A Multi-center, Prospective Clinical Trial Evaluating the Combination of BlastX and Negative Pressure Wound Therapy (VAC).To evaluate the 4-week healing trajectory/wound area reduction with BlastX/VAC as compared with historical pre-study 4-week healing trajectory data and data from the US Wound Registry.

The study is a prospective, clinical trial designed to evaluate the combination of BlastX™ and VAC® in facilitating healing and reduction in bio-burden in pressure ulcers. After consenting, the ulcers of eligible subjects are treated with BlastX. After a 5 minute dwell time the wound VAC® is applied as per manufacturers guidelines. The subjects return to the center three times per week for dressing changes and application of BlastX. The duration of the trial is four weeks. Subjects undergo study procedures (biopsy for quantitative tissue culture, photography, fluorescence imaging and swabbing for protease testing) on a weekly basis. The standard of care for pressure ulcers will be continued including debridement, off-loading, and nutritional supplementation when appropriate.

Inclusion Criteria:

1. Adult patients with a Full Thickness Pressure Ulcer Stage 3 through Stage 4 without exposed bone of greater than or equal to one month in duration located on the trunk (Sacral, trochanteric, ischial or posterior heel).
2. A signed and dated informed consent form.
3. Subject is able to comply with instructions and scheduled visits.
4. Ulcer surface area >2cm2 and < 100cm2.
5. The patient is a candidate for negative pressure wound therapy.

Exclusion Criteria:

1.Subject or caregiver is unable to manage VAC®device OR the patient cannot return for VAC dressing changes OR the patient does not qualify for home health visits. 2.Subject has major uncontrolled medical disorders such as serious cardiovascular, renal, liver or pulmonary disease, lupus, palliative care or sickle cell anemia.

3.Subject currently being treated for an active malignant disease or subjects with history of malignancy within the wound.

4.The Subject has other concurrent conditions that in the opinion of the Investigator may compromise subject safety.

5.Known contraindications to VAC® or Blast-X® 6.Known allergies to any of the Blast-X®components 7.Concurrent participation in another clinical trial that involves an investigation drug or device that would interfere with this study.

8.Subject is pregnant or breast feeding. 9.Subjects with a history of more than two weeks treatment with immunosuppressants (including systemic corticosteroids >10mg daily dose), cytotoxic chemotherapy, or application of topical steroids to the ulcer surface within one month prior to first Screening Visit, or who receive such medications during the screening period, or who are anticipated to require such medications during the course of the study.

10.Index ulcer has been previously treated with tissue engineered materials (e.g. Apligraf® or Dermagraft®) or other scaffold materials (e.g. Oasis, Matristem) within the last 30 days preceding the first treatment visit.

11.Mini-nutritional assessment Malnutrition Indication score <17. 12.Patient does not have adequate 4-week historical data on comparison in change of wound measurements, photos, costs and supplies used.