This study is designed to know the safety and efficacy of 2 different doses of mesenchymal stem cells in patients suffering from osteoarthritis of knee joint.

Inclusion Criteria:

1. Males or females in the age 20 - 70 years (both inclusive)
2. Radiographic evidence of grade 2 to 3 osteoarthritis based on the Kellgren and Lawrence radiographic entry 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 for the past three months.
6. Patients who have not received intra articular steroids or hyaluronan within the last three months.
7. Female patients of childbearing age must be willing to use accepted methods of contraception during the course of the study
8. 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, including arthroscopy, or major trauma to the study joint in the previous 12 months
3. 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
4. Infections in or around the knee.
5. Patients awaiting a replacement knee or hip joint
6. Patients with other conditions that cause pain
7. Significantly incapacitated or disabled and would be categorized as ACR Functional Class IV (largely or wholly incapacitated), or unable to walk without assistive devices
8. Patients with other known rheumatic or inflammatory disease such as rheumatoid arthritis
9. Other pathologic lesions on x-rays of knee
10. Positive hepatitis B surface antigen, hepatitis C antibody test, Anti human immunodeficiency virus (HIV) antibody test, or VDRL
11. History of Bleeding disorders
12. Known hypersensitivity to Hyaluronan products or animal sera
13. For women of child-bearing potential: positive pregnancy test or lactating