The present invention relates to a recombinant process for the production of truncated or mutated dextransucrases while conserving the enzymatic activity or their specificity in the synthesis of the ?-1,6 bonds. The present invention relates to nucleic acid sequences of truncated or mutated dextransucrases, vectors containing the nucleic acid sequences and host cells transformed by sequences encoding truncated or mutated dextransucrases. In another aspect, the invention concerns a method for producing, in a recombinant manner, truncated or mutated dextransucrases which conserve their enzymatic activity or which conserve their specificity in the synthesis of ?-1,6 bonds and can produce, from saccharose, dextrans with high molar mass and modified rheological properties compared with the properties of dextran obtained with the native enzyme and isomalto-oligosaccharides with a controlled molar mass and dextrans. The dextrans and isomalto-oligosaccharides of the invention can be used namely as texturing agents or as prebiotics.

A novel diazirine-based biocompatible polymer that can be used as on-demand or tunable bioadhesive and applied across various clinically important surfaces. The biocompatible polymer comprises a single strand of repeating units and up to 5,000 photoreactive diazirine groups covalently attached to it. A bioadhesive composition comprises the polymer of the present invention and suitable solvents, surfactants, stabilizers, fillers and other additives. The composition may additionally contain metallic particles of size less than 50 micron made of rare earth elements and has UV or NIR transparency less than 1 optical density unit per 1 centimeter. The poly-diazirine surface grafted thin films can be used for minimally invasive surgeries.

A process of preparing a cross-linked polysaccharide product including hyaluronic acid and dextran, the process including the steps of: (a) providing a hyaluronic acid and a dextran; (b) binding the dextran to the hyaluronic acid by ether bonds using a bi- or polyfunctional cross-linking agent, wherein the hyaluronic acid provided in step (a) is a cross-linked hyaluronic acid gel, and the dextran provided in step (a) is a non-cross-linked dextran; and wherein step (b) includes cross-linking the dextran to the hyaluronic acid by ether bonds using a bi- or polyfunctional cross-linking agent.

The present invention relates to a method for detecting a target nucleic acid using a catalytic nucleic acid, which can improve the reaction efficiency of a catalytic nucleic acid and achieve continuous reaction under isothermal conditions. The method for detecting a target nucleic acid includes a reaction step to obtain a first nucleic acid product by hybridizing a first nucleic acid which is a substrate to a first binding site of a catalytic nucleic acid equipped with an active site having a catalytic action; and a detection step for detecting at least one of the first nucleic acid product or unreacted first nucleic acids, wherein, the hybridization is carried out in the presence of a cationic comb-type polymer.

Polypeptides having the ability to specifically form connections of glucosyl units in alpha 1,3 on an acceptor having at least one hydroxyl moiety are presented. The polypeptides include i) the pattern I of sequence SEQ ID NO: 1, ii) the pattern II of sequence SEQ ID NO: 2, iii) the pattern III of sequence SEQ ID NO: 3, and iv) the pattern IV of sequence SEQ ID NO: 4, or derivates from one or several of said patterns, wherein the polypeptide furthermore has an aspartic residue (D) at position 5 of the pattern II (SEQ ID NO: 2), a glutamic acid residue (E) at position 6 of the pattern III (SEQ ID NO: 3) and an aspartic acid residue (D) at position 6 of the pattern IV (SEQ ID NO: 4). Methods for producing acceptors connected to glucosyl units in alpha 1,3 using the polypeptides are also provided.

The invention in the various aspects provides nanogel compositions that are safe for topical, local, and/or systemic delivery, and which can be targeted to select tissues or cells, including pathogens. In some embodiments, conjugation of antibiotics to the nanogel surface, and in particular antibiotics that disrupt outer membranes of Gram negative bacteria or antibiotics that inhibit cell wall synthesis, provide for highly effective targeting and killing of bacterial pathogens, including drug-resistant bacteria.

Compositions comprising oxidized dextran compounds are disclosed herein. Oxidized dextran compounds are produced by contacting dextran under aqueous conditions with at least one N-oxoammonium salt, at least one periodate compound, and/or at least one peroxide compound.

Methods of preparing dried powders of biologically active compositions are disclosed. They are designed to provide dried material that maintains biological activity at low economic cost. Compositions made by the above methods are also described.

Compositions are disclosed herein comprising dextran that comprises (i) 87-93 wt % glucose linked at positions 1 and 6; (ii) 0.1-1.2 wt % glucose linked at positions 1 and 3; (iii) 0.1-0.7 wt % glucose linked at positions 1 and 4; (iv) 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; and (v) about 0.4-1.7 wt % glucose linked at (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6. Aqueous forms of this composition have enhanced viscosity profiles. Further disclosed are methods of using compositions comprising dextran, such as increasing the viscosity of an aqueous composition. Enzymatic reactions for producing dextran are also disclosed.

Compositions are disclosed herein comprising a graft copolymer that comprises: (i) a backbone comprising dextran that has been modified with about 1%-25% alpha-1,2 branches, and (ii) one or more alpha-1,3-glucan side chains comprising at least about 50% alpha-1,3 glycosidic linkages. Further disclosed are reactions for producing such graft copolymers, as well as their use in derivatives, films and various other applications.