Purpose: Photobiomodulation (PBM), encompassing low-energy laser treatment and light-emitting diode (LED) phototherapy, has demonstrated positive impacts on skin rejuvenation and wound healing. Organic light-emitting diodes (OLEDs) present a promising advancement as wearable light sources for PBM. However, the biological and biochemical substantiation of their skin rejuvenation and wound healing effects remains limited. This study aimed to ascertain the safety and efficacy of OLEDs as a nextgeneration PBM modality through comprehensive in vitro and in vivo investigations. Materials and Methods: Cell viability assays and human ex vivo skin analyses were performed after exposure to OLED and LED irradiation to examine their safety. Subsequent evaluations examined expression levels and wound healing effects in human dermal fibroblasts (HDFs) using quantitative reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and wound healing assays post-irradiation. Additionally, an in vivo study was conducted using a ultra violet (UV)-irradiated animal skin model to explore the impact of OLED exposure on dermal collagen density and wrinkles, employing skin replica and tissue staining techniques. Results: OLED irradiation had no significant morphological effects on human skin tissue, but caused a considerably higher expression of collagen than the control and LED-treated groups. Moreover, OLED irradiation reduced the expression levels of matrix metalloproteinases (MMPs) more effectively than did LED on HDFs. OLED irradiation group in HDFs had significantly higher expression levels of growth factors compared to the control group, but similar to those in the LED irradiation group. In addition, OLED irradiation on photo-aged animal skin model resulted in increased collagen fiber density in the dermis while reducing ultra violet radiation-mediated skin wrinkles and roughness, as shown in the skin replica. Conclusion This study established comparable effectiveness between OLED and LED irradiation in upregulating collagen and growth factor expression levels while downregulating MMP levels in vitro. In the UV-irradiated animal skin model, OLED exposure post UV radiation correlated with reduced skin wrinkles and augmented dermal collagen density. Accelerated wound recovery and demonstrated safety further underscore OLEDs’ potential as a future PBM modality alongside LEDs, offering promise in the realms of skin rejuvenation and wound healing.

Background: Korea’s aging population has raised several challenges, especially concerning healthcare costs. Consequently, this study evaluated the association of frailty transitions with healthcare utilization and costs for older adults aged 70 to 84. Methods: This study linked the frailty status data of the Korean Frailty and Aging Cohort Study to the National Health Insurance Database. We included 2,291 participants who had frailty measured by Fried Frailty phenotype at baseline in 2016–2017 and follow-up in 2018– 2019. We conducted a multivariate regression analysis to determine the association between their healthcare utilization and costs by frailty transition groups. Results: After 2 years, changes from “pre-frail” to “frail” (Group 6) and “frail” to “pre-frail” (Group 8) were significantly associated with increased inpatient days (P < 0.001), inpatient frequency (P < 0.001), inpatient cost (P < 0.001 and P < 0.01, respectively), and total healthcare cost (P < 0.001) than “robust” to “robust” (Group 1) older adults. A transition to frailty from “pre-frail” to “frail” (Group 6) resulted in a $2,339 total healthcare cost increase, and from “frail” to “pre-frail” (Group 8), a $1,605, compared to “robust” to “robust” older adults. Conclusion Frailty among community-dwelling older adults is economically relevant.Therefore, it is crucial to study the burden of medical expenses and countermeasures for older adults to not only provide appropriate medical services but also to prevent the decline in their living standards due to medical expenses.