Photodynamic Treatment of Colorectal Cancer Using Chlorin e6-Loaded Poly(lactide-co-glycolide)- Based Nanoparticles

Abstract

We prepared poly(lactide-co-glycolide) (PLGA) encapsulated with chlorin e6 (Ce6) in an effort to increase the stability and efficiency of photosensitizers for photodynamic therapy (PDT). We determined that Ce6-loaded PLGA nanoparticles (PLGA-Ce6 NPs) had drug-loading efficiency of 5%. The efficiency of encapsulation was 82%, the zeta potential was- 25 mV, and the average diameter was 130 nm. The encapsulation of Ce6 in PLGA nanoparticles showed excellent stability. The nanoparticles exhibited sustained Ce6 release profiles with 50% released at the end of 3 days, whereas free Ce6 showed rapid release within 1 day. Ce6 release patterns were controlled by encapsulation into PLGA. The uptake of PLGA-Ce6 NPs was significantly enhanced by endocytosis in the first 8 hours in the HCT-116 cell line. An intracellular reactive oxygen species assay revealed the enhanced uptake of the nanoparticles. An in vitro anti-tumor activity assay showed that the PLGA-Ce6 NPs exhibited enhanced phototoxicity toward HCT-116 cells and a slightly lower IC50 value in HCT-116 cells than Ce6 solution alone. Exposure of HCT-116 cell spheroids to PLGA-Ce6 NPs penetrated more profoundly and had better phototoxicity than pure drugs. These findings suggest that PLGA-Ce6 NPs might serve as PDT for colorectal cancer.

β-Cyclodextrin Nanophotosensitizers for Redox-Sensitive Delivery of Chlorin e6

“…To solve these problems, various vehicles such as nanoparticles, polymer conjugates, proteins, polymeric micelles, nanomaterials, and cyclodextrins have been studied [16][17][18][19][20]. Nano-dimensional carriers have various advantages such as long blood circulation, solubilization of hydrophobic drugs, active/passive targeting of tumors, avoidance of reticuloendothelial system uptake, and site-specific delivery of bioactive agents [21][22][23].…”

“…Nano-dimensional carriers have various advantages such as long blood circulation, solubilization of hydrophobic drugs, active/passive targeting of tumors, avoidance of reticuloendothelial system uptake, and site-specific delivery of bioactive agents [21][22][23]. For example, Lin et al reported that Ce6-encapsulated poly(lactide-co-glycolide) nanoparticles show sustained drug release properties over 3 days, enhanced cellular uptake against HCT-116 cells, and higher phototoxicity than Ce6 itself [16]. Polymeric micelles are frequently employed for the site-specific delivery of bioactive agents against tumors [22].…”

Biomimetic Materials Based on Poly-3-hydroxybutyrate and Chlorophyll Derivatives

“…In general, success in combining porphyrins and polymers as carriers has been observed in a large number of scientific papers. Systems with polymers such as chitosan [ 21 ], polyethylene glycol [ 22 ], and poly(lactide-co-glycolide) [ 23 , 24 ] are well studied. But special attention should be paid to a polymer such as poly-3-hydroxybutyrate (PHB) [ 25 , 26 ].…”

Biomimetic Materials Based on Poly-3-Hydroxybutyrate and Chlorophyll Derivatives

“…2 In general, success in combining porphyrins and polymers as the carriers is observed in a large number of scientific papers. Systems with polymers such as chitosan [16]; polyethylene glycol [17]; poly(lactide-co-glycolide) [18,19] are well studied. But special attention should be paid to such a polymer as poly-3-hydroxybutyrate (PHB) [20,21].…”