Enhancing the anti-cancer therapeutic efficacy by optimizing molecular weight of metal-free fully alternating semi-aromatic polyester as nano-drug carriers

Organoboron-mediated polymerizations

The scientific community has witnessed extensive developments and applications of organoboron compounds as synthetic elements and metal-free catalysts for the construction of small molecules, macromolecules, and functional materials over the last two decades. This review highlights the achievements of organoboron-mediated polymerizations in the past several decades alongside the mechanisms underlying these transformations from the standpoint of the polymerization mode. Emphasis is placed on free radical polymerization, Lewis pair polymerization, ionic (cationic and anionic) polymerization, and polyhomologation. Herein, alkylborane/O2 initiating systems mediate the radical polymerization under ambient conditions in a controlled/living manner by careful optimization of the alkylborane structure or additives; when combined with Lewis bases, the selected organoboron compounds can mediate the Lewis pair polymerization of polar monomers; the bicomponent organoboron-based Lewis pairs and bifunctional organoboron-onium catalysts catalyze ring opening (co)polymerization of cyclic monomers (with heteroallenes, such as epoxides, CO2, CO, COS, CS2, episulfides, anhydrides, and isocyanates) with well-defined structures and high reactivities; and organoboranes initiate the polyhomologation of sulfur ylides and arsonium ylides providing functional polyethylene with different topologies. The topological structures of the produced polymers via these organoboron-mediated polymerizations are also presented in this review mainly including linear polymers, block copolymers, cyclic polymers, and graft polymers. We hope the summary and understanding of how organoboron compounds mediate polymerizations can inspire chemists to apply these principles in the design of more advanced organoboron compounds, which may be beneficial for the polymer chemistry community and organometallics/organocatalysis community.

In Vivo Toxicological Analysis of the ZnFe2O4@poly(tBGE-alt-PA) Nanocomposite: A Study on Fruit Fly

Recently, the use of hybrid nanomaterials (NMs)/nanocomposites has widely increased for the health, energy, and environment sectors due to their improved physicochemical properties and reduced aggregation behavior. However, prior to their use in such sectors, it is mandatory to study their toxicological behavior in detail. In the present study, a ZnFe2O4@poly(tBGE-alt-PA) nanocomposite is tested to study its toxicological effects on a fruit fly model. This nanocomposite was synthesized earlier by our group and physicochemically characterized using different techniques. In this study, various neurological, developmental, genotoxic, and morphological tests were carried out to investigate the toxic effects of nanocomposite on Drosophila melanogaster. As a result, an abnormal crawling speed of third instar larvae and a change in the climbing behavior of treated flies were observed, suggesting a neurological disorder in the fruit flies. DAPI and DCFH-DA dyes analyzed the abnormalities in the larva's gut of fruit flies. Furthermore, the deformities were also seen in the wings and eyes of the treated flies. These obtained results suggested that the ZnFe2O4@poly(tBGE-alt-PA) nanocomposite is toxic to fruit flies. Moreover, this is essential to analyze the toxicity of this hybrid NM again in a rodent model in the future.

Anti-cancer Application of Nat-ZnFe2O4 Nanoparticles on 2D Tumor Models

Metal/Metal Oxide nanoparticles (M/MO NPs) exhibit potential biomedical applications due to their tunable physicochemical properties. Recently, the biogenic synthesis of M/MO NPs has gained massive attention due to their economical and eco-friendly nature. In the present study, Nyctanthes arbor-tristis (Nat) flower extract-derived Zinc Ferrite NPs (Nat-ZnFe2O4 NPs) were synthesized and physicochemically characterized by FTIR, XRD, FE-SEM, DLS, and other instruments to study their crystallinity, size, shape, net charge, presence of phytocompounds on NP's surface and several other features. The average particle size of Nat-ZnFe2O4 NPs was approx. 25.87 ± 5.67 nm. XRD results showed the crystalline nature of Nat-ZnFe2O4 NPs. The net surface charge on NPs was -13.28 ± 7.18 mV. When tested on mouse fibroblasts and human RBCs, these NPs were biocompatible and hemocompatible. Later, these Nat-ZnFe2O4 NPs exhibited potent anti-neoplastic activity against pancreatic, lung, and cervical cancer cells. In addition, NPs induced apoptosis in tested cancer cells through ROS generation. These in vitro studies confirmed that Nat-ZnFe2O4 NPs could be used for cancer therapy. Moreover, further studies are recommended on ex vivo platforms for future clinical applications.

In Vivo Toxicological Analysis of MnFe2O4@poly(tBGE-alt-PA) Composite as a Hybrid Nanomaterial for Possible Biomedical Use

Nanocomposites have significantly contributed to biomedical science due to less aggregation behavior and enhanced physicochemical properties. This study synthesized a MnFe₂O₄@poly(tBGE-alt-PA) nanocomposite for the first time and physicochemically characterized it. The obtained hybrid nanomaterial was tested in vivo for its toxicological properties before use in drug delivery, tissue engineering fields, and environmental applications. The composite was biocompatible with mouse fibroblast cells and hemocompatible with 2% RBC suspension. This nanocomposite was tested on Drosophila melanogaster due to its small size, well-sequenced genome, and low cost of testing. The larvae's crawling speed and direction were measured after feeding. No abnormal path and altered crawling pattern indicated the nonappearance of abnormal neurological disorder in the larva. The gut organ toxicity was further analyzed using DAPI and DCFH-DA dye to examine the structural anomalies. No apoptosis and necrosis were observed in the gut of the fruit fly. Next, adult flies were examined for phenotypic anomalies after their pupal phases emerged. No defects in the phenotypes, including the eye, wings, abdomen, and bristles, were found in our study. Based on these observations, the MnFe₂O₄@poly(tBGE-alt-PA) composite may be used for various biomedical and environmental applications.

Recent trends in biodegradable polyester nanomaterials for cancer therapy

Biodegradable polyester nanomaterials-based drug delivery vehicles (DDVs) have been largely used in most of the cancer treatments due to its high biological performance and wider applications. In several previous studies, various biodegradable and biocompatible polyester backbones were used which are poly(lactic acid) (PLA), poly(ε-caprolactone) (PCL), poly(propylene fumarate) (PPF), poly(lactic-co-glycolic acid) (PLGA), poly(propylene carbonate) (PPC), polyhydroxyalkanoates (PHA), and poly(butylene succinate) (PBS). These polyesters were fabricated into therapeutic nanoparticles that carry drug molecules to the target site during the cancer disease treatment. In this review, we elaborately discussed the chemical synthesis of different synthetic polyesters and their use as nanodrug carriers (NCs) in cancer treatment. Further, we highlighted in brief the recent developments of metal-free semi-aromatic polyester nanomaterials along with its role as cancer drug delivery vehicles.

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.