Astaxanthin is a xanthophyll carotenoid with high beneficial biological activities, such as antioxidant function and scavenging oxygen free radicals, but its application is limited because of poor water solubility and low bioavailability. Here, we prepared and optimized poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with astaxanthin using the emulsion solvent evaporation technique and investigated the anti-photodamage effect in HaCaT cells. The four-factor three-stage Box-Behnken design was used to optimize the nanoparticle formulation. The experimental determination of the optimal nanoparticle size was 154.4 ± 0.35 nm, the zeta potential was 22.07 ± 0.93 mV, encapsulation efficiency was 96.42 ± 0.73%, and drug loading capacity was 7.19 ± 0.12%. The physicochemical properties of the optimized nanoparticles were characterized by dynamic light scattering, SEM, TEM, FTIR, XRD, DSC, and TGA. In vitro study exhibited the excellent cell viability and cellular uptake of optimized nanoparticle on HaCaT cells. The anti-photodamage studies (cytotoxicity assay, ROS content, and JC-1 assessment) demonstrated that the optimized nanoparticles were more effective and safer than pure astaxanthin in HaCaT cells. These results suggest that our PLGA-coated astaxanthin nanoparticles synthesis method was highly feasible, and can be used in cosmetics or the treatment of skin diseases.

The Box–Behnken  design optimized the parameters and obtained the optimal process conditions of AST-PLGA NP

The various physicochemical and morphological properties of the optimized AST-PLGA NP were characterized:Particle Size and zeta potential;Evaluation of the encapsulation efficiency and drug loading capacity ;Morphologic analysis of nanoparticles;Fourier Transform Infrared (FTIR) Spectroscopic;X-ray Diffraction Patterns (XRD);Thermal analysis.

In vitro cell viability and cytotoxicity use MTT method.

The antioxidant activity use ROS and JC-1 method.

dataset: F.B.H-Table1.csv
Table1. Factors and levels used in the Box–Behnken design.

dataset: F.B.H-Table2.csv
Table 2. Box-Behnken Design Matrix and Observed Response Value

dataset: F.B.H-Table3.csv
Table 3. Statistical analysis of variance for EE in Box-Behnken Design

dataset: F.B.H-Table4.csv
Table 4. Statistical analysis of variance for DL in Box-Behnken Design

dataset: F.B.H-Table5.csv
Table 5. Statistical analysis of variance for size in Box-Behnken Design

dataset: F.B.H-Table6.csv
Table 6. Optimized values obtained by constraints applied on EE， DL, Size.

dataset: F.B.H-Figure2sizedata.csv                                                                                                                                                                      

Raw data of experiments with size

dataset:F.B.H-Figure3DSCdata.csv                                                                                                                                                                      

Raw data of experiments with differential scanning calorimetry

dataset:F.B.H-Figure3FTIRdata.csv                                                                                                                                                                       

Raw data of experiments with Fourier Transform Infrared Spectroscopic

dataset:F.B.H-Figure3TGdata.csv                                                                                                                                                                       

Raw data of experiments with thermo-gravimetric analyzer    

dataset:F.B.H-Figure3XRDdata.csv                                                                                                                                                                      

Raw data of experiments with X-ray Diffraction Patterns                                                                                                                                                         
dataset:F.B.H-Figure4celluptakedata.csv

Raw data of FACS experiments with HaCaT cell uptake

dataset: F.B.H-Figure5MTT24hdata.csv; F.B.H-Figure5MTT48hdata.csv; F.B.H-Figure5UVBMTTdata.csv

Raw data of MTT experiments with HaCaT cell viability in different time

dataset: F.B.H-Figure6ROSdata.CSV

Raw data of FACS experiments with ROS

dataset: F.B.H-Figure7JC1ASTdata.csv

Raw data of FACS experiments with JC1 for Astaxanthin

dataset: F.B.H-Figure7JC1AST-PLGANPdata.csv

Raw data of FACS experiments with JC1 for PLGA nanoparticles loaded with Astaxanthin

dataset:F.B.H-Figure4celluptakeconfocal                                                                                                                                                        

 Image of cellular uptake of the nanoparticles on Figure 4C

dataset:F.B.H-Figure6ROSconfocal                                                                                                                                                                

 Image of the ROS level  in cells on Figure 6C   

dataset:F.B.H-Figure7JC1confocal                                                                                                                                                                  

Image of  ΔΨm in cells on Figure 7C