Hongshan Liang

Fabrication of zein/quaternized chitosan nanoparticles for the encapsulation and protection of curcumin

In this article, we report the successful assembly of nanoparticles (NPs) from a water-soluble chitosan (CS) derivative (N-(2-hydroxyl)propyl-3-trimethyl ammonium chitosan chloride, HTCC) and zein via a low-energy phase separation method. The fabricated NPs were investigated for the first time to encapsulate and protect curcumin (Cur). The particle size and zeta potential of the zein–HTCC NPs varied from 66 to 170 nm and +36.3 to +62.5 mV, respectively. The encapsulation efficiency (EE) was greatly improved to 94.9% after HTCC coating, compared with 85.2% that using zein as a single encapsulant. The microstructure of the NPs was revealed by transmission electron microscopy (TEM). The physicochemical and structural analysis showed that the electrostatic interactions and hydrogen bonds were the major forces responsible for the formation of NPs. The encapsulation forms were evaluated for their efficiency in overcoming Curs heat and UV sensitivity, which improve the stability about 2.7 fold, 3.5 fold and 2.5 fold when disposed with 60 °C treatment for 30 min, 80 °C treatment for 1 min and ultraviolet radiation for 2 h, respectively at zein–HTCC1 = 1u2006:u20061. The results of the stability and DPPH assays indicated that the bioactivity was being protected upon encapsulation. Zein–HTCC NPs are believed to be promising delivery systems for the supplementation or treatment of hydrophobic nutrients or drugs.

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 1u2009:u20093 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.

In situ synthesis of gold nanoparticles on LBL coated nanofibers by tannic acid for catalytic application

Electrospinning nanofibrous mats are extensively studied as efficient two-dimensional nanomaterials and applied in the fields of filtration, catalysis, and biosensors due to their flexibility and porosity. In this article, gold nanoparticle (AuNPs) loaded composite nanofibers were fabricated by a simple method, which consisted of the preparation of the nanofibers by electrospinning, the deposition of tannic acid (TA) on the surface of the nanofibers via layer-by-layer assembly and the reduction of the AuNPs on the nanofibrous mats. The as-prepared nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. The results revealed that AuNPs were successfully generated on the nanofibers without aggregation. In addition, by adjusting the number of the bilayers in the assembly process, the content of gold supported on the nanofibrous mats could be easily controlled. The catalytic performance of the hybrid nanofibrous mats on the reduction of 4-nitrophenol (4-NP) with sodium borohydride was monitored by UV-visible spectroscopy (UV-vis). Notably, the hybrid composite nanofibrous mats could be easily separated from the reaction mixture.

pH-Degradable antioxidant nanoparticles based on hydrogen-bonded tannic acid assembly

Hydrogen-bonded polyphenol-based assemblies have attracted increasing interest for biomedical applications. Polyphenolic drug-loaded films can be coated on various devices with different shapes and sizes. Here, we report a novel versatile pH-responsive system based on hydrogen-bonded poly(ethylene glycol) (PEG)/tannin acid (TA) coatings on zein/TA colloidal nanoparticles (zein/TA/PEG NPs). Hydrogen bonding was considered to be the driving force for the coating buildup between PEG and TA, which was confirmed by Fourier transform infrared (FTIR) spectra. Because of the reversible/dynamic nature of hydrogen bonding, the release profile of TA was directed by pH value, temperature, ionic strength and TA concentration. The release rate of TA increased with increasing pH and temperature, but decreased with increasing ionic strength. This new drug delivery vehicle could also be used to load hydrophobic and unstable molecules through interacting with zein by hydrophobic interaction to achieve efficient protection. We demonstrated that the hydrophobic molecular nutrient, VD3, can be successfully loaded into zein/TA/PEG NPs with high encapsulation efficiency. Photostability against UV light was significantly improved after encapsulation. The encapsulated VD3 could be regulated not only by the pH of the solutions but also by TA concentration.

Structural and rheological properties of xanthan gum/lysozyme system induced by in situ acidification

Structural and rheological properties of xanthan gum/lysozyme (XG/Ly) system induced by electrostatic interaction through in situ acidification were investigated. The two biopolymers transited from co-solubility state to form soluble complexes, and finally produced tenuous network as the pH further decreased. The fluorescent images indicated that the network was cross-linked of XG chains by Ly, liking a polymerization process which resulted in the sol-gel transition by electrostatic interactions. High Ly content could accelerate the phase transition at the same pH condition, while XG played a contrary role. XG addition could enhance the thermal stability of Ly. The phase transition was also illustrated by ζ-potential at different pHs. The boundary parameters were determined to distinguish the phase transition regions. At the pH higher than pHφ, the negatively liked XG and Ly were in co-soluble state. They formed soluble complexes at the pH between pHφ and pHg, and gel was obtained with net microstructure as the pH continuously decreased (lower than pHg). The paper provides practical parameters that may be applicable in controlling the structure, texture, and stability of polysaccharide/protein system, as well as in food and medicinal application with various purposes.

Folate-functionalized assembly of low density lipoprotein/sodium carboxymethyl cellulose nanoparticles for targeted delivery

In this study, well-defined folate (FA)-functionalized low density lipoproteins (LDL)/sodium carboxymethyl cellulose (CMC) nanoparticles (NP) were first formulated, utilized in tumor targeting and pH-triggered drug release. CMC was modified with FA before the preparation of NP. A model anti-tumor drug, doxorubicin (DOX), was effectively loaded into the LDL/CMC-FA NP by ionic bonding and hydrophobic interactions. To enhance non-covalent encapsulation stability, self-assembly of DOX-loaded LDL/CMC-FA NP (NP-DOX) was cross-linked by multivalent cations such as Ca2+ (Ca2+-NP-DOX). The active targeting efficiency of NP-DOX and Ca2+-NP-DOX was tested against KB cells (FA-receptor over-expressing cells, FR+) and A549 cells (FA-receptor negative-expressing cells, FR-), using FA non-modified DOX-loaded LDL/CMC NP (NG-DOX) as control. The competition assay proved that free FA molecules prevented the cellular uptake of the NP by competitive binding to the FA receptors on the surface of KB cells. This new pH-responsive and FA-targeted nanocarrier may be a promising efficient drug delivery system for potential cancer therapy.

Coordination-driven multilayer of phosvitin-polyphenol functional nanofibrous membranes: antioxidant and biomineralization applications for tissue engineering

The layer-by-layer (LBL) deposition technique has been widely used to decorate the nanofibers formed from polymer pairs with complementary functional groups. In the current study, an antioxidative coordination-driven multilayer electrospun nanofibrous film was fabricated from tannic acid (TA) and phosvitin (PV) obtained from egg yolk. PV was reported to bond with 95% of yolk iron which could provide chelating sites for TA. The surface morphology of the nanofibrous mats was observed by scanning electron microscopy (SEM). Also the TEM image of the cross-section illustrated a uniform shell formed around the cellulose nanofibers. The deposition of TA and PV was further confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). TA/PV nanofibrous mats showed good 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity regardless of the outmost component. While for superoxide-scavenging and hydroxyl radical-scavenging activity, the outmost component affected the scavenging capacity of nanofibrous mats. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were combined to characterize the morphology and structure of the deposited mineral phase on the scaffolds after culturing in a simulated body fluid (SBF) for 5 days. From the result, the TA/PV nanofibrous mats were satisfactory for use in bioapplications.

Confirmation and measurement of hydrophobic interaction in sol-gel system of konjac glucomannan with different degree of deacetylation

Fluorescence measurement was used as a tool to study the hydrophobic interaction in sol-gel system of konjac glucomannan (KGM) with different degree of deacetylation (DD). In the concentration from 0 to 10g/L, I1/I3 ratio of native KGM declined from 1.75 to 1.25. Before and after heating, the critical associating concentration of the native KGM was 0.60g/L and 0.95g/L respectively, but this value of deacetylated KGM (DD=32.58%) was 0.58g/L and 0.45g/L respectively. The addition of Na2SO4 and NaSCN exhibited more significant influence on deacetylated KGM compared with native KGM. All the phenomenons correlated well with the theory of salting in and salting out, indicating that the difference of DD leaded to the diversity of intramolecular and intermolecular forces in KGM solutions, namely, as DD increased, the contribution ratio from hydrophobic interactions grew up compared with hydrogen bonding.