Abstract: This invention discloses a natural polyphenols-based, multi-stage porous hydrogel sustained release drug delivery system, which relates to the field of drug delivery. It consists of the hydrogel matrix and the supramolecular filler, which is a complex of natural bio-based polymers and metal ions. The natural bio-based polymer can be natural polyphenols, dopamine or its derivatives, polysaccharide biomass, or protein biomass. The hydrogel matrix can be chitosan, carboxymethyl chitosan, sodium alginate, carboxymethyl cellulose, hyaluronic acid, collagen, gelatin, or agarose. The metal ion can be one of the cations of Al, Fe, Zn, Mn, Ni, Co, or V. By this invention, the supramolecular filler based on natural bio-based polymer can form in situ in the hydrogel, to regulate the pores of the hydrogel and interact with different drugs, thus adjusting the drug release rate.

Abstract: An encapsulated probiotic, an encapsulating layer and a method of encapsulating probiotics are disclosed. The encapsulated probiotic includes an encapsulating layer and probiotics, and the encapsulating layer includes a nano-film having two layers for encapsulating probiotics. A first layer is formed through biological macromolecules and metal ions on surfaces of the probiotics by covalent cross-linking or metal chelating action in situ, and a second layer is formed by interactions between a bio-enzyme and the biological macromolecules. The nano-film formed in situ on cell walls of probiotics is used for encapsulation and protection of probiotics.

Abstract: A biomass-based encapsulating material for protection of probiotic activity and an encapsulating method are disclosed. The biomass-based encapsulating material includes a nano-film having two layers for encapsulating probiotics. A first layer is formed through natural biological macromolecules and metal ions on surfaces of the probiotics by covalent cross-linking or metal chelating action in situ, and a second layer is formed by interactions between a bio-enzyme and the natural biological macromolecules. The nano-film formed in situ on cell walls of probiotics is used for encapsulation and protection of probiotics. The nano-film is made of natural biomass, has low cost and has no toxic side effects. The relative activity of encapsulated probiotics is close to or higher than 90%, whether they are cultivated in environments under high concentration of antibiotics or active-free radicals. The relative activity of unprotected probiotics is below 30%, or even completely unable to survive.