Biomimetic microenvironment complexity to redress the balance between biodegradation and de novo matrix synthesis during early phase of vascular tissue engineering

- TP/gel nanofibers together with shear stress can influence behavior of SMCs.
- Application of shear stress resulted in greater SMC proliferation and more collagen synthesis.
- Application of shear stress led to the balance between biodegradation and matrix synthesis.
- SMC-seeded constructs exposed to shear stress showed higher mechanical properties.
- SMCs seeded on TP/gel nanofibers and exposed to shear stress preserved their contractility.

Physiological functionality of a tissue engineered vascular construct depends on the phenotype of smooth muscle cells (SMCs) cultured into the scaffold and mechanical robust of the construct relies on two simultaneous mechanisms including scaffold biodegradation and de novo matrix synthesis by SMCs which both can be influenced by scaffold properties and culture condition. Our focus in this study was to provide an appropriate environmental condition within tissue engineering context to meet foregoing requisites for a successful vascular regeneration. To this end, SMCs seeded onto electrospun Tecophilic/gelatin (TP(70)/gel(30)) scaffolds were subjected to orbital shear stress. Given the improvement in mechanical properties of dynamically stimulated cell-seeded constructs after a span of 10 days, effect of fluctuating shear stress on scaffold biodegradation and SMC behavior was investigated. Compared to static condition, SMCs proliferated more rapidly and concomitantly built up greater collagen content in response to dynamic culture, suggesting a reasonable balance between scaffold biodegradation and matrix turnover for maintaining the structural integrity and mechanical support to seeded cells during early phase of vascular tissue engineering. Despite higher proliferation of SMCs under dynamic condition, cells preserved nearly spindle like morphology and contractile protein expression likely thanks to composition of the scaffold.

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