Methods and compositions for optimized expansion and implantation of mesenchymal stem cells

A method of expanding mesenchymal stem cells (MSC) in vitro for use in an implant to regenerate cartilage, the method comprising:

• (a) obtaining mesenchymal stem cells (MSCs) from an older patient in the 5th to 7th decade of life who is diagnosed with osteoarthritis, avascular necrosis, or severe degenerative joint disease;
• (b) expanding the MSCs with a growth medium comprising the patient's platelet lysate in an initial amount of 10% of the growth medium for at least one passage to obtain at least 10 million to 100 million cells;
• (c) determining whether the MSCs of step (b) are outside the scope of one or more of the following parameters:
• (i) a doubling time of about 1 to about 3 days;
• (ii) cellular confluence greater than about 27 calculated according to the equation
• Surface area×(% Confluence)/Cell Number;
• (iii) random distribution of MSCs as a monolayer culture;
• or
• (iv) greater than 30% of MSCs without a spindle shape;
• and
• (d) adjusting the growth medium in the following passages wherein the MSC are outside of the scope of at least one parameter in step (c) by increasing the amount of platelet lysate in the growth medium to between 15-20% platelet lysate;
• wherein the expanded MSCs are capable of regenerating new cartilage when implanted into the patient at a site in need thereof no later than the tenth ex-vivo passage.