News Column

Patent Application Titled "Delivery Systems Containing Bioactive Materials" Published Online

August 5, 2014



By a News Reporter-Staff News Editor at Life Science Weekly -- According to news reporting originating from Washington, D.C., by NewsRx journalists, a patent application by the inventors Shimko, Daniel A. (Germantown, TN); Kalpakci, Kerem N. (Memphis, TN), filed on January 14, 2013, was made available online on July 24, 2014 (see also Warsaw Orthopedic, Inc.).

The assignee for this patent application is Warsaw Orthopedic, Inc.

Reporters obtained the following quote from the background information supplied by the inventors: "The use of bone grafts and bone substitute materials in orthopedic medicine is known. While bone wounds can regenerate without the formation of scar tissue, fractures and other orthopedic injuries take a long time to heal, during which time the bone is unable to support physiologic loading unaided. Metal pins, screws, rods, plates and meshes are frequently required to replace the mechanical functions of injured bone. However, metal is significantly more stiff than bone. Use of metal implants may result in decreased bone density around the implant site due to stress shielding. Physiologic stresses and corrosion may cause metal implants to fracture. Unlike bone, which can heal small damage cracks through remodeling to prevent more extensive damage and failure, damaged metal implants can only be replaced or removed. The natural cellular healing and remodeling mechanisms of the body coordinate removal of bone and bone grafts by osteoclast cells and formation of bone by osteoblast cells.

"Conventionally, bone tissue regeneration is achieved by filling a bone repair site with a bone graft. Over time, the bone graft is incorporated by the host and new bone remodels the bone graft. In order to place the bone graft, it is common to use a monolithic bone graft or to form an osteoimplant comprising particulated bone in a carrier. The carrier is thus chosen to be biocompatible, to be resorbable, and to have release characteristics such that the bone graft is accessible.

"The rapid and effective repair of bone defects caused by injury, disease, wounds, or surgery is a goal of orthopedic surgery. Toward this end, a number of compositions and materials have been used or proposed for use in the repair of bone defects. The biological, physical, and mechanical properties of the compositions and materials are among the major factors influencing their suitability and performance in various orthopedic applications.

"Demineralized bone matrix ('DBM') implants have been reported to be particularly useful. Demineralized bone matrix is typically derived from cadavers. The bone is removed aseptically and/or treated to kill any infectious agents. The bone is then particulated by milling or grinding and then the mineral components are extracted for example, by soaking the bone in an acidic solution.

"Current DBM formulations have various drawbacks. First, while the collagen-based matrix of DBM is relatively stable, the active factors within the DBM matrix are rapidly degraded. The osteogenic activity of the DBM may be significantly degraded within 24 hours after implantation, and in some instances the osteogenic activity may be inactivated within 6 hours. Therefore, the factors associated with the DBM are only available to recruit cells to the site of injury for a short time after transplantation. For much of the healing process, which may take weeks to months, the implanted material may provide little or no assistance in recruiting cells.

"Attempts to overcome these problems have lead researchers to utilize delivery systems such as polymer mesh bags or pouches to release DBM at a surgical site. Pouch closure is typically done by suturing, which is often time consuming and may require special equipment to bring about pouch closure.

"Thus, there is a need to improve the efficacy and consistency of DBM delivery systems by utilizing more expeditious and simpler approaches to closing the open end of a DBM containing polymer mesh bag."

In addition to obtaining background information on this patent application, NewsRx editors also obtained the inventors' summary information for this patent application: "A delivery system for delivering a substance or material to a surgical site is provided. The delivery system comprises a covering and a substance to be retained within and delivered by the covering. Generally, the covering may be at least a single compartment capable of retaining a substance provided therein until the covering is placed at a surgical site. In some examples, upon placement, the covering facilitates transfer of the substance and/or materials from the covering to the surgical site. The covering may participate in, control, or otherwise adjust, the release of the substance or penetration of the covering by surrounding materials, such as cells or tissues.

"In certain embodiments the covering of the delivery system includes an elongated containment portion having at least one compartment and at least a first substance which can be mixed with another substance prior to delivery at a surgical site. The first substance can be particles, fibers or chips of demineralized bone matrix (DBM) and the second substance can be bone graft material such as autologous milled bone particles and growth factors.

"In some embodiments, the delivery system comprises a closing member that can be attached at any location along the elongated container. In various embodiments, the closing member can be attached at a location effective to define an upper and lower portion of the elongated containment. In other embodiments, after securing the elongated containment with the closing member, the upper portion can be folded over the lower portion of the elongated containment. In yet other embodiments, the upper portion of the elongated containment can be folded over the lower portion in the absence of a closing member, simply by twisting the upper portion at a selected location and folding over the lower portion of the elongated containment.

"In various embodiments, the closing member comprises drawing strings, stitches, sutures, wing sutures, heat seals, adhesion, pressure fittings, coil ring, twist tie or combinations thereof. In certain embodiments, either the covering or the closing member or both comprise a material selected from bioerodible polymers, bioabsorbable polymers, biodegradable biopolymers, synthetic polymers, copolymers or combinations thereof.

"In some embodiments, the elongated containment portion has a cross sectional shape selected from generally circular or generally oval and a shape that can be tubular, rectangular, or cubic. The covering can have two ends opposite each other and be made from porous mesh to provide, for example, a porous mesh bag.

"In various embodiments, the at least one compartment is unfilled at manufacture but configured to be filled prior to or during the surgical procedure.

"In other embodiments, the at least one compartment of the delivery system can be filled with autograft or allograft. In certain embodiments, the at least one substance in the at least one compartment comprises demineralized bone matrix fibers and particles in a ratio of about 30:70.

"In various embodiments, a second substance can be added to the delivery systems described herein includes protein, bone morphogenetic proteins, carbohydrate, lipids, collagen, allograft bone, autograft bone, tricalcium phosphate, hydroxyapatite, growth and differentiation factors, carriers for growth factors, growth factors extracts of tissue, bone marrow aspirate, concentrates of lipid derived or marrow derived adult stem cells, umbilical cord derived stem cells, committed or partially committed cells from osteogenic or chondrogenic lineage, antimicrobials, antibiotics, or combinations thereof.

"In certain embodiments, a delivery system comprising a covering configured for implantation into a bone defect site is provided. The covering contains at least one compartment having an elongated containment with a first end and second end opposite each other, the elongated containment defining an opening configured to receive at least one substance. In many embodiments, the elongated containment is adapted to receive slidably a closing member at a selected location along the elongated containment, the selected location effective to define around the closing member an upper and a lower portion of the containment, the upper portion foldable over the lower portion.

"In various embodiments, the present application provides a method for preparing a delivery system comprising a covering for implantation into a bone defect. The method for preparing the delivery system comprises providing the covering having an elongated containment and defining an opening at one end, the opening configured for receiving at least one substance. Subsequently, the method includes filling the elongated containment with the at least one substance, closing the elongated containment with a closing member at a selected location along the elongated containment, and implanting the closed delivery system into a bone defect.

"The present application also provides a method for treating a bone defect in a patient in need of such treatment. The method of treatment comprises implanting into the bone defect all or at least a portion of a covering comprising one or more biodegradable polymers, the covering being porous and comprising at least one compartment, the at least one compartment comprising an elongated containment, which elongated containment defines an opening configured to receive at least one substance, the elongated containment adapted to receive slidably a closing member at a selected location along the elongated containment.

"Reference will now be made in detail to certain embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the illustrated embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover all alternatives, modifications, and equivalents that may be included within the invention as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

"In part, other aspects, features, benefits and advantages of the embodiments will be apparent with regard to the following description, appended claims and accompanying drawings where:

"FIG. 1 illustrates a side view of a delivery system comprising a covering having an elongated containment portion, a sealed end, an open end and a closing member in accordance with one embodiment of the present disclosure;

"FIG. 2 illustrates a side view of a delivery system comprising a covering such as a porous mesh bag having an elongated containment and a closing member defining an upper portion of the containment and a lower portion of the containment accordance with another embodiment of the present disclosure;

"FIG. 3 illustrates a top view of a delivery system comprising a covering having an elongated containment and a closing member, wherein the upper portion of the containment is folded over the lower portion of the containment in accordance with an embodiment of the present disclosure;

"FIG. 4 illustrates a side view of a delivery system comprising a covering such as a mesh bag comprising a closed end and an open end that can be closed by draw strings in accordance with another embodiment of the present disclosure;

"FIG. 5 illustrates a side view of the delivery system comprising a mesh bag having an open end that can be closed by draw strings in accordance with another embodiment of the present disclosure;

"FIG. 6 illustrates side view of the delivery system wherein the draw string is positioned about midway the elongated container in accordance with another embodiment of the present disclosure;

"FIG. 7 illustrates a top view of a delivery system according to another aspect of the present application;

"FIG. 8 illustrates a top view of a delivery system according to yet another aspect of the present application.

"It is to be understood that the figures are not drawn to scale. Further, the relation between objects in a figure may not be to scale, and may in fact have a reverse relationship as to size. The figures are intended to bring understanding and clarity to the structure of each object shown, and thus, some features may be exaggerated in order to illustrate a specific feature of a structure."

For more information, see this patent application: Shimko, Daniel A.; Kalpakci, Kerem N. Delivery Systems Containing Bioactive Materials. Filed January 14, 2013 and posted July 24, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=1202&p=25&f=G&l=50&d=PG01&S1=20140717.PD.&OS=PD/20140717&RS=PD/20140717

Keywords for this news article include: Warsaw Orthopedic Inc.

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Source: Life Science Weekly


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