Is It Possible to Create a “Mechanical” Arteriovenous Fistula in Hemodialysis Patients?

The effect of source animal age, decellularization protocol, and sterilization method on bovine acellular dermal matrix as a scaffold for wound healing and skin regeneration

BACKGROUND

Healing the full-thickness skin wounds has remained a challenge. One of the most frequently used grafts for skin regeneration is xenogeneic acellular dermal matrices (ADMs), including bovine ADMs. This study investigated the effect of the source animal age, enzymatic versus non-enzymatic decellularization protocols, and gamma irradiation versus ethylene oxide (EO) sterilization on the scaffold.

METHODS

ADMs were prepared using the dermises of fetal bovine or calf skins. All groups were decellularized through chemical and mechanical methods, unless T-FADM samples, in which an enzymatic step was added to the decellularization protocol. All groups were sterilized with ethylene oxide (EO), except G-FADM which was sterilized using gamma irradiation. The scaffolds were characterized through scanning electron microscopy, differential scanning calorimetry, tensile test, MTT assay, DNA quantification, and real-time PCR. The performance of the ADMs in wound treatment was also evaluated macroscopically and histologically.

RESULTS

All ADMs were effectively decellularized. In comparison to FADM (EO-sterilized fetal ADM), morphological, and mechanical properties of G-FADM, T-FADM, and CADM (EOsterilized calf ADM) were changed to different extents. In addition, the CADM and G-FADM were thermally more stable than the FADM and T-FADM. Although all ADMs were noncytotoxic, the wounds of the FADM, T-FADM, and G-FADM groups were contracted to almost 30.0% of the original area on day 7, significantly faster than the CADM (17.5% ± 1.7) and control (12.2% ± 1.59) groups. However, by day 21, all ADMs were mostly closed except for the untreated group (60.1 ± 1.8).

CONCLUSION

Altogether, fetal source and EO-sterilized samples performed better than calf source and gamma-sterilized samples unless in some mechanical properties. There was no added value in using enzymatic treatment during the decellularization process. Our results suggest that the age, decellularization, and sterilization methods of animal source should be selected based on the clinical requirements.

Renal Transplantation by Automatic Anastomotic Device in a Porcine Model

Automatic vascular staplers for vascular anastomoses in kidney transplantation may dramatically reduce the operative time and, in particular, warm ischemia time, thus increasing the outcome of transplantation. Ten pigs underwent kidney auto-transplantation by automatic anastomotic device. Kidneys were collected by laparotomy with selective ligations at the renal hilum and perfused with cold storage solution. To overcome the shortage in length of renal hilum, a tract of the internal jugular vein was harvested to increase the length of the vessels. The anastomoses were totally performed by the use of the anastomotic device. On 10 kidney transplants, nine were successful and no complications occurred. Renal resistive indexes showed a slight increase in the immediate postoperative period returning normal at 10 days of follow-up. We demonstrated the possibility to perform renal vascular anastomoses by means of an automatic anastomotic device. This instrument developed for coronary bypass surgery by virtue of the small caliber of the vessels could be adopted on a larger scale for renal transplantation. The reduced warm ischemia time needed for anastomosis may help to achieve a better outcome for the graft and expand the pool of marginal donors in renal transplantation.

Artificial organs 2010: a year in review

In this Editor's Review, articles published in 2010 are organized by category and briefly summarized. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, and the International Society for Rotary Blood Pumps, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level."Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide such meaningful suggestions to the author's work whether eventually accepted or rejected and especially to those whose native tongue is not English. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, Wiley-Blackwell, for their expert attention and support in the production and marketing of Artificial Organs. In this Editor's Review, that historically has been widely received by our readership, we aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. We look forward to recording further advances in the coming years.