Optimization of cardiac cell seeding and distribution in 3D porous alginate scaffolds

Abstract

Cardiac tissue engineering has evolved as a potential therapeutic approach to assist in cardiac regeneration. We have recently shown that tissue-engineered cardiac graft, constructed from cardiomyocytes seeded within an alginate scaffold, is capable of preventing the deterioration in cardiac function after myocardial infarction in rats. The present article addresses cell seeding within porous alginate scaffolds in an attempt to achieve 3D high-density cardiac constructs with a uniform cell distribution. Due to the hydrophilic nature of the alginate scaffold, its >90% porosity and interconnected pore structure, cell seeding onto the scaffold was efficient and short, up to 30 min. Application of a moderate centrifugal force during cell seeding resulted in a uniform cell distribution throughout the alginate scaffolds, consequently enabling the loading of a large number of cells onto the 3D scaffolds. The percent cell yield in the alginate scaffolds ranged between 60-90%, depending on cell density at seeding; it was 90% at seeding densities of up to 1 x 10(8) cells/cm(3) scaffold and decreased to 60% at higher densities. The highly dense cardiac constructs maintained high metabolic activity in culture. Scanning electron microscopy revealed that the cells aggregated within the scaffold pores. Some of the aggregates were contracting spontaneously within the matrix pores. Throughout the culture there was no indication of cardiomyocyte proliferation within the scaffolds, nor was it found in 3D cultures of cardiofibroblasts. This may enable the development of cardiac cocultures, without domination of cardiofibroblasts with time.

Cell colonization in degradable 3D porous matrices

“…28 One way to overcome the heterogeneity in natural matrices uses polymers to fabricate degradable 3D porous matrices. Scaffolds generated from natural polymers such as alginates, [29][30][31] chitosan, [32][33][34][35][36][37][38] collagen, 39 GAGs and elastin, [40][41][42][43] gelatin [44][45][46] and fibrin [47][48][49] have also been used as scaffolding materials. [50][51][52] A commonly used system is collagen/GAGs; 53,54 collagen/GAG based skin equivalents are already in clinical use 41,42 and under investigation for other applications such as heart valves, vascular grafts [55][56][57][58][59][60] and vascular networks.…”

A Rapid Seeding Technique for the Assembly of Large Cell/Scaffold Composite Constructs

“…15,16 Typically, in the passive seeding methods, cells are laid on top of the scaffold and allowed to infiltrate the scaffold over time. The primary advantage of passive seeding is that it is a simple process in which cells are not subjected to potentially damaging large mechanical forces, for example, high shear stresses, 17,18 resulting in a greater viability.…”

A review on electrospun bio-based polymers for water treatment

“…Alginate is a well-known polyelectrolyte binary copolymer derived from seaweeds/algae [199][200][201][202]. It contributes to the flexibility and strength of the seaweeds against adverse water forces.…”

“…This phenomenon has been exploited to prepare different morphologies and structures for certain applications. Beads [203], films [204,205], hydrogels [206], as well as porous membranes and nanofibers [200] were fabricated for different applications such as wound dressings and metal adsorption. There has been significant interest in the use of alginate in biomedical applications because of its antimicrobial efficiency and structural resemblance to glycosamineglycan (GAG) (one of the significant components of natural extracellular matrices (EMCs) found in mammalian tissues).…”