This study is a continuation of a previously approved protocol conducted at Ohio State University and Indiana University. The first two aims of the original protocol have been completed, and this protocol will finish enrollment for the third aim, comparing Hi TEWL and Low TEWL measurements, and whether a HiTEWLmeasurement indicates a seemingly healed wound is more likely to recur/reopen toa new wound.

Of the 105 desired subjects, 62 subjects have already been recruited and completed their study participation at the previous university. 43 additional subjects will be recruited to complete the enrollment goal here at the University of Pittsburgh.

In the United States, chronic wounds represent a major public health burden. Estimates put the number of chronic wounds cases at over 6.5 million with a cost burden of over $50 billion14. According to the current standard of care (SoC), wound closure is assessed visually. The FDA defines complete wound closure of chronic non-healing wounds as "skin closure (as assessed visually) without drainage or dressing requirements identified at two consecutive study visits that are 2 weeks apart" and requires therapeutic trials for chronic wounds to be designed such that the enrolled patients will be evaluated for at least 3 months following completeclosure19.

The expectation is that successful intervention should keep the wound closed for at least 90 days. This study contends that visual inspection of wounds is insufficient to certify closure - a critical endpoint that drives treatment decisions. Considering that almost two-thirds of all chronic wounds are estimated to be biofilminfected6, and the observation that biofilm-infected wounds may be visually closed but functionally (barrier function) open, the significance of the proposed hypothesis is substantial.

The proposed study has the clear potential to lay a strong rationale that would potentially change the wound care paradigm by requiring that measurement of skin barrier function be the new endpoint to define wound closure. Reported recurrence rates for most chronic ulcer types remain extremely high, ranging from 40-79%4,5, 24%-57% for venous ulcers, and upward of 60% for diabetic ulcers supporting the importance of preventive efforts1,2. In that context it is of extraordinary significance to ask whether "defective closure" (visually closed with TEWL (Trans-Epidermal Water Loss) >3x the value of intact skin; high TEWL) predicts poor post-closure outcome e.g. recurrence. These questions may only be meaningfully asked in a patient-based pilot and that is exactly the intent of Aim 2. Findings of the proposed pilot will inform a larger future trial.

Inclusion Criteria:

1. Age ≥ 18

2. Willing to comply with protocol instructions, including all study visits and study activities.

3. One of the following: Healed wound (within 10 days prior to consent/screening visit) that was previously a chronic wound of multiple etiologies and open for at least30 days, including:

   i. Diabetic foot ulcers, Wagner grade 1-3 ii. Pressure ulcers, stage 2-3 iii. Venous leg ulcers, confirmed by venous duplex iv. Burn wounds

4. If candidate has a diabetic foot ulcer, ABI score measurement at Visit 1 must be between 0.7 and 1.2. If score is below or above, candidate will be considered a screen fail. Score can be gathered from EMR in previous 3 months to visit 1 if done as SOC or completed during visit 1.

Exclusion Criteria:

1. Individuals who are deemed unable to understand the procedures, risks and benefits of the study, (i.e. unable to provide informed consent).
2. Subjects with marked immunodeficiency (HIV/AIDS, organ transplant patients and cancer patients and patients with autoimmune disease on immunosuppressive medications).
3. Wounds closed or to be closed by flap or graft coverage - including stage 4pressure ulcers and Wagner grade 4 or 5 diabetic foot ulcers.
4. Prisoners
5. Patients with allergies to petrolatum
6. Patients who are currently enrolled in another research study which includes investigational treatment and/or medication
7. Patients with an HbA1c score greater than 10.0 at Visit 1, will be considered a screen fail. Score can be gathered from EMR in previous 12 months to visit 1 if done as SOC, or completed during visit 1.

Final processed data will be shared.

January 8, 2019 - December 31, 2027

Data will be made available by the PI per Institution sharing policy and via published paper.