Poly(3-hydroxybutyrate)/poly(amine)-coated nickel oxide nanoparticles for norfloxacin delivery: antibacterial and cytotoxicity efficiency

Dopamine / Artesunate loaded polyhydroxybutyrate-g-cellulose- magnetite zinc oxide core shell nanocomposites: Synergistic antimicrobial and anticancer efficacy

In this study, polyhydroxybutyrate-g-cellulose - Fe3O4/ZnO (PHB-g-cell- Fe3O4/ZnO) nanocomposites (NCs) was synthesized and used as a delivery system for Dopamine (DO) /Artesunate (ART) drugs. Different types of cells (Ccell, Scell, Pcell) grafted with PHB were designed and mixed with different contents of Fe3O4/ZnO. Physical and chemical features of PHB-g-cell-Fe3O4/ZnO NCs were detected by FTIR, XRD, dynamic light scattering, transmission electron microscopy, and scanning electron microscopy. ART/DO drugs were loaded into PHB-g-cell- Fe3O4/ZnO NCs by single emulsion technique. The rate of drugs release was studied at different pHs (5.4, 7.4). Owing to the overlap between the absorption bands of both drugs, differential pulse adsorptive cathodic stripping voltammetry (DP-AdCSV) was used for the estimation of ART. To study the mechanism of ART and DO release, zero-order, first order, Hixon Crowell, Higuchi and Korsmeyer-Peppas models were applied to the experiment results. The results showed that Ic50 of ART @PHB-g-Ccell-10% DO@ Fe3O4/ZnO, ART @PHB-g-Pcell-10% DO@ Fe3O4/ZnO and ART @PHB-g-Scell-10% DO@ Fe3O4/ZnO were 21.22, 12.3, and 18.11 μg/mL, respectively. The results revealed that ART @PHB-g-Pcell-10% DO@ Fe3O4/ZnO was more effective against HCT-116 than the carriers loaded by a single drug. The antimicrobial efficacy of the nano-loaded drugs was considerably improved compared with free drugs.

pH-driven enhancement of anti-tubercular drug loading on iron oxide nanoparticles for drug delivery in macrophages

Nanoparticle deployment in drug delivery is contingent upon controlled drug loading and a desired release profile, with simultaneous biocompatibility and cellular targeting. Iron oxide nanoparticles (IONPs), being biocompatible, are used as drug carriers. However, to prevent aggregation of bare IONPs, they are coated with stabilizing agents. We hypothesize that, zwitterionic drugs like norfloxacin (NOR, a fluoroquinolone) can manifest dual functionality - nanoparticle stabilization and antibiotic activity, eliminating the need of a separate stabilizing agent. Since these drugs have different charges, depending on the surrounding pH, drug loading enhancement could be pH dependent. Hence, upon synthesizing IONPs, they were coated with NOR, either at pH 5 (predominantly as cationic, NOR+) or at pH 10 (predominantly as anionic, NOR-). We observed that, drug loading at pH 5 exceeded that at pH 10 by 4.7-5.7 times. Furthermore, only the former (pH 5 system) exhibited a desirable slower drug release profile, compared to the free drug. NOR-coated IONPs also enable a 22 times higher drug accumulation in macrophages, compared to identical extracellular concentrations of the free drug. Thus, lowering the drug coating pH to 5 imparts multiple benefits - improved IONP stability, enhanced drug coating, higher drug uptake in macrophages at reduced toxicity and slower drug release.

The Synthesis, Characterization and Applications of Polyhydroxyalkanoates (PHAs) and PHA-Based Nanoparticles

Polyhydroxyalkanoates (PHAs) are storage granules found in bacteria that are essentially hydroxy fatty acid polyesters. PHA molecules appear in variety of structures, and amongst all types of PHAs, polyhydroxybutyrate (PHB) is used in versatile fields as it is a biodegradable, biocompatible, and ecologically safe thermoplastic. The unique physicochemical characteristics of these PHAs have made them applicable in nanotechnology, tissue engineering, and other biomedical applications. In this review, the optimization, extraction, and characterization of PHAs are described. Their production and application in nanotechnology are also portrayed in this review, and the precise and various production methods of PHA-based nanoparticles, such as emulsion solvent diffusion, nanoprecipitation, and dialysis are discussed. The characterization techniques such as UV-Vis, FTIR, SEM, Zeta Potential, and XRD are also elaborated.

Co-delivery of norfloxacin and tenoxicam in Ag-TiO2/poly(lactic acid) nanohybrid

A nanohybrid formulation of silver‑titanium dioxide nanoparticles/poly(lactic acid) (Ag-TiO₂/PLA) was designed for Norfloxacin/Tenoxicam (NOR/TENO) targeted delivery to maximize the bioavailability and minimize the side effects of the drugs. Ag-TiO₂ nanoparticles were prepared via Stober method. NOR, TENO and a mixture of NOR/TENO (NT) were loaded onto Ag-TiO₂ nanoparticles and coated by PLA via solution casting. The physical interaction between the drugs and carrier was confirmed by Fourier-transform infrared (FTIR) analysis. X-ray diffraction (XRD) demonstrated that Ag-TiO₂ consists of a cubic phase of Ag with two phases of TiO₂ (anatase and brookite). Ag nanoparticle fine spots coated with TiO₂ were collected to form spheres averaging at 100 nm in size. In-vitro release behavior of drugs was studied at different pH (5.4, 7.4) and the release of drug from NT/Ag-TiO₂/PLA was faster at pH 7.4. Gram-positive and Gram-negative bacteria were used to investigate antibacterial properties of the nanohybrid. Cytotoxicity of the nanohybrid using an MTT assay was studied against different tumor and normal cell lines. It was found that NT/Ag-TiO₂/PLA has an excellent cytotoxic effect against various bacterial cells and tumor cell lines. In addition, antioxidant properties of the nanohybrids were tested using ABTS method and the nanohybrid showed moderate antioxidant activity.