Living bacterial sacrificial porogens to engineer decellularized porous scaffolds.

Feng Xu,Banupriya Sridharan,Utkan Demirci,Naside Gozde Durmus,Shuqi Wang,Ahmet Sinan Yavuz,Umut Atakan Gurkan,Che John Connon

doi:10.1371/journal.pone.0019344

Abstract

Decellularization and cellularization of organs have emerged as disruptive methods in tissue engineering and regenerative medicine. Porous hydrogel scaffolds have widespread applications in tissue engineering, regenerative medicine and drug discovery as viable tissue mimics. However, the existing hydrogel fabrication techniques suffer from limited control over pore interconnectivity, density and size, which leads to inefficient nutrient and oxygen transport to cells embedded in the scaffolds. Here, we demonstrated an innovative approach to develop a new platform for tissue engineered constructs using live bacteria as sacrificial porogens. E.coli were patterned and cultured in an interconnected three-dimensional (3D) hydrogel network. The growing bacteria created interconnected micropores and microchannels. Then, the scafold was decellularized, and bacteria were eliminated from the scaffold through lysing and washing steps. This 3D porous network method combined with bioprinting has the potential to be broadly applicable and compatible with tissue specific applications allowing seeding of stem cells and other cell types.

Highlights

Porous materials are of scientific and technological interest and find broad applications in multiple areas such as storage, separation, catalytic technologies as well as emerging microelectronics and medicine [1,2,3,4,5]
The optimal pore size of porous hydrogels has been shown to be in the range of 100–400 mm for cell seeding and tissue engineering applications [11,12,13,14] and,100 mm for other applications including wound healing and vascularization (5–15 mm) [16]
To investigate the growth characteristics of porogens encapsulated in hydrogels (1% and 2% agarose), we monitored colony size and density over time (0–96 hours for 1% agarose and 0– 240 hours for 2% agarose), Figure 2

Summary

Introduction

Porous materials are of scientific and technological interest and find broad applications in multiple areas such as storage, separation, catalytic technologies as well as emerging microelectronics and medicine [1,2,3,4,5]. In the 2% agarose gel, the colony size (,20 mm diameter) was similar to that in 1% agarose during the first 6 hours of culture (Fig. 2b). We observed that there was no significant change of colony size and pore diameters in 2% hydrogels (in the range from 18.1 mm to 24.5 mm) with culture time and the initial bacterial concentration (p.0.05, Fig. 2f).

Results

Conclusion