Biogenic Polymers for Congenital Cardiac Surgery: In Vitro Durability Testing.

Objectives
Currently available materials in congenital cardiac surgery (CCS) are far from optimal, as they do not facilitate growth, remodelling, or renewal, resulting in poorer long-term outcomes due to material-related limitations. Bacterial cellulose (BC), a biogenic polymer-based material produced by Acetobacter xylinum, has emerged as a promising alternative exhibiting excellent bio- and hemocompatibility. This study aimed to develop BC specifically for application in CCS by modifying culturing conditions to enhance its biomechanical resilience.Methods
BC was produced according to a standard protocol, and its biomechanical properties were evaluated using inflation pressure testing, thickness measurement, and uniaxial tensile testing. To improve these characteristics, two modifications, a change in the growth media composition and an extended incubation time, were implemented and subsequently evaluated in five further test series. The long-term durability of BC patches was assessed in a fatigue tester for 20 ± 0.5 million cycles, and potential structural damage was investigated using scanning electron microscopy.Results
Utilizing the two modifications, BC patches demonstrated a capability to reach and maintain pressures exceeding 1000 mmHg with a durability of 100% (n = 24), compared to the standard 20.8% (n = 24) at 500 mmHg. The maximum tensile strength was enhanced from 0.311 ± 0.057 megapascal (MPa) to 0.986 ± 0.397 MPa (p < 0.0001), with a thickness of 3.89 ± 0.95 mm (p < 0.0001). In the long-term durability testing patches endured durations equaling six months without failure while retaining structural integrity.Conclusions
The potential of BC for use in CCS was demonstrated by enhancing its biomechanical properties through culturing modifications, warranting further investigation and development of the biomaterial.