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- Cretella, Margherita, et al.
(author)
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Determination of Density of Starch Hydrogel Microspheres from Sedimentation Experiments Using Non-Stokes Drag Coefficient
- 2024
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In: Gels. - 2310-2861. ; 10:4
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Journal article (peer-reviewed)abstract
- Sedimentation is an important property of colloidal systems that should be considered when designing pharmaceutical formulations. In pharmaceutical applications, sedimentation is normally described using Stokes' law, which assumes laminar flow of fluid. In this work we studied swelling and hydration of spherical cross-linked amorphous starch microspheres in pure water, solutions of sodium chloride, and in pH-adjusted aqueous solutions. We demonstrated that Reynolds numbers obtained in these experiments correspond to the transition regime between the laminar flow and the turbulent flow and, hence, expressions based on the non-Stokes drag coefficient should be used for calculations of sedimentation velocity from known density or for assessment of density from observed sedimentation velocity. The density of starch microparticles hydrated in water was about 1050 kg/m3, while densities obtained from experiment with other liquids were dependent on the liquids' densities. The data indicate that the swelling of the cross-linked starch microparticles as characterized by their densities is not sensitive to pH and salt concentration in the studied range of these parameters.
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| 2. |
- Mansha, Saira, et al.
(author)
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Development of pH-Responsive, Thermosensitive, Antibacterial, and Anticancer CS/PVA/Graphene Blended Hydrogels for Controlled Drug Delivery
- 2024
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In: Gels. - : MDPI. - 2310-2861. ; 10:3
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Journal article (peer-reviewed)abstract
- Drug delivery techniques based on polymers have been investigated for their potential to improve drug solubility, reduce systemic side effects, and controlled and targeted administration at infection site. In this study, we developed a co-polymeric hydrogel composed of graphene sheets (GNS), polyvinyl alcohol (PVA), and chitosan (CS) that is loaded with methotrexate (MTX) for in vitro liver cancer treatment. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) was employed to check the structural properties and surface morphology. Moreover, tests were conducted on the cytotoxicity, hemolytic activity, release kinetics, swelling behaviour and degradation of hydrogels. A controlled release of drug from hydrogel in PBS at pH 7.4 was examined using release kinetics. Maximal drug release in six hours was 97.34%. The prepared hydrogels did not encourage the HepG2 growth and were non-hemolytic. The current study highlights the potential of GNS-based hydrogel loaded with MTX as an encouraging therapy for hepatocellular carcinoma. HepG2 cell viability of MTX-loaded CS-PVA-GNS hydrogel was (IC50 5.87 mu g/200 mL) in comparison to free MTX (IC50 5.03 mu g/200 mL). These outcomes recommend that hydrogels with GNS ensure improved drug delivery in cancer microenvironment while lessening adverse consequences on healthy cells.
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