Acute toxicity and genotoxicity studies on poly(ɛ-caprolactone)-poly(ethylene glycol)-poly(ɛ-caprolactone) nanomaterials

Biodegradable PEG-PCL Nanoparticles for Co-delivery of MUC1 Inhibitor and Doxorubicin for the Confinement of Triple-Negative Breast Cancer

Combating triple-negative breast cancer (TNBC) is still a problem, despite the development of numerous drug delivery approaches. Mucin1 (MUC1), a glycoprotein linked to chemo-resistance and progressive malignancy, is unregulated in TNBC. GO-201, a MUC1 peptide inhibitor that impairs MUC1 activity, promotes necrotic cell death by binding to the MUC1-C unit. The current study deals with the synthesis and development of a novel nano-formulation (DM-PEG-PCL NPs) comprising of polyethylene glycol-polycaprolactone (PEG-PCL) polymer loaded with MUC1 inhibitor and an effective anticancer drug, doxorubicin (DOX). The DOX and MUC1 loaded nanoparticles were fully characterized, and their different physicochemical properties, viz. size, shape, surface charge, entrapment efficiencies, release behavior, etc., were determined. With IC₅₀ values of 5.8 and 2.4 nm on breast cancer cell lines, accordingly, and a combination index (CI) of < 1.0, DM-PEG-PCL NPs displayed enhanced toxicity towards breast cancer cells (MCF-7 and MDA-MB-231) than DOX-PEG-PCL and MUC1i-PEG-PCL nanoparticles. Fluorescence microscopy analysis revealed DOX localization in the nucleus and MUC1 inhibitor in the mitochondria. Further, DM-PEG-PCL NPs treated breast cancer cells showed increased mitochondrial damage with enhancement in caspase-3 expression and reduction in Bcl-2 expression.In vivo evaluation using Ehrlich Ascites Carcinoma bearing mice explicitly stated that DM-PEG-PCL NPs therapy minimized tumor growth relative to control treatment. Further, acute toxicity studies did not reveal any adverse effects on organs and their functions, as no mortalities were observed. The current research reports for the first time the synergistic approach of combination entrapment of a clinical chemotherapeutic (DOX) and an anticancer peptide (MUC1 inhibitor) encased in a diblock PEG-PCL copolymer. Incorporating both DOX and MUC1 inhibitors in PEG-PCL NPs in the designed nanoformulation has provided chances and insights for treating triple-negative breast tumors. Our controlled delivery technology is biodegradable, non-toxic, and anti-multidrug-resistant. In addition, this tailored smart nanoformulation has been particularly effective in the therapy of triple-negative breast cancer.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10924-022-02654-4.

Glycyrrhizic acid Poly(D,L-lactide-co-glycolide) nanoparticles: anti-aging cosmeceutical formulation for topical applications

Glycyrrhizic acid (GA) is one of the components of licorice roots (Glycyrrhiza glabra L.). GA is a triterpenoid saponin can be used as a medicinal plant with its antiallergic, antiviral, anti-inflammatory, anti-ulcer, hepatoprotective, anticancer, anti-oxidation activities and several other therapeutic properties. The aim of this study is to develop an anti-aging formulation for topical application containing GA. In this context, GA-loaded Poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were prepared using the double emulsion method, and were characterized by various spectroscopic methods. The efficacy of GA-PLGA NPs was evaluated with in vitro and in silico methods. The encapsulation efficiency and loading capacity were calculated. The in vitro release study was conducted, and the GA release profile was determined. The genotoxic activity of GA and GA-PLGA NPs was evaluated by the Ames test using TA98 and TA100 mutant strains of Salmonella typhimurium. The cytotoxic potential of GA-PLGA NPs was evaluated on the HaCaT cell line using the MTT assay. According to the genotoxicity and cytotoxicity results, it was found that the GA-PLGA NP formulation did not exhibit genotoxic and cytotoxic effects. Moreover, the efficacy of GA in preventing UVB-induced photo-aging in HaCaT cells and the clarification of the molecular mechanism of GA binding to MMPs were revealed by molecular docking analysis. In addition, through molecular dynamics (MD) analysis, the binding interaction of GA with MMPs in a dynamic system, and protein-ligand stability were predicted as a result of 50 ns MD simulation studies considering various analysis parameters. Finally, it was evaluated that GA-PLGA nanoformulation might be used as an alternative anti-aging skin care product candidate via topical application.

Hazard Assessment of Polymeric Nanobiomaterials for Drug Delivery: What Can We Learn From Literature So Far

The physicochemical properties of nanobiomaterials, such as their small size and high surface area ratio, make them attractive, novel drug-carriers, with increased cellular interaction and increased permeation through several biological barriers. However, these same properties hinder any extrapolation of knowledge from the toxicity of their raw material. Though, as suggested by the Safe-by-Design (SbD) concept, the hazard assessment should be the starting point for the formulation development. This may enable us to select the most promising candidates of polymeric nanobiomaterials for safe drug-delivery in an early phase of innovation. Nowadays the majority of reports on polymeric nanomaterials are focused in optimizing the nanocarrier features, such as size, physical stability and drug loading efficacy, and in performing preliminary cytocompatibility testing and proving effectiveness of the drug loaded formulation, using the most diverse cell lines. Toxicological studies exploring the biological effects of the polymeric nanomaterials, particularly regarding immune system interaction are often disregarded. The objective of this review is to illustrate what is known about the biological effects of polymeric nanomaterials and to see if trends in toxicity and general links between physicochemical properties of nanobiomaterials and their effects may be derived. For that, data on chitosan, polylactic acid (PLA), polyhydroxyalkanoate (PHA), poly(lactic-co-glycolic acid) (PLGA) and policaprolactone (PCL) nanomaterials will be evaluated regarding acute and repeated dose toxicity, inflammation, oxidative stress, genotoxicity, toxicity on reproduction and hemocompatibility. We further intend to identify the analytical and biological tests described in the literature used to assess polymeric nanomaterials toxicity, to evaluate and interpret the available results and to expose the obstacles and challenges related to the nanomaterial testing. At the present time, considering all the information collected, the hazard assessment and thus also the SbD of polymeric nanomaterials is still dependent on a case-by-case evaluation. The identified obstacles prevent the identification of toxicity trends and the generation of an assertive toxicity database. In the future, in vitro and in vivo harmonized toxicity studies using unloaded polymeric nanomaterials, extensively characterized regarding their intrinsic and extrinsic properties should allow to generate such database. Such a database would enable us to apply the SbD approach more efficiently.

Metal-free semi-aromatic polyester as nanodrug carrier: A novel tumor targeting drug delivery vehicle for potential clinical application

Polyester nanomaterials have been widely used in drug delivey application from a longer period of time. This study reports the synthesis of metal-free semi-aromatic polyester (SAP) nanomaterial for drug delivery and evaluate its in vivo acute and systemic toxicity for potential clinical application. The ring opening coplymerization of commercially available cyclohexene oxide (CHO) and phthalic anhydride (PA) monomers was carried out to synthesize fully alternating poly(CHO-co-PA) copolymer using metal-free activators. The obtained low M_n SAP was found to be biocompatible, hemocompataible and biodegradable nature. This copolymer was first-time used to fabricate curcumin (CUR) loaded nanoparticles (NPs). These NPs were physicochemically characterized by thermogravimetric analyzer (TGA), X-ray diffraction (XRD), and UV/visible spectrophotometer analysis. Further, these negatively charged core-shell spherical NPs exhibited slow sustained release behavior of CUR with anomalous transport and further displayed its higher intracellular uptake in SiHa cells at different time-periods compared to free CUR. In vitro anti-cancer therapeutic effects of free CUR and poly(CHO-alt-PA)-CUR NPs were evaluated on different cancer cells. We observed the increased cytotoxicity of CUR NPs with low IC₅₀ values compared to free CUR. These results were further substantiated with ex vivo data where, a significant reduction was observed in CUR NPs treated tumor spheroid's size as compared to free CUR. Furthermore, the different doses of metal-free poly(CHO-alt-PA) nanomaterial were tested for its acute and systemic toxicity in BALB/c mice. We did not observe any significant toxicity of tested nanomaterial on vital organs, blood cells and the body weight of mice. Our study suggest that this metal-free SAP nanomaterial can be used for potential clinical application.

Monitoring characteristics and genotoxic effects of engineered nanoparticle-protein corona

Engineered nanoparticles (ENPs) possess different physical and chemical properties compared to their bulk counterparts. These unique properties have found application in various products in the area of therapeutics, consumer goods, environmental remediation, optical and electronic fields. This has also increased the likelihood of their release into the environment thereby affecting human health and ecosystem. ENPs, when in contact with the biological system have various physical and chemical interactions with cellular macromolecules including proteins. These interactions lead to the formation of protein corona around the ENPs. Consequently, living systems interact with the protein-coated ENP rather than with a bare ENP. This ENP-protein interaction influences uptake, accumulation, distribution and clearance and thereby affecting the cytotoxic and genotoxic responses. Although there are few studies which discussed the fate of ENPs, there is a need for extensive research in the field of ENPs, to understand the interaction of ENPs with biological systems for their safe and productive application.

PEG-PCL-based nanomedicines: A biodegradable drug delivery system and its application

The lack of efficient therapeutic options for many severe disorders including cancer spurs demand for improved drug delivery technologies. Nanoscale drug delivery systems based on poly(ethylene glycol)-poly(ε-caprolactone) copolymers (PEG-PCL) represent a strategy to implement therapies with enhanced drug accumulation at the site of action and decreased off-target effects. In this review, we discuss state-of-the-art nanomedicines based on PEG-PCL that have been investigated in a preclinical setting. We summarize the various synthesis routes and different preparation methods used for the production of PEG-PCL nanoparticles. Additionally, we review physico-chemical properties including biodegradability, biocompatibility, and drug loading. Finally, we highlight recent therapeutic applications investigated in vitro and in vivo using advanced systems such as triggered release, multi-component therapies, theranostics, or gene delivery systems.

Safety assessment of nanopesticides using the roundworm Caenorhabditis elegans

The extensive use of pesticides is causing environmental pollution, affecting animal organisms in different habitats and also leading human health at risk. In this study, we present as an alternative the use of nanoparticles loaded with pesticides and report their toxicological assessment to a soil organism, Caenorhabditis elegans. Three nanoparticle formulations were analyzed: solid lipid nanoparticles loaded or not with atrazine and simazine, SLN; polymeric nanoparticles, NC_PCL loaded with atrazine; and chitosan/tripolyphosphate, CS/TPP, loaded or not with paraquat. All formulations, loaded or not with pesticides, increased lethality in a dose- dependent manner with similar LC50. Both loaded and unloaded NC_PCL were the most toxic formulations to developmental rate, significantly reducing worms length, even at low concentrations. In contrast, both CS/TPP nanoparticles were the least toxic, not affecting reproduction and body length at higher concentrations, probably due to the biocompatibility of chitosan. The physico-chemical characterization of nanoparticles after incubation in saline solution (used in exposure of organisms) has shown that these colloidal systems are stable and remain with the same initial characteristics, even in the presence of saline environment. Notably, our results indicate that the observed effects were caused by the nanoparticles per se. These results suggest that the development of nanoparticles aiming agriculture applications needs more studies in order to optimize the composition and then reduce their toxicity to non-target organisms.

Determination of mutagenicity and genotoxicity of indium tin oxide nanoparticles using the Ames test and micronucleus assay

In this study, the mutagenicity and genotoxicity of indium tin oxide (ITO) nanomaterial were assessed using two standard genotoxicity assays, the Salmonella reverse mutation assay (Ames test) and the in vitro micronucleus (MN) assay. Seven different concentrations (12.5, 25, 50, 75, 100, 125, and 150 µg/plate) of this nanomaterial were tested using the Ames test on the TA98 and TA100 strains in the presence and absence of the S9 mixture. At all the concentrations tested, this substance did not significantly increase the number of revertant colonies compared with the control with or without S9 mixture. The genotoxic effects of ITO were investigated in human peripheral lymphocytes treated with 125, 250, 500, and 750 µg/ml concentrations of this substance for 24- and 48-h treatment periods using an MN test. Nuclear division index (NDI) was also calculated in order to determine the cytotoxicity of ITO. It was determined that ITO increased MN frequency in the 750 µg/ml concentration in 24- and 48-h treatments. In addition, ITO dose dependently decreased the NDI significantly for two treatment periods.

Synthesis of poly(ɛ-caprolactone) nanospheres in the presence of the protective agent poly(glutamic acid) and their cytotoxicity, genotoxicity and ability to induce oxidative stress in HepG2 cells

Nanospheres of poly(ɛ-caprolactone) (PCL) with sizes smaller than 200 nm were produced by combining the freeze drying method and the physicochemical solvent/non-solvent approach. The influence of various types of cryoprotectants (poly(glutamic acid) (PGA) or sacharose) and their concentrations on the outcome of freeze-dried poly(ɛ-caprolactone) particles was evaluated. The physiochemical properties, structural and morphological characteristics of thereby obtained PCL particles were determined by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The cytotoxicity of the samples was examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT assay). The formation of intracellular reactive oxygen species was measured spectrophotometrically using a fluorescent probe (DCFH-DA assay). In addition, the genotoxic response of PCL particles obtained using PGA as a cryoprotectant was investigated by the Comet assay. This paper focuses on the role of PGA in the synthesis of PCL particles and demonstrates that PGA plays a dual role in the synthesis, i.e. it acts as a stabilizer but also as a cryoprotective agent. The sufficient and optimal concentration of PGA for producing uniform, spherical but also biocompatible PCL nanoparticles is established to be 0.05%.

Genotoxicity evaluation of asymmetric lipid polymer hybrid nanoparticles of doxycycline hydrochloride following intravenous administration

Nanoparticles, being small (<1,000 nm) in size, provide high surface area-to-volume ratio as compared with the bulk materials which increase the concern about their potential toxicities. The present investigation was undertaken to evaluate the genotoxic potential of asymmetric lipid polymer hybrid nanoparticles of doxycycline hydrochloride (DH lipomer) following intravenous route. DH lipomer was prepared by modified nano-precipitation method as reported earlier. Doxycyline loading was found to be 20 ± 2.5 %. Average particle size of DH lipomer and blank lipomer was 512 ± 8 and 520 ± 6 nm, respectively. Micronucleus (MN) assay was performed in adult healthy Swiss mice whereas chromosomal aberration (CA) test and comet assay were performed in healthy Holtzman rats following intravenous administration. Animals were divided into two sets, male and female, each set comprising of six groups (n = 5/group), viz., three test groups, blank lipomer (BL), vehicle control (VC), and positive control. Groups treated with 1.5 mg/kg BW DH lipomer did not show micronuclei formation in bone marrow cell, DNA damage, and CA, respectively, as compared with VC, suggesting no genotoxicity. On the other hand 3 and 6 mg/kg BW revealed significant (P > 0.001) increase in micronuclei formation, DNA damage, and chromosomal aberrations. Furthermore, BL (6 mg/kg BW) did not reveal genotoxic response in any of the tests, suggesting lipomer components as non-genotoxic. No sex-dependent variation in genotoxicity was observed. This study therefore suggests the potential safety of the proposed dose of DH lipomer at 1 mg/kg BW. An interesting highlight of the study is safety of lipomer matrix which could be exploited for other biomedical application.

In vitro genotoxicity testing strategy for nanomaterials and the adaptation of current OECD guidelines

There is a pressing requirement to define a hazard identification and risk management strategy for nanomaterials due to the rapid growth in the nanotechnology industry and their promise of life-style revolutions through the development of wide-ranging nano-containing consumer products. Consequently, a battery of well defined and appropriate in vitro assays to assess a number of genotoxicity endpoints is required to minimise extensive and costly in vivo testing. However, the validity of the established protocols in current OECD recognised genotoxicity assays for nanomaterials is currently being questioned. In this report, we therefore consider the in vitro OECD genotoxicity test battery including the Ames, micronucleus and HPRT forward mutation assays, and their potential role in the safety assessment of nanomaterial induced DNA damage in vitro.

Exploration on the safety assessment of nanomaterials in China

More and more applications of nanomaterials have been achieved in the biomedicine field. Numerous nanomedical devices, such as bone grafts with nano-hydroxyapatite and the silver-based anti-bacteria products, have been developed and have been trying to enter into the Chinese market. The State Food and Drug Administration of China (SFDA) is facing a critical challenge of how to explore and supervise the safety assessment of the nanomedical products. This paper briefly introduces the approval status of nanomedical products and the current advances of the safety assessment of nanomaterials in China.