Construction and Application of EGCG-Loaded Lysozyme/Pectin Nanoparticles for Enhancing the Resistance of Nematodes to Heat and Oxidation Stresses.

Novel nanoparticles (NPs) were constructed with lysozyme (LY) and pectin (Ps) through self-assembly, which were used as a carrier to encapsulate epigallocatechin-3-gallate (EGCG). The binding of EGCG and LY is a static quenching process. Hydrogen bonds might play a major role in the formation of NPs, which has also been verified by a lower binding constant of EGCG with LY/Ps NPs. Meanwhile, EGCG could lead to conformational and microenvironmental changes of LY, resulting in more folding of LY secondary structures. In addition, attaching Ps to LY might inhibit LY aggregation induced by addition of free EGCG. At the LY/Ps mass ratio of 1:1, the constructed LY/Ps NPs had a high EGCG-loading capacity without a significant change in mean particle size, thus, our NPs could be used as an effective nanocarrier for loading EGCG. In vivo, compared with free EGCG, EGCG loaded onto LY/Ps NPs significantly increased Caenorhabditis elegans' (C. elegans) resistance to heat stress and oxidative injury and prolonged their lifespan. This study provides theoretical basis and reference for constructing nanoactive substance carriers so as to improve the resistance of organisms to heat stress and oxidative damage and to increase their survival rate and extend their lifespan under environment stresses.

Green-step assembly of low density lipoprotein/sodium carboxymethyl cellulose nanogels for facile loading and pH-dependent release of doxorubicin.

In this study, a simple and green approach was developed to produce a novel nanogel via self-assembly of low density lipoproteins (LDL) and sodium carboxymethyl cellulose (CMC), to efficiently deliver doxorubicin (DOX) to cancer cells. Under optimal conditions, the stable nanogels were of spherical shape with an average diameter of about 90 nm, PDI<0.3 and a zeta potential -35 mV. Furthermore, the cationic anticancer drug, doxorubicin (DOX) was effectively encapsulated into LDL/CMC nanogels with an exceptionally high encapsulation efficiency of ∼ 98%. The release of DOX from DOX-LDL/CMC nanogels was pH-dependent, and DOX was released at a quicker rate at pH 6.2 than at pH 7.4. Importantly, the DOX-LDL/CMC nanogels were shown to effectively kill cancer cells in vitro. The IC50 of the DOX-LDL/CMC nanogels in HeLa and HepG2 cells was approximately 2.45 and 1.72 times higher than that of free DOX. The slightly reduced antitumor efficacy was primarily due to the less cellular uptake of the DOX-LDL/CMC nanogels, which was confirmed by confocal laser scanning microscope (CLSM) and flow cytometry analysis. The high DOX payload and pH-dependent drug release rendered LDL/CMC nanogels as an efficient carrier for doxorubicin and possibly be used for other cationic drugs in different biomedical applications.

Construction of pH-sensitive lysozyme/pectin nanogel for tumor methotrexate delivery.

Novel nano-particles were developed from lysozyme-pectin through self-assembly, and the nanogels could be used as a carrier for the antitumor agent, methotrexate (MTX). The nanogels exhibited spherical with diameters about 109 ± 2 nm and narrow particle size distribution, as well as negative surface charge. Furthermore, the particle size and morphology of the nanogels hardly changed with the incorporation of MTX. The loading capacity of MTX in nanogels could reach 17.58 ± 0.85%. MTX-loaded nanogels were pH-dependent, accelerated release of MTX at a decreasing pH from 7.4 to 5.3. The MTT assay indicated that encapsulated MTX exhibited higher anticancer activity than free MTX. Meanwhile, MTX-loaded nanogels could be effectively endocytosed by HepG2 cells, resulting in enhanced cancer-cell apoptosis comparing to free MTX. It indicated that the nanogels had good biocompatibility and low toxicity. The obtained nanogels had great potential in the development of a new nanocarrier for anti-cancer drug delivery.

Self-assembled zein-sodium carboxymethyl cellulose nanoparticles as an effective drug carrier and transporter.

In this work, biodegradable nanoparticles (NPs) were assembled with sodium carboxymethyl cellulose (CMC) and zein to produce zein-CMC NPs. Paclitaxel (PTX) was 95.5% encapsulated at a zein-CMC weight ratio of 1 : 3 and the NPs were spherical with an average particle size of approximately 159.4 nm, with the PTX concentration maintained at 80 µg mL-1. The NPs demonstrated good stability over a broad range of pH ranging from 3.7 to 11.0. The zein-CMC NPs were seen to provide a sustained release of PTX for up to 72 h, which led to an 80% release of the total loaded PTX in vitro. Confocal laser scanning microscopy (CLSM) and flow cytometry studies showed that the zein-CMC NPs could effectively transport encapsulated molecules into both drug-sensitive (HepG2 cells) and drug-resistant cancer cells (MCF-7 cells). Moreover, in vitro viability studies revealed that the PTX-loaded zein-CMC NPs had greater potency than free PTX in the PTX resistant MCF-7 cells at higher concentration. Furthermore, PTX-loaded NPs displayed obvious efficiency in the apoptosis of HepG2 cells. Zein-CMC NPs have shown significant potential as a highly versatile and potent platform for cancer therapy.

Phase behavior of ovalbumin and carboxymethylcellulose composite system.

The phase behavior, rheological properties and microstructure of ovalbumin and carboxymethylcellulose (OVA-CMC) conjugates were studied and the influence parameters were investigated. The results showed that the phase behavior of OVA-CMC conjugates was related to pH and concentration of CMC and NaCl. When pH was over 5.0, discrete phase separation occurred in the mixture system, which indicated that OVA and CMC were thermodynamic incompatible. The mixture system turned into uniform stable emulsion system when pH reduced below 5.0. The addition of NaCl can improve the stability of composite system against pH sensitivity. CLSM and particle size distribution and ultraviolet spectrum analysis results confirm that emptying interactions play a leading role in the separation system.

Green synthesis of xanthan conformation-based silver nanoparticles: antibacterial and catalytic application.

Silver nanoparticles (Ag NPs) were green synthetized using xanthan gum (XG) dissolved in water as reducing and capping agent for the first time. The structure, morphology, and size of Ag NPs in XG aqueous solutions were investigated with UV-vis spectroscopy, transmission electron microscopy and Fourier transform infrared. The results indicated Ag NPs were integrated successfully in the XG matrix and the optical properties and morphology of Ag NPs could be regulated by the synthesis condition. The aggregation of the XG-bonded Ag NPs increased with storage, whereas the size barely changed. The assemble behavior was related to the XG conformation transition of denaturation and renaturation. The one spot formed Ag NPs showed favorable antibacterial effect on Escherichia coli and Staphyloccocus aureus and excellent catalytic capability of 4-nitrophenol reduction. This work provided a feasible method to detect the biopolymer space structure transition through the intensity of metal nanoparticles labeled on the chain.