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Self-assembled nanoparticles present unique properties that have potential applications in the development of a successful drug delivery system. Doxorubicin (DOX) is an important anti-neoplastic anthracycline chemotherapeutic drug widely described. However, it suffers from serious dose-dependent cardiotoxicity. d-Limonene is a major constituent of numerous citrus oils that is considered a specific monoterpene against free radicals producing antioxidant activity. Herein, we aimed to design three types of self-assembled nanodelivery systems (nanoemulsion, niosomes, and polylactide nanoparticles) for loading both DOX and d-limonene to enhance the solubilization of d-limonene and provide antioxidant activity with excellent anticancer activity. As confirmed by dynamic light scattering and transmission electron microscopy, the nanoparticles were prepared successfully with diameter sizes of 52, 180, and 257 nm for the DOX-loaded nanoemulsion, niosomes, and polylactide nanoparticles, respectively. The zeta potential values were above -30 mV in all cases, which confirms the formation of stable nanoparticles. The loading efficiency of DOX was the highest in the case of the DOX-loaded nanoemulsion (75.8%), followed by niosomes (62.8%), and the least was in the case of polylactide nanoparticles with a percentage of 50.2%. The in vitro release study of the DOX-loaded nanoparticles showed a sustained release profile of doxorubicin with the highest release in the case of DOX-loaded PDLLA nanoparticles. The kinetic release model for all developed nanoparticles was the Peppas-Sahlin model, demonstrating DOX release through Fickian diffusion phenomena. Moreover, all developed nanoparticles maintain the antioxidant activity of d-limonene. The cytotoxicity study of the DOX-loaded nanoparticles showed concentration-dependent anticancer activity with excellent anticancer activity in the case of the DOX-loaded nanoemulsion and polylactide nanoparticles. These nanoparticles will be further studied in vivo to prove the cardioprotective effect of d-limonene in combination with DOX., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The rate constant for the self-reaction of the acetonyl peroxy radicals, CH 3 C(O)CH 2 O 2 , has been determined using laser photolysis/continuous wave cavity ring down spectroscopy (cw-CRDS). CH 3 C(O)CH 2 O 2 radicals have been generated from the reaction of Cl atoms with CH 3 C(O)CH 3 , and the concentration time profiles of four radicals (HO 2 , CH 3 O 2 , CH 3 C(O)O 2 , and CH 3 C(O)CH 2 O 2 ) have been determined by cw-CRDS in the near-infrared. The rate constant for the self-reaction was found to be k = (5.4 ± 1.4) × 10 -12 cm 3 s -1 , in good agreement with a recently published value (Zuraski, K., et al. J. Phys. Chem. A 2020 , 124 , 8128); however, the branching ratio for the radical path was found to be ϕ 1b = (0.6 ± 0.1), which is well above the recently published value (0.33 ± 0.13). The influence of a fast reaction of Cl atoms with the CH 3 C(O)CH 2 O 2 radical became evident under some conditions; therefore, this reaction has been investigated in separate experiments. Through the simultaneous fitting of all four radical profiles to a complex mechanism, a very fast rate constant of k = (1.35 ± 0.8) × 10 -10 cm 3 s -1 was found, and experimental results could be reproduced only if Cl atoms would partially react through H-atom abstraction to form the Criegee intermediate with a branching fraction of ϕ Criegee = (0.55 ± 0.1). Modeling the HO 2 concentration-time profiles was possible only if a subsequent reaction of the Criegee intermediate with CH 3 C(O)CH 3 was included in the mechanism leading to HO 2 formation with a rate constant of k = (4.5 ± 2.0) × 10 -14 cm 3 s -1 .

The ongoing spread of multi-drug-resistant bacteria over the past few decades necessitates collateral efforts to develop new classes of antibacterial agents with different mechanisms of action. The utilization of graphene nanosheets has recently gained attention with this respect. Herein, we have synthesized and tested the antibacterial activity of an array of graphene materials covalently functionalized with hydroxyl-, amine-, or carboxyl-containing groups. Fourier transform infrared spectroscopy and transmission electron microscopy confirmed successful functionalization of the few-layer graphene (FLG). The percentage of weight loss was measured by thermogravimetric analysis, which was found to be 22%, 23%, and 37% for FLG-TEG-OH, FLG-NH 2 , and FLG-DEG-COOH, respectively. In comparison with pristine graphene sheets, the functionalized few-layer graphene ( f -FLG) materials gained an adequate dispersibility in water as confirmed by ζ potential analysis. Moreover, there was a significant improvement in the antibacterial activity against Staphylococcus aureus and Escherichia coli , where all f -FLG compounds were able to suppress bacterial growth, with a complete suppression achieved by FLG-DEG-COOH. The minimum inhibitory concentration (MIC) was 250 μg mL -1 for both FLG-TEG-OH and FLG-NH 2 , while it was 125 μg mL -1 for FLG-DEG-COOH. The glutathione oxidation test demonstrated an oxidative stress activity by all f -FLG compounds. However, FLG-DEG-COOH demonstrated the highest reduction in glutathione activity. FLG-DEG-COOH and FLG-TEG-OH showed adequate biocompatibility and hemocompatibility. The chemical functionalization of graphene might be a step toward the foundation of an effective class of antimicrobial agents.

Herein, we describe the first report on a new class of disk-shaped and quite monodisperse water-soluble nanomaterials that we named glyconanosomes (GNS). GNSs were obtained by sliding out the cylindrical structures formed upon self-organization and photopolymerization of glycolipid 1 on single-walled carbon nanotube (SWCNT) sidewalls. GNSs present a sheltered hydrophobic inner cavity formed by the carbonated tails, surrounded by PEG and lactose moieties. The amphiphilic character of GNSs allows the water solubility of insoluble hydrophobic cargos such as a perylene-bisimide derivative, [60]fullerene, or the anti-carcinogenic drug camptothecin (CPT). GNS/C60 inclusion complexes are able to establish specific interactions between peanut agglutinin (PNA) lectin and the lactose moiety surrounding the complexes, while CPT solubilized by GNS shows higher cytotoxicity toward MCF7-type breast cancer cells than CPT alone. Thus, GNS represents an attractive extension of nanoparticle-based drug delivery systems.