Promising applications in drug delivery systems of a novel β-cyclodextrin derivative obtained by green synthesis

Pharmacological Polarization of Tumor-Associated Macrophages Toward a CXCL9 Antitumor Phenotype

Tumor-associated macrophages (TAM) are a diverse population of myeloid cells that are often abundant and immunosuppressive in human cancers. CXCL9Hi TAM has recently been described to have an antitumor phenotype and is linked to immune checkpoint response. Despite the emerging understanding of the unique antitumor TAM phenotype, there is a lack of TAM-specific therapeutics to exploit this new biological understanding. Here, the discovery and characterization of multiple small-molecule enhancers of chemokine ligand 9 (CXCL9) and their targeted delivery in a TAM-avid systemic nanoformulation is reported. With this strategy, it is efficient encapsulation and release of multiple drug loads that can efficiently induce CXCL9 expression in macrophages, both in vitro and in vivo in a mouse tumor model. These observations provide a window into the molecular features that define TAM-specific states, an insight a novel therapeutic anticancer approach is used to discover.

Highly Active Myeloid Therapy for Cancer

Tumor-associated macrophages (TAM) interact with cancer and stromal cells and are integral to sustaining many cancer-promoting features. Therapeutic manipulation of TAM could therefore improve clinical outcomes and synergize with immunotherapy and other cancer therapies. While different nanocarriers have been used to target TAM, a knowledge gap exists on which TAM pathways to target and what payloads to deliver for optimal antitumor effects. We hypothesized that a multipart combination involving the Janus tyrosine kinase (JAK), noncanonical nuclear factor kappa light chain enhancer of activated B cells (NF-κB), and toll-like receptor (TLR) pathways could lead to a highly active myeloid therapy (HAMT). Thus, we devised a screen to determine drug combinations that yield maximum IL-12 production from myeloid cells to treat the otherwise highly immunosuppressive myeloid environments in tumors. Here we show the extraordinary efficacy of a triple small-molecule combination in a TAM-targeted nanoparticle for eradicating murine tumors, jumpstarting a highly efficient antitumor response by adopting a distinctive antitumor TAM phenotype and synergizing with other immunotherapies. The HAMT therapy represents a recently developed approach in immunotherapy and leads to durable responses in murine cancer models.

A promising synthetic citric crosslinked β-cyclodextrin derivative for antifungal drugs: Solubilization, cytotoxicity, and antifungal activity

Effective antifungal therapy for the treatment of fungal keratitis requires a high drug concentration at the corneal surface. However, the use of natural β-cyclodextrin (βCD) in the preparation of aqueous eye drop formulations for treating fungal keratitis is limited by its low aqueous solubility. Here, we synthesized water-soluble anionic βCD derivatives capable of forming water-soluble complexes and evaluated the solubility, cytotoxicity, and antifungal efficacy of drug prepared using the βCD derivative. To achieve this, a citric acid crosslinked βCD (polyCTR-βCD) was successfully synthesized, and the aqueous solubilities of selected antifungal drugs, including voriconazole, miconazole (MCZ), itraconazole, and amphotericin B, in polyCTR-βCD and analogous βCD solutions were evaluated. Among the drugs tested, complexation of MCZ with polyCTR-βCD (MCZ/polyCTR-βCD) increased MCZ aqueous solubility by 95-fold compared with that of MCZ/βCD. The inclusion complex formation of MCZ/βCD and MCZ/polyCTR-βCD was confirmed by spectroscopic techniques. Additionally, the nanoaggregates of saturated MCZ/polyCTR-βCD and MCZ/βCD solutions were observed using dynamic light scattering and transmission electron microscopy. Moreover, MCZ/polyCTR-βCD solution exhibited good mucoadhesion, sustained drug release, and high drug permeation of porcine cornea ex vivo. Hen's Egg test-chorioallantoic membrane assay and cell viability study using Statens Seruminstitut Rabbit Cornea cell line showed that both MCZ/polyCTR-βCD and MCZ/βCD exhibited no sign of irritation and non-toxic to cell line. Additionally, antifungal activity evaluation demonstrated that all isolated fungi, including Candida albicans, Aspergillus flavus, and Fusarium solani, were susceptible to MCZ/polyCTR-βCD. Overall, the results showed that polyCTR-βCD could be a promising nanocarrier for the ocular delivery of MCZ.

Synthesis and characterization of a new cyclodextrin derivative with improved properties to design oral dosage forms

This work aimed to synthesize a novel β-cyclodextrin derivative, itaconyl-β-cyclodextrin to evaluate whether albendazole inclusion complexes with the new β-cyclodextrin derivative-improved albendazole dissolution efficiency and its anthelminthic activity. The new derivative was thoroughly evaluated and characterized, and an average degree of substitution of 1.4 per cyclodextrin molecule was observed. Albendazole:itaconyl-β-cyclodextrin complexes were prepared by spray drying procedures and investigated using phase solubility diagrams, dissolution efficiency, X-ray diffraction, differential scanning calorimetry, Fourier transform infrared, scanning electronic microscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy. Phase solubility diagrams and mass spectrometry studies showed that the inclusion complex was formed in an equimolar ratio. Stability constant values were 602 M^-1 in water, and 149 M^-1 in HCl 0.1 N. Nuclear magnetic resonance experiments of the inclusion complex showed correlation signals between the aromatic and propyl protons of albendazole and the itaconyl-β-cyclodextrin inner protons. The studies indicated solid structure changes of albendazole included in itaconyl-β-cyclodextrin. The maximum drug release was reached at 15 min, and the inclusion complex solubility was 88-fold higher than that of the pure drug. The in vitro anthelmintic activity assay showed that the complex was significantly more effective than pure albendazole.

Succinyl-β-cyclodextrin: Influence of the substitution degree on albendazole inclusion complexes probed by NMR

Succinyl-β-CD derivatives were obtained by green synthesis with degrees of substitution (DS) 1.3 and 2.9. The spray-drying technique was used to obtain albendazole (ABZ):succinyl-β-CD inclusion complexes. Phase solubility diagrams indicated that both succinyl-β-CD derivatives formed 1:1 molar ratio ABZ complexes, but the complex with DS 2.9 has a lower formation constant. The presence of stable inclusion complexes in aqueous solution was confirmed by NMR. For both complexes the aromatic moiety is encapsulated into the host cavity. In the solid-state, ¹³C and ¹⁵N NMR spectral differences between ABZ and ABZ included in spray-dried systems showed that strong structural changes occurred in the systems. At least two different ABZ amorphous species were identified based on DS. ABZ species were stable over more than six months based on spectral data. Finally, the influence of DS in the number and type of the inclusion complexes was elucidated.

Repositioning of Anti-parasitic Drugs in Cyclodextrin Inclusion Complexes for Treatment of Triple-Negative Breast Cancer

Drug repositioning refers to the identification of new therapeutic indications for drugs already approved. Albendazole and ricobendazole have been used as anti-parasitic drugs for many years; their therapeutic action is based on the inhibition of microtubule formation. Therefore, the study of their properties as antitumor compounds and the design of an appropriate formulation for cancer therapy is an interesting issue to investigate. The selected compounds are poorly soluble in water, and consequently, they have low and erratic bioavailability. In order to improve their biopharmaceutics properties, several formulations employing cyclodextrin inclusion complexes were developed. To carefully evaluate the in vitro and in vivo antitumor activity of these drugs and their complexes, several studies were performed on a breast cancer cell line (4T1) and BALB/c mice. In vitro studies showed that albendazole presented improved antitumor activity compared with ricobendazole. Furthermore, albendazole:citrate-β-cyclodextrin complex decreased significantly 4T1 cell growth both in in vitro and in vivo experiments. Thus, new formulations for anti-parasitic drugs could help to reposition them for new therapeutic indications, offering safer and more effective treatments by using a well-known drug.

Development and in vitro evaluation of solid dispersions as strategy to improve albendazole biopharmaceutical behavior

Aim: Solid dispersions using Poloxamer 407 as carrier were developed to improve albendazole (ABZ) solubility and dissolution profiles. Methods: ABZ/poloxamer solid dispersions were prepared, and dissolution profiles were mathematically modeled and compared with physical mixtures, pharmaceutical ABZ and a commercial formulation. Results: Poloxamer 407 increased exponentially ABZ solubility, in about 400% when 95% w/w of polymer compared with its absence. Solid dispersions initial dissolution rate was three to 20-fold higher than physical mixtures, the drug and the commercial formulation. All the solid dispersions required less than 2.2 min to reach an 80% of ABZ dissolution, while the commercial formulation needed around 40 min. Conclusion: Solid dispersions improved ABZ solubility and dissolution rate, which could result in a faster absorption and an increased bioavailability.

PLGA Microspheres Loaded with β-Cyclodextrin Complexes of Epigallocatechin-3-Gallate for the Anti-Inflammatory Properties in Activated Microglial Cells

Although epigallocatechin-3-gallate (EG) is well-known as a potent antioxidant and free radical scavenger for neurodegenerative diseases, it still has disadvantages that reduce its treatment effectiveness due to low bioavailability, slow absorption, and water solubility. Therefore, the aim of this study is to improve the bioavailability of EG and increase the effectiveness of anti-inflammatory properties to microglial cells by using Poly(Lactide-co-Glycolide) (PLGA) microspheres as carriers. In this study, we used UV–Vis spectroscopy to show the formation of the complex of β-cyclodextrin (β-CD) and EG (CD-EG). The loading efficiency of EG in PLGA microspheres was optimized by the addition of β-CD. The highest loading efficiency of 16.34% was found among other formulations. The results of Fourier transform infrared spectroscopy indicated the loading of CD-EG in PLGA microspheres. The scanning electron microscopic images demonstrated the spherical PLGA particles with controlled particles size ranging from 1–14 µm. Moreover, the in vitro release of EG was conducted to explore the sustained release property of the PLGA formulations. In the in vitro model of mouse microglial cells (BV-2 cells) stimulated by lipopolysaccharide, the cytotoxicity test showed that for up to 1 mg/mL of PLGA microspheres no toxicity to BV-2 cells was found. PLGA microspheres can significantly suppress the nitric oxide production from BV-2 cells, indicating EG loaded in PLGA microspheres can suppress the inflammation of activated microglial cells. Furthermore, the intracellular iNOS in BV-2 cells was also found to be down regulated. In summary, we have successfully shown that the use of β-CD can increase the loading efficiency of EG in PLGA microspheres and provide neuroprotective effect on the activated microglial cells.

Synthesis of a poly(ester) dendritic β-cyclodextrin derivative by "click" chemistry: Combining the best of two worlds for complexation enhancement

In spite of the progress in the cyclodextrins chemistry, the synthesis of monodisperse derivatives with a defined degree of substitution is still a challenge. In this work we present a novel dendritic material produced by combining βCD and second generation poly(ester) dendrons. The selective attachment of dendrons in the seven positions of the βCD-primary face was performed through a CuAAC click reaction, which along with a very simple work-up, allowed obtaining the monodisperse material in very high yields. The product showed a great aqueous solubility and an in vitro non-toxic profile. The enhanced complexation potential of the product was evidenced through the formation of an inclusion complex with albendazole, which presented a K_c = 29636.17 M^-1. In this system, albendazole was 45 times more water-soluble in comparison to the complex albendazole-native βCD. All these features make the dendritic material very attractive for further applications in the formulation and drug delivery fields.