Mesenchymal Stem Cells for The Treatment of Knee Osteoarthritis (KOA).

Inclusion Criteria:

1. Ambulatory subjects with osteoarthritis of the knee with symptoms for at least 3months, that may be taking conservative therapy (e.g. oral anti-inflammatorymedication), and/or undergoing physical therapy. In subjects with bilateral kneeosteoarthritis, the more symptomatic knee will be the target knee.
2. Subjects of age between ≥40 through ≦ 90 years.
3. Subject diagnosed with knee osteoarthritis of grade II and III according to theKellgren-Lawrence Grading Scale on the target knee.
4. Subject with joint pain equal or greater than 7 (total pain score 24 point) on thetarget knee assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
5. Subject or legal guardian is willing to provide written informed consent toparticipate in the study after reading the informed consent form and the informationprovided, and has had the opportunity to discuss the study with the investigator ordesignee.
6. Women of child-bearing potential should have a negative urine pregnancy test prior toadministration of investigational product, and the subject must agree within at least 4 weeks after the study administration to use a double barrier method of birthcontrol.UNLESS they meet the following criteria:(1) Post-menopausal: 12 months ofnatural (spontaneous) amenorrhea or 6 months of spontaneous amenorrhea with serumFollicle Stimulating Hormone (FSH) levels > 40mIU/mL, OR; (2) 6 weeks post-surgicalbilateral oophorectomy with or without hysterectomy.
7. If a male and heterosexually active with a female of childbearing potential, thesubject must agree within at least 4 weeks after the study administration to use adouble barrier method of birth control (or must have been surgically sterilized) andto not donate sperm.

Exclusion Criteria:

1. Subjects with body mass index (BMI) over 40.
2. Subjects with knee deformity (knee varus or valgus greater than 10 degrees) on thetarget knee.
3. Subjects with acute inflammation or tense effusion (e.g., infection), or bleeding onthe target knee as judged by principal investigator (PI).
4. Subjects with ligament instability (cruciate ligaments or collateral ligaments) orligament laxity of the target knee as judged by PI.
5. Subjects with a history of surgery of articular injury, ligament reconstruction andmeniscus repair on the target knee joint within previous 6 months.
6. Subjects with history of arthroscopic surgery in the target knee in the past 6 monthsor planned to have arthroscopy surgery during the trial period (e.g., scheduledfor/awaiting arthroscopy or a knee replacement procedure)
7. Subjects with history of knee replacement procedure on the target knee.
8. Subjects with intra-articular infiltration of any treatments on the target knee (suchas hyaluronic acid, corticosteroids or platelet rich plasma (PRP)) in the last 3months prior to study inclusion.
9. Subjects with known history of osteoarthritis of hip or ankle.
10. Subjects with known history of any systemic autoimmune rheumatic disease including butnot limited to: Reiter's syndrome, rheumatoid arthritis, psoriatic arthritis,ankylosing spondylitis, lymphoma, arthritis associated with inflammatory boweldisease, sarcoidosis or amyloidosis.
11. Subjects with Rheumatoid Factor levels (>15.9 IU/mL) in laboratory tests.
12. Subjects with joint diseases (except knee osteoarthritis) or infectious arthritis onthe target knee considered by investigator not eligible to enter the study.
13. Subjects who are known to be infected with HIV.
14. Subjects with active hepatitis B or active hepatitis C.
15. Subjects who have a significant concomitant illness as judged by principalinvestigator (PI) including, but not limited to:
16. Severe renal insufficiency (eGFR < 30 mL/min/1.73 m2); or
17. hepatic (e.g. Child-Pugh Class C); or
18. Severe congestive heart failure (NYHA class 3 and 4); or
19. Severe pulmonary dysfunction, including severe chronic obstructive pulmonarydisease (COPD) and history of lung resection; or
20. Any type of malignancy; or
21. Uncontrolled Diabetes Mellitus (HbA1c > 10%)
22. Subjects with uncorrected hematology test including, but not limited to:
23. Hemoglobin < 8 g/dl; or
24. White blood cell count < 3,000/mm3; or
25. International normalized ratio (INR) of Coagulopathy >1.5; or
26. Platelet count < 80,000/mm3
27. Subjects who have the following conditions in laboratory tests:
28. >2 × upper limit of normal for alanine aminotransferase (ALT) or aspartateaminotransferase (AST) ; or
29. Total bilirubin > 1.5 mg/dl
30. Subjects with known history of allergy or hypersensitivity to any component ofinvestigational product, including dimethyl sulfoxide, cell therapies, or hyaluronicacid.
31. Subjects with known history of allergy or hypersensitivity to any concomitantmedications, or rescue medications.
32. Subjects who have a significant skin disease at the injection site on target knee asjudged by principal investigator (PI).
33. Subjects who are pregnant (or planning to become pregnant within 2 years ofinvestigational product treatment) or lactating.
34. Participation in another clinical trial or treatment (e.g., immunosuppressanttherapies, systemic steroids, cytotoxic drugs, chemotherapy, radiation therapy, newinvestigational drugs or cell therapy) within 3 months prior to inclusion in thestudy.
35. Contraindication to MRI:

• Indwelling medical devices such as pacemakers, aneurysm clip, etc.
• Indwelling metal from any other cause (trauma, etc.). To be excluded with historyand/or radiographs, as necessary

24. Other pathologic conditions or circumstances that difficult participation in the studyaccording to medical criteria.