138 Evaluation of Healing Outcomes Combining Negative Pressure Wound Therapy with Autologous Skin Cell Suspension and Meshed Autografts: Pre-Clinical and Clinical Evidence

Introduction Negative pressure wound therapy (NPWT) is an option for securing meshed split thickness skin grafts (mSTSGs) after burn excision to optimize skin graft adherence, working by minimizing disruption by shear forces and promoting the continual removal of wound bed drainage. Recently, the use of autologous skin cell suspension (ASCS) has been approved for use in treating full-thickness burn injuries in conjunction with mSTSGs. Limited data exists regarding the impact of NPWT on healing outcomes when the cellular suspension is utilized. It was hypothesized that NPWT in conjunction with ASCS+mSTSGs would aid in skin graft adherence without compromise to healing outcomes. Methods In this study, a Duroc pig model of burn, excision, mSTSG, ASCS + NPWT was used (n=2), where each animal had 2 sets of paired burns. Four wounds received mSTSG+ASCS+NPWT through post-operative day 3, and 4 wounds received mSTSG+ACSC+ traditional ASCS dressings. Percent re-epithelialization was measured using digital planimetry and Image J. Graft-adherence was evaluated using a scale with blinded reviewers (0=no graft loss, 4= >50% graft loss). Histological architecture, pigmentation, elasticity, and blood perfusion and blood vessel density were assessed at multiple time points through 2 weeks. After the evaluation of its effectiveness in animal models, the same surgical technique, including NPWT, was used in patients with full-thickness burns (n=9), and wound healing trajectories were described. Results In the Duroc pig study, all wounds healed within 14 days with minimal scar pathology and no significant differences in percent re-epithelialization between NPWT and non-NPWT wounds were observed (61.09 ± 9.01 and 61.15 ± 0.82% at Day 7). Additionally, no differences were detected for pigmentation, perfusion, or blood vessel density. Overall, the non-NPWT group had higher amounts of graft loss (1.0 ± 1.41 vs. 0 ± 0). NPWT-treated wounds had significantly improved elasticity (NPWT=109.5 ± 21.23 vs. non-NPWT=177.5 ± 35.4, p< 0.05). There were no differences in histological architecture between treatment groups. Patients had a median age of 53 (37–69), and median TBSA of 12.5 (8–18) resulting primarily from scald burns (67%). There were no reported morbidities, and all wounds were re-epithelialized within an expected time period. The use of NPWT promoted graft adherence, and was useful as a bolster dressing in wounds that crossed joints. Conclusions These data suggest the positive attributes of the cellular suspension delivered are retained following the application of NPWT. Re-epithelialization, revascularization, and repigmentation are not adversely impacted.

Evaluation of preserving the viability of sheep's teeth PDL cells according to the different times and storage medias

Introdution: Vitality of periodontal ligament (PDL) cells is very critical for replantation of complete avulsion teeth due to traumatic injuries. This is important for transferring an avulsed tooth to clinic for replantation that which Medias used for storage.This study aimed to compare the vitality of PDL cells of sheep teeth cultured in different storage medias including α-Minimum Essential Medium (αMEM), Dulbecco’s Modified Eagle’s Medium (DMEM), Hank’s Balanced Salt Solution (HBSS), and mint extract Methods: In this lab trial study, PDL cells were obtained from 124 healthy anterior and posterior sheep teeth and cultured in αMEM, DMEM, HBSS, and mint extract for periods of 2, 6, 24, 48, 72, or 96 hours (24 groups). For each solution, positive control group were PDL cells without incubation in any storage media. For each group, there was a negative control considered cells growing in dry plate with no medium. After exposure of PDL cells to scheduled solution for scheduled incubation time, centrifuge was performed for 10 minutes at rate of 2000G. Then cell percipitates were added into the solution of collagenase (3mgr/ml) and Dispase (4mgr/ml to cell precipitates, which were incubated at 37° C for 60 minutes. After washing cellular suspension in PBS, vitality of the cells was assessed by Trypan blue exclusion, on a neobar slide by magnification of 200X. The data were analyzed statistically using 2-way ANOVA test by SPSS version 15. Results: Statistically significant differences in efficacy of different medias were obtained at least between two media (P=0.0001). PDL cells cultured in αMEM and mint extract showed 90% and 52.22% vitality representing, respectively, the best and the weakest storage media. Conclusion: αMEM can be a suitable transport medium up to 96 hours to preserve the vitality of the PDL cells of avulsed teeth. There is a reverse correlation between the viability of PDL cells and incubation time, increasing the time decreases the viability.

Performance evaluation of in situ fluorometers for real-time cyanobacterial monitoring

Detecting the presence of cyanobacteria is an integral part of maintaining high water quality standards. In situ fluorometers are tools which may allow for the detection of cyanobacteria in real-time but there are few studies that review fluorometer performance. A systematic study that evaluated the performance of a range of fluorometers using key cyanobacterial species of interest and two known sources of interference (green algae and added turbidity) was undertaken. Specifically, six fluorometers and four cyanobacterial species were investigated. A good correlation (R2 ≥ 0.92 and p-value of <0.001) was obtained for mono cell culture suspensions, with robust performance exhibited for all fluorometers. Limits of detection for the fluorometers and multiplier factors which enable direct comparison of fluorometers were developed. The addition of green algae caused fluorometer performance to decrease by either overestimating or underestimating the concentration of cyanobacteria in a cellular suspension. Some fluorometers were more susceptible to these interference sources; the magnitude of the fluorometer measurement inaccuracy was dependent on cyanobacteria concentration and interference source. This study indicates that while there are inherent problems with fluorometers, the extent of the impact from interference sources can be characterised and potentially corrected to enable successful cyanobacteria detection in the field.

The Angiogenic Activity of Ascites in the Course of Ovarian Cancer as a Marker of Disease Progression

Ovarian cancer cells are able to create invasive implants in the peritoneum and their growth is directly associated with the angiogenetic potential. This effect is probably stimulated by vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8), which are both found in ascites. The aim of this study was to assess the influence of ascites produced by ovarian cancer on the angiogenesis. Peritoneal fluid was collected from patients with advanced ovarian cancer; cancer cells were separated from CD45+ leukocytes. Angiogenesis was assessed in mice, after intradermal injection of full cellular suspension together with supernatant or phosphate buffered saline, purified cancer cells suspension, or CD45+ leukocytes suspension. The angiogenesis index (AI) was assessed after 72 hours. VEGF and Il-8 were measured in the supernatant and cellular suspension. AI was the highest in the isolated cancer cells suspensions as well in the group stimulated with supernatant. Both VEGF and IL-8 were high in supernatants from ascites rich in cancer cells (>45%). A significant correlation was revealed between IL-8 concentration and AI. We conclude that ascites in patients with advanced ovarian cancer stimulates angiogenesis and this mechanism is dependent mostly on cancer cells activity and enhanced by cooperation with infiltrating leukocytes.