Sterilizing tissue-materials using pulsed power plasma.
This paper investigates the potential of pulsed power to sterilize hard and soft tissues and its impact on their physico-mechanical properties. It hypothesizes that pulsed plasma can sterilize both vascular and avascular tissues and the transitive layers in between without deleterious effects on their functional characteristics. Cartilage/bone laminate was chosen as a model to demonstrate the concept, treated at low temperature, at atmospheric pressure, in short durations and in buffered environment using a purposed-built pulsed power unit. Input voltage and time of exposure were assigned as controlling parameters in a full factorial design of experiment to determine physical and mechanical alteration pre- and post-treatment. The results demonstrated that, discharges of 11 kV sterilized samples in 45 s, reducing intrinsic elastic modules from 1.4 ± 0.9 to 0.9 ± 0.6 MPa. There was a decrease of 14.1 % in stiffness and 27.8 % in elastic-strain energy for the top quartile. Mechanical impairment was directly proportional to input voltage (P value < 0.05). Bacterial inactivation was proportional to treatment time for input voltages above 32 V (P < 0.001; R Sq = 0.98). Thermal analysis revealed that helix-coil transition decelerated with exposure time and collagen fibrils were destabilized as denaturation enthalpy reduced by 200 μV. We concluded by presenting a safe operating threshold for pulsed power plasma as a feasible protocol for effective sterilization of connective tissues with varying level of loss in mechanical robustness which we argue to be acceptable in certain medical and tissue engineering application.
Biomechanics Group, School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Ashkan
A
Heidarkhan Tehrani
Pooya
P
Davari
Sanjleena
S
Singh
Adekunle
A
Oloyede
D000818:Animals; D001672:Biocompatible Materials; D001698:Biomedical Engineering; D055592:Biophysical Phenomena; D001842:Bone and Bones / Q000382:microbiology / Q000502:physiology; D002356:Cartilage / Q000382:microbiology / Q000502:physiology; D002417:Cattle; D003238:Connective Tissue / Q000382:microbiology / Q000502:physiology; D055119:Elastic Modulus; D011211:Electric Power Supplies; D005240:Feasibility Studies; D006801:Humans; D058626:Plasma Gases; D013242:Sterilization / Q000295:instrumentation / Q000379:methods*; D023822:Tissue Engineering
D001672:Biocompatible Materials; D058626:Plasma Gases