This trial is planed to study if allogeneic mesenchymal stem cells would be safe and beneficial in osteoarthritis of knee joint. This is a double blind study. Different doses of stem cells will be used in this study.

Inclusion Criteria:

1. Males or females in the age 40 - 70 years (both inclusive)
2. Radiographic evidence of grade 2 to 3 osteoarthritis based on the Kellgren and Lawrence radiographic criteria.
3. History of primary idiopathic osteoarthritis of the knee characterized by pain which requires intake of analgesics.
4. Self-reported difficulty in at least one of the following activities attributed to knee pain: lifting and carrying groceries, walking 400 metres, getting in and out of a chair, or going up and down stairs.
5. Patients who have been on stable medication which may be NSAIDs / Opioid or opiate analgesics, for the past three months.
6. Female patients of childbearing age must be willing to use accepted methods of contraception during the course of the study
7. Ability to provide written informed consent.

Exclusion Criteria:

1. Prior or ongoing medical conditions (e.g., concomitant illness, psychiatric condition, alcoholism, drug abuse), medical history, physical findings, ECG findings, or laboratory abnormality that, in the investigator's opinion, could adversely affect the safety of the subject, makes it unlikely that the course of treatment or follow-up would be completed, or could impair the assessment of study results.
2. History of surgery, or major trauma to the study joint
3. Arthroscopy on the study joint in the previous 12 months
4. Signs of active study joint inflammation including redness, warmth, and/or, if qualifying with osteoarthritis of the knee, a large, bulging effusion of the study knee joint with the loss of normal contour of the joint at the screening visit or at the baseline examination
5. Patients who had received intraarticular steroids or hyaluronan within the last three months.
6. Infections in or around the knee.
7. Patients awaiting a replacement knee or hip joint
8. Patients with other conditions that cause pain
9. Patients with deformity of the knee joint.
10. Significantly incapacitated or disabled and would be categorized as ACR Functional Class IV (largely or wholly incapacitated), or unable to walk without assistive devices
11. Patients with other known rheumatic or inflammatory disease such as rheumatoid arthritis
12. Other pathologic lesions on x-rays of knee
13. Positive hepatitis B surface antigen, hepatitis C antibody test, Anti human immunodeficiency virus (HIV) antibody test, or RPR
14. History of Bleeding disorders
15. Known hypersensitivity to Hyaluronan products or animal sera
16. For women of child-bearing potential: positive pregnancy test or lactating [Females who are planning pregnancy within next one year should be excluded]