Oxygen-Generating Scaffolds for Cardiac Tissue Engineering Applications

Abstract

Homogeneous vascularization of implanted tissue constructs can extend to 5 weeks, during which cell death can occur due to inadequate availability of oxygen. Researchers are engineering biomaterials that generate and release oxygen in a regulated manner, in an effort to overcome this hurdle. A main limitation of the existing oxygen-generating biomaterials is the uncontrolled release of oxygen, which is ultimately detrimental to the cells. This study demonstrates the incorporation of calcium peroxide (CaO 2 ) within a hydrophobic polymer, polycaprolactone (PCL), to yield composite scaffolds with controlled oxygen release kinetics sustained over 5 weeks. Oxygen-generating microparticles coencapsulated with cardiomyocytes in a gelatin-based hydrogel matrix can serve as model systems for cardiac tissue engineering. Specifically, the results reveal that the oxygen-generating microspheres significantly improve the scaffold mechanical strength ranging from 5 kPa to 35 kPa, have an average scaffold pore size of 50−100 μm, swelling ratios of 33.3−29.8%, and degradation with 10−49% remaining mass at the end of a 48 h accelerated enzymatic degradation. The oxygen-generating scaffolds demonstrate improvement in cell viability, proliferation, and metabolic activity compared to the negative control group when cultured under hypoxia. Additionally, the optimized oxygen-generating constructs display no cytotoxicity or apoptosis. These oxygen-generating scaffolds can possibly assist the in vivo translation of cardiac tissue constructs.

Injectable Antioxidant and Oxygen-Releasing Lignin Composites to Promote Wound Healing

“…A recent study utilized microparticles (MPs) formed with the encapsulation of CaO 2 in PCL (polycaprolactone). These particles are incorporated in composites with GelMA and release O 2 for up to 5 weeks . Over 2 weeks, 2.5 μM of H 2 O 2 is released without the formation of MPs, whereas 1.0 μM of H 2 O 2 is released with the formation of MPs.…”

“…These particles are incorporated in composites with GelMA 39 and release O 2 for up to 5 weeks. 40 Over 2 weeks, 2.5 μM of H 2 O 2 is released without the formation of MPs, whereas 1.0 μM of H 2 O 2 is released with the formation of MPs. With 5 to 20 mg/mL of CaO 2 , the cumulative release of O 2 is 25% without MP and up to 30% with MP.…”

Engineering Antioxidant and Oxygen-Releasing Lignin Composites to Promote Wound Healing

“…Injectable cryogels are formed with methacrylated hyaluronic acid and CaO 2 [89]. Cumulative release of H 2 O 2 is up to 468 μmol over 3 h. Microparticles (MPs) are formed with the encapsulation of CaO 2 in PCL, then formed composites with GelMA[90] and release O 2 up to 5 weeks[91]. Over 2 weeks, 2.5 μM of H 2 O 2 is released without the formation of MPs while 1.0 μM with the formation of MPs.…”

Hydrogels for the Treatment of Myocardial Infarction: Design and Therapeutic Strategies

“…Further studies are needed to ensure their safety, feasibility, and efficacy, and to optimize their formulation and delivery strategy to further enhance their therapeutic potential. [187,188] The hydrogel can be loaded with oxygen-generating compounds, allowing it to act as a carrier of oxygen to the ischemic tissue, generating oxygen through specific triggering conditions and relieving hypoxia to enhance tissue repair. The hydrogel matrix acts as a scaffold to retain and release oxygen within the ischemic tissue and promote oxygen diffusion to surrounding cells.…”

“…Further studies are needed to ensure their safety, feasibility, and efficacy, and to optimize their formulation and delivery strategy to further enhance their therapeutic potential. [ 187,188 ]…”