摘要:
Bioactive molecules are entrapped within a matrix for the controlled delivery of these compounds for therapeutic healing applications. The matrix may be formed of natural or synthetic compounds. The primary method of entrapment of the bioactive molecule is through precipitation of the bioactive molecule during gelation of the matrix, either in vitro or in vivo. The bioactive molecule may be modified to reduce its effective solubility in the matrix to retain it more effectively within the matrix, such as through the deglycosylation of members within the cystine knot growth factor superfamily and particularly within the TGFβ superfamily. The matrix may be modified to include sites with binding affinity for different bioactive molecules, for example, for heparin binding.
摘要:
Biomaterial comprises a three dimensional polymeric network obtainable from the reaction of at least a first and second precursor molecule. The first precursor molecule is at least a trifunctional, branched component comprising at least three arms substantially similar in molecular weight and the second precursor molecule is at least a bifunctional component The ratio of equivalent weight or the functional groups of the first and second precursor molecule is in a range of between 0.9 and 1.1. The molecular weight of the arms of the first precursor molecule. the molecular weight of the second precursor molecule and the functionality of the branching points are selected so that the water content of the polymeric networks is between the equilibrium weight % and 92 weitht of the total weight of the polymeric network after completion of water uptake. The present invention teaches a way to improve characteristics of synthetic matrices which are useful for wound healing applications.
摘要:
Biomaterials containing a three-dimensional polymeric network formed from the reaction of a composition containing at least a first synthetic precursor molecule having n nucleophilic groups and a second precursor molecule having m electrophilic groups wherein the sum of n+m is at least five and wherein the sum of the weights of the first and second precursor molecules is in a range from about 8 to about 16% b weight of the composition, preferably from about 10 to about 15%, more preferably from about 12 to about 14.5% by weight of the composition. In one embodiment, the first and second precursor molecules are polyethylene glycols functionalized with nucleophilic and electrophilic groups, respectively. In a preferred embodiment, the nucleophilic groups are amino and/or thiol groups and the electrophilic groups are conjugated, unsaturated groups. The ratio of the equivalent weights of the electrophilic groups (second precursor molecule) and the nucleophilic groups (first precursor molecule) is in the range of between 0.7 and 1.1, more preferably between 0.8 and 1.0. The first and/or second precursor molecule may be covalently bound to one or more molecules selected from the group consisting of cell adhesion peptides, growth factors, and growth factor-like peptides.
摘要:
Proteins are incorporated into protein or polysaccharide matrices for use in tissue repair, regeneration and/or remodeling and/or drug delivery. The proteins can be incorporated so that they are released by degradation of the matrix, by enzymatic action and/or diffusion. As demonstrated by the examples, one method is to bind heparin to the matrix by either covalent or non-covalent methods, to form a heparin-matrix. The heparin then non-covalently binds heparin-binding growth factors to the protein matrix. Alternatively, a fusion protein can be constructed which contains a crosslinking region such as a factor XIIIa substrate and the native protein sequence. Incorporation of degradable linkages between the matrix and the bioactive factors can be particularly useful when long-term drug delivery is desired, for example in the case of nerve regeneration, where it is desirable to vary the rate of drug release spatially as a function of regeneration, e.g. rapidly near the living tissue interface and more slowly farther into the injury zone. Additional benefits include the lower total drug dose within the delivery system, and spatial regulation of release which permits a greater percentage of the drug to be released at the time of greatest cellular activity.
摘要:
The invention features materials and methods for the liquid to solid transition of an injectable pre-hydrogel composition to a hydrogel. These methods can be carried out in situ.
摘要:
The present invention relates to compositions and methods of treating a disease, such as diabetes, by implanting encapsulated biological material with a growth factor and conjugate into a patient in need of treatment. Several methods are presented to accomplish transplanting several different types of biological materials. This invention also provides methods of utilizing these encapsulated biological materials to treat different human and animal diseases or disorders by implanting them into several areas in the body including the subcutaneous site.
摘要:
A device with chemical surface patterns (defined surface areas of at least two different chemical compositions) with biochemical or biological relevance on substrates with prefabricated patterns of at least two different types of regions (α, β, . . . ), whereas at least two different, consecutively applied molecular self-assembly systems (A, B, . . . ) are used in a way that at least one of the applied assembly systems (A or B or . . . ) is specific to one type of the prefabricated patterns (α or β or . . . ).
摘要:
The present invention provides highly porous, biocompatible and biostable scaffold constructs for improving overall cell engraftment, survival, function and long-term viability. These scaffolds can provide mechanical protection to implanted cells, afford retrievability from a subject, and allow for both intra-device vascularization and a means to spatially distribute the cells within the device. The scaffold surface or material may be modified with one or more different adhesion proteins and optionally other biological factors for enhanced cell adherence and viability. Further, the scaffold surface or material may be modified with one or more agents with slow/sustained release characteristics to aid engraftment, survival, function or long-term viability. Implanted cells of the invention may be insulin-producing cells such as islets.
摘要:
Nanoparticles that activate complement in the absence of biological molecules are described. The nanoparticles are shown to specifically target antigen presenting cells in specifically in lymph nodes, without the use of a biological molecule for targeting. These particles are useful vehicles for delivering immunotherapeutics.
摘要:
This invention provides novel methods for the formation of biocompatible membranes around biological materials using photopolymerization of water soluble molecules. The membranes can be used as a covering to encapsulate biological materials or biomedical devices, as a “glue” to cause more than one biological substance to adhere together, or as carriers for biologically active species. Several methods for forming these membranes are provided. Each of these methods utilizes a polymerization system containing water-soluble macromers, species, which are at once polymers and macromolecules capable of further polymerization. The macromers are polymerized using a photoinitiator (such as a dye), optionally a cocatalyst, optionally an accelerator, and radiation in the form of visible or long wavelength UV light. The reaction occurs either by suspension polymerization or by interfacial polymerization. The polymer membrane can be formed directly on the surface of the biological material, or it can be formed on material, which is already encapsulated.