Successful 14-day preservation of rat skin using a two-layer cold-storage method

Platelet-Rich Plasma for Skin Graft Storage: An Experimental Study Using Rabbit Ears

BACKGROUND

Storage of surplus grafts for later use is one of the standard procedures used in plastic surgery. For the delayed use of skin grafts, various methods and media have been investigated for short-term storage. This study aimed to investigate the effect of platelet-rich plasma (PRP) skin graft storage on the survival of skin grafts obtained from rabbit ears.

MATERIALS AND METHODS

Twelve rabbits were used in this study. A total of 12 skin grafts measuring 1 × 1 cm were obtained from the inner surfaces of the rabbits' ears. The grafts were stored at +4°C in saline, Hartmann's, and PRP media. On days 3, 7, 10, and 14, the grafts were implanted into the ears in areas measuring 1 × 1 cm where the skin, cartilage, and perichondria were excised. After the implantation of the grafts, the survival rates were evaluated by measuring the graft areas on day 0, day 10, and day 30.

RESULTS

The graft survival rate decreased as the storage period increased in all 3 of the media. The decrease in survival rate was higher in the grafts that were stored in the Hartmann's media in comparison with the saline and PRP media, and the difference was statistically significant. The decrease in graft survival was similar between the storage in saline and PRP media; however, the differences were statistically insignificant.

CONCLUSIONS

Although in vitro criteria are important for evaluating graft survival, in vivo studies showing the graft take rate in the recipient area are required. When the in vivo criteria are evaluated, the use of PRP is not superior to the use of saline for graft storage. However, additional studies are required to evaluate the effects of PRP media on graft quality.

Skin graft storage in platelet rich plasma (PRP)

Storage of skin grafts for later use is one of the standard applications in surgery. It is the most preferred method to maintain at +4°C in refrigeration after wrapping the surplus grafts into sterile gauze pad moistened with saline. Although there are many studies on the storage of skin grafts, less is known about storing skin grafts with PRP. Twenty-five pieces of 1 × 1 cm² partial thickness skin graft were harvested from 12 patients during the reduction mammoplasty operation. Twenty-four grafts were divided into 4 groups, and each group consisted of 6 grafts, 1 graft was analyzed as Day 0. Grafts in Group 1, 2, and 3 were wrapped by sterile gauze pad moistened by either saline (Group 1) or Hartman (Group 2) or PRP (Group 3). Grafts were analyzed macroscopically and microscopically. There were no significant differences between media for the first 10 days. Decrease in viability was less in saline and PRP wrapped grafts at 20 day, viability decreased significantly in all environments after 20 days. Although there was no significant difference in saline or PRP storage, it was observed macroscopically that the grafts stored in the PRP appeared better.

Cold preservation of islets in UW solution--with special reference to apoptosis

BACKGROUND

Apoptosis progresses in cultured islets. Little is known with regard to apoptosis under cold preservation. We examined viability and function of islets in University of Wisconsin (UW) solution.

MATERIALS AND METHODS

Isolated rat islets were cultured overnight (overnight group) and further treated with 7-day culture in RPMI 1640 medium at 37 degrees C (culture group) or 7-day preservation in UW solution at 4 degrees C (preservation group). They were evaluated by glucose-stimulated insulin secretion test. Apoptosis was examined by TdT-mediated dUTP-biotin nick end-labeling (TUNEL) assay. Expression of caspase mRNA and the ratio of Bax to Bcl-2 were evaluated by reverse-transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Islet recovery after 7 days was significantly lower in culture group than in preservation group (44.0 +/- 3.7% versus 75.0 +/- 4.9%, P < 0.05). The stimulation index in the culture group was significantly lower than in the overnight group (2.1 +/- 0.2 versus 4.1 +/- 0.4, P < 0.05). The apoptotic index in the culture group was significantly higher than both in the overnight group and in the preservation group (38.0 +/- 3.0% versus 10.8 +/- 2.0 and 27.0 +/- 4.0%, P < 0.05). Caspase 3, 8, and 9 mRNA in the culture group expressed more than in the other groups. Bax/Bcl-2 in the culture group was significantly lower than in the overnight group (3.2 +/- 0.66 versus 8.1 +/- 0.95, P < 0.05), suggesting that apoptosis had been already destined early after isolation.

CONCLUSIONS

The preservation group showed better recovery and function than the culture group. Apoptosis contributed to islet loss under culture and it was significantly suppressed under cold preservation.