Engineered Nanomaterials Suppress the Soft Rot Disease (Rhizopus stolonifer) and Slow Down the Loss of Nutrient in Sweet Potato.

About 45% of the world's fruit and vegetables are wasted, resulting in postharvest losses and contributing to economic losses ranging from $10 billion to $100 billion worldwide. Soft rot disease caused by Rhizopus stolonifer leads to postharvest storage losses of sweet potatoes. Nanoscience stands as a new tool in our arsenal against these mounting challenges that will restrict efforts to achieve and maintain global food security. In this study, three nanomaterials (NMs) namely C60, CuO, and TiO2 were evaluated for their potential application in the restriction of Rhizopus soft rot disease in two cultivars of sweet potato (Y25, J26). CuO NM exhibited a better antifungal effect than C60 and TiO2 NMs. The contents of three important hormones, indolepropionic acid (IPA), gibberellic acid 3 (GA-3), and indole-3-acetic acid (IAA) in the infected J26 sweet potato treated with 50 mg/L CuO NM were significantly higher than those of the control by 14.5%, 10.8%, and 24.1%. CuO and C60 NMs promoted antioxidants in both cultivars of sweet potato. Overall, CuO NM at 50 mg/L exhibited the best antifungal properties, followed by TiO2 NM and C60 NM, and these results were further confirmed through scanning electron microscope (SEM) analysis. The use of CuO NMs as an antifungal agent in the prevention of Rhizopus stolonifer infections in sweet potatoes could greatly reduce postharvest storage and delivery losses.

Effect of the Dispersion States of Azone in Hydroalcoholic Gels on Its Transdermal Permeation Enhancement Efficacy.

The objective of this study was to investigate the effect of dispersion states of azone in gels on the transdermal permeation of levamisole hydrochloride (LH). LH hydroalcoholic gels containing azone of different dispersion states were prepared by varying the contents of azone and Tween 80, and the in vitro transdermal permeation of LH across excised rat skin was evaluated. Depending on the content of azone, mixed solvents, and solubilizer used, azone presented as dissolved molecules, solubilized in micelles, and fine or coarse emulsion droplets in gels. Dramatically increased transdermal permeation of LH within the azone contents between 0.25% and 0.75% indicated high transdermal enhancement efficiency of the molecular or micellar azone, and extra azone that existed as oil droplets did not fully exert transdermal penetration enhancement of LH. Although solubilizer (Tween 80) can greatly increase the solubility of azone, only small amount of Tween 80 (0.5%) in the gel significantly increased the steady-state flux of LH. Addition of extra amount of Tween 80 (>0.5%) reduced the amount of azone distributed in the skin, and thus decreased the transdermal drug permeation. The results partly elucidated the versatile effects of the dispersion states of azone on the transdermal permeation of hydrophilic drug from semisolid gels.

Combretastatin A4/poly(L-glutamic acid)-graft-PEG conjugates self-assembled to nanoparticles.

Combretastatin A4 (CA4) possesses varying ability to cause vascular disruption in tumors, while the short half-life, low water solubility and deactivation of many CA4 analogs during storage limited its antitumor efficacy and drug stability. A novel macromolecular conjugate of CA4 (CA4-PL) was synthesized by covalent bonding of CA4 onto poly(L-glutamic acid)-graft-polyethylene glycol (PLG-g-PEG) via Yamaguchi reaction. The obtained CA4-PL was characterized by 1H NMR, GPC, and UV methods, and the properties of the nanoparticles composed of CA4-PL, including critical aggregation concentration, size and size distribution, and morphology, were investigated. CA4-PL can self-assemble to form micelle-like nanoparticles of 80~120 nm in diameter, which may have potential to improve the blood circulation period as well as the targetability of CA4, and find applications to treat various tumors when combined with traditional chemotherapy or radio therapy.

Improvement of the Antitumor Efficacy of Intratumoral Administration of Cucurbitacin Poly(Lactic-co-Glycolic Acid) Microspheres Incorporated in In Situ-Forming Sucrose Acetate Isobutyrate Depots.

Localized drug delivery strategies for cancer therapy have been introduced for decades as a means of increasing drug concentration at tumor target site and minimizing systemic toxicities. In this paper, a combination of microspheres (MSs) and sucrose acetate isobutyrate (SAIB) in situ-forming implants (ISFIs) was evaluated for improving antitumor efficacy via intratumoral injection. Monodispersed cucurbitacin (Cuc)-loaded Poly (lactic-co-glycolic acid) (PLGA) MSs with mean diameter of about 5 µm were fabricated by Shirasu porous Glass (SPG) membrane emulsification technique, and their properties were investigated. The in vitro drug release pattern, antimelanoma efficiency, and drug distribution in tumor of three different intratumoral injection systems, that is, MSs, SAIB ISFIs, and combination of MSs and SAIB ISFIs (SAIB-MSs), was investigated. The Cuc-loaded MSs prepared by PLGA (LA/GA = 50:50, inherent viscosity = 0.87 dL/g), has an appropriate release pattern with lower initial burst and delayed drug release. SAIB-MSs have a much slower drug release rate than that of MSs or SAIB ISFIs. SAIB-MSs showed the best antitumor efficacy in melanoma-bearing mice model, and the results of drug distribution in tumor revealed that the incorporation MSs in SAIB solution obviously extended the residence of drug in tumor. The low Cuc concentration in tumor periphery region after intratumoral administration of SAIB-MSs demonstrated poor drug penetration of this system. For further improving the antitumor efficacy of intratumoral chemotherapy, elegant designing to carriers with both extended residency and wide drug distribution in tumor is needed.