Pharmaceutically versatile sulfated polysaccharide based bionano platforms

Marine polysaccharide-based nanomaterials as a novel source of nanobiotechnological applications

Research on marine polysaccharide-based nanomaterials is emerging in nanobiotechnological fields such as drug delivery, gene delivery, tissue engineering, cancer therapy, wound dressing, biosensors, and water treatment. Important properties of the marine polysaccharides include biocompatibility, biodegradability, nontoxicity, low cost, and abundance. Most of the marine polysaccharides are derived from natural sources such as fucoidan, alginates, carrageenan, agarose, porphyran, ulvan, mauran, chitin, chitosan, and chitooligosaccharide. Marine polysaccharides are very important biological macromolecules that widely exist in marine organisms. Marine polysaccharides exhibit a vast variety of structures and are still under-exploited and thus should be considered as a novel source of natural products for drug discovery. An enormous variety of polysaccharides can be extracted from marine organisms such as algae, crustaceans, and microorganisms. Marine polysaccharides have been shown to have a variety of biological and biomedical properties. Recently, research and development of marine polysaccharide-based nanomaterials have received considerable attention as one of the major resources for nanotechnological applications. This review highlights the recent research on marine polysaccharide-based nanomaterials for biotechnological and biomedical applications.

Stimulation of RAW264.7 macrophages by sulfated Escherichia coli K5 capsular polysaccharide in vitro

The aim of the present study was to explore the immunomodulatory effects of sulfated K5 polysaccharide derivatives on RAW264.7 macro-phage cells, and to further elucidate the structure‑activity relationship. In the present study, chemically sulfated polysaccharides were derived from Escherichia coli K5 capsular polysaccharide (K5PS), and molecular weight determination, sugar analysis, and other physical and chemical characterizations were performed on the derived polysaccharides. Enzyme‑linked immunosorbent assay and reverse transcription‑polymerase chain reaction analyses demonstrated that K5‑OS2 stimulated murine RAW264.7 macrophage cells to release TNF‑α and IL‑1β proinflammatory cytokines. K5‑OS2 also induced the expression of inducible nitric oxide synthase iNOS, which is responsible for the production of nitric oxide. In addition, K5‑OS2 markedly induced macrophage‑mediated cytotoxicity against cancer cells and promoted the phagocytic activity of the RAW264.7 cells. Therefore, K5‑OS2 activated macrophages and acted as a potent immunomodulator. Observations of the present study also indicated that sulfation modification enhanced the immune‑enhancing activity of K5PS, and that the high sulfation in the O‑position of K5PS may be required for the immunomodulatory activities of the Escherichia coli K5 capsular polysaccharide.

Seaweed polysaccharides and their potential biomedical applications

Over the past two decades numerous studies have been reported on seaweeds‐derived polysaccharides for biomedical and biological applications (tissue engineering, drug delivery, wound healing, and biosensor). Alginate, carrageenan, fucoidan, and ulvan are widely used marine derived polysaccharides for biological and biomedical applications due to their biocompatibility and availability. The gel forming property of alginate has increased its applications in tissue engineering and drug delivery as an extracellular matrix and delivery vehicle, respectively. Other sulfated polysaccharides such as carrageenan and fucoidan show promising application in tissue engineering due to their capacity of inducing important osteogenic, adipogenic, and chondrogenic differentiation in stem cells. In this review, we explained the extraction/isolation methods and applications of these seaweed derived polysaccharides as well as their roles in therapeutics, drug delivery, and tissue engineering.

Biocompatible ι-carrageenan-γ-maghemite nanocomposite for biomedical applications - synthesis, characterization and in vitro anticancer efficacy

Background

Carrageenans are naturally occurring hydrophilic, polyanionic polysaccharide bioploymers with wide application in pharmaceutical industries for controlled drug delivery. Magnetic nanoparticles with their exceptional properties enable them to be an ideal candidate for the production of functional nanostructures, thus facilitating them for biomedical applications. The development of novel nanocomposite by coupling the synergistic effects of the sulfated polysaccharide (iota carrageenan) and a magnetic nanoparticle (maghemite) may offer new interesting applications in drug delivery and cancer therapy. The nanocomposite was characterized by ultraviolet–visible spectroscopy, high resolution scanning electron microscopy, dynamic light scattering analysis, Fourier transform infrared spectroscopy and powder XRD to highlight the possible interaction between the two components. Biocompatibility and the anticancer efficacy of the nanocomposite were assayed and analysed in vitro.

Results

Results suggested that iota carrageenans have electrostatically entrapped the maghemite nanoparticles in their sulfate groups. Biocompatibility of the nanocomposite (at different concentrations) against normal cell lines (HEK-293 and L6) was confirmed by MTT assay. Hoechst 33342 and 7-AAD staining studies under fluorescent microscopy revealed that the nanocomposite is able to induce appoptosis as the mode of cell death in human colon cancer cell line (HCT116). Cell apoptosis here is induced by following the ROS-mediated mitochondrial pathway, combined with downregulation of the expression levels of mRNA of XIAP and PARP-1 and upregulation of caspase3, Bcl-2 and Bcl-xL.

Conclusions

This novel nanocomposite is biocompatible with potential properties to serve in magnet aided targeted drug delivery and cancer therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-015-0079-3) contains supplementary material, which is available to authorized users.

Biological activities of derivatized D-glucans: a review

D-Glucans have triggered increasing interest in commercial applications in the chemical and pharmaceutical sectors because of their technological properties and biological activities. The glucans are foremost among the polysaccharide groups produced by microorganisms with demonstrated activity in stimulating the immune system, and have potential in treating human disease conditions. Chemical alterations in the structure of D-glucans through derivatization (sulfonylation, carboxymethylation, phosphorylation, acetylation) contributes to their increased solubility that, in turn, can alter their biological activities such as antioxidation and anticoagulation. This review surveys and cites the latest advances on the biological and technological potential of D-glucans following chemical modifications through sulfonylation, carboxymethylation, phosphorylation or acetylation, and discusses the findings of their activities. Several studies suggest that chemically modified d-glucans have potentiated biological activity as anticoagulants, antitumors, antioxidants, and antivirals. This review shows that in-depth future studies on chemically modified glucans with amplified biological effects will be relevant in the biotechnological field because of their potential to prevent and treat numerous human disease conditions and their clinical complications.

Sulfated glycosaminoglycan-based block copolymer: preparation of biocompatible chondroitin sulfate-b-poly(lactic acid) micelles

Despite a growing interest in amphiphilic polysaccharide-based diblock copolymers as functional polymeric drug delivery nanosystems, biologically relevant sulfated glycosaminoglycan systems were not yet investigated. Here, we report the synthesis and the self-assembly properties in water of chondroitin sulfate-b-poly(lactic acid) (CS-b-PLA(n)). The CS-b-PLA(n) were synthesized using click-grafting onto method implying reducing-end alkynation of low-molecular weight depolymerized CS (M(w) = 5000 g·mol(-1)) and azide-terminated functionalization of PLAn (M(w) = 6500 g·mol(-1) (n = 46) and M(w) = 1700 g·mol(-1) (n = 20)). The diblock copolymer self-assembled in water giving rise to spherical micelles that were characterized in solution using dynamic/static light scattering and at dry state by TEM technique. In vitro assays on healthy cells showed that at high concentrations, up to 10 μg·mL(-1), CS-b-PLA(n) were noncytotoxic. Those preliminary studies are promising in the perspective to use them as biocompatible nanovehicles for anticancer drug delivery.