*Article* **Highly E**ff**ective Fibrin Biopolymer Sca**ff**old for Stem Cells Upgrading Bone Regeneration**

**Camila Fernanda Zorzella Creste 1,2, Patrícia Rodrigues Orsi 1, Fernanda Cruz Landim-Alvarenga 3, Luis Antônio Justulin 4, Marjorie de Assis Golim 2, Benedito Barraviera 1,2 and Rui Seabra Ferreira Jr. 1,2,\***


Received: 11 May 2020; Accepted: 5 June 2020; Published: 17 June 2020

**Abstract:** Fibrin scaffold fits as a provisional platform promoting cell migration and proliferation, angiogenesis, connective tissue formation and growth factors stimulation. We evaluated a unique heterologous fibrin biopolymer as scaffold to mesenchymal stem cells (MSCs) to treat a critical-size bone defect. Femurs of 27 rats were treated with fibrin biopolymer (FBP); FBP + MSCs; and FBP + MSC differentiated in bone lineage (MSC-D). Bone repair was evaluated 03, 21 and 42 days later by radiographic, histological and scanning electron microscopy (SEM) imaging. The FBP + MSC-D association was the most effective treatment, since newly formed Bone was more abundant and early matured in just 21 days. We concluded that FBP is an excellent scaffold for MSCs and also use of differentiated cells should be encouraged in regenerative therapy researches. The FBP ability to maintain viable MSCs at Bone defect site has modified inflammatory environment and accelerating their regeneration.

**Keywords:** bioproduct; biomaterial; scaffold; fibrin; stem cell
