DCT

2:13-cv-00486

LifeNet Health v. LifeCell Corp

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:13-cv-00486, E.D. Va., 09/06/2013
  • Venue Allegations: Venue is based on Defendant's alleged substantial, continuing, and ongoing business contacts within the Eastern District of Virginia, including sales of the accused products.
  • Core Dispute: Plaintiff alleges that Defendant’s reconstructive tissue matrix products infringe a patent related to methods for plasticizing and preserving biological tissue grafts to maintain flexibility and readiness for use.
  • Technical Context: The technology involves preserving biological tissues for medical transplantation in a manner that avoids the brittleness of traditional freeze-drying and eliminates the need for time-consuming rehydration, thereby simplifying use in surgical settings.
  • Key Procedural History: The complaint alleges Defendant was aware of Plaintiff's technology due to a history at the U.S. Patent and Trademark Office (USPTO), where Defendant’s own patent application for a similar technology was repeatedly rejected as obvious in light of a patent in the same family as the patent-in-suit. Significantly, after the filing of this complaint, an Inter Partes Review (IPR) proceeding concluded, which resulted in the cancellation of most of the asserted claims of the patent-in-suit, leaving only a single asserted dependent claim patentable.

Case Timeline

Date Event
1998-06-30 '200 Patent Priority Date
2003-05-27 '200 Patent Issue Date
2004-10-06 Defendant LifeCell files related '780 patent application
2007 Plaintiff LifeNet introduces Preservon® technology
2009-04-29 USPTO issues first final rejection of LifeCell's '780 application
2010 LifeNet begins marking products with '200 patent number
2010-02-03 USPTO issues second final rejection of LifeCell's '780 application
2012-01-23 PTAB affirms rejection of LifeCell's '780 application claims
2012-03-28 LifeCell abandons its '780 patent application
2013-09-06 Complaint Filing Date
2021-07-02 IPR Certificate issued for '200 Patent, cancelling claims 1-3, 7-8

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,569,200 - "Plasticized Soft Tissue Grafts, and Methods of Making and Using Same"

  • Patent Identification: U.S. Patent No. 6,569,200, "Plasticized Soft Tissue Grafts, and Methods of Making and Using Same," issued May 27, 2003 (’200 Patent).

The Invention Explained

  • Problem Addressed: The patent describes a problem with prior methods of preserving biological tissue grafts, such as freeze-drying, which render the tissue "significantly more brittle" and prone to fracture (’200 Patent, col. 3:46-52). These brittle grafts typically require a rehydration step before clinical use, which is time-consuming and may not fully restore the tissue's original mechanical properties (’200 Patent, col. 3:55-64).
  • The Patented Solution: The invention addresses this problem by replacing the water in the tissue's molecular structure with one or more "plasticizers" (e.g., glycerol) prior to dehydration (’200 Patent, Abstract). This process results in a dehydrated or freeze-dried tissue product that is not brittle, possesses compressive and tensile properties similar to normal hydrated tissue, and can be implanted directly "without significant preparation in the operating room" (’200 Patent, col. 4:16-24).
  • Technical Importance: This technology offers a significant logistical advantage by creating shelf-stable tissue grafts that do not require refrigeration or lengthy pre-operative preparation, simplifying their use in clinical applications (’200 Patent, col. 4:20-24).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 7, and dependent claims 2-4 and 8 (Compl. ¶42).
  • A post-complaint Inter Partes Review (IPR2019-00571) concluded with a certificate issued on July 2, 2021, which cancelled claims 1-3, 5-10, 12, 13, and 15 (’200 Patent, IPR Certificate, p. 2). Consequently, among the claims asserted in the complaint, only dependent claim 4 survived the IPR.
  • Claim 4 depends from claims 1, 2, or 3. As claim 1 is the independent claim from which it ultimately derives, its limitations are incorporated into the analysis of claim 4.
  • Independent Claim 1 (Cancelled): The core elements were:
    • A plasticized soft tissue graft suitable for transplantation into a human, comprising:
    • a cleaned soft tissue graft having an internal matrix;
    • one or more plasticizers contained in said internal matrix; and
    • said one or more plasticizers are not removed from said internal matrix of said plasticized soft tissue graft prior to transplantation into a human.
  • Dependent Claim 4 (Surviving):
    • The soft tissue graft of any one of claims 1, 2, 3, wherein said soft tissue graft is suitable for direct transplant into a human without rehydration.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Defendant's Strattice™ Reconstructive Tissue Matrix and AlloDerm® RTM Ready to Use products (collectively, the "Infringing Products") (Compl. ¶10, ¶30).

Functionality and Market Context

  • The complaint describes Strattice™ as an "acellular reconstructive tissue matrix... derived from porcine dermis" that is "processed and preserved in a phosphate buffered aqueous solution containing matrix stabilizers" (Compl. ¶25). It is alleged to be storable at room temperature and to require "no rehydration" (Compl. ¶25).
  • AlloDerm® RTU is described as an "allograft human dermis, processed to remove cells" that is stored at room temperature (Compl. ¶28). The complaint alleges this product is "ready to use with a minimum 2-minute soak" and "saves substantial operating time by eliminating the rehydration step" (Compl. ¶28).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint's allegations were drafted prior to the IPR proceeding that cancelled most asserted claims. The analysis below focuses on the elements of surviving Claim 4, which incorporates the limitations of cancelled independent Claim 1.

’200 Patent Infringement Allegations

Claim Element (from Claim 4, incorporating Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A cleaned soft tissue graft having an internal matrix... Both Strattice and AlloDerm RTU are described as processed tissue matrices ("acellular reconstructive tissue matrix" or "allograft human dermis") from which cellular components have been removed (Compl. ¶25, ¶28). ¶25, ¶28 col. 4:32-34
...one or more plasticizers contained in said internal matrix... The complaint alleges on information and belief that the products are "plasticized soft tissue graft[s]" (Compl. ¶26, ¶29). Strattice is preserved in a solution with "matrix stabilizers" (Compl. ¶25). ¶25, ¶26, ¶29 col. 7:29-32
...said one or more plasticizers are not removed...prior to transplantation... The products are alleged to be ready to use from their packaging. Strattice "requires no rehydration or orientation" and AlloDerm RTU is "ready to use with a minimum 2-minute soak" (Compl. ¶25, ¶28). ¶25, ¶28 col. 1:19-24
...wherein said soft tissue graft is suitable for direct transplant...without rehydration. The complaint alleges Strattice "requires no rehydration" (Compl. ¶25). It alleges AlloDerm RTU "saves substantial operating time by eliminating the rehydration step," suggesting it does not require traditional rehydration (Compl. ¶28). ¶25, ¶28 col. 4:21-24
  • Identified Points of Contention:
    • Procedural Question: The primary issue for the case is its viability, as Plaintiff's infringement allegations now rest solely on a single dependent claim after an IPR cancelled all other asserted claims, including the independent claims.
    • Scope Questions: A central dispute may be whether the "phosphate buffered aqueous solution containing matrix stabilizers" used to preserve the Strattice product (Compl. ¶25) falls within the patent’s definition of a "plasticizer."
    • Technical Questions: A key factual question is whether the "minimum 2-minute soak" required for the AlloDerm RTU product (Compl. ¶28) constitutes "rehydration" as precluded by the express language of surviving Claim 4, or if it is functionally distinct from the kind of rehydration the patent sought to avoid.

V. Key Claim Terms for Construction

  • The Term: "plasticizer"

  • Context and Importance: This term is foundational to the invention. The infringement case may turn on whether the "matrix stabilizers" in Defendant's Strattice product are construed as "plasticizers". Practitioners may focus on this term because it appears to be a point of technical difference between the patent's specific examples and the accused product's description.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification defines a "plasticizer" functionally as "any biocompatible compounds which are soluble in water and can easily displace/replace water at the molecular level" to provide "the hydrating functions of water in that tissue" (’200 Patent, col. 7:29-32, col. 7:48-50).
    • Evidence for a Narrower Interpretation: The patent provides a list of specific examples, such as glycerol and other polyols (sugar alcohols), which could be argued to limit the term's scope to compounds of a similar chemical class (’200 Patent, col. 7:41-45).

  • The Term: "without rehydration"

  • Context and Importance: This phrase is the key limitation added by Claim 4, the only asserted claim to survive the IPR. Its construction is critical to determining infringement by the AlloDerm RTU product, which requires a "minimum 2-minute soak" (Compl. ¶28).

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification contrasts the invention with prior art grafts that clinicians "do not have time to adequately rehydrate" in the operating room (’200 Patent, col. 3:17-19). This may suggest "without rehydration" means avoiding a lengthy, substantive rehydration process. The patent also describes that after processing, plasticized grafts can be used following an optional "brief washing in sterile isotonic saline" (’200 Patent, col. 12:10-13), which could be argued to encompass a short soak.
    • Evidence for a Narrower Interpretation: The abstract states that "Replacement of the chemical plasticizers by water prior to implantation is not required" (’200 Patent, Abstract). This could support an argument that any required soaking step, however brief, constitutes "rehydration."

VI. Other Allegations

  • Willful Infringement: The complaint alleges that Defendant's infringement has been willful. The basis for this allegation is Defendant's alleged pre-suit knowledge of Plaintiff’s patented technology, evidenced by the prosecution history of Defendant’s own patent application (’780 application). During that prosecution, the USPTO and the Patent Trial and Appeal Board (PTAB) repeatedly rejected Defendant's claims as obvious in light of Plaintiff's related patents, placing Defendant on notice of the technology as early as 2009 (Compl. ¶31-40, ¶43-44).

VII. Analyst’s Conclusion: Key Questions for the Case

The dispute, as it now stands following the IPR, presents several fundamental questions for the court:

  • A threshold procedural question will be one of case viability: can Plaintiff's infringement action proceed effectively based on a single surviving dependent claim, when all other asserted claims, including the independent claims from which it descends, have been cancelled by the USPTO?
  • A core issue will be one of definitional scope: can the term "plasticizer," which is central to the patented invention, be construed to cover the "matrix stabilizers" allegedly used in Defendant’s Strattice product?
  • A key evidentiary question will be one of functional operation: does the "minimum 2-minute soak" associated with the AlloDerm RTU product constitute "rehydration" as prohibited by the plain language of Claim 4, or is it a functionally distinct, incidental step that falls outside the claim's scope?