Seltoplasmid Plus Revascularization for Diabetic Infrapopliteal Chronic Limb-Threatening Ischemia

The goal of this clinical trial is to learn whether Seltoplasmid Injection can improve outcomes after lower-extremity revascularization. Revascularization is a procedure used to restore blood flow to the leg. The study will include adults with type 2 diabetes, a foot ulcer caused by poor blood flow, and disease mainly affecting the arteries below the knee. The main questions are: * Does adding Seltoplasmid lower the risk of major amputation, another procedure to restore blood flow, or death? * What medical problems occur after treatment with Seltoplasmid? About 180 participants will undergo standard lower-extremity revascularization. After the procedure, eligible participants will be assigned by chance to one of two groups. One group will receive Seltoplasmid plus standard care. The other group will receive standard care alone. Participants in the Seltoplasmid group will receive injections into the muscles of the affected lower leg. The injections will be given on Day 0, Day 14, and Day 28. Participants will be followed for 12 months. Researchers will also assess wound healing, survival without amputation, heart and blood vessel problems, pain, and blood flow in the affected leg.