An hydrogel comprising chitosan and two weak bases having different pKb values. In some embodiments, one of the weak bases if sodium hydrogen carbonate (SHC). Also, use of the hydrogel in medical and cosmetic treatments.

Exemplary embodiments of the present invention provide adhesion barriers having anti-adhesion and tissue fixating properties. The adhesion barriers are formed of fatty acid based films. The fatty acid-based films may be formed from fatty acid-derived biomaterials. The films may be coated with, or may include, tissue fixating materials to create the adhesion barrier. The adhesion barriers are well tolerated by the body, have anti-inflammation properties, fixate, well to tissue, and have a residence time sufficient to prevent post-surgical adhesions.

Delivery systems, compositions, and methods for forming and delivering biomaterials from two components are described. Specifically, a composition includes a first component and a second component that are each formulated to be crosslinked with the other to form a hydrogel. The first component and the second component are formulated to have an initial storage modulus (initial G) and an initial loss modulus (initial G″) when initially combined such that a ratio of the initial G″ to the initial G is between about 5 and about 100. The first component and the second component are formulated to have a gelation storage modulus (gelation G) and a gelation loss modulus (gelation G″) at a gelation time after the first component and the second component are combined such that a atio of the gelation G″ to the gelation G is less than about 1. The gelation time is less than about 120 seconds.

The present invention recognizes that medical devices, such as but not limited to contact lenses, can be made having a coating made at least in part using printing technologies to provide drug storage and drug release structures. The coating preferably includes at least one drug reservoir layer and a least one barrier layer, and can include structures, such as but not limited to capillary structures that alone or in combination modulate the release of the drug from the coating. One aspect of the present invention is a medical device that incorporates a drug in at least one coating.

The present inventions are directed to shear-thinning and stabilizing hydrogels, especially for use in drug delivery and therapy. Various embodiments provide settable, shear-thinning hydrogels, each hydrogel comprising a hydrophilic polymer network, said hydrophilic polymer network comprising non-covalent crosslinks and at least one set of chemical moieties being capable of participating in at least one chemical covalent cross-linking reaction. In certain embodiments, these settable shear-thinning hydrogels are triggerable to cross-link by the application of a stimulus.

A biocompatible membrane comprised of alginate and hyaluronate. The membrane may be used to prevent unwanted scarring after surgery. The tissue adherence and the rate of bioresorption of the membrane may be modified through an external stimulus comprising a sequestering agent and a viscosity modifier.

Medical devices with a hydrogel layer covalently attached to a portion of the outer surface of the medical device are provided along with methods for applying the coating. The hydrogel layer can include a first polymer species comprising polyethylene glycol (PEG) and a second polymer species. Examples of the second polymer species include PEG and polyacrylamide (PAM). The first and second species can be at least partially cross-linked. Methods for forming the hydrogel coatings on the medical devices are provided including nucleophilic conjugate reactions, such as Click reactions.

A method for preparing non-free radical photo-crosslinked hydrogels includes: dissolving component A that is a polymer derivative modified with o-nitrobenzyl phototrigger in a biocompatible medium to obtain solution A; dissolving component B that is a polymer derivative containing hydrazide, hydroxylamine or primary amine in a biocompatible medium to obtain solution B; mixing solution A and solution B to obtain a precursor solution of hydrogel; under light irradiation, crosslinking aldehyde generated from the o-nitrobenzyl with the hydrazine, hydroxylamine or primary amine to obtain a hydrogel by forming hydrazone, oxime or schiff base, respectively. A kit for preparation and application of the hydrogel in tissue repair, beauty therapy, and cells, proteins or drugs carriers is also described. The method or kit can achieve in situ photo-gelling on tissue surface or in situ forming thin gel on wounds in clinical treatment of wounds.

A nanogel comprising a self-organizing peptide, a chitosan, and polyethylene glycol.

Disclosed are hydrogels polymerized with a free radical scavenger, for example a spin trap. The hydrogels are biodegradable and permanent, designed to be implantable in a mammalian body and intended to block or mitigate the formation of tissue adhesions. The hydrogels of the present invention are characterized by comprising four structural elements: a) a polymeric backbone which defines the overall polymeric morphology, b) linkage groups, c) side chains, and d) spin trap end groups. The hydrophobicity of the various structural elements are chosen to reduce tissue adhesion and enhance the free radical scavenging aspect of the end groups. The morphology of these polymers are typically of high molecular weight and have shape to encourage entanglement. Useful structures include branching chains, comb or brush, and dendritic morphologies.