Dyer

UNITED STATES DISTRICT COURT

MIDDLE DISTRICT OF FLORIDA

TAMPA DIVISION

DIANA DYER,

Plaintiff,

v. Case No. 8:24-cv-2867-VMC-SPF

COLOPLAST CORP. and COLOPLAST

MANUFACTURING US, LLC,

Defendants.

/

ORDER

This matter is before the Court on consideration of

Defendant Coloplast Corp.’s (“Coloplast”) Motion to Exclude

Expert Opinions of Jimmy Mays, Ph.D. (Doc. # 91), filed on

April 15, 2026. Plaintiff Diana Dyer responded on May 6, 2026.

(Doc. # 119). The Motion is granted in part and denied in

part.

I. Background

In December 2020, Ms. Dyer “was surgically implanted

with an Aris™ Trans-Obturator Sling System (hereinafter the

‘Aris’), a pelvic mesh product and medical device designed,

manufactured, and marketed by Defendants,” which “was

intended to treat pelvic organ prolapse and stress urinary

incontinence.” (Doc. # 1 at 1). Ms. Dyer alleges that neither

she “nor her healthcare providers were warned that the Aris

was defective and negligently designed and manufactured.”

(Id. at 1-2). Ms. Dyer claims that she “has suffered, and

continues to suffer, debilitating injuries” “[a]s a result of

being surgically implanted with Defendants’ unreasonably

dangerous defective pelvic mesh device.” (Id. at 2).

Ms. Dyer initiated this action to recover damages for

her claimed injuries. (Id.). In the complaint, Ms. Dyer

asserts three causes of action: (1) negligence, (2) strict

liability design defect, and (3) strict liability failure to

warn. (Id. at 33-47).

The case then proceeded through discovery. Ms. Dyer

retained as an expert Dr. Jimmy Mays, a “Professor Emeritus

in the Department of Chemistry at the University of

Tennessee.” (Doc. # 125-3 at 1-2). Dr. Mays has a Ph.D. in

polymer science and has “worked extensively in the area of

polymeric biomaterials.” (Id. at 2).

Dr. Mays offers the following opinions: (1)

“polypropylene is susceptible to oxidation and it degrades by

an oxidative mechanism in the body”; (2) “all polypropylene

transvaginal mesh implants will degrade in vivo”; (3) “[t]he

polypropylene resin used by Coloplast to make all their pelvic

repair meshes is susceptible to oxidative degradation”; (4)

“[f]oreign body reaction to the mesh in vivo leads to

oxidation, chain scission, reduction in molecular weight,

embrittlement, degradation, flaking, pitting, and cracking”;

(5) the mesh “cannot function properly after implantation,

which can lead to adverse events in an implantee”; (6)

polypropylene mesh’s properties change in vivo, “creating a

mechanical mismatch with surrounding soft tissue and

preventing the mesh from functioning in the manner in which

it was intended to function”; and (7) “[s]tudies on Coloplast

polypropylene mesh oxidative degradation in vivo have

revealed that polypropylene microparticles and nanoparticles

are produced and released into surrounding tissue.” (Id. at

6-7). Accordingly, Dr. Mays opines that the Aris is not

suitable to serve as a permanent implant. (Id. at 7).

Now, Coloplast moves to exclude the opinions of Dr. Mays.

(Doc. # 91). Ms. Dyer has responded. (Doc. # 119). The Motion

is ripe for review.

II. Legal Standard

Federal Rule of Evidence 702 states:

A witness who is qualified as an expert by

knowledge, skill, experience, training, or

education may testify in the form of an opinion or

otherwise if: (a) the expert’s scientific,

technical, or other specialized knowledge will help

the trier of fact to understand the evidence or to

determine a fact in issue; (b) the testimony is

based on sufficient facts or data; (c) the

testimony is the product of reliable principles and

methods; and (d) the expert has reliably applied

the principles and methods to the facts of the case.

Fed. R. Evid. 702.

Implementing Rule 702, Daubert v. Merrell Dow Pharms.,

Inc., 509 U.S. 579 (1993), requires district courts to ensure

that any scientific testimony or evidence admitted is both

relevant and reliable. See Id. at 589–90. District courts

must conduct this gatekeeping function “to ensure that

speculative, unreliable expert testimony does not reach the

jury under the mantle of reliability that accompanies the

appellation ‘expert testimony.’” Rink v. Cheminova, Inc., 400

F.3d 1286, 1291 (11th Cir. 2005).

The Eleventh Circuit “requires trial courts acting as

gatekeepers to engage in a ‘rigorous three-part inquiry.’”

Hendrix ex rel. G.P. v. Evenflo Co., 609 F.3d 1183, 1194 (11th

Cir. 2010). The district court must assess whether:

(1) the expert is qualified to testify competently

regarding the matters he intends to address; (2)

the methodology by which the expert reaches his

conclusions is sufficiently reliable as determined

by the sort of inquiry mandated in Daubert; and (3)

the testimony assists the trier of fact, through

the application of scientific, technical, or

specialized expertise, to understand the evidence

or to determine a fact in issue.

Id. The proponent of the expert testimony must show, by a

preponderance of the evidence, that the testimony satisfies

each requirement. Id.

III. Analysis

Coloplast challenges the admissibility of Dr. Mays’s

opinions on: (1) oxidative degeneration, (2) clinical

complications associated with polypropylene mesh, (3) the

reduction of mechanical properties of polypropylene mesh in

vivo, (4) the toxicity or irritability of polypropylene resin

or antioxidants, and (5) safer alternatives to polypropylene

mesh. Coloplast also asks the Court to preclude Dr. Mays from

offering legal conclusions, summarizing Coloplast’s internal

documents, or opining on Coloplast’s state of mind and

conduct. The Court addresses each contention in turn.

A. Oxidative Degradation Opinions

Dr. Mays opines that polypropylene mesh undergoes

oxidative degradation in the human body, which causes the

mechanical properties of the mesh to break down. (Doc. # 125-

3 at 9-15). Dr. Mays states that “when a foreign object is

implanted into living tissue, an inflammatory response occurs

resulting in attack on the foreign body by enzymes.” (Id. at

12). According to Dr. Mays, this “foreign body reaction”

causes degradation of polypropylene mesh implanted in living

organisms. (Id. at 13-14). Dr. Mays states that the

inflammation caused by the foreign body reaction “leads to

enhanced fibrosis, stiffness, erosion of adjacent organs,

nerve entrapment, and pain.” (Id. at 14) (internal quotation

marks omitted).

1. Relevance and Helpfulness to Jury

Coloplast argues that Dr. Mays’s opinions are

“irrelevant and unhelpful because there is no evidence that

[Ms. Dyer’s] Aris implant degraded or that any purported

degradation caused her alleged injuries.” (Doc. # 91 at 6).

Coloplast notes that Ms. Dyer’s “specific and general

causation medical expert, Neeraj Kohli, M.D., does not offer

the opinion that [her] Aris implant degraded or that

degradation of the Aris implant caused her injuries.” (Id.).

In response, Ms. Dyer asserts that there is evidence in the

record that the Aris’s mesh “was defective and that safer

alternatives would have mitigated the complications of the

‘excessive and unpredictable’ foreign body response

experienced by Ms. Dyer, even if Dr. Kohli did not

specifically utilize the term ‘degrade’ or refer to

‘oxidizing agents.’” (Doc. # 119 at 4-5). The Court agrees

with Ms. Dyer and finds Dr. Mays’s testimony relevant and

helpful to the jury.

Expert testimony must assist the trier of fact. Fed. R.

Evid. 702. “By this requirement, expert testimony is

admissible if it concerns matters that are beyond the

understanding of the average lay person.” United States v.

Frazier, 387 F.3d 1244, 1262 (citation omitted). “[T]he court

must ensure that the proposed expert testimony is relevant to

the task at hand, . . . i.e., that it logically advances a

material aspect of the proposing party’s case.” Allison v.

McGhan, 184 F.3d 1300, 1312 (11th Cir. 1999) (internal

quotation marks omitted). “Proffered expert testimony

generally will not help the trier of fact when it offers

nothing more than what lawyers for the parties can argue in

closing arguments.” Frazier, 387 F.3d at 1262-63 (citation

omitted).

Although Dr. Kohli does not use the word “degradation”

in his case-specific report, he opines that implantation of

polypropylene mesh causes chronic inflammation and the

foreign body response. (Doc. # 119-3 at 12). Dr. Kohli states

that “[t]he chronic pain syndromes of polypropylene mid-

urethral slings occur either acutely following implantation

or months to years later related to the chronic inflammatory

response of the foreign body response to polypropylene that

may be excessive, unpredictable, and lead to mesh shrinkage

or contraction of soft tissues adjacent to the mesh that may

be excessive.” (Id. at 8). Dr. Kohli opines that PVDF mesh

slings are safer alternative devices because “PVDF does not

appear to shrink, has improved biocompatibility compared with

polypropylene as it has less chronic inflammatory response

and fibrosis.” (Id. at 10). Dr. Kohli further opines that Ms.

Dyer’s “vaginal/groin pain . . . is the direct result of the”

Aris’s defects described throughout his report, including the

use of polypropylene mesh, and that “one of the safer

alternative devices/procedures not using mesh or avoiding the

transobturator space would have reduced the risk of these

complications.” (Id. at 32). Dr. Mays, in turn, opines that

the foreign body reaction causes oxidative degeneration of

the mesh and explains the effects of polypropylene

degradation in vivo. (Doc. # 125-3 at 12-17).

To succeed on any of her claims, Ms. Dyer must prove

that the Aris “is defective or unreasonably dangerous.” Brown

v. DePuy Orthopaedics, Inc., 978 F. Supp. 2d 1266, 1272 (M.D.

Fla. 2013). The Court agrees with Ms. Dyer that Dr. Mays’s

opinions are relevant and “helpful to the jury’s

understanding of what, specifically, about the properties of

the Aris mesh leads to the characteristic breakdown, erosion,

and scarring of surrounding tissues which Dr. Kohli opines

are common complications of the Aris.” (Doc. # 119 at 7).

This information is “beyond the understanding of the average

lay person.” Frazier, 387 F.3d at 1262 (citation omitted).

Thus, Dr. Mays’s opinions would be helpful to the jury.

Coloplast further claims that Dr. Kohli “admit[ted]” in

another cause that he “does not believe polypropylene

degrades in the human body at all.” (Doc. # 91 at 6). However,

Dr. Kohli’s testimony was that he does not “believe that

polypropylene is a degradative product which creates toxins

in the body.” (Doc. # 91-2 at 280:14-16) (emphasis added). In

any event, to the extent Dr. Kohli’s testimony is

contradictory to Dr. Mays’s opinions, this goes to the weight

rather than the admissibility of the evidence. See Souder v.

Floyd Cnty., No. CIV.A. 4:03CV0085HLM, 2005 WL 6218033, at *6

(N.D. Ga. Mar. 22, 2005) (“[C]ontrary evidence goes not to

the admissibility of the expert testimony; rather, it goes to

the weight of that testimony.”).

The Motion is denied as to this issue.

2. Reliability

Next, Coloplast argues that Dr. Mays’s degradation

opinions are unreliable because Dr. Mays fails to adequately

address scientific literature that “demonstrates that the

‘cracked’ surfaces of explanted polypropylene mesh, which

were previously assumed to be degradation of the

polypropylene, are in fact a layer of biological material

that is deposited on the implant.” (Doc. # 91 at 7). The Court

is not persuaded.

Dr. Mays thoroughly addresses the studies in question,

referred to as the “Thames papers,” but ultimately disagrees

with their conclusions. (Doc. # 125-3 at 30-42). As another

court in this District has held, “[t]o the extent [Coloplast]

disagrees with Dr. Mays’s rejection of Thames, such

disagreement goes to the weight of his opinion and is more

appropriately addressed on cross-examination.” Redding v.

Coloplast Corp., No. 6:19-cv-1857-CEM-GJK, 2022 WL 20829230,

at *6 (M.D. Fla. Mar. 26, 2022); see also Bayless v. Boston

Sci. Corp., No. 6:20-cv-831-RBD-DCI, 2020 WL 10058191, at *4

(M.D. Fla. Dec. 7, 2020) (“Other scientific literature that

may contradict an expert’s well-founded opinions is certainly

fertile ground for cross-examination. But the Court will not

make a credibility determination as to which scientific

opinions to believe or disbelieve, which studies to credit or

not — that is for the jury to decide.”).

Alternatively, Coloplast argues that Dr. Mays lacks a

reliable basis to opine that Coloplast’s polypropylene mesh

implants degrade in the body. (Doc. # 91 at 11-20). In this

regard, Coloplast contends that Dr. Mays’s opinion is based

on two “unfounded, stacked assumptions”: “(1) that

degradation results from aspects of the [foreign body

response] which continuously generate high concentrations of

oxidizing agents for the entire life of the implant; and (2)

that eventually these oxidizing agents exhaust the

antioxidant stabilizers included in Coloplast’s surgical mesh

implants.” (Id. at 13). The Court disagrees.

First, Coloplast argues that Dr. Mays “lacks the

qualifications and a reliable basis to assert that the human

body continues to release oxidants for the entire life of the

mesh implant.” (Id.). As to qualifications, Dr. Mays has

extensive educational and clinical experience in polymer

science and biomaterials. (Doc. # 125-3 at 1-4). As other

courts have determined, “Dr. Mays is qualified to opine as to

polypropylene generally and the effects of oxidation on

polypropylene, which includes the foreign body response to

polypropylene.” Redding, 2022 WL 20829230, at *2; see also

Boneta v. Am. Med. Sys., Inc., No. 20-CIV-60409-RAR, 2021 WL

6134790, at *5 (S.D. Fla. Sept. 27, 2021) (“Dr. Mays holds a

Ph.D. in polymer science and has conducted extensive research

in the field of biomaterials and developed new biomaterials

for medical applications, among other qualifications. Dr.

Mays, therefore, may opine on polypropylene oxidation and

degradation in the body.”); Nunez v. Coloplast Corp., No. 19-

cv-24000, 2020 WL 2315077, at *3 (S.D. Fla. May 11, 2020)

(finding Dr. Mays qualified to offer opinions on “the effects

of polypropylene mesh in the human body”).

As to reliability, Coloplast argues that Dr. Mays’s

“assumption that the [foreign body response] releases high

concentrations of oxidants for the life of the implant” is

not supported by the “Biomaterials Science text.” (Doc. # 91

at 14). As previously discussed, “[o]ther scientific

literature that may contradict an expert’s well-founded

opinions is certainly fertile ground for cross-examination”

but does not warrant exclusion of expert testimony. Bayless,

2020 WL 10058191, at *4). Coloplast has not demonstrated that

Dr. Mays’s opinion is unreliable as Dr. Mays has cited

multiple other scientific texts in support. (Doc. # 125-3 at

12-15). See Redding, 2022 WL 20829230, at *3 (declining to

exclude Dr. Mays’s opinion that “the release of oxidating

agents in response to a foreign body is continuous for as

long as the mesh product remains implanted” despite

Coloplast’s assertion that it was contradicted by new

scientific literature); Nunez, 2020 WL 2315077, at *4 (same).

This is an issue to be addressed in cross-examination.

Second, Coloplast challenges the reliability of Dr.

Mays’s opinion that antioxidants added to the polypropylene

mesh used in the Aris “cannot permanently protect these mesh

products from in vivo oxidation.” (Doc. # 125-3 at 20; Doc.

# 91 at 17-20). Specifically, Coloplast argues that the

opinion is unreliable because Dr. Mays relies on a study

“regarding the purported in vivo degradation of surgical mesh

implants” manufactured by another company, which was

published prior to the first Thames paper. (Id. at 17). “[I]n

most cases, objections to the inadequacies of a study are

more appropriately considered an objection going to the

weight of the evidence rather than its admissibility.” Quiet

Tech. DC-8, Inc. v. Hurel-Dubois UK Ltd., 326 F.3d 1333, 1345

(11th Cir. 2003). However, “[a] court may conclude that there

is simply too great an analytical gap between the data and

the opinion proffered.” Gen. Elec. Co. v. Joiner, 522 U.S.

136, 146 (1997). Here, Dr. Mays cites many scientific studies

to support his opinion that the addition of antioxidants may

delay but cannot prevent the oxidative degradation of

polypropylene mesh. (Doc. # 125-3 at 17). Coloplast has not

demonstrated that there is too great an analytical gap between

the studies Dr. Mays cited and his opinion regarding the

Aris’s polypropylene mesh.

The Motion is denied as to this issue.

B. Clinical Complications

Coloplast argues that Dr. Mays “lacks the necessary

qualifications to offer opinions concerning potential

clinical complications resulting from the purported

degradation because he is not a medical doctor and has no

medical training.” (Doc. # 91 at 20). In response, Ms. Dyer

represents that Dr. Mays will not opine on the medical

complications associated with polypropylene mesh. (Doc. # 119

at 21). Accordingly, this issue is moot.

C. Reduction of Mechanical Properties

Dr. Mays states that the degradation of polypropylene in

vivo is “accompanied by a decrease in mechanical properties

(embrittlement, loss of mass, decreased melting temperature,

reduced compliance) of the polypropylene.” (Doc. # 125-3 at

46). According to Dr. Mays, “[s]tiffening or reduced

compliance of the polypropylene mesh upon degradation has

important implications on the intended performance of the

mesh as a biomaterial.” (Id. at 48).

Coloplast notes that Dr. Mays admittedly “is not

qualified to quantify the degree of stiffness purportedly

resulting from oxidative degradation in vivo or the degree of

stiffness necessary to produce clinical symptoms in a

patient, and he is unaware of any scientific literature

attempting to do so.” (Doc. # 91 at 21). Coloplast asserts

that Dr. Mays “has never performed any test or seen any test

result on Coloplast’s Aris implant indicating that it had a

loss of mechanical properties after being implanted in vivo.”

(Id.). Accordingly, Coloplast argues that Dr. Mays “lacks any

reliable basis to opine that Coloplast’s surgical mesh

implants will stiffen as a result of oxidative degradation or

that the degree of the purported stiffening is sufficient .

. . to produce clinical complications.” (Id.).

As previously discussed, Ms. Dyer represents that Dr.

Mays will not offer opinions regarding clinical complications

associated with polypropylene mesh. (Doc. # 119 at 21).

Accordingly, Coloplast’s challenge to the reliability of Dr.

Mays’s opinion regarding clinical complications of stiffened

mesh is moot.

Dr. Mays, an expert in polymer science and biomaterials,

cites multiple scientific articles in support of his opinions

regarding the reduction of the mesh’s mechanical properties.

(Doc. # 125-3 at 48-50). The Court finds that Dr. Mays’s

opinions on this issue are reliable. See Arevalo v. Coloplast

Corp., No. 3:19-cv-3577-TKW-MJF, 2020 WL 3958505, at *8 (N.D.

Fla. July 7, 2020), aff’d sub nom. Arevalo v. Mentor Worldwide

LLC, No. 21-11768, 2022 WL 16753646 (11th Cir. Nov. 8, 2022).

(finding Dr. Mays’s opinion reliable “because even though Dr.

Mays admitted that he could not cite a published paper

specifically finding a loss of tensile strength in explanted

implants as a result of in vivo conditions, his opinion that

oxidative degradation results in loss of mechanical

properties was the product of a reliable methodology since he

relied on his experience and various published papers”).

The Motion is denied as to this issue.

D. Toxicology Opinions

Coloplast argues that Dr. Mays “is unqualified to opine

on the alleged toxicity or irritability of polypropylene

resin or antioxidants.” (Doc. # 91 at 22). In response, Ms.

Dyer represents that “Dr. Mays will not opine as to the

toxicity of polypropylene resin or antioxidants.” (Doc.# 119

at 22-23). Accordingly, the issues of whether Dr. Mays is

qualified to offer opinions on toxicity and whether his

opinions are reliable and helpful to the jury are moot.

However, Ms. Dyer does not address the issue of whether

Dr. Mays is qualified to testify as to the alleged

irritability of polypropylene resin or antioxidants.

Accordingly, the Court treats this portion of the Motion as

unopposed. See Jones v. Bank of Am., N.A., 564 F. App’x 432,

434 (11th Cir. 2014) (“[A] party’s failure to respond to any

portion or claim in a motion indicates such portion, claim or

defense is unopposed.”). The Court grants the Motion to the

extent of excluding Dr. Mays’s opinions on the alleged

irritability of polypropylene resin or antioxidants.

E. Safer Alternatives

Coloplast argues that Dr. Mays “lacks both the

qualifications and the necessary data to opine that

polyethylene, poly(vinylidene fluoride) (PVDF), and P4HB

meshes” are safer alternatives to polypropylene mesh. (Doc.

# 91 at 23). In response, Ms. Dyer represents that Dr. Mays

will not opine as to whether PVDF or P4HB is “safer” than

polypropylene mesh. (Doc. # 119 at 24). Accordingly,

Coloplast’s argument regarding PVDF and P4HB mesh is moot. As

Ms. Dyer does not address Coloplast’s contention that Dr.

Mays is not qualified to opine that polyethylene mesh is a

safer alternative to polypropylene mesh, the Court treats

this portion of the Motion as unopposed. Jones, 564 F. App’x

at 434.

The Court grants the Motion to the extent of excluding

Dr. Mays’s opinion that polyethylene mesh is a safer

alternative to polypropylene mesh.

F. Legal Conclusions, Contents of Internal Documents,

and Opinions on Coloplast’s State of Mind and

Conduct

Finally, Coloplast asks the Court to exclude Dr. Mays’s

legal conclusions, summaries of internal documents, and

opinions on Coloplast’s state of mind or corporate conduct.

(Doc. # 91 at 25). In response, Ms. Dyer represents that “Dr.

Mays will not offer opinions on Coloplast’s state of mind or

corporate conduct, nor will he offer any legal conclusions.”

(Doc. # 119 at 25). However, Ms. Dyer asserts that “Dr. Mays

will testify about any documents, including corporate

documents, that form the basis for his admissible opinions.”

(Id.). Ms. Dyer argues that the Court should deny the Motion

to the extent Coloplast seeks “to exclude the bases for” Dr.

Mays’s opinions or “his non-legal conclusions.” (Id.). The

Court agrees with Ms. Dyer.

The Motion is denied as moot to the extent Coloplast

seeks to preclude Dr. Mays from offering legal conclusions or

opining on Coloplast’s state of mind or corporate conduct.

Dr. Mays “is not precluded from offering testimony that uses

terms that do not have a separate, distinct, and specialized

meaning in the law.” Warren v. C. R. Bard, Inc., No. 8:19-

cv-2657-TPB-JSS, 2020 WL 3567299, at *4 (M.D. Fla. July 1,

2020).

The Motion is granted to the extent Coloplast asks the

Court to “preclude Dr. Mays from testifying as to the content

of Coloplast’s internal documents.” (Doc. # 91 at 25); see

Salinero v. Johnson & Johnson, No. 1:18-cv-23643-UU, 2019 WL

7753453, at *18 (S.D. Fla. Sept. 5, 2019) (“[S]imply parroting

documents or other testimony does nothing to assist the trier

of fact.”). However, Dr. Mays “may testify as to a review of

internal corporate documents solely for the purpose of

explaining the basis for his or her opinions — assuming the

opinions are otherwise admissible.” Redding, 2020 WL

13882977, at *7 (internal quotation marks omitted).

Accordingly, it is hereby

ORDERED, ADJUDGED, and DECREED:

(1) Defendant Coloplast Corp.’s Motion to Exclude Expert

Opinions of Jimmy Mays, Ph.D. (Doc. # 91) is GRANTED in

part and DENIED in part.

(2) Dr. Mays may not offer opinions regarding: (1) the

alleged irritability of polypropylene resin or

antioxidants or (2) polyethylene mesh as a safer

alternative to polypropylene mesh. Dr. Mays also may not

summarize Coloplast’s internal documents.

DONE and ORDERED in Chambers in Tampa, Florida, this 2nd

day of July, 2026.

VIR IA M. HERNANDEZ’COVINGTON

UNITED STATES DISTRICT JUDGE

20