Regulatory insights into nanomedicine and gene vaccine innovation: Safety assessment, challenges, and regulatory perspectives.

This analysis explores the principal regulatory concerns linked to nanomedicines and gene vaccines, including the complexities involved and the perspectives on how to navigate them. In the realm of nanomedicines, ensuring the safety of nanomaterials is paramount due to their unique characteristics and potential interactions with biological systems. Regulatory bodies are actively formulating guidelines and standards to assess the safety and risks associated with nanomedicine products, emphasizing the need for standardized characterization techniques to accurately gauge their safety and effectiveness. Regarding gene vaccines, regulatory frameworks must be tailored to address the distinct challenges posed by genetic interventions, necessitating special considerations in safety and efficacy evaluations, particularly concerning vector design, target specificity, and long-term patient monitoring. Ethical concerns such as patient autonomy, informed consent, and privacy also demand careful attention, alongside the intricate matter of intellectual property rights, which must be balanced against the imperative of ensuring widespread access to these life-saving treatments. Collaborative efforts among regulatory bodies, researchers, patent offices, and the private sector are essential to tackle these challenges effectively, with international cooperation being especially crucial given the global scope of nanomedicine and genetic vaccine development. Striking the right balance between safeguarding intellectual properties and promoting public health is vital for fostering innovation and ensuring equitable access to these ground-breaking technologies, underscoring the significance of addressing these regulatory hurdles to fully harness the potential benefits of nanomedicine and gene vaccines for enhancing healthcare outcomes on a global scale. STATEMENT OF SIGNIFICANCE: Several biomaterials are being proposed for the development of nanovaccines, from polymeric micelles, PLGA-/PEI-/PLL-nanoparticles, solid lipid nananoparticles, cationic lipoplexes, liposomes, hybrid materials, dendrimers, carbon nanotubes, hydrogels, to quantum dots. Lipid nanoparticles (LNPs) have gained tremendous attention since the US Food and Drug Administration (FDA) approval of Pfizer and Moderna's COVID-19 vaccines, raising public awareness to the regulatory challenges associated with nanomedicines and genetic vaccines. This review provides insights into the current perspectives and potential strategies for addressing these issues, including clinical trials. By navigating these regulatory landscapes effectively, we can unlock the full potential of nanomedicine and genetic vaccines using a range of promising biomaterials towards improving healthcare outcomes worldwide.

In Vitro Assessment of Pesticides Toxicity and Data Correlation with Pesticides Physicochemical Properties for Prediction of Toxicity in Gastrointestinal and Skin Contact Exposure.

In this work, three pesticides of different physicochemical properties, namely, glyphosate (herbicide), imidacloprid (insecticide) and imazalil (fungicide), were selected to assess their cytotoxicity against distinct cell models (Caco-2, HepG2, A431, HaCaT, SK-MEL-5 and RAW 264.7 cells) to mimic gastrointestinal and skin exposure with potential systemic effect. Cells were subjected to different concentrations of selected pesticides for 24 h or 48 h. Cell viability was assessed by Alamar Blue assay, morphological changes by bright-field microscopy and the IC50 values were calculated. Cytotoxic profiles were analysed using the physico-chemical parameters of the pesticides, namely: molecular weight, water solubility, the partition coefficient in the n-octanol/water (Log Pow) system, the topological polar surface area (TPSA), and number of hydrogen-bonds (donor/acceptor) and rotatable bonds. Results showed that glyphosate did not reduce cell viability (up to 1 mM), imidacloprid induced moderate toxicity (IC50 > 1 mM for Caco-2 cells while IC50 = 305.9 ± 22.4 µM for RAW 264.7 cells) and imazalil was highly cytotoxic (IC50 > 253.5 ± 3.37 for Caco-2 cells while IC50 = 31.3 ± 2.7 µM for RAW 264.7 cells) after 24 h exposure. Toxicity was time-dependent as IC50 values at 48 h exposure were lower, and decrease in cell viability was accompanied by changes in cell morphology. Pesticides toxicity was found to be directly proportional with their Log Pow, indicating that the affinity to a lipophilic environment such as the cell membranes governs their toxicity. Toxicity is inverse to pesticides TPSA, but lower TPSA favours membrane permeation. The lower toxicity against Caco-2 cells was attributed to the physiology and metabolism of cell barriers equipped with various ABC transporters. In conclusion, physicochemical factors such as Log Pow, TPSA and H-bond are likely to be directly correlated with pesticide-induced toxicity, thus being key factors to potentially predict the toxicity of other compounds.

Genotoxicity Assessment of Metal-Based Nanocomposites Applied in Drug Delivery.

Nanocomposites as drug delivery systems (e.g., metal nanoparticles) are being exploited for several applications in the biomedical field, from therapeutics to diagnostics. Green nanocomposites stand for nanoparticles of biocompatible, biodegradable and non-toxic profiles. When using metal nanoparticles for drug delivery, the question of how hazardous these "virus-sized particles" can be is posed, due to their nanometer size range with enhanced reactivity compared to their respective bulk counterparts. These structures exhibit a high risk of being internalized by cells and interacting with the genetic material, with the possibility of inducing DNA damage. The Comet Assay, or Single-Cell Gel Electrophoresis (SCGE), stands out for its capacity to detect DNA strand breaks in eukaryotic cells. It has huge potential in the genotoxicity assessment of nanoparticles and respective cells' interactions. In this review, the Comet assay is described, discussing several examples of its application in the genotoxicity evaluation of nanoparticles commonly administered in a set of routes (oral, skin, inhaled, ocular and parenteral administration). In the nanoparticles boom era, where guidelines for their evaluation are still very limited, it is urgent to ensure their safety, alongside their quality and efficacy. Comet assay or SCGE can be considered an essential tool and a reliable source to achieve a better nanotoxicology assessment of metal nanoparticles used in drug delivery.

Ocular Cell Lines and Genotoxicity Assessment.

Genotoxicity screening tests aim to evaluate if and to what extent a compound in contact with the human body (e.g., a drug molecule, a compound from the environment) interacts with DNA. The comet assay is a sensitive method used to predict the risk of DNA damage in individual cells, as it quantifies the tape breaks, being the alkaline version (pH > 13) the most commonly used in the laboratory. Epithelial cells serve as biomatrices in genotoxicity assessments. As ca. 80% of solid cancers are of epithelial origin, the quantification of the DNA damage upon exposure of epithelial cells to a drug or drug formulation becomes relevant. Comet assays run in epithelial cells also have clinical applications in human biomonitoring, which assesses whether and to what extent is the human body exposed to environmental genotoxic compounds and how such exposure changes over time. Ocular mucosa is particularly exposed to environmental assaults. This review summarizes the published data on the genotoxicity assessment in estimating DNA damage in epithelial cells with a special focus on ocular cell lines. General comet assay procedures for ex vivo and in vivo epithelium samples are also described.

Loading, release profile and accelerated stability assessment of monoterpenes-loaded solid lipid nanoparticles (SLN).

Glycerol monostearate solid lipid nanoparticles (SLN) were produced by hot high-pressure homogenization technique to load alpha-pinene, citral, geraniol or limonene. SLN were composed of 1 wt.% monoterpene, 4 wt.% of Imwitor® 900K as a solid lipid and 2.5 wt.% of Poloxamer188 as a surfactant. Empty SLN consisted of 5 wt.% of Imwitor® 900K and 2.5 wt.% of Poloxamer188. The mean particles size (Z-Ave) and polydispersity index (PDI) of SLN were analyzed by dynamic light scattering (DLS), while the zeta potential (ZP) of each formulation were measured by electrophoretic light scattering. LUMiSizer® was applied to calculate the velocity distribution in the centrifugal field and instability index. Drug release profile from SLN was analyzed using Franz cell diffusion cells assayed by UV-Vis spectrophotometry, whereas the gas chromatography technique was applied to determine the encapsulation parameters of volatile monoterpenes. The matrix state, polymorphism and phase behavior of SLN were studied by X-ray diffraction (XRD, low and wide angles) and differential scanning calorimetry (DSC). Selected monoterpenes were successfully loaded in glycerol monostearate SLN. A burst release profile within the first 15 min was observed for all formulations, being the modified release profile dependent on the type of monoterpene and on the encapsulation efficiency.

A note on regulatory concerns and toxicity assessment in lipid-based delivery systems (LDS).

Lipid-based Delivery Systems (LDS) has been the focus of potential strategies in drug delivery for several years. A great deal of work has been invested on how to exploit their biocompatible and biodegradable nature, in combination with their nanosize range in a profitable way in the field of nanomedicines. A number of drugs loaded in LDS have been already tested in vivo successfully. However, in vivo behaviour of nanosized materials differs from their bulk counterparts (and also change drug properties), mainly depending on the particular LDS physicochemical characteristics. These may have huge impact on the toxicity of the system, despite the physiological nature of the lipid materials. This note on the regulatory concerns and toxicity assessment in LDS suggests that current knowledge of public and scientific communities is lacking, requiring intensive research and policy measures to provide a deep understanding on toxicological risks.