Читать книгу Polysaccharides - Группа авторов - Страница 79

Carrageenan has an array of biological activities including anti-coagulants, anti-viruses, immunomodulation, anti-tumors and anti-thrombosis. Among different types, λ-carrageenan shows approximately 2–4 times higher activity compared to non-fractioned and k-carrageenan, respectively. For example, in contrast to k, an enhanced antithrombic activity is likely due to a higher content of sulfur in α-carrageen, was observed. Kindness et al. have provided the activity of carrageenan, that inhibits thrombin by antithrombin-III similar to heparin [181].

Chondrus crispus derived carrageenan gels have demonstrated a selective inhibition of many human pathogenic viruses [182]. Recent studies suggest their in vitro cancer activity and tumor growth inhibition in vivo [183]. Furthermore, a report has shown that carrageenan promotes immune response against cancer cells by increasing activation of cells [183]. Moreover, the unique properties of carrageenans represent the perfect candidate for controlled and targeted drug delivery systems [184]. They are also extremely amenable to nanoparticle (NP) formulation. Report on the erythropoietin-linked carrageenan nanoparticles prepared using ionotropic gelation process, demonstrated the in vitro controlled release with enhanced encapsulation efficiency [185]. Carrageenan are also considered as transporters in gene delivery process. It was stated that siRNA-primed nanoparticles charged with the required antibodies were dispersed using μ-carrageenan and biodegradable film in the therapeutic prevention of HIV [186].