Review: doxorubicin delivery systems based on chitosan for cancer therapy

Lipid quantification method using FTIR spectroscopy applied on cancer cell extracts

Reprogramming energy metabolism constitutes one of the hallmarks of cancer. Changes in lipid composition of cell membranes also appear early in carcinogenesis. Quantification of various molecules such as lipids evidences the modifications in the metabolism of tumour cells and can serve as potential markers for cancer diagnosis and treatment. Fourier Transform Infrared (FTIR) spectroscopy is a powerful tool used for the detection and characterization of various types of molecules. This technique remains an attractive approach as it is cheap (equipment and reagents), does not require high grade solvents or expensive internal standards, equipment is widely available in standard laboratories and the method is robust and suitable for routine analyses. In this work we established partial least square (PLS) models based on FTIR spectra able to quantify lipids in complex mixtures such as cell extracts. In the first part, we attempted to build PLS models with FTIR spectra of 53 mixtures of 8 well-characterized pure lipids. Second, the PLS models were verified using FTIR spectra of mixtures that did not contribute to the calibration. The third step was the validation of the models on lipid cell extracts. In order to obtain reference values for cell extracts, high performance liquid chromatography was carried out by AVANTI. The lipid distribution were globally similar with both techniques, PLS models and chromatography. Finally, the models were applied to determine the lipid composition of cells exposed to four treatments. We could not evidence significant changes in the lipid composition of cell extracts after treatment, in terms of polar head groups. However, the models established in this study appear reliable and could be applied for high throughput measurements. This article is part of a Special Issue entitled Tools to study lipid functions.

Doxorubicin-induced death in tumour cells and cardiomyocytes: is autophagy the key to improving future clinical outcomes?

Objectives

Doxorubicin, a commonly used frontline chemotherapeutic agent for cancer, is not without side-effects. The original thinking that the drug causes necrosis in tumours has largely given way to its link with apoptosis over the past two decades.

Key findings

More recently, major biomarkers such as AMPK, p53 and Bcl-2 have been identified as important to apoptosis induction by doxorubicin. It is Bcl-2 and its interaction with Beclin-1 that has refocussed research attention on doxorubicin, albeit this time for its ability to induce autophagy. Autophagy can be either anticancerous or procancerous however, so it is critical that the reasons for which cancer cells undergo this type of cell biological event be clearly identified for future exploitation.

Summary

Taking a step back from treating patients with large doses of doxorubicin, which causes toxicity to the heart amongst other organs, and further research with this drug's molecular signalling in not only neoplastic but normal cells, may indeed redefine the way doxorubicin is used clinically and potentially lead to better neoplastic disease management.

Microbial natural products: molecular blueprints for antitumor drugs

Microbes from two of the three domains of life, the Prokarya, and Eukarya, continue to serve as rich sources of structurally complex chemical scaffolds that have proven to be essential for the development of anticancer therapeutics. This review describes only a handful of exemplary natural products and their derivatives as well as those that have served as elegant blueprints for the development of novel synthetic structures that are either currently in use or in clinical or preclinical trials together with some of their earlier analogs in some cases whose failure to proceed aided in the derivation of later compounds. In every case, a microbe has been either identified as the producer of secondary metabolites or speculated to be involved in the production via symbiotic associations. Finally, rapidly evolving next-generation sequencing technologies have led to the increasing availability of microbial genomes. Relevant examples of genome mining and genetic manipulation are discussed, demonstrating that we have only barely scratched the surface with regards to harnessing the potential of microbes as sources of new pharmaceutical leads/agents or biological probes.

Immunomodulatory effects of hexane insoluble fraction of Ficus septica Burm. F. in doxorubicin-treated rats

The use of chemotherapeutics induces cardiotoxicity and affects immune functions, therefore development of combinatorial agents against cardiotoxicity and immunosuppression needs to be explored. Previous studies of the hexane insoluble fraction (HIF) of an ethanolic extract of Ficus septica leaves showed anticancer effects singly and in combination with doxorubicin on T47D breast cancer cells. In this present study, it was evaluated for its immunomodulatory activities in doxorubicin-treated rats. Thirty male Sprague Dawley rats were divided into five groups consisting of six rats each as follows: Group 1, receiving oral saline 10 ml/kg BW (control group); Group 2, receiving HIF dose 750 mg/kg BW orally, once daily; Group 3, receiving HIF dose 1.500 mg/kg BW orally, once daily; Group 4, given oral saline 10 ml/kg BW (normal group); Group 5, receiving HIF dose 1.500 mg/kg BW orally, once daily. The rats of group 1-3 were intramuscularly administered with doxorubicin at a dose of 4.67 mg/kg BW at the days 1 and 4 to suppress immune functions. Concomitantly, the rats were treated with saline or HIF for seven consecutive days (1 to 7). Treatment of HIF succeeded in reducing side effects of doxorubicin based on increasing lymphocyte density and phagocytosis activity and capacity of macrophages, as well as increasing the CD8+blood level and decreasing spleen IL-10 expression. Hexane insoluble fraction of of ethanolic extract of Ficus septica leaves has potential as a protective agent combined with doxorubicin.

Enhancing the Effects of Low Dose Doxorubicin Treatment by the Radiation in T47D and SKBR3 Breast Cancer Cells

Purpose

Breast cancer is the most common malignancy of women worldwide. Radiotherapy consists of a vital element in the treatment of breast cancer but relative side effects and different radioactive responses are limiting factors for a successful treatment. Doxorubicin has been used to treat cancers for over 30 years and is considered as the most effective drug in the treatment of breast cancer. There are also many chronic side effects that limit the amount of doxorubicin that can be administered. The combined radio-drug treatment, with low doses, can be an approach for reducing side effects from single modality treatments instead of suitable cure rates.

Methods

We have studied the effect of 1, 1.5, and 2 Gy doses of 9 MV X-rays along with 1 µM doxorubicin on inducing cell death, apoptosis and also p53 and PTEN gene expression in T47D and SKBR3 breast cancer cells.

Results

Doxorubicin treatment resulted in upregulation of radiation-induced levels of p53 and downregulation of PTEN at 1 and 1.5 Gy in T47D breast cancer cells, as well as downregulation of p53 mRNA level of expression and upregulation of PTEN mRNA level of expression in SKBR3 breast cancer cell line. In addition, doxorubicin in combination with radiation decreased the viability of breast cancer cell lines in the both cell lines.

Conclusion

Low doses of doxorubicin, with least cell toxicity, may be an effective treatment for breast cancer when used in conjunction with ionizing radiation.

Delivery of chemotherapeutic drugs in tumour cell-derived microparticles

Cellular microparticles are vesicular plasma membrane fragments with a diameter of 100-1,000 nanometres that are shed by cells in response to various physiological and artificial stimuli. Here we demonstrate that tumour cell-derived microparticles can be used as vectors to deliver chemotherapeutic drugs. We show that tumour cells incubated with chemotherapeutic drugs package these drugs into microparticles, which can be collected and used to effectively kill tumour cells in murine tumour models without typical side effects. We describe several mechanisms involved in this process, including uptake of drug-containing microparticles by tumour cells, synthesis of additional drug-packaging microparticles by these cells that contribute to the cytotoxic effect and the inhibition of drug efflux from tumour cells. This study highlights a novel drug delivery strategy with potential clinical application.

Enhanced dissolution and oral bioavailability of tanshinone IIA base by solid dispersion system with low-molecular-weight chitosan

OBJECTIVES

The aim of this study is to improve the dissolution and oral bioavailability of tanshinone IIA (TAN).

METHODS

Solid dispersions of TAN with low-molecular-weight chitosan (LMC) were prepared and the in-vitro dissolution and in-vivo performance were evaluated.

KEY FINDINGS

At 1 h, the extent of dissolution of TAN from the LMC-TAN system (weight ratio 9 : 1) increased about 368.2% compared with the pure drug. Increasing the LMC content from 9 : 1 to 12 : 1 in this system did not significantly increase the rate and the extent of dissolution. Differential scanning calorimetry, X-ray diffraction and scanning electron microscopy demonstrated the formation of amorphous tanshinone IIA and the absence of crystallinity in the solid dispersion. Fourier transform infrared spectroscopy revealed that there was no interaction between drug and carrier. In-vivo test showed that LMC-TAN solid dispersion system presented significantly larger AUC0-t , which was 0.67 times that of physical mixtures and 1.17 times that of TAN. Additionally, the solid dispersion generated obviously higher Cmax and shortened Tmax compared with TAN and physical mixtures.

CONCLUSIONS

In conclusion, the LMC -based solid dispersions could achieve complete dissolution, accelerated absorption rate and superior oral bioavailability.

Encapsulation of antitumor drug Doxorubicin and its analogue by chitosan nanoparticles

Biodegradable chitosan of different sizes were used to encapsulate antitumor drug doxorubicin (Dox) and its N-(trifluoroacetyl) doxorubicin (FDox) analogue. The complexation of Dox and FDox with chitosan 15, 100, and 200 KD was investigated in aqueous solution, using FTIR, fluorescence spectroscopic methods, and molecular modeling. The structural analysis showed that Dox and FDox bind chitosan via both hydrophilic and hydrophobic contacts with overall binding constants of K(Dox-ch-15) = 8.4 (±0.6) × 10(3) M(-1), K(Dox-ch-100) = 2.2 (±0.3) × 10(5) M(-1), K(Dox-ch-200) = 3.7 (±0.5) × 10(4) M(-1), K(FDox-ch-15) = 5.5 (±0.5) × 10(3) M(-1), K(FDox-ch-100) = 6.8 (±0.6) × 10(4) M(-1), and K(FDox-ch-200) = 2.9 (±0.5) × 10(4) M(-1), with the number of drug molecules bound per chitosan (n) ranging from 1.2 to 0.5. The order of binding is ch-100 > 200 > 15 KD, with stronger complexes formed with Dox than FDox. The molecular modeling showed the participation of polymer charged NH(2) residues with drug OH and NH(2) groups in the drug-polymer adducts. The presence of the hydrogen-bonding system in FDox-chitosan adducts stabilizes the drug-polymer complexation, with the free binding energy of -3.89 kcal/mol for Dox and -3.76 kcal/mol for FDox complexes. The results show chitosan 100 KD is a more suitable carrier for Dox and FDox delivery.

Antibiotic doxorubicin and its derivative bind milk β-lactoglobulin

β-Lactoglobulin (β-LG) is a member of lipocalin superfamily of transporters for small hydrophobic molecules such as doxorubicin and its derivatives. We located the binding sites of doxorubicin (DOX) and N-(trifluoroacetyl) doxorubicin (FDOX) with β-lactoglobulin in aqueous solution at physiological conditions, using FTIR, CD and fluorescence spectroscopic methods as well as molecular modeling. Structural analysis showed that DOX and FDOX bind β-LG via both hydrophilic and hydrophobic contacts with overall binding constants of K(DOX-)(β)(-LG)=1.0 (± 0.4)× 10(4)M(-1) and K(FDOX-)(β)(-LG)=2.5 (± 0.5)× 10(4)M(-1) and the number of drug molecules bound per protein (n) 1.2 for DOX and 0.6 for FDOX. Molecular modeling showed the participation of several amino acids in the drug-protein complexes with the free binding energy of -8.12 kcal/mol for DOX-β-LG and -7.74 kcal/mol for FDOX-β-LG complexes. DOX and FDOX do not share similar binding sites with β-LG. Protein conformation showed minor alterations with reduction of β-sheet from 58% (free protein) to 57-51% in the drug-β-LG complexes. β-LG can transport doxorubicin and its derivative in vitro.

Co-nanoencapsulated doxorubicin and Dz13 control osteosarcoma progression in a murine model

Objectives

Chitosan is a green (natural, abundant, biodegradable, biocompatible) biopolymer that can be formulated to encapsulate a variety of therapeutic compounds. This study aimed to investigate chitosan nanoparticles (NPs) as a means of improving delivery of the clinically used anti-cancer agent doxorubicin (Dox) and the preclinical lead compound Dz13 oligonucleotide together.

Methods

A novel chitosan NP system encapsulating Dox and Dz13 was designed, biophysically characterised and tested in a clinically relevant model of the metastasising bone tumour, osteosarcoma (OS).

Key findings

By careful alteration of the concentration of the individual components, a final formulation of Dz13-Dox NPs (DDNPs) was achieved, with high (>91%) loading of both compounds, which consisted of individual 50-nm particles forming aggregates as large as 500 nm, with a large positive ζ-potential. The DDNPs could be stored at various temperatures for a week without loss in activity but were prone to degradation in serum. DDNPs successfully inhibited OS tumour growth more effectively than treatment with NPs of Dz13 and Dox-chitosan, as well as Dox administered intraperitoneally. Apart from inhibiting tumour growth, DDNPs protected the affected bone from substantial destruction by aggressive tumour growth and reduced the incidence of metastasis to the lungs without causing adverse effects in mice.

Conclusion

This NP is a promising formulation that could be useful for clinical management of OS.

Hematopoietic and myeloprotective activities of an acidic Angelica sinensis polysaccharide on human CD34+ stem cells

ETHNOPHARMACOLOGICAL RELEVANCE

Angelica sinensis (AS) is a Chinese herbal medicine traditionally used in prescriptions for replenishing blood and treating abnormal menstruation and other women's diseases.

AIM OF THE STUDY

This study aimed to separate and identify the major hematopoietic fraction from Angelica sinensis polysaccharides (ASPS), and to investigate the myeloprotective activity of the major bioactive fraction of ASPS as a possible supporting agent for cancer treatments.

MATERIALS AND METHODS

The ASPS was fractionated with DEAE-Sepharose CL-6B column to obtain four fractions (F1, F2, F3 and F4). Each fraction was cultured with human peripheral blood mononuclear cells (MNCs) to collect conditioned medium (CM). The hematopoietic ability of various MNC-CM was then evaluated by the colony-forming assay on CD34(+) cells collected by the MACS method from human umbilical cord blood (UCB). In myeloprotective experiment, Adriblastina was used to act as the myelosuppressive agent. The monosaccharide composition of ASPS was analyzed by high-performance anion-exchange chromatography-pulse amperometric detector.

RESULTS

The F2 fraction, which was found to have the highest hematopoietic activity, stimulated the human peripheral blood MNCs to secret GM-CSF and IL-3. F2 could also protect the hematopoietic function of CD34(+) cells from Adriblastina. F2 occupies 19% of ASPS and contains 0.53% protein. The monosaccharide composition of F2 was arabinose (51.82%), fructose (1.65%), galactose (29.96%), glucose (4.78%) and galacturonic acid (14.80%), with molecular weight 2.5-295 kDa.

CONCLUSIONS

The bioactive fraction identified and fractionated from ASPS may be used as a health-promoting agent for anemia patients and cancer patients under chemoradiation treatment.

Antiproliferative activity of nanofibers containing quaternized chitosan and/or doxorubicin against MCF-7 human breast carcinoma cell line by apoptosis

The antiproliferative activity of electrospun mats of poly(L-lactide- co-D,L-lactide) (coPLA) containing quaternized chitosan (QCh) and/or doxorubicin hydrochloride (DOX) was evaluated against the Michigan Cancer Foundation-7(MCF-7) human breast carcinoma cell line. QCh- and DOX-containing nanofibrous mats possess good antiproliferative activity and decrease considerably the viability of the MCF-7 cells for the different periods of cell incubation as confirmed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Fluorescent microscopy analyses and scanning electron microscopy observations revealed that apoptosis was one of the major mechanisms of MCF-7 cell death induced by the QCh- and DOX-containing mats.

Doxorubicin as a molecular nanotheranostic agent: effect of doxorubicin encapsulation in micelles or nanoemulsions on the ultrasound-mediated intracellular delivery and nuclear trafficking

Doxorubicin (DOX) is one of the most commonly used chemotherapeutic drugs and is a popular research tool due to the inherent fluorescence of the DOX molecule. After DOX injection, fluorescence imaging of organs or cells can provide information on drug biodistribution. Therapeutic and imaging capabilities combined in a DOX molecule make it an excellent theranostic agent. However, DOX fluorescence depends on a number of factors that should be taken into consideration when interpreting results of DOX fluorescence measurements. Discussing these problems is the main thrust of the current paper. The sensitivity of DOX fluorescence intensity to DOX concentration, local microenvironment, and interaction with model cellular components is illustrated by fluorescence spectra of paired DOX/phospholipid, DOX/histone, DOX/DNA, and triple DOX/histone/DNA and DOX/phospholipid/DNA systems. DOX fluorescence is dramatically quenched upon intercalation into the DNA; DOX fluorescence is also self-quenched at high concentrations of molecularly dissolved DOX; in contrast, DOX fluorescence is increased after binding to the histone or partitioning into the phospholipid phase of PEG-phospholipid micelles or hydrophobic cores of polymeric micelles. While flow cytometry is commonly used for characterization of DOX intracellular uptake, the above aspects of DOX fluorescence may significantly complicate interpretation of flow cytometry results. High cell fluorescence measured by flow cytometry may provide deceptive information on the actual intracellular DOX concentration and may not correlate with the therapeutic efficacy if DOX does not penetrate into the site of action in cell nuclei. These problems are illustrated in the experiments on the intracellular trafficking of DOX encapsulated in poly(ethylene glycol)-co-polycaprolactone (PEG-PCL) micelles or PEG-PCL stabilized perfluorocarbon nanodroplets, with and without the application of ultrasound used as an external trigger. For efficient encapsulation in micelle cores, DOX is usually deprotonated, which removes the positive charge and enhances hydrophobicity of DOX molecule. It was found that the deprotonated DOX accumulated in the cell cytoplasm but did not penetrate into the cell nuclei. The same was true for the DOX encapsulated in micelles or nanodroplets, which may explain their low therapeutic efficacy in the absence of ultrasound. Ultrasound triggers DOX trafficking into the cell nuclei, which is especially pronounced in the presence of nanoemulsions that convert into microbubbles under the ultrasound action. Microbubble cavitation results in the transient permeabilization of both plasma and nuclear membranes, thus allowing DOX penetration into the cell nuclei, which dramatically enhances therapeutic efficacy of DOX-loaded nanodroplet systems.

Longer-acting factor VIII to overcome limitations in haemophilia management: the PEGylated liposomes formulation issue

Injected factor VIII (FVIII), the current treatment for haemophilia A, leads to major improvements in the quality of life and life expectancy of individuals with this disorder. However, because injected FVIII has a short half-life in vivo, this strategy has major limitations for highly demanding regimens (e.g. prophylaxis, immune tolerance induction, surgery). Newer formulations of longer-acting FVIII are presently under investigation. The use of low molecular weight polyethylene glycol (PEG)-containing liposomes as carriers for recombinant FVIII (rFVIII) results in the prolongation of haemostatic efficacy. Data from preclinical experiments in mice, early clinical evaluations, and pharmacokinetics and pharmacodynamics results indicate that an rFVIII pegylated liposomal formulation may provide potential clinical benefit to patients with severe haemophilia A by prolonging the protection from bleeding. In light of this potential clinical benefit, a multicentre, randomized, active-controlled, non-inferiority phase II trial with two parallel treatment arms and equal randomization after stratification for the presence or absence of target joints in patients and for ages >/=18 years vs. <18 years is currently being conducted. The study will test the hypothesis that rFVIII-Lip once-weekly prophylaxis is not inferior to rFVIII-water for injection thrice-weekly prophylaxis. A total of 250 patients will be enrolled with severe haemophilia A (<1% FVIII) on on-demand or secondary prophylaxis treatment and with documented bleeds or injections during the 6 months before study entry. Sixty-four centres in 14 different countries are involved in the study; recruitment is underway. In Italy, six centres have already included 15 patients (no screening failure). Eight of these patients have completed the run-in phase and have begun the home treatment. No unexpected serious adverse events have been reported thus far. Data emerging from this phase II study will help collect relevant data to overcome current limitations in haemophilia management by employing treatment with longer-acting rFVIII.