Construction of tissue-engineered vascular sinoatrial node in vitro

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Cardiovascular Biology

Background:

• Developing a biological pacemaker is crucial for treating bradyarrhythmias.
• Tissue engineering offers a promising approach to creating functional cardiac tissues.
• Vascularization is essential for the survival and function of engineered tissues.

Purpose of the Study:

• To differentiate rabbit bone marrow stromal cells (BMSCs) into vascular endothelial cells (VECs) and pacemaker-like cells.
• To construct a 3D vascularized sinoatrial node (SAN) in vitro using these differentiated cells.
• To evaluate the optimal cell co-culture ratio for forming functional vascularized constructs.

Main Methods:

• BMSCs were isolated and differentiated into VECs (CD31+/CD34+) and pacemaker-like cells (HCN2+/cTnT+) using specific induction media and sinoatrial node cell lysate.
• Differentiated VECs and pacemaker-like cells were co-cultured on Matrigel at varying ratios (1:1, 1:2, 2:1).
• Constructs were analyzed for cell distribution, network formation, and angiogenesis via histology and marker expression.

Main Results:

• BMSCs successfully differentiated into VECs and pacemaker-like cells, confirmed by specific cell surface and intracellular markers.
• The 1:1 co-culture ratio demonstrated optimal uniform cell distribution, robust network formation, and enhanced angiogenesis within the Matrigel scaffold.
• The study successfully created a 3D vascularized tissue-engineered SAN in vitro.

Conclusions:

• Rabbit BMSCs can be effectively differentiated into functional VECs and pacemaker-like cells.
• Co-culturing these differentiated cells in a 1:1 ratio on Matrigel supports the development of a vascularized, tissue-engineered SAN.
• This research presents a significant advancement towards the development of a functional biological pacemaker.