| dc.description.abstract | In past decade, researches of skin probiotics come out one and another. The concept is derived from the use of yogurt to promote the balance of the gastrointestinal flora and maintain body health. Previous studies show that Staphylococcus epidermidis (S. epidermidis) uses the carbon source from glycerol to stimulate the fermentation reaction. From fermentation products, short-chain fatty acids (SCFAs) can effectively inhibit Cutibacterium acnes (C. acnes, Propionibacterium acnes formerly) growth. Based on this research, nanotechnology can provide a novel way to simultaneously be a drug carrier and provide probiotic carbon source. In recent years, polyethylene glycol (PEG) polymers, which were formed from ethylene oxide, or their derivatives were studied to be drug vehicles. Such polymers contain a large amount of carbon source and be able to stimulate S. epidermidis generating SCFAs.
In this study, PEG-derived polymer was used as a drug carrier, encapsulating Rifampicin (RIF) and Indocyanine green (ICG) to form nanoparticles. Through the nanoparticles, the polymer shell stimulates the activity of probiotics, followed by phototherapy activation and antibiotics release. We anticipate this triple-functional treatment, named photo-chemo-biotic therapy, could combat severe acne symptoms.
In preliminary research, nanoparticle RIPNDs was fabricated by PEO-PPO-PEO polymer, rifampicin, indocyanine green and perfluorocarbon, forming a double-layer system through ultrasonic emulsification. The size and surface charge were 240.7 ± 6.73 nm and -20.9 ± 2.40 mV, respectively. And the encapsulation rates of rifampicin and indocyanine green were 54.0 ± 10.5% and 95.0 ± 4.84%, respectively. In vitro experiments aimed on the bactericidal effect of C. acnes, With the presence of probiotic fermentation product medium (FPM) and RIPNDs with concentration higher than 20-μM ICG/3.8-μM RIF under laser irradiation (808 nm, 6 W /cm2), C. acnes can be completely eradicated.
In the further mouse experiment, the infected mice ears by C. acnes were treated by photo-chemo-biotic therapy of RIPNDs. The degree of inflammation decreased 70.5% and 23.1% compared to rifampicin alone and nanoparticle RIPNDs with laser exposure (i.e. photo-chemo therapy), respectively. And the antibacterial effect increased 97% and 85%, respectively. This experiment not only shows RIPNDs gives a good therapeutic effect, but also point out the novelty and importance of probiotics effect.
To sum up the study, RIPNDs can not only effectively inhibit C. acnes growth, but also catalyze skin probiotics to generate probiotic activity. This photo-chemical-probiotic therapy are highly potential for use in the clinical anti-C. acnes treatment with reduced chemotoxicity | en_US |