Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Peptide containing doai
Reexamination Certificate
2001-06-28
2004-06-22
Witz, Jean C. (Department: 1651)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Peptide containing doai
C514S021800
Reexamination Certificate
active
06753311
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to polymeric fiber matrices, film coatings or braided/woven structures for the controlled release of bioactive compounds. The delivery systems of the present invention may be comprised of either biodegradable or nondegrading polymeric fibers. In one embodiment, these fibers have submicron and/or micron diameters. Bioactive compounds are included in the delivery system either by suspending the compound particles or dissolving the compound in the polymer solution used to produce the fibers. In one embodiment of the present invention, the polymeric matrix is used as a tissue engineering scaffold and the bioactive compound of the polymeric matrix comprises collagen or a collagen-like polypeptide incorporated within or between the polymeric fibers. This tissue engineering scaffold is particularly useful in promoting attachment and growth of chondrocytes and thus is useful in cartilage repair and replacement.
BACKGROUND OF THE INVENTION
A number of polymer matrices for use in the controlled release and/or delivery of bioactive compounds, and for particular drugs, have been described.
U.S. Pat. No. 3,991,766 describes a medicament repository consisting of a surgical element in the form of tubes, sheets, sponges, gauzes or prosthetic devices of polyglycolic acid having incorporated therein an effective amount of a medicament.
U.S. Pat. No. 4,655,777 describes a method for producing a biodegradable prothesis or implant by encasing an effective amount of fibers of calcium phosphate or calcium aluminate in a matrix of polymer selected from the group consisting of polyglycolide, poly(DL-lactide), poly(L-lactide), polycaprolactone, polydioxanone, polyesteramides, copolyoxalates, polycarbonates, poly(glutamic-co-leucine) and blends, copolymers and terpolymers thereof to form a composite.
U.S. Pat. No. 4,818,542 discloses a method for preparing a spherical microporous polymeric network with interconnecting channels having a drug distributed within the channels.
U.S. Pat. No. 5,128,170 discloses a medical device and methods for manufacturing medical devices with a highly biocompatible surface wherein hydrophillic polymer is bonded onto the surface of the medical device covalently through a nitrogen atom.
U.S. Pat. No. 5,545,409 discloses a composition and method for controlled release of water-soluble proteins comprising a surface-eroding polymer matrix and water-soluble bioactive growth factors.
U.S. Pat. No. 5,898,040 discloses a polymeric article for use in drug delivery systems which comprises a polymeric substrate with a highly uniform microporous polymeric surface layer on at least part of the substrate.
Encapsulation of a bioactive compound within a polymer matrix has also been described. For example, WO 93/07861 discloses polymer microspheres of 50 to 100 microns comprising a compound contained in a fixed oil within the polymer microsphere. U.S. Pat. No. 5,969,020 discloses a foam precursor comprising a crystalline thermoplastic polymer and solid crystalline additive for use in preparation of drug delivery systems.
Recently, it has been shown that polymer fibers of nanometer diameter can be electrospun from sulfuric acid into a coagulation bath (Reneker, D. H. and Chun, I. Nanotechnology 1996 7:216). In these studies more than 20 polymers including polyethylene oxide, nylon, polyimide, DNA, polyaramide and polyaniline were electrospun into electrically charged fibers which were then collected in sheets or other useful geometrical forms. Electrospinning techniques have also been applied to the production of high performance filters (Doshi, J. and Reneker, D. H. Journal of Electrostatics 1995 35:151; Gibson et al. AIChE Journal 1999 45:190) and for scaffolds in tissue engineering (Doshi, J. and Reneker, D. H. Journal of Electrostatics 1995 35:151; Ko et al. “The Dynamics of Cell-Fiber Architecture Interaction,” Proceedings, Annual Meeting, Biomaterials Research Society, San Diego, Calif., Apr. 1998; and WO 99/18893).
A number of polymer matrices for use as tissue engineering scaffolds have been described.
WO 99/18893 describes a method for preparing nanofibrils from both nondegrading and biodegradable polymers for use as tissue engineering scaffolds.
U.S. Pat. No. 5,769,830 discloses synthetic, biocompatible, biodegradable polymer fiber scaffolds for cell growth. Fibers are spaced apart by a distance of about 100 to 300 microns for diffusion and may comprise polyanhydrides, polyorthoesters, polyglycolic acid or polymethacrylate. The scaffolds may be coated withe materials such as agar, agarons, gelatin, gum arabic, basement membrane material, collagen type I, II, III, IV or V, fibronectin, laminin, glycosaminoglycans, and mixtures thereof.
The present invention relates to delivery systems for the controlled release of bioactive compounds which comprise polymeric fibers, and the bioactive compound. In one embodiment, the system of the present invention is used as a tissue engineering scaffold wherein the bioactive compound comprises collagen or a collagen-like peptide.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system for delivery of bioactive compounds comprising a bioactive compound incorporated within or between a polymeric fiber matrix or linear assembly, film coating or braided/woven structure. In one embodiment of the present invention, the system is used as a tissue engineering scaffold and the bioactive compound incorporated within or between a polymeric fiber matrix comprises collagen or a collagen-like peptide. These tissue engineering scaffolds are particularly useful in cartilage repair or replacement as they promote the attachment, growth and spreading of chondrocytes.
DETAILED DESCRIPTION OF THE INVENTION
Electrospinning is a simple and low cost electrostatic self-assembly method capable of fabricating a large variety of long, meter-length, organic polymer fibers with micron or submicron diameters, in linear, 2-D and 3-D architecture. Electrospinning techniques have been available since the 1930's (U.S. Pat. No. 1,975,504). In the electrospinning process, a high voltage electric field is generated between oppositely charged polymer fluid contained in a glass syringe with a capillary tip and a metallic collection screen. As the voltage is increased, the charged polymer solution is attracted to the screen. Once the voltage reaches a critical value, the charge overcomes the surface tension of the suspended polymer cone formed on the capillary tip of the syringe and a jet of ultrafine fibers is produced. As the charged fibers are splayed, the solvent quickly evaporates and the fibers are accumulated randomly on the surface of the collection screen. This results in a nonwoven mesh of nano and micron scale fibers. Varying the charge density (applied voltage), polymer solution concentration, solvent used, and the duration of electrospinning can control the fiber diameter and mesh thickness. Other electrospinning parameters which may be varied routinely to effect the fiber matrix properties include distance between the needle and collection plate, the angle of syringe with respect to the collection plate, and the applied voltage.
In the present invention, electrospinning is used to produce polymeric fiber matrices with the capability of releasing bioactive compounds in a controlled manner over a selected period of time. In one embodiment, the delivery system of the present invention is used to maintain delivery of a steady concentration of bioactive compound. In another embodiment, the delivery system is used in pulsed delivery of the bioactive compound wherein the compound is released in multiple phases in accordance with either rapid or slow degradation of the polymer fibers or diffusion of the bioactive compound from the polymer fibers. In yet another embodiment, the delivery system is used to obtain a delayed release of a bioactive compound. For example, the bioactive compound-containing fiber polymer matrix can be coated with a layer of nonwoven polymer fiber matrix with no bioactive co
Fertala Andrzej
Ko Frank
Drexel University
Licata & Tyrrell P.C.
Witz Jean C.
LandOfFree
Collagen or collagen-like peptide containing polymeric matrices does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Collagen or collagen-like peptide containing polymeric matrices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Collagen or collagen-like peptide containing polymeric matrices will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3330898