This disclosure relates to compositions comprising a fibrin polymer produced by mixing platelet lysates with a minimal essential medium and thrombin. Typically, an optimized concentration of a calcium salt is utilized. In certain embodiments, the disclosure contemplates compositions comprising a fibrin polymer made by processes disclosed herein that contains cells, endothelial cells, stem cells, adipose tissue derived stem cell (ASC), and/or human mesenchymal stem cells (MSCs). In certain embodiments, the disclosure contemplates uses of composition disclosed herein containing cells, or cells replicated in compositions reported herein, to improve vascularizing, repairing, and healing of a tissue due to an ischemic condition or injury.