Uptake of Well-Defined, Highly Glycosylated, Pentafluorostyrene-Based Polymers and Nanoparticles by Human Hepatocellular Carcinoma Cells

Carbohydrate-Based Macromolecular Biomaterials

Carbohydrates are the most abundant and one of the most important biomacromolecules in Nature. Except for energy-related compounds, carbohydrates can be roughly divided into two categories: Carbohydrates as matter and carbohydrates as information. As matter, carbohydrates are abundantly present in the extracellular matrix of animals and cell walls of various plants, bacteria, fungi, etc., serving as scaffolds. Some commonly found polysaccharides are featured as biocompatible materials with controllable rigidity and functionality, forming polymeric biomaterials which are widely used in drug delivery, tissue engineering, etc. As information, carbohydrates are usually referred to the glycans from glycoproteins, glycolipids, and proteoglycans, which bind to proteins or other carbohydrates, thereby meditating the cell-cell and cell-matrix interactions. These glycans could be simplified as synthetic glycopolymers, glycolipids, and glycoproteins, which could be afforded through polymerization, multistep synthesis, or a semisynthetic strategy. The information role of carbohydrates can be demonstrated not only as targeting reagents but also as immune antigens and adjuvants. The latter are also included in this review as they are always in a macromolecular formulation. In this review, we intend to provide a relatively comprehensive summary of carbohydrate-based macromolecular biomaterials since 2010 while emphasizing the fundamental understanding to guide the rational design of biomaterials. Carbohydrate-based macromolecules on the basis of their resources and chemical structures will be discussed, including naturally occurring polysaccharides, naturally derived synthetic polysaccharides, glycopolymers/glycodendrimers, supramolecular glycopolymers, and synthetic glycolipids/glycoproteins. Multiscale structure-function relationships in several major application areas, including delivery systems, tissue engineering, and immunology, will be detailed. We hope this review will provide valuable information for the development of carbohydrate-based macromolecular biomaterials and build a bridge between the carbohydrates as matter and the carbohydrates as information to promote new biomaterial design in the near future.

Carbohydrate-based nanocarriers and their application to target macrophages and deliver antimicrobial agents

Many deadly infections are produced by microorganisms capable of sustained survival in macrophages. This reduces exposure to chemadrotherapy, prevents immune detection, and is akin to criminals hiding in police stations. Therefore, the use of glyco-nanoparticles (GNPs) as carriers of therapeutic agents is a burgeoning field. Such an approach can enhance the penetration of drugs into macrophages with specific carbohydrate targeting molecules on the nanocarrier to interact with macrophage lectins. Carbohydrates are natural biological molecules and the key constituents in a large variety of biological events such as cellular communication, infection, inflammation, enzyme trafficking, cellular migration, cancer metastasis and immune functions. The prominent characteristics of carbohydrates including biodegradability, biocompatibility, hydrophilicity and the highly specific interaction of targeting cell-surface receptors support their potential application to drug delivery systems (DDS). This review presents the 21^st century development of carbohydrate-based nanocarriers for drug targeting of therapeutic agents for diseases localized in macrophages. The significance of natural carbohydrate-derived nanoparticles (GNPs) as anti-microbial drug carriers is highlighted in several areas of treatment including tuberculosis, salmonellosis, leishmaniasis, candidiasis, and HIV/AIDS.

Preparation of Fluoroalkyl End-Capped Vinyltrimethoxysilane Oligomeric Silica Nanocomposites Containing Gluconamide Units Possessing Highly Oleophobic/Superhydrophobic, Highly Oleophobic/Superhydrophilic, and Superoleophilic/Superhydrophobic Characteristics on the Modified Surfaces

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [R_F-(CH₂-CHSi(OMe)₃)_n-R_F (R_F-(VM)_n-R_F)] undergoes the sol-gel reaction in the presence of N-(3-triethoxysilylpropyl)gluconamide [Glu-Si(OEt)₃] under alkaline conditions to afford the corresponding fluorinated oligomeric silica nanocomposites containing gluconamide units [R_F-(VM-SiO_3/2)_n-R_F/Glu-SiO_3/2]. These obtained nanocomposites were applied to the surface modification of glass to provide the unique wettability characteristics such as highly oleophobic/superhydrophobic and highly oleophobic/superhydrophilic on the modified surfaces under a variety of conditions. Such a highly oleophobic/superhydrophobic characteristic was also observed on the modified PET (polyethylene terephthalate) fabric swatch, which was prepared under similar conditions, and this modified PET fabric swatch was applied to the separation membrane for the separation of the mixture of fluorocarbon oil and hydrocarbon oil. The R_F-(VM-SiO_3/2)_n-R_F/Glu-SiO_3/2 nanocomposites, which were prepared under lower feed amounts of basic catalyst (ammonia), were found to cause gelation in water. Interestingly, it was demonstrated that these gelling nanocomposites are also applied to the surface modification of the PET fabric swatch to give a highly oleophobic/superhydrophobic characteristic on the surface. On the other hand, the modified glass surfaces treated with the corresponding nanocomposite possessing no gelling ability were found to supply the usual hydrophobic characteristic with a highly oleophobic property. More interestingly, the wettability change on the modified PET fabric swatch from highly oleophobic to superoleophilic was observed, and remained superhydrophobic after immersing the modified PET fabric swatch into water.

Carbohydrate-Specific Uptake of Fucosylated Polymeric Micelles by Different Cancer Cell Lines

Inspired by upregulated levels of fucosylated proteins on the surfaces of multiple types of cancer cells, micelles carrying β-l-fucose and β-d-glucose were prepared. A range of block copolymers were synthesized by reacting a mixture of 2-azidoethyl β-l-fucopyranoside (FucEtN3) and 2-azideoethyl β-d-glucopyranoside (GlcEtN3) with poly(propargyl methacrylate)-block-poly(n-butyl acrylate) (PPMA-b-PBA) using copper-catalyzed azide-alkyne cycloaddition (CuAAC). Five block copolymers were obtained ranging from 100 mol % fucose to 100% glucose functionalization. The resulting micelles had hydrodynamic diameters of around 30 nm. In this work, we show that fucosylated micelles reveal an increased uptake by pancreatic, lung, and ovarian carcinoma cell lines, whereas the uptake by the healthy cell lines (CHO) is negligible. This finding suggests that these micelles can be used for targeted drug delivery toward cancer cells.

Lignocellulosic biomass: a sustainable platform for the production of bio-based chemicals and polymers

The ongoing research activities in the field of lignocellulosic biomass for production of value-added chemicals and polymers that can be utilized to replace petroleum-based materials are reviewed.

N-acetylgalactosamine functionalized mixed micellar nanoparticles for targeted delivery of siRNA to liver

Due to its efficient and specific gene silencing ability, RNA interference has shown great potential in the treatment of liver diseases. However, achieving in vivo delivery of siRNA to critical liver cells remains the biggest obstacle for this technique to be a real clinic therapeutic modality. Here, we describe a promising liver targeting siRNA delivery system based on N-acetylgalactosamine functionalized mixed micellar nanoparticles (Gal-MNP), which can efficiently deliver siRNA to hepatocytes and silence the target gene expression after systemic administration. The Gal-MNP were assembled in aqueous solution from mixed N-acetylgalactosamine functionalized poly(ethylene glycol)-b-poly(ε-caprolactone) and cationic poly(ε-caprolactone)-b-poly(2-aminoethyl ethylene phosphate) (PCL-b-PPEEA); the properties of nanoparticles, including particle size, zeta potential and the density of poly(ethylene glycol) could be easily regulated. The hepatocyte-targeting effect of Gal-MNP was demonstrated by significant enriching of fluorescent siRNA in primary hepatocytes in vitro and in vivo. Successful down-regulation of liver-specific apolipoprotein B (apoB) expression was achieved in mouse liver, at both the transcriptional and protein level, following intravenous injection of Gal-MNP/siapoB to BALB/c mice. Systemic delivery of Gal-MNP/siRNA did not induce the innate immune response or positive hepatotoxicity. The results of this study suggested therapeutic potential for the Gal-MNP/siRNA system in liver disease.