0/w-emulsion of alpha-linolenic acid stabilized with hydrophobized polysaccharide. Its effect on the growth of human colon cancer cells

Microbial polysaccharides: An emerging family of natural biomaterials for cancer therapy and diagnostics

Microbial polysaccharides (MPs) offer immense diversity in structural and functional properties. They are extensively used in advance biomedical science owing to their superior biodegradability, hemocompatibility, and capability to imitate the natural extracellular matrix microenvironment. Ease in tailoring, inherent bio-activity, distinct mucoadhesiveness, ability to absorb hydrophobic drugs, and plentiful availability of MPs make them prolific green biomaterials to overcome the significant constraints of cancer chemotherapeutics. Many studies have demonstrated their application to obstruct tumor development and extend survival through immune activation, apoptosis induction, and cell cycle arrest by MPs. Synoptic investigations of MPs are compulsory to decode applied basics in recent inclinations towards cancer regimens. The current review focuses on the anticancer properties of commercially available and newly explored MPs, and outlines their direct and indirect mode of action. The review also highlights cutting-edge MPs-based drug delivery systems to augment the specificity and efficiency of available chemotherapeutics, as well as their emerging role in theranostics.

Surface Coating of Liposomes with Hydrophobized Polysaccharides

Coating the outermost surface of a liposomal membrane with several different hydrophobized polysaccharides was investigated by fluorescence depolarization, gel chromatography, and dynamic light scattering methods. The binding of cholesterol-bearing pullulan to the liposomal surface was biphasic. The first process was finished within minutes while the subsequent slow stages took over several hours. The binding isotherms followed Langmuir-type adsorption. The binding constant (K) increased with increases in the substitution degree of the cholesteryl moiety and the molecular weight of the pullulan derivatives used, while the maximum amount of the polysaccharide coating (qs) was almost the same. The apparent liposome size increased by 20-30 nm upon coating. Chemical structure of the parent polysaccharide had only a slight effect on the binding constant, while the structures of the hydrophobic moiety had a significant effect on the coating behavior of the liposomes. In the case of dodecyl diglyceryl group-bearing pullulan, both K and qs were smaller than those of other cholesterol-bearing polysaccharides. The addition of hexadecyl-bearing pullulan to the liposome induced aggregation of the liposomes. The cholesteryl moiety is an excellent hydrophobic anchor for polysaccharide coating liposomal surfaces compared with simple monoalkyl or dialkyl chains.

Cell Specificity of Macromolecular Assembly of Cholesteryl and Galactoside Groups-Conjugated Pullulan

Galactose or lactose groups were conjugated to cholesterol-bearing pullulan (CHP). The CHP derivatives obtained formed monodisperse nanoparticles upon self-aggregation in water. Nanoparticles of galactoside-conjugated CHP self-aggregates were specifically internalized by rat hepatocytes and HepG2 cells. Galactoside-bearing CHP-coated liposome or oil droplet of O/W-emulsion was also taken up by HepG2 cells. Tissue distribution of the nanoparticle CHP self-aggregates changed dramatically with chemical conjugation of the galactose moiety. Galactoside-bearing nanoparticles were specifically accumulated in the liver.