The Rejuran® is a new filler product made from purified polynucleotides. Here we present data from an animal study and a clinical trial to examine the durability, efficacy and safety of the Rejuran® on crow's feet. For the animal study, 25 mice were divided into three groups: Group 1 received phosphate buffered saline (PBS); Group 2 were treated with Yvoire®; and Group 3 were treated with Rejuran®. The durability and efficacy of each treatment were assessed by microscopy and staining. In the clinical trial, 72 patients were randomized to receive Rejuran® treatment for crow's feet on one side and Yvoire-Hydro® on the contralateral side, at a ratio of 1:1. Repeated treatments were performed every two weeks for a total of three times, over a total of 12 weeks' observation. All injections and observations of efficacy and safety were performed by the same two investigators. In the animal study, the Rejuran® group showed similar durability and inflammatory response to the Yvoire® group. Upon efficacy assessment, the Rejuran® group showed the greatest elasticity and collagen composition, and a significant difference in skin surface roughness and wrinkle depth. In the clinical trial, the primary and secondary objective efficacy outcome measure showed no statistical significance between the two groups, and in safety outcomes there were no unexpected adverse effects. Our data suggest that the Rejuran®, as a new regenerative filler, can be useful to reduce wrinkles, by showing evidence for its efficacy and safety.Graphical Abstract

BackgroundFacial rejuvenation can be achieved using a variety of techniques. Since minimally invasive procedures for face lifting have become popular because of their convenience and short operating time, numerous minimally invasive surgical procedures have been developed. In this study, a nonabsorbable polypropylene mesh is introduced as a new face lifting instrument, with the nasolabial fold as the main target area. In this paper, we report the efficacy and safety of a polypropylene mesh in midface rejuvenation.MethodsThirty-three subjects with moderate-to-severe nasolabial folds were enrolled from two medical institutions for a noncomparative single-sample study. A mesh was inserted above the superficial muscular aponeurotic system layer, reaching the nasolabial folds through a temporal scalp incision. After 3 weeks, the temporal end of the mesh was pulled to provide a lifting effect. Then, the mesh was fixed to the deep temporal fascia using nonabsorbable sutures. To evaluate efficacy, we compared the scores on the Wrinkle Severity Rating Scale and a visual analog scale for patient satisfaction between the baseline and 7 weeks postoperatively. In addition, we evaluated safety based on the incidence of adverse events.ResultsThe treatment was deemed effective at improving wrinkles in 23 of 28 cases, and patient satisfaction improved significantly during the study period. There were seven cases of skin or subcutaneous tissue complications, including edema and erythema, but there were no suspected serious adverse events.ConclusionsFace lifting using a nonabsorbable mesh can improve nasolabial folds without serious adverse effects. Thus, this technique is safe and effective for midface rejuvenation.

Background In staged excision procedures, it is difficult to estimate the number of excisions that will be required and the extent of scar lengthening. The purpose of this study was to investigate the effects of the size, shape, and resection amount of lesions on the outcomes of staged excision through an animal experiment. Methods In total, 20 ellipses with five different designs (n=4) were evaluated on pig skin. The experiment consisted of two groups: group 1 had excisions of the same length, but with different widths, while group 2 had excisions of the same size, but with different amounts of resection. The size of the lesions and the amount of resection were analyzed in terms of the ratio of length (long axis) and width (short axis) (S/L ratio). Results In the first group, initial ellipses measuring 5×4, 5×3, and 5×2 cm increased in size to 9.25±0.07 (185%), 8.55±0.07 (171%), and 8.10±0.14 cm (162%), respectively. In the second group, in which all ellipses measured 5×3 cm, those with a resection amount of 5×1.5, 5×2, and 5×2 cm with a fish fin grew to 8.75±0.15 (175%), 8.55±0.07 (171%), and 8.60±0.17 cm (172%), respectively. In group 1, the larger the S/L ratio, the longer the final length. In group 2, a greater resection amount was associated with a shorter final length. Conclusions We believe that the measurements of this study in terms of shape, size, and excision amount will be reasonable predictive references for staged excision procedures.

Introduction: Recipient site preparation using external volume expansion (EVE) increases graft survival in large-volume fat grafting. To improve patient compliance with using the device, we tested a new cyclic high negative-pressure (CHNP) mode that involves 1 h/day at −55 mm Hg, cycled between 1-second negative-pressure activation, followed by a 2-second deactivation period in an animal model. Material and Method: A miniaturized EVE device was applied to 30 8-week-old male Sprague-Dawley rats. The rats were assigned to 3 groups (no pressure for the control group, conventional −25 mm Hg for 8 h/day for conventional EVE, and CHNP mode for the CHNP group). After 28 days, micro-computed tomography was performed and skin biopsy specimens were obtained. Results: The CHNP group showed a 6.6-fold increase and the conventional EVE group showed a 4.4-fold increase in volume compared to the control group. Hematoxylin and eosin staining showed a similar increase in subcutaneous tissue thickness in both EVE groups, compared to the control group. Masson's trichome and proliferating cell nuclear antigen staining showed significantly higher collagen deposition and subdermal adipocytes in EVE groups. Immunohistochemistry against platelet endothelial cell adhesion molecule 1 showed 2.5- and 2.7-times higher vessel density in the conventional and CHNP EVE groups, respectively. There was no statistically significant difference in subcutaneous tissue thickness, collagen deposition, subdermal adipocyte proliferation, and vessel density between the 2 EVE groups. Conclusion: CHNP produced comparable results in recipient site preparation (subcutaneous tissue thickening and angiogenesis) compared to the conventional protocol, while markedly reducing the daily wear-time from 8 hours to 1 hour. Although further clinical data must be acquired, our new pressure setting seems promising and provides a more patient-friendly pre-expansion environment.