Lyopreserved amniotic membrane is cellularly and clinically similar to cryopreserved construct for treating foot ulcers

Abstract

We compared cellular viability between cryopreserved and lyopreserved amniotic membranes and clinical outcomes of the lyopreserved construct in a prospective cohort study of 40 patients with neuropathic foot ulcers. Patients received weekly application of lyopreserved membrane for 12 weeks with standard weekly debridement and offloading. We evaluated the proportion of foot ulcers that closed, time to closure, closure trajectories, and infection during therapy. We used chi-square tests for dichotomous variables and independent t-tests for continuous variables with an alpha of α = .10. Cellular viability was equivalent between cryo-and lyopreserved amniotic tissues. Clinically, 48% of subjects' wounds closed in an average of 40.0 days. Those that did not close were older (63 vs 59 years, P = .011) and larger ulcers at baseline (7.8 vs 1.6 cm 2 , P = .012). Significantly more patients who achieved closure reached a 50% wound area reduction in 4 weeks compared with non-closed wounds (73.7% vs 47.6%, P = .093). There was no difference in the slope of the wound closure trajectories between closed and non-closed wounds (0.124 and 0.159, P = .85), indicating the rate of closure was similar. The rate of closure was 0.60 mm/day (SD = 0.47) for wounds that closed and 0.50 mm/day (SD = 0.58) for wounds that did not close (P = .89).

Industrial Biotechnology Conservation Processes: Similarities with Natural Long-Term Preservation of Biological Organisms

“…Cryopreservation and lyophilization deal with extremely low temperatures, multiple physical states of water, and multiple water phase transition types (e.g., freezing, thawing, sublimation). Both conservation processes have been extensively and successfully employed in biotechnological, pharmaceutical, or food industries and in human medical transplantation workflows [ 13 , 14 , 15 , 16 , 17 , 18 ]. Specifically, notable biotechnological applications comprise the successful long-term storage of biological samples and products, with a reversible quasi-arrest of metabolic activities (e.g., cryogenic cell storage in liquid nitrogen).…”

Contemporary Review: The Use of Human Placental Tissues in Foot and Ankle Surgery

“…Despite this, AM use continues to increase. 42,46,54 AMs have been used in various procedures, such as the management of refractory diabetic foot ulcers 12,39,42,46,50,52 and tendinopathy, 5 as well as the treatment of arthritis 35 and plantar fasciitis. 7,54 Although a previous review outlined the use of AM in foot and ankle surgery, 26 additional literature has been produced since the time of this writing in 2015.…”