A Phase 1/2a to Evaluate the Safety and Efficacy of Adipose Tissue Allograft (BRC-OA) in Patients With Osteoarthritis of the Knee

The study will be conducted in two parts: * Part 1 (Safety Evaluation phase) - without control arm * Part 2 (Randomized Controlled phase) - with control arm In Part 1, six subjects will be treated with a 7-day staggering interval between each subject's enrollment. The initial 3 subjects will receive a 2 mL dose of BRCOA, and if deemed safe and well-tolerated by the investigator, the next 3 subjects will receive an 8 mL dose, also following a 7-day staggering interval to assess safety and tolerability. Once both dose levels (2 mL and 8 mL) are confirmed to be safe and tolerable, the study will advance to Part 2. In Part 2, a total of 36 subjects (12 subjects per arm) will be randomized 1:1:1 to three parallel arms to be administered via intraarticular injection of 2 mL or 8 mL of BRC-OA, or 2 mL of normal saline (control).