Compositions and methods for production and use of an injectable naturally secreted extracellular matrix

Abstract

The present invention discloses compositions containing natural human extracellular matrices and methods for the use thereof. More particularly, the present invention provides compositions and methods for the repair of skin defects using natural human extracellular matrix by injection.

Description

[0001] This application is a continuation-in-part application of U.S. patent application Ser. No. 08 / 470,101 filed Jun. 6, 1995, which is incorporated by reference herein in its entirety.1. INTRODUCTION[0002] The present invention relates to compositions and methods for the treatment and repair of soft tissue and skin defects such as wrinkles and scars. More particularly, the invention relates to an injectable composition of human extracellular matrix components and methods of preparing and using same. The injectable preparation is obtained from three-dimensional living stromal tissues that are prepared in vitro.2. BACKGROUND OF THE INVENTION[0003] The idea of using an injectable material for soft tissue augmentation and repair developed soon after the invention of the hypodermic needle. Various products have been injected into the human body for correction of soft tissue and skin defects including paraffin, petrolatum, vegetable oils, lanolin, bees wax, and silicone. Injectable liq...

AI Technical Summary

Benefits of technology

[0015] The injectable preparations of the present invention have many advantages over conventional injectable collagen preparations used for the repair of skin defects. The extracellular matrix preparations of the present invention contain only human proteins, therefore, there is a reduced risk of an immune response due to foreign proteins or peptides, especially the type of immune response seen with bovine collagen found in conventional injectable collagen preparations. Additionally, the injected preparations of the present invention should persist longer and even if multiple injections are required, the injections should not be subject to the "no more than three injections per year" rule of bovine collagen-based preparations due to the lack of immunogenicity. Another advantage provided by the present invention is that the preparations of native extracellular matrix contain a mixture of extracellular matrix proteins which closely mimics the compositions of physiologically normal conditions, for example, in an extracellular matrix derived from dermal cells, type I and III collagens, hyaluronic acid as well as various glycosaminoglycans and natural growth factors are present. Many of these extracellular matrix proteins and growth factors have been studied extensively and have been shown to be critical for wound healing and tissue restoration.

[0016] In another aspect of the invention, the preparations can be used in highly improved systems for in vitro tissue culture. In this embodiment, naturally secreted extracellular matrix coated three-dimensional frameworks can be used to culture cells which require attachment to a support in order to grow but do not attach to conventional tissue culture vessels. In addition to culturing cells on a coated framework, the extracellular matrix secreted by the cells onto the framework can be collected and used to coat vessels for use in tissue culture. The extracellular matrix, acting as a base substrate, may allow cells normally unable to attach to conventional tissue culture dish base substrates to attach and subsequently grow.

Problems solved by technology

Injectable liquid silicone has been used extensively, however, due to long term side effects, such as nodules, recurring cellulitis and skin ulcers which are now being followed more closely, the use of injectable silicone is on the decline.

Further, in the State of Nevada it is a felony to use injectable silicone in a human.

A major disadvantage of solid cross-linked collagen implants is the requirement for surgical implantation by means of incision.

In addition, lack of deformability and flexibility are other disadvantages of solid collagen implants.

A main problem with such solid implants is that they must be implanted surgically.

Other disadvantages are that they are not as deformable as injectable implants and residual glutaraldehyde may cause the implant to lose its flexibility due to continuing cross-linking in situ.

While effective, the implant shrinks in volume after implantation due primarily to absorption of its fluid component by the body.

This specific composition has many serious drawbacks, e.g., the collagen is from a bovine source, not human, and the preparation process is not only lengthy and expensive but also requires the addition of microfibrils.

Despite the advantages and overall usefulness of the injectable collagen implant-materials disclosed above, problems associated with producing and injecting the materials have been encountered.

The preparation of fibrillar collagen suitable for human use is relatively time consuming and expensive.

In particular, the complete removal of contaminating and potentially immunogenic substances to produce atelocollagen is a relatively complex and expensive procedure.

Moreover, the persistence, shape retention, cohesiveness, stability, elasticity, toughness and intrudability of the fibrillar collagen compositions are not optimal.

In addition to the problems associated with producing and injecting the collagen implant materials, problems with the actual use of the above mentioned patented injectable implants are also abundant.

Due to these allergic reactions the injectable collagen implants described above cannot be given to many people and others are limited to receiving only three injections per year.

Further, the problems associated with injecting xenogeneic collagen seem so intractable that rather than injecting collagen, biocompatible ceramic matrices have been injected to achieve similar results as described in U.S. Pat. No. 5,204,382.

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