Diabetic Foot Ulcer (DFU) Biofilm Infection and Recurrence (DFUBiofilm)

Diabetic foot ulcers (DFU) are one of the most common reasons for hospitalization of diabetic patients and frequently results in amputation of lower limbs. Of the one million people who undergo non-traumatic leg amputations annually worldwide, 75% are performed on people who have type 2 diabetes (T2DM). The risk of death at 10 years for a diabetic with DFU is twice as high as the risk for a patient without a DFU. The rate of amputation in patients with DFU is 38.4%4. Infection is a common (>50%) complication of DFU. Emerging evidence underscores the significant risk that biofilm infection poses to the non-healing DFU. Biofilms are estimated to account for 60% of chronic wound infections. In the biofilm form, bacteria are in a dormant metabolic state. Thus, standard clinical techniques like the colony forming unit (CFU) assay to detect infection may not detect biofilm infection. Thus, biofilm infection may be viewed as a silent maleficent threat in wound care.

Study Overview

• Status: Recruiting
• Conditions: Diabetic Foot; Diabetic Foot Infection; Chronic Wounds; Biofilm Infection; Trans-epidermal Water Loss (TEWL)
• Intervention / Treatment: Procedure: Observation of wound infection and time to wound closure; Device: Pericam PSI-NR Laser Speckle imaging

Detailed Description

In the current standard of care (SoC), wound closure is defined (FDA) by wound area re-epithelialization without drainage. The investigators' pre-clinical large animal work demonstrates that wounds with a history of biofilm infection may meet above criteria but the repaired wound-site skin is deficient in barrier function. This has led to the concept of functional wound closure wherein the current clinical definition of wound closure is supplemented with a functional parameter - restoration of skin barrier function as measured by low trans-epidermal water loss (TEWL).

This study rests on DFU-patient based findings from a NIDDK-DIACOMP funded pilot study (Sen/Gurtner) showing that closed DFU with deficient barrier function are more likely to recur. Biofilm infection as assessed through scanning electron microscopy and wheat germ aggluttin assay performed on debrided tissue causes faulty re-epithelialization, compromising skin barrier function at the closed wound site. Such defects are caused by biofilm-inducible miRs which silence junctional proteins necessary for skin barrier function. The IRB protocol associated with this study, rests on our novel patient-based observation that in wound-edge tissue catenin delta1/p120 catenin (CTNND1) is suppressed as measured through immunohistochemistry. CTNND1 is an essential regulator of E-cadherin stability which is regarded as a master organizer in epithelial phenotype and plays a critical role in maintaining the barrier integrity of skin. Our prior study identified miR-9 is a biofilm induced microRNA that targets adherens junction protein E-cadherin. We propose that miR-9 can target CTNND1 (Aim 1). The validation of miR targeting will be performed quantitative real time PCR, Western blot analyses, Argonaute 2 pull down assay and on bead assay. Thus, this proposal, fully based on the study of DFU patients, seeks to conduct a fully powered clinical study testing whether DFU with a history of biofilm infection closes with deficient barrier function (Aim 2). Aim 3 tests whether such functionally deficient wound closure, manifested as high TEWL, is associated with greater wound recurrence. Per FDA, the significance of association studies is heightened by support of a well-founded biological rationale provided by mechanistic studies22. This proposal rests on such mechanisms that have been reported by us in pre-clinical large animal studies18-20. The primary parent study will address molecular mechanisms implicated in biofilm-induced loss of skin epithelial barrier integrity in DFU patients.

• Study Type: Observational
• Enrollment (Estimated): 405

Contacts and Locations

• Study Contact: Name: Bryce Hockman, CCRP; Phone Number: 317 278 2715; Email: bbhockma@iu.edu
• Study Contact Backup: Name: Kaitlyn Depinet, FNP-C; Phone Number: 317 278 2747; Email: kdepinet@iu.edu

Study Locations

• United States
  • Arizona
    • Tucson, Arizona, United States, 85724
      • Terminated
      • University of Arizona
  • Pennsylvania
    • Cranberry Township, Pennsylvania, United States, 16066
      • Recruiting
      • UPMC Wound Healing Services at UPMC Passavant
      • Principal Investigator: Chandan K Sen, Phd

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

clinically diagnosed Diabetic Foot Ulcer (DFU) patients who are suspected to be infected will be recruited for this larger cohort of patients in the parent study.

Description

Inclusion Criteria:

• Male or Female, Age ≥ 18
• Willing to comply with protocol instructions, including all study visits and study activities.
• Patient with an open Diabetic Foot Ulcer
• Adequate arterial blood flow as evidenced by at least one of the following (for wounds below the knee):
• TcOM >30 mmHg
• Ankle-brachial index ≥0.7-1.20
• Toe pressure > 30 mmHg
• TBI > 0.6 mmHg

Exclusion Criteria:

• Individuals who are deemed unable to understand the procedures, risks, and benefits of the study.
• Wounds closed or to be surgically closed by flap or graft coverage
• Subjects with marked immunodeficiency (HIV/AIDS, or on immunosuppressive medications.
• TcOM < 30mmHg
• Diabetics with a hemoglobin A1c > 12 within 3 months prior to enrollment
• Subject with autoimmune connective tissue disease
• Ulcer size and location that does not allow the TEWL measurement per SOP
• Pregnant women
• Prisoners
• Unable to comply with study procedures and/or complete study visits

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Diabetic Foot Ulcer parent study; 405 clinically diagnosed Diabetic Foot Ulcer (DFU) patients who are suspected to be infected will be recruited . Wound swab for culture obtained. Baseline digital imaging of target wound(s). SF-12 Health survey, Visual Analogue Pain scale, Cardiff wound impact questionnaires. Wound site evaluation including TcOM/TBI/ankle brachial index (ABI) will be completed for subjects with wounds below the knee, if not already completed per standard of care within the previous 12 months. Hemoglobin A1c point of care testing will be drawn for diabetic subjects who do not have an A1c available within 90 days prior to enrollment; 3mm biopsy tissue or debrided tissue will be collected. Ideally, two tissue samples will be obtained; the subject's medical records will be reviewed and followed for up to 16 weeks or until their wound has closed, whichever comes first. The research staff will also call the patient or care facility as needed to check for wound closure.	Procedure: Observation of wound infection and time to wound closure; Observational: collecting data on length of time to wound closure
Imaging sub study- 40 subjects; All of the above items will be performed in this arm in addition to the below: Wound perfusion will also be measured by laser speckle imaging (LSI) using the Pericam PSI-NR instrument (Perimed Inc.). PeriCam PSI is a non-invasive non-contact device providing two-dimensional imaging of peripheral tissue blood perfusion. Reduced blood flow may lead to insufficient tissue oxygenation and, thus, assessment of peripheral vascular function has several clinical applications. The PeriCam PSI System is FDA 510(k) (#K063586) approved instrument imaging of peripheral tissue blood perfusion. The additional Pericam imaging for perfusion will be performed only in a small pilot cohort of n=40 patients at an IU site to compare this imaging modality with established modalities such as TcOM/TBI/ABI measurements performed within this study.	Device: Pericam PSI-NR Laser Speckle imaging; non-invasive non-contact device providing two-dimensional imaging of peripheral tissue blood perfusion. Reduced blood flow may lead to insufficient tissue oxygenation and, thus, assessment of peripheral vascular function has several clinical applications.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Aim 1	Determine how biofilm-induced DFU tissue microRNA's disrupt barrier function of the repairing DFU	16 weeks
Aim 2	Test the incidence of wound biofilm infection at initial visit and test its association with deficient skin barrier function at the closed DFU-site	16 weeks
Aim 3	Test whether closed DFU with deficient barrier function is associated with higher rate of recidivism	12 weeks

Collaborators and Investigators

• Sponsor: University of Pittsburgh
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); University of Arizona
• Investigators: Principal Investigator: Chandan K Sen, PhD, University of Pittsburgh

Study record dates

Study Major Dates

• Study Start (Actual): April 2, 2024
• Primary Completion (Estimated): June 27, 2027
• Study Completion (Estimated): June 27, 2029

Study Registration Dates

• First Submitted: December 12, 2021
• First Submitted That Met QC Criteria: December 12, 2021
• First Posted (Actual): December 29, 2021

Study Record Updates

• Last Update Posted (Actual): April 19, 2024
• Last Update Submitted That Met QC Criteria: April 16, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: wound infection; diabetic foot; diabetic foot ulcer; foot ulcer
• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Skin Diseases; Endocrine System Diseases; Disease Attributes; Diabetic Angiopathies; Leg Ulcer; Skin Ulcer; Diabetes Complications; Diabetes Mellitus; Diabetic Neuropathies; Foot Diseases; Diabetic Foot; Foot Ulcer; Infections; Communicable Diseases; Recurrence
• Other Study ID Numbers: STUDY23050116; 3R01DK125835-02S1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No