Revolutionizing Bone Regeneration and Wound Healing: Mechanical Stromal Vascular Fraction and Hyaluronic Acid in a Mouse Calvaria Defect Model

Riccardo Ossanna¹Lindsey Alejandra Quintero Sierra¹Sara Ghazanfar Tehrani¹Vivekanand Jha¹Chiara Curatola¹Alice Busato²Anita Conti¹Giamaica Conti¹Nicola Zingaretti³Pier Camillo Parodi³Francesco De Francesco^4*Michele Riccio⁴Andrea Sbarbati¹

• ¹University of Verona, Verona, Veneto, Italy
• ²Aptuit (Italy), Verona, Veneto, Italy
• ³Department of Medicine, University of Udine, Udine, Italy
• ⁴Azienda Ospedaliero Universitaria Ospedali Riuniti, Ancona, Italy

The Stromal Vascular Fraction (SVF) is a complex and heterogeneous suspension derived from adipose tissue, containing both cellular and non-cellular components. Its cellular fraction includes adipose-derived stem cells (ASCs), endothelial precursor cells, pericytes, macrophages, lymphocytes, and smooth muscle cells. The acellular 'secretome' of SVF includes bioactive molecules such as growth factors, cytokines, chemokines, extracellular vesicles, and fragments of extracellular matrix (ECM), which contribute to its regenerative potential. Bone defeatures can be stimulated by mesenchymal stem cells that differentiate into osteoblast for healing process and repairment. In addition to the cell content, the Stromal Vascular Fraction highly contains growth factors, cytokines and chemokines, extracellular vesicles, and extracellular matrix components, that could stimulate regenerative processes by a trophic effect. Studies showed that Hyaluronic Acids are usually involved in healing processes. This study was focused on the healing potency of stromal stem cells isolated from adipose tissues by mechanical digestion and role of Low Molecular Weight Hyaluronic Acid (ACP) in the healing process was tested in calvaria defeatures in mouse model, in comparison with enzymatic digestion method. Bone healing and remodeling process was in-vivo evaluated by Magnetic Resonance Imaging up to 15 days post treatment and differences of quality in bone regeneration were assessed by ex vivo Histological analysis, Immunofluorescences, and ultrastructural analysis. The bone matrix formed after treatment in HT-SVF+ACP (Mechanical Digestion Hy Tissue Stromal Vascular Fraction + Hyaluronic Acid) was compared to ED-SVF+ACP (Enzymatic Digestion Stromal Vascular Fraction + Hyaluronic Acid) and Saline group as a control group. This study explores a groundbreaking approach using mechanically processed stromal vascular fraction (HT-SVF) combined with Low Molecular Weight Hyaluronic Acid (ACP) to promote bone regeneration. Through comparative analysis with enzymatically processed SVF (ED-SVF) in a calvaria defect mouse model, we demonstrate the superior efficacy of HT-SVF + ACP in enhancing bone healing, reducing fibrotic tissue, and improving bone matrix maturity. The findings establish the potential of HT-SVF as a cost-effective and efficient method for bone regenerative therapy.