Artificial Red Blood Cells as Potential Photosensitizers in Dye Laser Treatment Against Port-Wine Stains

Abstract

We suggest a novel method that uses artificial blood cells (hemoglobin vesicles, Hb-Vs) as photosensitizers in dye laser treatment (at 595-nm wavelength) for port-wine stains (i.e., capillary malformations presenting as red birthmarks) based on the results of animal experiments. As compared with human red blood cells, Hb-Vs have the same absorbance of 595 nm wavelength light and produce the same level of heat following dye laser irradiation. Small sized Hb-Vs (250 nm) distribute in the plasma phase in blood and tend to flow in the marginal zone of microvessels. Intravenous injections of Hb-Vs caused the dilatation of microvessels, and dye laser treatment with Hb-Vs destroyed the vessel wall effectively. Following the intravenous injection of Hb-Vs, the microvessels contained more Hb that absorbed laser photons and produced heat. This extra Hb tended to flow near the endothelial cells, which were the target of the laser treatment. These attributes of Hb-Vs will potentially contribute to enhancing the efficacy of dye laser treatment for port-wine stains. Hemoglobin is a type of porphyrin. Thus, our proposed treatment may have aspects of photodynamic therapy using porphyrin that leads to a cytotoxicity effect by active oxygen.

Artificial red blood cells increase large vessel wall damage and decrease surrounding dermal tissue damage in a rabbit auricle model after subsequent flashlamp‐pumped pulsed‐dye laser treatment

“…Hb-Vs can effectively work in combination with existing phototherapy devices used around the world and there is no need to buy new, expensive laser equipment. 33 Further, they do not result in solar photosensitivity after treatment. 33 As such, the use of Hb-Vs is a suitable treatment for nonmalignant disorders and in pediatric patients.…”

“…33 Further, they do not result in solar photosensitivity after treatment. 33 As such, the use of Hb-Vs is a suitable treatment for nonmalignant disorders and in pediatric patients. 33 The creation of artificial RBCs in Japan was originally initiated with the aim of recycling outdated and expired RBCs whose cell membranes have deteriorated over time.…”

“…33 As such, the use of Hb-Vs is a suitable treatment for nonmalignant disorders and in pediatric patients. 33 The creation of artificial RBCs in Japan was originally initiated with the aim of recycling outdated and expired RBCs whose cell membranes have deteriorated over time. 13 The Hb concentration in Hb-Vs is approximately 35 to 40 g/dL in each particle, which is almost the same as that of RBCs.…”

Creation of Artificial Cell-Like Structures Promoted by Microfluidics Technologies

“…In this context, creating cell-like structures that mimic the functions of a living cell in a confined space (also known as artificial cells) may give us clues to answer the question. In addition, because artificial cells have a defined molecular composition, they can provide useful platforms to investigate biological phenomena under defined chemical conditions and can serve as tools for multiple biological applications, such as therapeutic techniques, fermentation by artificial cells, the construction of artificial red blood cells, and simplified cell models [3,4,5,6].…”

Gold nanospheres enhanced photothermal therapy in a rat model

“…This vacuum‐assisted laser therapy may be used for efficiently destroying small PWS blood vessels. Rikihisa et al put forward a novel approach to improve clinical outcomes of PDL‐resistance PWS. The in vivo results showed that hemoglobin concentration in microvessels was increased significantly through intravenously injection of prepared artificial red cells (hemoglobin vesicles) before laser irradiation, thereby producing more heat to photocoagulate small blood vessels which do not contain enough red blood cells.…”