This is a randomized, blinded, placebo and standard of care controlled study of the efficacy of a novel antibiotic containing gel compared to placebo gel in preventing surgical site infection after abdominal surgery. patients will be randomized to active or placebo gel in a double-blind manner. The gel will be applied a single time in the incision during closure at the end of surgery. A cohort of patients will also be randomized to standard of care, saline irrigation at prior to skin closure, in an open manner. The efficacy, safety and tolerability of the active gel will be assessed compared to the control group (combined placebo gel and standard of care groups). Patients will be randomized to DFA-02 active gel: placebo gel: standard of care in a 4:1:1 ratio.

Inclusion Criteria:

1. Males and females 18 years of age or older;
2. If female, the subject must be postmenopausal, surgically sterilized or, if of child-bearing potential, she must have a negative serum or urine pregnancy test within 48 hours of surgery and agree to use adequate birth control during the study and for 30 days after the administration of study agent;
3. Body mass index (BMI) ≥ 20;
4. Scheduled to undergo non-emergent abdominal surgery involving a planned incision of 7 cm or greater;
5. Willing and able to give informed consent;
6. Available for evaluation from Baseline until final evaluation at 30 days post-surgery.

Exclusion Criteria:

1. Known hypersensitivity to gentamicin, vancomycin, other aminoglycoside antibiotics or the excipients of the study products;
2. Emergency surgery;
3. Significant concomitant surgical procedure;
4. Prior laparotomy within the last 60 days of the planned procedure;
5. Planned second laparotomy or abdominal surgical procedure within 30 days of the planned first procedure;
6. Expectation that a surgical drain will be placed in the incision;
7. Preoperative sepsis, severe sepsis, or septic shock;
8. Abdominal wall infection/surgical site infection from previous laparotomy/laparoscopy or for any reason;
9. Active systemic infection or systemic (oral or intravenous) antibiotic therapy within the 1 week prior to the date of surgery other than specified preoperative antimicrobial prophylaxis;
10. Requirement for gentamicin or vancomycin preoperative antimicrobial prophylaxis;
11. Concurrent systemic use of other potentially neurotoxic, nephrotoxic, and/or ototoxic drugs;
12. Preoperative evaluation suggesting an intra-abdominal process that might preclude full closure of the skin;
13. Ongoing treatment (e.g. chemotherapy, radiation) for non-colorectal cancer;
14. History of significant drug or alcohol abuse;
15. Serum Creatinine > 1.8 mg/dL;
16. Serum Bilirubin > 2.5 times upper limit of normal;
17. Subjects who are immunocompromised including but not limited to systemic corticosteroid use or chemotherapy/radiation during the 30 days prior to surgery, organ transplantation, or HIV infection;
18. Known history of HIV;
19. Pregnant or lactating, or if of childbearing potential not practicing a birth control method with a high degree of reliability;
20. Refusal to accept medically indicated blood products;
21. Participation within 30 days before the start of this study in any experimental drug or device study, or currently participating in a study in which the administration of investigational drug or device within 60 days is anticipated;
22. Unable to participate in the study for any reason in the opinion of the Principal Investigator;
23. Postsurgical life expectancy of less than 30 days;
24. Expected discharge from the hospital less than 3 days after surgery.