Albumin-stabilized epirubicin nanocarriers of core–shell type based on poly(butyl cyanoacrylate) and poly(styrene-co-maleic acid)

Aminolysis-mediated single-step surface functionalization of poly (butyl cyanoacrylate) microbubbles for ultrasound molecular imaging

Molecular ultrasound imaging with actively targeted microbubbles (MB) proved promising in preclinical studies but its clinical translation is limited. To achieve this, it is essential that the actively targeted MB can be produced with high batch-to-batch reproducibility with a controllable and defined number of binding ligands on the surface. In this regard, poly (n-butyl cyanoacrylate) (PBCA)-based polymeric MB have been used for US molecular imaging, however, ligand coupling was mostly done via hydrolysis and carbodiimide chemistry, which is a multi-step procedure with poor reproducibility and low MB yield. Herein, we developed a single-step coupling procedure resulting in high MB yields with minimal batch-to-batch variation. Actively targeted PBCA-MB were generated using an aminolysis protocol, wherein amine-containing cRGD was added to the MB using lithium methoxide as a catalyst. We confirmed the successful conjugation of cRGD on the MB surface, while preserving their structure and acoustic signal. Compared to the conventional hydrolysis protocol, aminolysis resulted in higher MB yields and better reproducibility of coupling efficiency. Optical imaging revealed that under flow conditions, cRGD- and rhodamine-labelled MB, generated by aminolysis, specifically bind to tumor necrosis factor-alpha (TNF-α) activated endothelial cells in vitro. Furthermore, US molecular imaging demonstrated a markedly higher binding of the cRGD-MB than of control MB in TNF-α activated mouse aortas and 4T1 tumors in mice. Thus, using the aminolysis based conjugation approach, important refinements on the production of cRGD-MB could be achieved that will facilitate the production of clinical-scale formulations with excellent binding and ultrasound imaging performance.

Epirubicin: Biological Properties, Analytical Methods, and Drug Delivery Nanosystems

Epirubicin (EPI) is a chemotherapeutic agent belonging to the anthracycline drug class indicated for treating several tumors. It acts by suppressing the DNA and RNA synthesis by intercalating between their base pair. However, several side effects are associated with this therapy, including cardiotoxicity and myelosuppression. Therefore, EPI delivery in nanosystems has been an interesting strategy to overcome these limitations and improve the safety and efficacy of EPI. Thus, analytical methods have been used to understand and characterize these nanosystems, including spectrophotometric, spectrofluorimetric, and chromatography. Spectrophotometric and spectrofluorimetric methods have been used to quantify EPI in less complex matrices due to their efficiency, low cost, and green chemistry character. By contrast, high-performance liquid chromatography is a suitable method for detecting EPI in more complex matrices (e.g., plasm and urine) owing to its high sensitivity. This review summarizes physicochemical and pharmacokinetic properties of EPI, its application in drug delivery nanosystems, and the analytical methods employed in its quantification in different matrices, including blood, plasm, urine, and drug delivery nanosystems.

In vitro and in vivo evaluation of 10-hydroxycamptothecin-loaded poly (n-butyl cyanoacrylate) nanoparticles prepared by miniemulsion polymerization

In this paper, 10-hydroxycamptothecin (HCPT)-loaded poly (n-butyl cyanoacrylate) nanoparticles (HCPT-PBCA-NPs) co-modified with polysorbate 80, soybean phospholipids, and polyethylene glycol (100) monostearate were successfully prepared via miniemulsion polymerization, and were characterized for particle size, morphology, zeta potential, encapsulation efficiency (EE) and drug loading capacity (DL). The chemical structure of HCPT-PBCA-NPs and the state of HCPT in the PBCA-NPs were investigated by DSC, FTIR and ¹H NMR. Additionally, drug release, cytotoxicity, cellular uptake capacity, cellular uptake mechanism, and in vivo behavior of NPs were investigated as well. The particles were 92.7nm in size with a high EE of 94.24%. FTIR, ¹H NMR, and DSC demonstrated complete polymerization of BCA monomers and the drug was in a molecular or amorphous form inside the NPs. In vitro release of the drug from HCPT-PBCA-NPs exhibited sustained-release and less than 60% of HCPT was released from the NPs within 24h of dialysis. Cellular uptake study displayed that Caco-2 cell uptake of NPs was governed by active endocytosis, clathrin- and caveolin-mediated process, and increased with the increase of the NPs concentration and the time. The pharmacokinetic study in rats showed that encapsulation of HCPT into PBCA-NPs increased the C_max and AUC_0-t about 6.52 and 7.56 times, respectively, in comparison with the HCPT suspension. It was concluded that HCPT loaded PBCA-NPs prepared by miniemulsion polymerization could be promising in oral drug delivery.