.8), the DMMA groups were gradually cleaved to convert the surface charge of the PAMA nanogels from negative to positive (Fig. 2.19a). When the PAMA nanogels were coated with succinic anhydride (SA), they were not able to undergo effective charge conversion and the zeta potential remained negative. The charge-converting PSMA-DMMA nanogels elicited more accumulation in tumor cells (MDA-MB-435s) in vitro at pH 6.8 than at pH 7.4 (Fig. 2.19b,c). When loaded with doxorubicin, PAMA-DMMA nanogels also caused higher mortality for MDA-MA-435s cells in vitro in a pH-dependent manner compared with the PAMA-SA nanogels (Fig. 2.19d).
Nanoparticles for treatment of bovine Staphylococcus aureus mastitis
Published in Drug Delivery, 2020
Samah Attia Algharib, Ali Dawood, Shuyu Xie
Prolonged serum half-life attributable to its tremendously smaller size enhances the invasion capability and prevents the rapid elimination by the kidney (Sultana et al., 2013). Furthermore, the nanogel is reflected as an ideal tool for transport the drug intracellular, and rapid responsiveness to ecological changes as (temperature and pH) resulted from “its ability to elude clearance by phagocytic cells and uptake with the assistance of reticuloendothelial organs, improved penetration into diseased sites as (solid tumors, inflamed tissue, and infarcted areas) in addition, its ability to enter the blood-brain barrier and carrying the drug safely into the cytoplasm of target cells”.
Topically applied pH-responsive nanogels for alkyl radical-based therapy against psoriasiform hyperplasia
Published in Drug Delivery, 2023
G.R. Nirmal, Chia-Chih Liao, Zih-Chan Lin, Abdullah Alshetaili, Erica Hwang, Shih-Chun Yang, Jia-You Fang
Nanogels are more responsive to stimuli such as pH than other nanoparticles because of their unique 3D network, which easily changes in different environments (Smeets & Hoare, 2013). The large difference in the nanogel size between hydrodynamic detection and the dry state could verify this perspective. The flexibility in nanogel size in responding to external stimuli makes nanogels an ideal nanocarrier system for controlling drug delivery. We found that the nanogels showed swelling at pH 6 and 7.4, whereas a deswelling pattern was detectable in the acidic environment (<pH 5.5). The reduction in chitosan nanogel size under acidic conditions has been demonstrated previously (Qi et al., 2016), and it is due to the disassembly of the particles. The increased chitosan solubility in acidic solution leads to protonation of the amino moiety. This protonation ensures chain relaxation, resulting in rapid hydrogen bond dissociation. The protonation extent is reduced when the pH is increased (Algharib et al., 2020). The decreased zeta potential at pH 6 compared with that at pH 5 confirmed this concept. The reduced protonation led to the agglomeration of nanogels. This phase transition also allowed nanogel swelling due to water penetration into the free space of the nanostructure. In the deswelling state, we expected that the nanogels could protect AIPH or free radicals from release due to their rigid structure with less water. This reduced dimension of nanogels permits nanogel transport across biological barriers (Cuggino et al., 2019). Our ABTS assay manifested a diffusional release of alkyl radicals from the nanogels, indicating possible swelling in response to pH to accelerate free radical escape from the crosslinked network.
Nanoreactor activated in situ for starvation-chemodynamic therapy of breast cancer
Published in Journal of Drug Targeting, 2022
Linyu Gao, Xiangyang Xuan, Mingli Sui, Jingjing Wang, Yaping Wang, Huijuan Zhang
Finally, in order to explore the biological safety of FeAlg/GOx, the weight changes of mice were recorded during the entire treatment period. As shown in Figure 6D, there was no obvious change in the weight of mice in each group, indicating that the nanogel had no distinct systemic toxicity. In addition, there were no significant differences in liver and kidney indexes among all groups, which further proved that FeAlg/GOx had good safety for application in vivo (Figures 6E and 6F).