Safety of Extracellular Vesicles for Burn Wounds

1. Eighteen years of age or older with deep second degree thermal burn wounds
2. Index burn injury within the prior 72 hours
3. Subjects must understand and be willing and able to give written informed consent
4. Subjects must agree to have blood draws performed per protocol
5. Subjects must be accessible for wound treatment and assessment visits
6. Males and females must agree to use an acceptable method of contraception. Exceptions will be females of non-childbearing age and monogamous males who are partners of females of non-childbearing age. Acceptable methods of birth control include; history of sterilization, oral contraceptives, depo-progesterone injections, a barrier contraceptive such as a condom with or without spermicide cream or gel, diaphragms or cervical cap with or without spermicide cream or gel, or an intrauterine device (IUD).
7. Maximum index wound size at screening limited to single or multiple wounds (in a defined anatomical area) cumulatively ≤ 600 cm2. Minimum wound size at screening: 30 cm2. Other wounds may be present that are treated separately from this protocol subject to the maximum TBSA exclusion criteria listed below.

Exclusion Criteria:

1. Solely first degree or solely third degree burns
2. Cumulative burn area ≥ 20% TBSA (20% TBSA corresponds to 3700 cm2 in a 70 kg, 175 cm subject)
3. Burns that occur over a previous scar
4. Chemical, radiation, or electrical burns
5. Subjects with superficial second degree burn who are expected to heal within 2 weeks with standard therapy
6. Evidence of active infection at the wound site
7. Evidence of significant wound healing prior to treatment
8. Burn wounds requiring surgery (other than debridement), or skin grafting
9. Wound exclusively located in the area of fingers, toes, face, or perineum
10. Wound that extends > 50% across one or more joints
11. Have any requirement for the use of systemic steroids or immunosuppressive medications
12. Subjects allergic to human albumin, streptomycin, or penicillin
13. Be a pregnant female or nursing mother
14. Subjects who are known or found to be HIV positive
15. History of alcohol or substance abuse requiring treatment within the past 12 months.

16. Severe medical conditions

    1. Malignancy (other than non-melanoma skin cancer) not in remission or in remission less than 5 years
    2. Life expectancy less than two years
    3. Severe cardiopulmonary disease restricting ambulation to the clinical facility
17. WBC \<3 or > 20 x109/L, Hgb \< 9g/dL, platelet count 100x109/L or less, serum creatinine > 1.5 times the upper normal limit, AST or ALT > 2.4 times upper normal limit
18. Known history of coagulopathy
19. Subjects who have a reasonable likelihood of being a recipient of tissue or organ transplantation
20. History of poor compliance, unreliability