Table 1 Summary of Recent Advances in Flexible Phototherapy Devices
From: Challenges and opportunities in next-generation LED therapeutic devices
Phototherapy mechanism | Clinical application | Light emitting material | Light parameters | Substrate | Device type | Highlights | Refs | |
|---|---|---|---|---|---|---|---|---|
Wavelength | Power | |||||||
Optogenetics | Nerve stimulation | OLED | 400 ~ 580 nm | 0.5 mW mm-2 | Parylene C | Implantable | Ultra-flexible film OLEDs provide precise light stimulation to the brain and can conform to various anatomical structures. | |
Vision loss | OLED | 600 nm | 0.1 mW mm-2 | Silicon | Wearable | High-brightness, highly directional OLEDs have been incorporated into wearable prosthetics to facilitate optogenetic therapy for retinal cells. | ||
Control of cardiac rhythms | Micro-LED | 591 nm | 0.1 mW mm-2 | Wearable | The 591 nm micro-LED was integrated into a wearable textile vest, enabling non-invasive optogenetic control of heart rate in mice through the chest wall. | |||
Diabetes | LED | 545 nm | 0.15 mW cm-2 | Wearable | An innovative approach combining smartwatches with green light control provides new possibilities for the precise regulation of transdermal therapeutic gene delivery. | |||
Bladder pain syndrome | Micro-inorganic LED | 530 nm | 3.3 or 10 mW mm-2 | Silicone | Implantable | An innovative wireless closed-loop system has been developed for the optogenetic modulation of peripheral nerves. | ||
Cardiac pacing | Micro-LED array | Blue light | Pulse width of 10 ms, 101 mW mm-2 | PI | Implantable | A customized soft, thin-film micro-LED array enables high spatiotemporal precision in optogenetic stimulation delivery, while a closed-loop system allows for rapid pacing or defibrillation upon detection of arrhythmias. | ||
Spinal cord injury | Micro-LED | 470 nm 535 nm | Pulse width of 10 ms, 50 mW mm-2 | PI | Implantable | Optogenetic stimulation is applied to the entire spinal cord region without the use of wires, while the closed-loop system enables real-time monitoring of physiological responses in mice and automatic adjustment of light stimulation based on feedback. | ||
Diabetes | LED | 660 nm | 20 mW cm-2 | Wearable | An optogenetic switch responsive to red and far-red light has been developed, offering high controllability for precise regulation of target genes. | |||
Diabetes | LED | 730 nm | 1 mW cm-2 | Implantable | Remote control of optogenetic cells is enabled via a smartphone, enhancing operational flexibility and improving patient autonomy in diabetes management. | |||
PBM | Wound healing | OLED | 629 nm 534 nm 466 nm | 5 mW cm-2 | Cylindrical-shaped materials, textiles and paper | Wearable | Sandwich-structured transferable OLEDs can be applied to various flexible substrates, such as textiles, enabling them to conform to the complex surfaces of human skin. | |
Ischemic stroke | LED array | 630 nm | 17 mW cm-2 | PI | Implantable | An implantable multi-LED array achieves stable contact with the target cortical region and the skull for PBM. Optimal results indicate that 630 nm is most effective in reducing infarct volume and neuronal damage following ischemic stroke. | ||
Skin anti-aging | Micro-LED | 627 nm | 19.78 μW cm−2 | GaAs | Wearable | The face-fit surface-lighting µLED mask conforms to complex facial contours (elevations and curves), enhancing the effectiveness of PBM and resulting in significant improvements in facial elasticity, sagging, and wrinkles. | ||
Diabetic retinopathy | LED | 630 ~ 1000 nm | 120 µW | PET | Wearable | Intelligent wireless near-infrared emitting contact lenses can non-invasively stimulate retinal repair and regeneration, integrated with a smart control system. | ||
Hair-growth | Micro-LED | 650 nm | ∼30 mW mm–2 | GaAs | Wearable | Monolithic flexible red vertical LEDs offer excellent light uniformity and are suitable for wearable applications aimed at stimulating hair growth. | ||
Melanogenesis inhibition | Micro-LED | 630 nm | 0.4 mW cm−2 | Plastic substrate | Wearable | The wearable design allows users to incorporate the device more easily into their daily lives. | ||
Wound healing | LED array | 630 nm | ~13.37 mW cm−2 | PI | Wearable | The adhesive nanofiber membrane wound dressing is combined with LED phototherapy. | ||
Hair-growth | OLED | 640 nm | 10 mW cm−2 | Wearable | Red OLEDs have been utilized for the first time in a mouse model to validate the stimulation of hair growth and assess their effects on hair follicle cells. | |||
Diabetes | OLED | 600 ~ 700 nm | 1.33 mW cm-2 | Parylene C | Implantable | Utilizing OLED catheters, uniform PBM within the duodenum has been achieved, with potential implications for the regulation of glucose and insulin metabolism. | ||
QLED | 620 nm | ∼8 mW cm−2 | Glass | Wearable | The narrow emission band and wavelength tunability of QLEDs made it possible to fit the emission spectrum into the absorption window of cytochrome C (for PBM). | |||
Hair growth | QD-LED | 630, 700 and 730 nm | >23.28 mW·cm−2 | PET | Wearable | Wearable QD-OLED patch is developed for real-time wavelength controllable high-power NIR photomedicine. NIR QD-OLED demonstrated that it could increase the proliferation of HFDP cells by up to 131% through NIR wavelength control. | ||
Wound healing | QD-LED | NIR | 2.5 mW cm-2 | Wearable | A red/NIR light source that matches 81.7% of the absorption spectrum of CCO enzyme was produced. Exposure of the produced light source to the wound area accelerated wound healing. | |||
PDT | Anticancer | OLED | Color-tunable | >100 mW cm-2 | Wearable | The parallel stacked OLED structure enhances light output intensity and therapeutic effectiveness while also possessing color adjustment capabilities. | ||
Wound management & antibacterial | OLED | 669 ~ 737 nm | >9 mW cm-2 | PET | Wearable | Using flexible OLED as the light source enables uniform illumination for PDT. When combined with methylene blue as a photosensitizer, this approach effectively eliminates over 99% of S. aureus. | ||
Long-term autonomous cancer therapy | Miniature LED | 470 nm | PET | Implantable | An implantable system that integrates human motion with PDT has been developed, creating a self-powered treatment solution that reduces reliance on external power sources. | |||
Anti-cancer | LED | 630, 530 and 460 nm | <100 μW cm-2 | PDMS | Implantable | An implantable, wirelessly powered PDT system utilizes tissue-adhesive optoelectronics that securely adhere to the internal tissue surface without the need for surgical sutures. | ||
Oral cancer treatment or diabetic wound repairs | QLED | 620 nm | PEN | Wearable | The first in vitro study demonstrates that QLED-based photodynamic therapy effectively eradicates methicillin-resistant Staphylococcus aureus. High-efficiency QLED featuring narrow emission spectra and specific peak wavelengths achieves a luminance exceeding 20,000 cd m-² under a low driving voltage of 6 V. | |||
Blue light therapy | Neonatal jaundice | OLED | 470 nm | >20 µW cm-2 nm-1 | Textile | Wearable | Textile-based blue OLEDs combine wearable technology with phototherapy, offering a convenient at-home treatment solution for neonatal jaundice. | |
UVA therapy | Dermatological diseases | LED | 360 nm | 20 ~ 80 mW cm-2 | PI | Wearable | The integration of PLGA microneedles for light conduction enhances the depth of illumination. | |
