Bioprinting Oxygen Releasing Microparticles for Improved Cell Tissue Viability

A major challenge in regenerative medicine/tissue engineering is the difficulty of providing adequate oxygen to all cells within implanted engineered tissues before full vascularization is achieved. To overcome this limitation, a variety of oxygen-releasing particles have been developed to improve cell and tissue survival. However, most of these particles are used in random mixtures within scaffolding materials, which usually leads to an uneven distribution of oxygen in bioengineered tissues. An ideal oxygen supply requires a precise depositing control of oxygen-releasing particles in scaffolds. Cell bioprinting is a novel tissue fabrication approach, in which the bio-printer can be programmed to deposit cells and/or biomaterials of various types and sizes in a very precise manner. In this study we have applied the inkjet printing technology to deposit calcium peroxide (CaO2) using various designed concentrations. On top of that, a hydrogel was deposit to provide encapsulation enabling progressive oxygen release. Various rates were utilized searching for optimal cell viability and growth in a period of 10 days under hypoxic environment (~1%O2). This controlled oxygen-releasing platform (CaO2 - two printing times scaffold) increase levels of cell viability by approximately 300% in comparison to control samples without CaO2 present during the experiment. In consequence, these biomaterials were able to extend cell viability and growth under hypoxic conditions. Results indicate the use of bio-printing technology to precisely deposit oxygen exerting biomaterials in vitro. Such technology shows promising application in regenerative medicine/tissue engineering where currently oxygen diffusion limits the engineering of tissue implants