In vitro evaluation of 5-aminolevulinic acid (ALA) loaded PLGA nanoparticles.
BACKGROUND
5-Aminolevulinic acid (ALA) is a prodrug for topical photodynamic therapy. The effectiveness of topical ALA can be limited by its bioavailability. The aim of this study was to develop a novel ALA delivery approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs).


METHODS
A modified double emulsion solvent evaporation method was used to prepare ALA loaded PLGA NPs (ALA PLGA NPs). The characteristics, uptake, protoporphyrin IX fluorescence kinetics, and cytotoxicity of ALA PLGA NPs toward a human skin squamous cell carcinoma cell line were examined.


RESULTS
The mean particle size of spherical ALA PLGA NPs was 65.6 nm±26 nm with a polydispersity index of 0.62. The encapsulation efficiency was 65.8%±7.2% and ALA loading capacity was 0.62%±0.27%. When ALA was dispersed in PLGA NPs, it turned into an amorphous phase. ALA PLGA NPs could be taken up by squamous cell carcinoma cells and localized in the cytoplasm. The protoporphyrin IX fluorescence kinetics and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that ALA PLGA NPs were more effective than free ALA of the same concentration.


CONCLUSIONS
PLGA NPs provide a promising ALA delivery strategy for topical ALA-photodynamic therapy of skin squamous cell carcinoma.
Shanghai Skin Disease Hospital, Shanghai, People's Republic of China.
Lei
L
Shi
Xiuli
X
Wang
Feng
F
Zhao
Hansen
H
Luan
Qingfeng
Q
Tu
Zheng
Z
Huang
Hao
H
Wang
Hongwei
H
Wang
D000622:Aminolevulinic Acid / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D000704:Analysis of Variance; D002152:Calorimetry, Differential Scanning; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D011100:Polyglycolic Acid / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
D017319:Photosensitizing Agents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D000622:Aminolevulinic Acid
5-Aminolevulinic acid (ALA); nanoparticles; photodynamic therapy (PDT); poly(lactic-co-glycolic acid) (PLGA); skin squamous cell carcinoma