Acne is the over growth of the commensal bacteria Propionibacterium acnes (P. acnes) on human skin. Lauric acid (LA) has been investigated as an effective candidate to suppress the activity of P. acnes. Although LA is nearly insoluble in water, dimethyl sulfoxide (DMSO) has been reported to effectively solubilize LA. However, the toxicity of DMSO can limit the use of LA on the skin. In this study, LA-loaded poly(ɛ-caprolactone)-poly(ethylene glycol)-poly(ɛ-caprolactone) micelles (PCL-PEG-PCL) were developed to improve the bactericidal effect of free LA on P. acnes. The block copolymers mPEG-PCL and PCL-PEG-PCL with different molecular weights were synthesized and characterized using ¹H Nuclear Magnetic Resonance spectroscopy (¹H NMR), Fourier-transform infrared spectroscopy (FT-IR), Gel Permeation Chromatography (GPC), and Differential Scanning Calorimetry (DSC). In the presence of LA, mPEG-PCL diblock copolymers did not self-assemble into nano-sized micelles. On the contrary, the average particle sizes of the PCL-PEG-PCL micelles ranged from 50–198 nm for blank micelles and 27–89 nm for LA-loaded micelles. The drug loading content increased as the molecular weight of PCL-PEG-PCL polymer increased. Additionally, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of free LA were 20 and 80 μg/mL, respectively. The MICs and MBCs of the micelles decreased to 10 and 40 μg/mL, respectively. This study demonstrated that the LA-loaded micelles are a potential treatment for acne.

Although epigallocatechin-3-gallate (EG) is well-known as a potent antioxidant and free radical scavenger for neurodegenerative diseases, it still has disadvantages that reduce its treatment effectiveness due to low bioavailability, slow absorption, and water solubility. Therefore, the aim of this study is to improve the bioavailability of EG and increase the effectiveness of anti-inflammatory properties to microglial cells by using Poly(Lactide-co-Glycolide) (PLGA) microspheres as carriers. In this study, we used UV–Vis spectroscopy to show the formation of the complex of β-cyclodextrin (β-CD) and EG (CD-EG). The loading efficiency of EG in PLGA microspheres was optimized by the addition of β-CD. The highest loading efficiency of 16.34% was found among other formulations. The results of Fourier transform infrared spectroscopy indicated the loading of CD-EG in PLGA microspheres. The scanning electron microscopic images demonstrated the spherical PLGA particles with controlled particles size ranging from 1–14 µm. Moreover, the in vitro release of EG was conducted to explore the sustained release property of the PLGA formulations. In the in vitro model of mouse microglial cells (BV-2 cells) stimulated by lipopolysaccharide, the cytotoxicity test showed that for up to 1 mg/mL of PLGA microspheres no toxicity to BV-2 cells was found. PLGA microspheres can significantly suppress the nitric oxide production from BV-2 cells, indicating EG loaded in PLGA microspheres can suppress the inflammation of activated microglial cells. Furthermore, the intracellular iNOS in BV-2 cells was also found to be down regulated. In summary, we have successfully shown that the use of β-CD can increase the loading efficiency of EG in PLGA microspheres and provide neuroprotective effect on the activated microglial cells.