The purpose of this study is to determine the safety of a biological therapeutic PEP in participants who have skin graft donor site wounds.

This is an open label phase 1b study of PEP (a leukocyte depleted blood preparation derived from human U.S. sourced pooled apheresed platelets) in patients with at least two donor split-thickness skin graft wounds. One donor site will be treated with the standard post-operative dressing, while the other site will be treated with PEP or PEP+TISSEEL and covered with a standard dressing. TISSEEL is a commercially available fibrin sealant.

Main Criteria for Inclusion:

1. Males and females 18-75 years of age.

2. Requiring at least two 20-40 cm2 split-thickness skin grafts by a licensed surgeon or dermatologist

3. Skin graft that meets all the following criteria:

   1. Each graft site has a size of 20-40 cm2 (but can be up to 90 cm2 if found to be clinically indicated during the graft procedure)
   2. Located anywhere on the body (with exception of oral mucosal membranes)
   3. Split-thickness skin graft wound depth of between 8/1000-14/1000 inch
   4. Study donor sites are ≥ 1 cm apart

4. Ability to safely undergo skin graft harvest procedure

5. Capacity to provide informed consent

6. Ability to comply with protocol

7. Subject is judged, by the clinical investigator, to be healthy as evidenced by lack of clinically significant abnormal findings on medical history, physical examination, vital signs, and clinical laboratory tests

8. Subject is able and willing to return to study site for all follow-up visits

Main Criteria for Exclusion:

1. Actively undergoing chemotherapy treatment (localized radiation treatment is allowed if it is not on the skin graft donor site and no active cancer is present)
2. Known history of MRSA (methicillin-resistant Staphylococcus aureus)
3. Known hypersensitivity to aprotinin (Trasylol®)
4. Subjects who are positive for hepatitis B surface antigen (HbsAg), hepatitis C antibody or human immunodeficiency virus (HIV)
5. Any known allergy or sensitivity to adhesive dressings (e.g., Tegaderm)
6. Clinically significant cardiovascular, pulmonary, renal, endocrine, hepatic, neurological, psychiatric, immunological, gastrointestinal, hematological, or metabolic disease that is, in the opinion of the investigator, not stabilized or may otherwise impact the results of the study
7. Participation in another interventional clinical study or trial in the past 30 days or concurrent participation in another interventional clinical study or trial
8. Subjects with poorly controlled diabetes mellitus (Hemoglobin A1c [HbA1c] ≥ 8%)
9. Subjects with known peripheral neuropathy, or known concomitant vascular problems (such as peripheral artery disease, arterial insufficiency, or venous hypertension) or calciphylaxis
10. Subjects with burns covering ≥ 30% of Total Body Surface Area
11. Currently on or planned to receive hyperbaric wound therapy
12. Pregnant or lactating female subjects
13. Sexually active woman of childbearing potential who is unwilling to use approved contraception method for 3 months after receiving dose of investigational drug
14. Prisoners