Acera Surgical Inc v. RegeniSource LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Acera Surgical, Inc. (Delaware), Retectix, LLC (Missouri), and Washington University (Missouri)
  • Defendant: RegeniSource LLC (Texas)
  • Plaintiff’s Counsel: Denko & Bustamante LLP; Knobbe, Martens, Olson & Bear, LLP
• Case Identification: 5:22-cv-00447, W.D. Tex., 05/06/2022
• Venue Allegations: Plaintiffs allege venue is proper because Defendant resides in the district, maintains a regular and established place of business in the district, and engages in the business of selling and offering for sale the accused products within the district.
• Core Dispute: Plaintiffs allege that Defendant’s Anthem Wound Matrix, a biomedical patch product, infringes four patents related to nanofiber scaffolds for tissue repair and regeneration.
• Technical Context: The technology involves creating synthetic, bioresorbable nanofiber matrices for wound healing that are engineered to mimic the body's native extracellular matrix, thereby promoting and guiding cellular growth.
• Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or specific licensing history concerning the patents-in-suit.

Case Timeline

Date	Event
2010-06-17	Earliest Priority Date for ’617 Patent
2012-09-21	Earliest Priority Date for ’234 and ’635 Patents
2016-05-12	Earliest Priority Date for ’677 Patent
2021-07-27	’617 Patent Issued
2021-11-16	’234 Patent Issued
2022-01-18	’677 Patent Issued
2022-02-22	’635 Patent Issued
2022-05-06	Complaint Filing Date

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

U.S. Patent No. 11,224,677 - "Tissue Substitute Materials and Methods for Tissue Repair"

• Patent Identification: U.S. Patent No. 11,224,677, "Tissue Substitute Materials and Methods for Tissue Repair," issued January 18, 2022.

The Invention Explained

• Problem Addressed: The patent’s background section describes the shortcomings of existing dural substitutes used in neurosurgery, including the risk of disease transmission from biologic grafts (allografts and xenografts) and the poor mechanical properties or adverse tissue response associated with some synthetic materials (’677 Patent, col. 1:41 - col. 2:52).
• The Patented Solution: The invention is a non-woven graft material made from at least two distinct polymeric fiber compositions that are combined into a single scaffold (’677 Patent, Abstract). This approach allows for the creation of a synthetic, bioresorbable graft whose mechanical properties (e.g., strength, flexibility) and biological properties (e.g., resorption rate) can be precisely engineered by selecting and combining different polymers, overcoming the limitations of single-material grafts (’677 Patent, col. 5:1-5).
• Technical Importance: This composite fiber approach provides a method for creating advanced synthetic tissue substitutes that can be tailored to better mimic the properties of native tissue and provide a more controlled healing environment than previously available materials (’677 Patent, col. 2:53-61).

Key Claims at a Glance

• The complaint asserts dependent Claim 15, which relies on Claim 12 and independent Claim 1 (Compl. ¶21).
• The essential elements of asserted Claim 15, incorporating Claim 1 and Claim 12, include:
  • A bioabsorbable non-woven graft material for facilitating regeneration of tissue.
  • Consisting of a single non-woven electrospun polymeric scaffold.
  • The scaffold is formed by a first set and a second set of non-woven electrospun polymeric fibers.
  • The first and second sets of fibers are commingled in the scaffold.
  • The first set of fibers is formed from a first polymer composition comprising poly(glycolic) acid.
  • The second set of fibers is formed from a second, different polymer composition comprising poly(lactide-co-caprolactone).
• The complaint does not explicitly reserve the right to assert other dependent claims for the ’677 Patent.

U.S. Patent No. 11,173,234 - "Biomedical Patches with Spatially Arranged Fibers"

• Patent Identification: U.S. Patent No. 11,173,234, "Biomedical Patches with Spatially Arranged Fibers," issued November 16, 2021.

The Invention Explained

• Problem Addressed: The patent background explains that existing surgical meshes often lead to excessive fibrosis or scarification, poor tissue integration, and pain, while nanofiber materials that promote better biological response often lack the mechanical strength required for surgical handling and implantation (’234 Patent, col. 1:24-41).
• The Patented Solution: The invention is a three-dimensional, multi-scaffold biomedical patch. It comprises a first polymeric scaffold with fibers arranged to facilitate cellular migration, and a second, distinct polymeric scaffold overlaid on the first to provide structural reinforcement (’234 Patent, Abstract). This layered design separates the biological function from the mechanical function, allowing each to be optimized independently to create a patch that is both biocompatible and surgically robust (’234 Patent, col. 13:42-51).
• Technical Importance: The multi-scaffold structure addresses the trade-off between mechanical strength and biological activity in tissue engineering, offering a design that provides structural support for a required period while also guiding tissue regeneration.

Key Claims at a Glance

• The complaint asserts independent Claim 1 (Compl. ¶31).
• The essential elements of Claim 1 include:
  • A three-dimensional electrospun biomedical patch.
  • A first polymeric scaffold with a first structure of deposited electrospun fibers extending in three dimensions to facilitate cellular migration for a first period of time (less than twelve months).
  • A second polymeric scaffold with a second structure of deposited electrospun fibers, overlaid on the first scaffold.
  • The second scaffold includes portions with a higher deposition of fibers than the first scaffold.
  • The second scaffold's fibers provide structural reinforcement for a second period of time (less than twelve months).
  • A plurality of deposited electrospun fibers connects the first and second scaffolds, comprising interweaved fibers made from a first and second polymer.
• The complaint does not explicitly reserve the right to assert dependent claims for the ’234 Patent.

U.S. Patent No. 11,253,635 - "Three Dimensional Electrospun Biomedical Patch for Facilitating Tissue Repair"

• Patent Identification: U.S. Patent No. 11,253,635, "Three Dimensional Electrospun Biomedical Patch for Facilitating Tissue Repair," issued February 22, 2022 (Compl. ¶14).
• Technology Synopsis: This patent addresses the need for implantable surgical materials that possess sufficient mechanical properties for handling and suturing without causing adverse biological reactions like excessive scarring (’635 Patent, col. 1:20-41). The solution is a multi-layered, three-dimensional electrospun patch comprising a first scaffold to promote cellular migration and a second, overlaid scaffold with higher fiber deposition to provide structural reinforcement, with the layers designed to degrade over different time periods (’635 Patent, Abstract).
• Asserted Claims: The complaint asserts independent Claim 1 (Compl. ¶43).
• Accused Features: The complaint alleges the Anthem Wound Matrix embodies this technology by having a first polymeric scaffold for cellular migration and a second, overlaid scaffold with a higher fiber deposition that provides structural reinforcement (Compl. ¶¶46, 48-49).

U.S. Patent No. 11,071,617 - "Biomedical Patches with Aligned Fibers"

• Patent Identification: U.S. Patent No. 11,071,617, "Biomedical Patches with Aligned Fibers," issued July 27, 2021 (Compl. ¶15).
• Technology Synopsis: This patent addresses the challenge of directing cell migration to accelerate wound healing (’617 Patent, col. 7:14-22). The invention is a biomedical patch with specifically aligned fibers, such as radially aligned fibers, that provide "nanoscale topographical cues" to guide cells to migrate from the periphery of a wound toward its center, thereby promoting faster and more organized tissue regeneration compared to scaffolds with randomly oriented fibers (’617 Patent, col. 9:13-25).
• Asserted Claims: The complaint asserts independent Claim 1 (Compl. ¶54).
• Accused Features: The complaint alleges the Anthem Wound Matrix infringes by including a first scaffold with randomly oriented fibers and a second scaffold comprising both radially aligned and randomly oriented fiber sections, with some radially aligned sections transitioning into or overlaying the randomly oriented sections (Compl. ¶¶57, 59-60).

III. The Accused Instrumentality

Product Identification

• The accused product is the "Anthem Wound Matrix," which the complaint alleges is a private label version of the "Phoenix Wound Matrix" (Compl. ¶¶16, 19).

Functionality and Market Context

• The complaint, citing Defendant's marketing materials, describes the Anthem Wound Matrix as a "3D electrospun, synthetic polymer matrix designed to provide a multi-dimensional scaffold stimulus for tissue regeneration and repair of acute and chronic wounds, and burns" (Compl. ¶17). An image provided in the complaint shows the product is offered in various sizes and shapes, including fenestrated versions (Compl. ¶18, p. 6). The matrix is alleged to be a bioresorbable, non-woven graft material made from two types of polymer fibers: Poly(lactide-co-caprolactone) and Polyglycolic acid (Compl. ¶¶23, 27). Another image shows product branding and a magnified view of the material's fibrous structure (Compl. ¶23, p. 7).
• The complaint alleges the product is sold and offered for sale throughout the United States (Compl. ¶16).

IV. Analysis of Infringement Allegations

’677 Patent Infringement Allegations

Claim Element (from Independent Claim 1, as limited by Claims 12 and 15)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A bioabsorbable non-woven graft material for facilitating regeneration of tissue...	The Anthem Wound Matrix is described as a bioresorbable material for tissue regeneration and repair.	¶23	col. 2:53-61
...consisting of: a single non-woven electrospun polymeric scaffold...	The accused product is alleged to include a single non-woven electrospun polymeric scaffold.	¶24	col. 15:1-11
...the non-woven electrospun polymeric scaffold formed by a first set of non-woven electrospun polymeric fibers and a second set of non-woven electrospun polymeric fibers...	The scaffold is allegedly formed by a first set and a second set of non-woven electrospun polymeric fibers.	¶25	col. 15:12-19
...wherein the first set of non-woven electrospun polymeric fibers and the second set of non-woven electrospun polymeric fibers are commingled in the non-woven electrospun polymeric scaffold...	The first and second sets of polymeric fibers are alleged to be commingled within the scaffold.	¶26	col. 20:1-11
...the first set...formed by depositing via electrospinning a first polymer composition comprising poly(glycolic) acid...	The first set of fibers is allegedly formed by electrospinning a polymer composition comprising glycolic acid.	¶27	col. 15:12-19
...the second set...formed by depositing via electrospinning a second polymer composition...comprising poly(lactide-co-caprolactone)...	The second set of fibers is allegedly formed by electrospinning a different polymer composition comprising poly(lactide-co-caprolactone).	¶27	col. 15:12-19

• Identified Points of Contention:
  • Scope Questions: The interpretation of "commingled" may become a central issue. A dispute could arise over whether this term requires an intimate, uniform mixture of the two fiber types throughout the scaffold, or if it can read on a structure where the fibers are merely interlaid, potentially in non-uniform distributions or gradients.
  • Technical Questions: The complaint's allegations regarding the product's composition rely on Defendant's marketing materials (Compl. ¶27). A key factual question will be whether the actual manufactured product's physical structure meets the "commingled" limitation, or if the two fiber types exist in a more layered or otherwise distinct arrangement that falls outside the claim's scope.

’234 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A three-dimensional electrospun biomedical patch for facilitating tissue repair...	The Anthem Wound Matrix is described as a "3D electrospun synthetic polymer matrix...for tissue regeneration and repair".	¶33	col. 13:42-43
...a first polymeric scaffold comprising a first structure of deposited electrospun fibers...extending in a plurality of directions in three dimensions to facilitate cellular migration...	The product is alleged to have a first polymeric scaffold made of electrospun fibers that extend in three dimensions to facilitate cellular migration.	¶¶34, 35	col. 13:44-50
...a second polymeric scaffold comprising a second structure of deposited electrospun fibers, the second polymeric scaffold overlaid on the first polymeric scaffold...	The product is alleged to comprise a second polymeric scaffold with a second fiber structure overlaid on the first scaffold.	¶37	col. 13:51-53
...the second polymeric scaffold comprising one or more portions with a higher deposition of fibers than one or more portions of the first polymeric scaffold...	The second structure is alleged to have portions with a higher fiber deposition than portions of the first scaffold.	¶38	col. 13:54-57
...the second structure...comprising the plurality of deposited electrospun fibers configured to provide structural reinforcement...	The fibers of the second structure are alleged to provide structural reinforcement to the patch.	¶39	col. 13:58-61
...the plurality of deposited electrospun fibers connecting the first polymeric scaffold and the second polymeric scaffold...comprising a first set of...fibers generated by...a first polymer and a second set of...fibers made from a second polymer...are interweaved.	The fibers connecting the two scaffolds are alleged to include a first set from a first polymer and a second set from a second polymer that are interweaved.	¶40	col. 13:66-col. 14:4

• Identified Points of Contention:
  • Scope Questions: The construction of "a second polymeric scaffold...overlaid on the first polymeric scaffold" will be critical. This raises the question of whether a product made in a continuous process, but with varying fiber densities, can meet this limitation, or if the claim requires two physically distinct, separately formed layers that are subsequently combined.
  • Technical Questions: The complaint's theory appears to be that the presence of two different polymer fiber types necessarily results in the claimed two-scaffold structure (Compl. ¶37). A central factual dispute may be whether the Anthem Wound Matrix possesses a physically distinct "second scaffold" that is "overlaid" on a "first scaffold," or if it is a single, integrated scaffold with heterogeneous properties that does not meet the structural requirements of the claim.

V. Key Claim Terms for Construction

’677 Patent

• The Term: "commingled"
• Context and Importance: This term defines the spatial relationship between the two required sets of fibers. The infringement analysis for the ’677 Patent may depend on whether the accused product's fibers are mixed in a way that satisfies the definition of "commingled," as opposed to being layered, zoned, or otherwise arranged.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent does not appear to provide an explicit definition. The specification describes forming non-woven graft materials from "at least two distinct fiber compositions composed of different polymeric materials" (’677 Patent, Abstract). Parties might argue that in the absence of a specific limitation on the degree of mixing, any interspersion of the two fiber types should be considered "commingled."
  • Evidence for a Narrower Interpretation: The patent consistently refers to the two fiber sets being formed into a "single non-woven electrospun polymeric scaffold" (e.g., ’677 Patent, Claim 1). This could suggest that "commingled" implies a level of integration that results in a single, unitary structure, potentially excluding simple layering.

’234 Patent

• The Term: "second polymeric scaffold...overlaid on the first polymeric scaffold"
• Context and Importance: This phrase is the core structural limitation of Claim 1. The infringement case rests on demonstrating that the accused product contains not just one scaffold with varying properties, but two distinct scaffolds, one placed over the other. Practitioners may focus on this term because it distinguishes the invention from single-scaffold structures.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes a method where a second layer is "coupled to the first layer using a coupling process" (’234 Patent, Abstract). A party could argue that "overlaid" does not require two entirely separate manufacturing runs, but could encompass a continuous process where material properties are changed mid-process to create a functionally distinct, reinforcing top layer.
  • Evidence for a Narrower Interpretation: The description of the invention as comprising "a first polymeric scaffold" and "a second polymeric scaffold" implies two separate entities (’234 Patent, Claim 1). Figures and descriptions of delamination and fusion processes for multiple layers may support an interpretation that "overlaid" requires the combination of pre-formed, distinct scaffold layers (’234 Patent, FIG. 8; col. 9:1-10).

VI. Other Allegations

• Indirect Infringement: The complaint alleges only direct infringement under 35 U.S.C. § 271(a) and does not plead facts to support claims for induced or contributory infringement.
• Willful Infringement: The complaint does not contain an explicit allegation of willful infringement or plead facts concerning Defendant's knowledge of the patents-in-suit. The prayer for relief requests a finding that the case is "exceptional" under 35 U.S.C. § 285, which relates to an award of attorney's fees (Compl. ¶65.B).

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

The resolution of this case may turn on the following central questions:

• A primary issue will be one of structural interpretation: Do the asserted claims require physically distinct, sequentially manufactured layers or scaffolds, or can they be read to cover a single, integrated scaffold manufactured in a continuous process but possessing the claimed combination of different polymers, densities, and fiber alignments?
• A related and critical question will be one of evidentiary proof: Independent of marketing claims, what is the actual physical architecture and chemical composition of the accused Anthem Wound Matrix? The case will likely depend on expert analysis and empirical evidence to determine if that physical reality maps onto the specific structural limitations—such as "commingled," "overlaid," and "radially aligned"—recited in the asserted claims of the four different patents.