Cytotoxicity and Genotoxicity of Azobenzene-Based Polymeric Nanocarriers for Phototriggered Drug Release and Biomedical Applications

Abstract

Drug nanoencapsulation increases the availability, pharmacokinetics, and concentration efficiency for therapeutic regimes. Azobenzene light-responsive molecules experience a hydrophobicity change from a polar to an apolar tendency by trans–cis photoisomerization upon UV irradiation. Polymeric photoresponse nanoparticles (PPNPs) based on azobenzene compounds and biopolymers such as chitosan derivatives show prospects of photodelivering drugs into cells with accelerated kinetics, enhancing their therapeutic effect. PPNP biocompatibility studies detect the safe concentrations for their administration and reduce the chance of side effects, improving the effectiveness of a potential treatment. Here, we report on a PPNP biocompatibility evaluation of viability and the first genotoxicity study of azobenzene-based PPNPs. Cell line models from human ventricular cardiomyocytes (RL14), as well as mouse fibroblasts (NIH3T3) as proof of concept, were exposed to different concentrations of azobenzene-based PPNPs and their precursors to evaluate the consequences on mitochondrial metabolism (MTT assay), the number of viable cells (trypan blue exclusion test), and deoxyribonucleic acid (DNA) damage (comet assay). Lethal concentrations of 50 (LC50) of the PPNPs and their precursors were higher than the required drug release and synthesis concentrations. The PPNPs affected the cell membrane at concentrations higher than 2 mg/mL, and lower concentrations exhibited lesser damage to cellular genetic material. An azobenzene derivative functionalized with a biopolymer to assemble PPNPs demonstrated biocompatibility with the evaluated cell lines. The PPNPs encapsulated Nile red and dofetilide separately as model and antiarrhythmic drugs, respectively, and delivered upon UV irradiation, proving the phototriggered drug release concept. Biocompatible PPNPs are a promising technology for fast drug release with high cell interaction opening new opportunities for azobenzene biomedical applications.

Light-Switchable Membrane Permeability in Giant Unilamellar Vesicles

“…The demonstration that these orthogonal methods could be used in combination to fine-tune the membrane permeability of GUVs provides additional capabilities relevant to numerous medical and biomedical applications, such as targeted drug delivery and topical localized treatments. Studies on the cytotoxicity of the 1•Zn 2+ amphiphile are ongoing; however, previous studies on azobenzene-functionalized drugs and drug delivery systems, including light-responsive liposomes [67,68], self-assembled polymeric nanoparticles [69], and azobased hydrogels [70], revealed the good biocompatibility of these engineered compounds. In particular, for cationic amphiphilic molecules with a similar chemical structure to that of 1•Zn 2+ , the absence of cytotoxic effects of the photoswitchable compound [68,71] and of photophospholipid-based vesicle preparations [72] was assessed in the same concentration range as that of our working conditions.…”

Tethered together: DASA design towards aqueous compatibility

“…7 Of particular interest is their use in biological studies due to their long wavelength activation wavelengths, which would avoid the cytotoxic UV activation that the most commonly used photoswitches (e.g., azobenzene, diarylethene) require. 8,9 To move to increasingly complex systems, such as biological systems, photoswitches must operate in polar protic solvents. Unfortunately, this is a feature not available for current DASA based photoswitches.…”

A Red-Light-Responsive DASA–Polymer with High Water Stability for Controlled Release

“…Subsequently, we investigate its assembly morphology in water and examine the influence of water on the isomerization of DASA within the DASA-polymer assemblies before and after irradiation. Finally, using the model drug Nile red (NR), known for its extensive use in drug release studies [35][36][37][38], we aim to illustrate the potential of our designed DASA-polymer as a platform for photocontrollable drug release. As shown below, the combination of the strong penetration capability of red light and the good water stability of DASA-based photoresponsive polymer nanovector not only advances the field of DASA-based nanovectors but also promotes the practical application of photoresponsive polymer nanomedicines.…”