Biosecurity Test of Conjugated Nanoparticles of Chitosan-Protoporphyrin IX-Vitamin B9 for Their Use in Photodynamic Therapy.

Nanotechnology proposes new applications for the development of nanotransporters and active targeting molecules with the use of biodegradable polymeric nanoparticles to improve the specificity towards target cells. However, these products must comply with safety tests to be endorsed as therapeutic alternatives by regulatory organizations. The goal of this work was to evaluate the biosafety (cytotoxicity and genotoxicity) of chitosan polymeric nanoparticles conjugate with protoporphyrin IX and vitamin B9 (CNPs-PpIX-B9) that were previously optimized from the established protocol by our laboratory and tested in CHO-K1 cells by bioassay following the recommendations of the chromosomal aberrations test by OECD 473 (2016) guideline. The conjugate did not show evidence of genotoxicity (clastogenicity). Surprisingly, the significant differences between the treatments performed and the negative control do not represent increases in chromosomal aberrations, whereby the safe concentrations to use the conjugate without inducing cytotoxic or genotoxic effects are less than 0.25 mg/mL. Since it induced a significant decrease of structural chromosomal aberrations, generating a positive effect on the genomic stability of CHO-K1 cells cultured in this test system.

Synthesis of Chitosan Nanoparticles Conjugated With Protoporphyrin IX and Vitamin B9 for Their Application in Photodynamic Therapy.

One of the main obstacles of Photodynamic Therapy (PDT) to damage and destroy abnormal cells is that most photosensitizers (Ps) have a highly hydrophobic nature with a tendency to aggregate in aqueous solutions and the non-specificity towards target cells. Nanotechnology proposes new tactics for the development of monomeric Ps nanotransporters and active targeting mole-cules with the use of biodegradable polymeric nanoparticles to improve the specificity towards target cells. The goal of this work was to optimize the synthesis of chitosan polymeric nanoparticles conjugated with protoporphyrin IX and vitamin B9 (CNPs-PpIX-B9) by the ionic gelation method from the established protocol previously carried out by our laboratory with 1.74 times fold of efficiency. They were characterized by ultraviolet-visible and infrared spectroscopy and transmission electron microscopy. The optimal conditions for CNPs synthesis was found at pH 5.11. The nanoconjugate shapes were more homogeneous and the average size resulted in 19.92 nm ± 7.52 nm. CNPs-PpIX-B9 were stable after the filter sterilization method and highly thermostable.

Biosecurity test of conjugated nanoparticles of chitosan-protoporphyrin IX-vitamin B9 for their use in photodynamic therapy.

The main obstacle of Photodynamic Therapy (PDT) to damage and destroy abnormal cells is that most photosensitizers (Ps) have a highly hydrophobic nature with a tendency to aggregate in aqueous solutions and the non-specificity towards target cells. Nanotechnology proposes new tactics for the development of monomeric Ps nanotransporters and active targeting molecules with the use of biodegradable polymeric nanoparticles to improve the specificity towards target cells. However, these products must comply with safety tests to be endorsed as therapeutic alternatives by regulatory organizations. The goal of this work was to optimize the synthesis of chitosan polymeric nanoparticles conjugated with protoporphyrin IX and vitamin B9 (CNPs-PpIX-B9) by the ionic gelation method from the established protocol previously carried out by our laboratory with 1.74 times fold of efficiency. They were characterized by ultraviolet light-visible light, infrared spectroscopy and transmission electron microscopy. In addition, in CHO-K1 cells the biosafety (cytotoxicity and genotoxicity) of conjugate was assessed following the recommendations of the chromosomal aberrations test by OEDC 473 (2016) guideline. The conjugate did not show evidence of genotoxicity (clastogenicity). Surprisingly, the significant differences between the treatments performed and the negative control do not represent increases in chromosomal aberrations, whereby the safe concentrations to use the conjugate without inducing cytotoxic or genotoxic effects are less than 0.25 mg / mL. Since it induced a significant decrease of structural chromosomal aberrations, generating a positive effect on the genomic stability of CHO-K1 cells cultured in this test system.