Molecular targets and cancer therapeutics: discovery, development and clinical validation

Coating of chitosan on poly D,L-lactic-co-glycolic acid thymoquinone nanoparticles enhances the anti-tumor activity in triple-negative breast cancer

Breast cancer is the second most common cancer around the world. Triple-negative breast cancer (TNBC) is characterized by the absence of three receptors: progesterone, estrogen, and human epidermal growth factor-2 receptor (HER2). Various synthetic chemotherapies have gained attention but they caused unwanted side effects. Therefore, some secondary therapies are now becoming famous against this disease. For instance, natural compounds have been extensively researched against many diseases. However, enzymatic degradation and low solubility remain a major concern. To combat these issues, various nanoparticles have been synthesized and optimized from time to time, which increases its solubility and hence therapeutic potential of a particular drug increases. In this study, we have synthesized Poly D,L-lactic-co-glycolic acid (PLGA) loaded thymoquinone (TQ) nanoparticle (PLGA-TQ-NPs) and then coated them by chitosan (CS) (PLGA-CS-TQ-NPs), which was characterized by different methods. Size of non-coated NPs was 105 nm with PDI value of 0.3 and the size of coated NPs was 125 nm with PDI value of 0.4. Encapsulation efficiency (EE%) and Drug loading (DL%) was found to be 70.5 ± 2.33 and 3.38 for non-coated and 82.3 ± 3.11 and 2.66 for coated NPs respectively. We have also analysed their cell viability against MDA-MB-231 and SUM-149 TNBC cell lines. The resultant, nanoformulations exhibit anti-cancerous activity in a dose and time-dependent manner for MDA-MB-231 and SUM-149 cell lines with an IC₅₀ value of (10.31 ± 1.15, 15.60 ± 1.25, 28.01 ± 1.24) and (23.54 ± 1.24, 22.37 ± 1.25, 35 ± 1.27) for TQ free, PLGA-TQ-NPs and PLGA-CS-TQ-NPs respectively. For the first time, we have developed a nanoformulations of PLGA loaded TQ coated with CS NPs (PLGA-CS-TQ-NPs) against TNBC which led to their enhanced anti-cancerous effects.

ROS-Generating Poly(Ethylene Glycol)-Conjugated Fe3O4 Nanoparticles as Cancer-Targeting Sustained Release Carrier of Doxorubicin

Purpose

Site-specific drug delivery systems can contribute to the development and execution of effective cancer treatment. Due to its favorable features (including high biocompatibility, high hydrophilicity and ease of functionalization), poly(ethylene glycol) (PEG) has been widely adopted to design drug carriers. Generating carriers for delivery of hydrophobic anticancer agents, however, is still a challenge in carrier design.

Methods

In the first step, PEG is functionalized with dialdehyde to generate PEG-(CHO)₂ using EDC/NHS chemistry. In the second step, Fe₃O₄ nanoparticles are functionalized with amino groups to generate Fe₃O₄-NH₂. In the third step, PEG-(CHO)₂, Fe₃O₄-NH₂ and doxorubicin (DOX) react in an acidic environment to yield a drug conjugate (PEGDA-MN-DOX), which is subsequently characterized by FT-IR, ¹H-NMR, SEM, TEM, DLS, TGA, and DSC.

Results

The chemical functionalities of the drug conjugate are confirmed by FTIR, H-NMRand XRD analysis.The release pattern of PEGDA-MN-DOX is investigated at 25 and 37 °C at different pH values. The results indicate that the developed drug conjugate cannot only behave as a sustained-release carrier, but can also generate a significant level of reactive oxygen species (ROS), leading to a high level of toxicity against MCF-7 cells while still showing excellent biocompatibility in 3T3 cells.

Conclusion

The reported conjugate shows anticancer potential, cancer-targeting ability, and ROS-generating capacity for effective drug encapsulation and sustained release in chemotherapy.

Zein as a versatile biopolymer: different shapes for different biomedical applications

In recent years, the interest regarding the use of proteins as renewable resources has deeply intensified. The strongest impact of these biomaterials is clear in the field of smart medicines and biomedical engineering. Zein, a vegetal protein extracted from corn, is a suitable biomaterial for all the above-mentioned purposes due to its biodegradability and biocompatibility. The controlled drug delivery of small molecules, fabrication of bioactive membranes, and 3D assembly of scaffold for tissue regeneration are just some of the topics now being extensively investigated and reported in the literature. Herein, we review the recent literature on zein as a biopolymer and its applications in the biomedical world, focusing on the different shapes and sizes through which it can be manipulated.

Zein a versatile biomaterial in the biomedical field. Easy to chemically functionalize with good emulsification properties, can be employed in drug delivery, fabrication of bioactive membranes and 3D scaffolds for tissue regeneration.

Cancer Patient Tissueoid with Self-Homing Nano-Targeting of Metabolic Inhibitor

The current paradigm of cancer medicine focuses on patient- and/or cancer-specific treatments, which has led to continuous progress in the development of patient representatives (e.g., organoids) and cancer-targeting carriers for drug screening. As breakthrough concepts, i) living cancer tissues convey intact profiles of patient-specific microenvironmental signatures. ii) The growth mechanisms of cancer mass with intense cell-cell interactions can be harnessed to develop self-homing nano-targeting by using cancer cell-derived nanovesicles (CaNVs). Hence, a tissueoid model of ovarian cancer (OC) is developed by culturing OC patient tissues in a 3D gel chip, whose microchannel networks enable perfusion to maintain tissue viability. A novel model of systemic cancer responses is approached by xenografting OC tissueoids into ischaemic hindlimbs in nude mice. CaNVs are produced to carry general chemotherapeutics or new drugs under pre/clinical studies that target the BRCA mutation or energy metabolism, thereby increasing the test scope. This pioneer study cross-validates drug responses from the OC clinic, tissueoid, and animal model by demonstrating the alignment of results in drug type-specific efficiency, BRCA mutation-dependent drug efficiency, and metabolism inhibition-based anti-cancer effects. Hence, this study provides a directional foundation to accelerate the discovery of patient-specific drugs with CaNV application towards future precision medicine.

Cancer: An unknown territory; rethinking before going ahead

Cancer is a disease of altered signaling and metabolism, causing uncontrolled division and survival of transformed cells. A host of molecules, factors, and conditions have been designated as underlying causes for the inception and progression of the disease. An enormous amount of data is available, system-wide interaction networks of the genes and proteins are generated over the years and have now reached up to a level of saturation, where we need to shift our focus to the more advanced and comprehensive methods and approaches of data analysis and visualization. Even with the availability of enormous literature on this one of the most pressing pathological conditions, a successful cure of the disease seems to be obscure. New treatment plans, like immunotherapy and precision medicine, are being employed for different studies. Nevertheless, their actual benefits to the patients would be known only after the evaluation of clinical data over the next few years. Therefore, we need to look at few fundamental challenges that should be addressed in more depth before we could devise better, rigorous, and comprehensive treatment plans and may successfully reach a possible cure of the disease. This article aims at bringing attention towards some fundamental gaps in our approach towards the disease that leads to failure in devising successful therapeutics.

Strategies for maximizing photothermal conversion efficiency based on organic dyes

Photothermal therapy (PTT) has emerged as a promising therapeutic approach for tumor control and ablation. Attention has focused on exploring advanced organic photothermal agents (OPTAs), with advantages of easy modification, adjustable photophysical and photochemical properties, good compatibility, and inherent biodegradability. However, few detailed studies on how to maximally channelize nonradiative heat generation from the viewpoint of the photothermal conversion mechanism have been reported. Thus, here we assimilate and elaborate on several available action mechanisms to maximize the photothermal conversion efficiency (PCE) of organic dyes. Moreover, we also propose several potential challenges that require substantial future work to address.

Phage Display-Based Nanotechnology Applications in Cancer Immunotherapy

Phage display is a nanotechnology with limitless potential, first developed in 1985 and still awaiting to reach its peak. Awarded in 2018 with the Nobel Prize for Chemistry, the method allows the isolation of high-affinity ligands for diverse substrates, ranging from recombinant proteins to cells, organs, even whole organisms. Personalized therapeutic approaches, particularly in oncology, depend on the identification of new, unique, and functional targets that phage display, through its various declinations, can certainly provide. A fast-evolving branch in cancer research, immunotherapy is now experiencing a second youth after being overlooked for years; indeed, many reports support the concept of immunotherapy as the only non-surgical cure for cancer, at least in some settings. In this review, we describe literature reports on the application of peptide phage display to cancer immunotherapy. In particular, we discuss three main outcomes of this procedure: (i) phage display-derived peptides that mimic cancer antigens (mimotopes) and (ii) antigen-carrying phage particles, both as prophylactic and/or therapeutic vaccines, and (iii) phage display-derived peptides as small-molecule effectors of immune cell functions. Preclinical studies demonstrate the efficacy and vast potential of these nanosized tools, and their clinical application is on the way.

Bcl-XL: A multifunctional anti-apoptotic protein

B-cell lymphoma-extra large (Bcl-X_L) is one of the anti-apoptotic proteins of the Bcl-2 family that is localized in the mitochondria. Bcl-X_L is one of the key regulators of apoptosis that can also regulate other important cellular functions. Bcl-X_L is overexpressed in many cancers, and its inhibitors have shown good therapeutic effects. Bcl-X_L interacts with Beclin 1, a key factor regulating autophagy. Bcl-X_L is essential for the survival of neurons and plays protective roles in neuronal injuries. It can promote the growth of neurons and the correct formation of neural networks, enhance synaptic plasticity, and control neurotoxicity. Bcl-X_L can also promote the transport of Ca²⁺ to mitochondria, increase the production of ATP, and improve metabolic efficiency. In addition, targeting Bcl-X_L has shown potential value in autoimmune diseases and aging. In this review, we summarize the functions of Bcl-X_L in cancer, autophagy, Ca²⁺ signaling, neuroprotection, neuronal growth and synaptic plasticity, energy metabolism, immunity, and senescence as revealed by investigations conducted in the past 10 years. Moreover, we list some inhibitors that have been developed based on the functions of Bcl-X_L.

Folate-targeted star-shaped cationic copolymer co-delivering docetaxel and MMP-9 siRNA for nasopharyngeal carcinoma therapy

The co-delivery of drug and gene has become the primary strategy in cancer therapy. Based on our previous work, to co-deliver docetaxel (DOC) and MMP-9 siRNA more efficiently for HNE-1 nasopharyngeal carcinoma therapy, a folate-modified star-shaped copolymer (FA-CD-PLLD) consisting of β-cyclodextrin (CD) and poly(L-lysine) dendron (PLLD) was synthesized, and then used for DOC and MMP-9 co-delivery. Different from commonly used amphiphilic copolymers micelles, the obtained CD derivative could be used directly for the combinatorial delivery of nucleic acid and hydrophobic DOC without a complicated micellization process. In vitro and in vivo assays are carried out to confirm the effectiveness of the target strategy and combined treatment. It was found that the conjugation of CD-PLLD with FA could enhance the DOC/MMP-9 delivery effect obviously, inducing a more significant apoptosis and decreasing invasive capacity of HEN-1 cells. In vivo assays showed that FA-CD-PLLD/DOC/MMP-9 could inhibit HNE-1 tumor growth and decrease PCNA expression effectively, indicating a promising strategy for nasopharyngeal carcinoma therapy. Moreover, the in vivo distribution of DOC and MMP-9, blood compatibility and toxicity are also explored.

CD-PLLD co-delivering docetaxel and MMP-9 siRNA plasmid for nasopharyngeal carcinoma therapy in vivo

The co-delivery of a drug and a target gene has become a primary strategy in cancer therapy. Based on our previous study, a synthesized star‑shaped co‑polymer consisting of β‑cyclodextrin (CD) and a poly(L‑lysine) dendron (PLLD) was used to co-deliver docetaxel (DOC) and matrix metalloproteinase 9 (MMP‑9) small interfering RNA, via CD‑PLLD/DOC/MMP‑9 complexes, into mice implanted with HNE‑1 human nasopharyngeal carcinoma (NPC) tumor cells in vivo. Unlike the commonly used amphiphilic co‑polymer micelles, the obtained CD derivative may be used directly for a combined delivery of nucleic acid and hydrophobic DOC without a complicated micellization process. In vivo assays demonstrated that CD‑PLLD/DOC/MMP‑9 inhibited HNE‑1 tumor growth and decreased proliferating cell nuclear antigen expression levels, indicating a potential strategy for NPC therapy. In addition, the distribution of DOC and MMP‑9 was investigated; CD‑PLLD/DOC/MMP‑9 complexes were phagocytized in reticuloendothelial systems, including the liver and spleen, which requires further study. Furthermore, the complexes did not cross the blood‑brain barrier due to their large molecular size, suggesting they may be relatively safe. Additionally, the complexes mediated increased DOC concentrations with prolonged blood circulation and EGFP expression in HNE‑1 tumors. These results suggest the future potential application of CD-PLLD/DOC/MMP-9 for NPC therapy.

Thermoresponsive Collagen/Cell Penetrating Hybrid Peptide as Nanocarrier in Targeting-Free Cell Selection and Uptake

The effective delivery of therapeutics and imaging agents to a selected group of cells has been at the forefront of biomedical research. Unfortunately, the identification of the unique cell surface targets for cell selection remains a major challenge, particularly if cells within the selected group are not identical. Here we demonstrate a novel approach to cell section relying on a thermoresponsive peptide-based nanocarrier. The hybrid peptide containing cell-penetrating peptide (CPP) and collagen (COLL) domains is designed to undergo coil-to-helix transition (folding) below physiological temperature. Because only the helical form undergoes effective internalization by the cells, this approach allows effective temperature-discriminate cellular uptake. The cells selected for uptake are locally cooled, thus enabling the carrier to fold and subsequently internalize. Our approach demonstrates a generic method as selected cells could differ from the adjacent cells or could belong to the same cell population. The method is fast (<15 min) and selective; over 99.6% of cells in vitro internalized the peptide carrier at low temperatures (15 °C), while less than 0.2% internalized at 37 °C. In vivo results confirm the high selectivity of the method. The potential clinical applications in mixed cell differentiation carcinoma, most frequently encountered in breast and ovarian cancer, are envisioned.

A subunit vaccine based on rH-NS induces protection against Mycobacterium tuberculosis infection by inducing the Th1 immune response and activating macrophages

Mycobacterium tuberculosis (Mtb) is a Gram-positive pathogen which causes tuberculosis in both animals and humans. All tested rH-NS formulations induced a specific Th1 response, as indicated by increased production of interferon γ (IFN-γ) and interleukin 2 (IL-2) by lymphocytes in the spleen of mice which were immunized with rH-NS alone or with rH-NS and the adjuvant cyclic GMP-AMP (cGAMP). Serum from mice immunized with rH-NS with or without adjuvant also had higher levels of IL-12p40 and TNF-α, compared with those from control mice immunized with phosphate-buffered saline. Both vaccines increased protective efficacy in mice which were challenged with Mtb H37Rv, as measured by reduced relative CFU counts in the lungs. We found that rH-NS induced the production of TNF-α, IL-6, and IL-12p40, which relied on the activation of mitogen-activated protein kinases by stimulating the rapid phosphorylation of ERK1/2, p38, and JNK, and on the activation of transcription factor NF-κB in macrophages. Additionally, we also found that rH-NS could interact with TLR2 but not TLR4 in pull-down assays. The rH-NS-induced cytokine production from TLR2-silenced RAW264.7 cells was lower than that from BALB/c macrophages. Prolonged exposure (>24 h) of RAW264.7 cells to rH-NS resulted in a significant enhancement in IFN-γ-induced MHC II expression, which was not found in shTLR2-treated RAW264.7 cells. These results suggest that rH-NS is a TLR2 agonist which induces the production of cytokines by macrophages and up-regulates macrophage function.

Porphyrin-loaded nanoparticles for cancer theranostics

Porphyrins have been used as pioneering theranostic agents not only for the photodynamic therapy, sonodynamic therapy and radiotherapy of cancer, but also for diagnostic fluorescence imaging, magnetic resonance imaging and photoacoustic imaging. A variety of porphyrins have been developed but very few of them have actually been employed in clinical trials due to their poor selectivity to tumorous tissue and high accumulation rates in the skin. In addition, most porphyrin molecules are hydrophobic and form aggregates in aqueous media. Nevertheless, the use of nanoparticles as porphyrin carriers shows great promise to overcome these shortcomings. Encapsulating or attaching porphyrins to nanoparticles makes them more suitable for tissue delivery because we can create materials with a conveniently specific tissue lifetime, specific targeting, immune tolerance, and hydrophilicity as well as other characteristics through rational design. In addition, various functional components (e.g. for targeting, imaging or therapeutic functions) can be easily introduced into a single nanoparticle platform for cancer theranostics. This review presents the current state of knowledge on porphyrin-loaded nanoparticles for the interwined imaging and therapy of cancer. The future trends and limitations of prophyrin-loaded nanoparticles are also outlined.

Rational Design of Targeted Next-Generation Carriers for Drug and Vaccine Delivery

Pattern recognition receptors on innate immune cells play an important role in guiding how cells interact with the rest of the organism and in determining the direction of the downstream immune response. Recent advances have elucidated the structure and function of these receptors, providing new opportunities for developing targeted drugs and vaccines to treat infections, cancers, and neurological disorders. C-type lectin receptors, Toll-like receptors, and folate receptors have attracted interest for their ability to endocytose their ligands or initiate signaling pathways that influence the immune response. Several novel technologies are being developed to engage these receptors, including recombinant antibodies, adoptive immunotherapy, and chemically modified antigens and drug delivery vehicles. These active targeting technologies will help address current challenges facing drug and vaccine delivery and lead to new tools to treat human diseases.

Co-delivery of siRNA and hypericin into cancer cells by hyaluronic acid modified PLGA-PEI nanoparticles

CONTEXT

Malignant tumors cause more death because of the resistance of the hypoxic cancer cell toward radiotherapy. Targeting for hypoxic cancer area and gene silencing to overcome the hypoxia are two kinds of important therapeutic strategies for treating tumors.

OBJECTIVE

In order to explore the combined effects of gene therapy and hypericin (Hy) on tumor cells, hypoxia-inducible factor 1 alpha (HIF-1α) small interfering ribonucleic acid (siRNA) was transfected into the hypoxic human nasopharyngeal carcinoma (CNE2) cells using Hy-encapsulated nanocomplexes (Hy-HPP NPs) as a carrier which would achieve dual targeting to the tumor necrosis area.

MATERIALS AND METHODS

NPs were prepared by emulsion-diffusion-evaporation method. Formulations were evaluated by conducting in vitro physicochemical studies, electrophoresis, in vivo study, and biochemical studies.

RESULTS AND DISCUSSIONS

Hy-loaded nanoparticles with a mean size of around 160 nm was able to enhance the accumulation in the tumors by enhanced permeability and retention effect. The electrophoresis confirmed the good stability of siRNA/Hy-HPP NPs in the presence of phosphate-buffered saline (pH 7.4), competitive heparin, and RNase. The results of transfection showed that the uptake of siRNA was significantly increased up to 50% in CNE2 cells. The level of the HIF-1α with Hy-encapsulated nanocomplexes was significantly reduced to 30% in the transfected CNE2 cells. In vivo studies, the carrier exhibited higher intensity at the tumor tissue cells and higher affinity toward the necrotic tumor tissue.

CONCLUSION

Results demonstrated that Hy-HPP NPs could significantly enhance the tranfection efficiency of siRNA, suggesting Hy-encapsulated nanoparticle as an efficient gene carrier. The co-delivery of HIF-1α siRNA (siHIF-1α) and Hy could efficiently decrease the level of HIF-1α and increase the affinity toward necrotic tissues. Hence, this is a promising strategy for further application in radiotherapy.

Comparison of doxorubicin anticancer drug loading on different metal oxide nanoparticles

Nanomaterials are being vigorously investigated for their use in anticancer drug delivery regimes or as biomarkers agents and are considered to be a candidate to provide a way to combat severe weaknesses of anticancer drug pharmacokinetics, such as their nonspecificity. Because of this weakness, a bigger proportion of the drug-loaded nanomaterials flow toward healthy tissues and result in undesirable side effects. It is very important to evaluate drug loading and release efficiency of various nanomaterials to find out true pharmacokinetics of these drugs.This observational study aims to evaluate various surface functionalized and naked nanomaterials for their drug loading capability and consequently strengthens the Reporting of Observational Studies in Epidemiology (STROBE). We analyzed naked and coated nanoparticles of transition metal oxides for their further loading with doxorubicin, a representative water-soluble anticancer drug.Various uncoated and polyethylene glycol-coated metal oxide nanoparticles were synthesized and loaded with anticancer drug using simple stirring of the nanoparticles in a saturated aqueous solution of the drug. Results showed that surface-coated nanoparticles have higher drug-loading capabilities; however, certain naked metal oxide nanoparticles, such as cobalt oxide nanoparticles, can load a sufficient amount of drug.

Co-delivery of siRNA and paclitaxel into cancer cells by hyaluronic acid modified redox-sensitive disulfide-crosslinked PLGA–PEI nanoparticles

Schematic diagram showing the structure of the co-delivery nano-complex and the process of entering tumor cells.

Antitumor effect of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles on mice bearing breast cancer: a systemic toxicity assay

Breast cancer is one of the most prevalent cancer types among women. The use of magnetic fluids for specific delivery of drugs represents an attractive platform for chemotherapy. In our previous studies, it was demonstrated that maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh2Cit) induced in vitro cytotoxicity and in vivo antitumor activity, followed by intratumoral administration in breast carcinoma cells. In this study, our aim was to follow intravenous treatment to evaluate the systemic antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Female Balb/c mice were evaluated with regard to toxicity of intravenous treatments through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine and liver, kidney, and lung histology. The antitumor activity of rhodium (II) citrate (Rh2Cit), Magh-Rh2Cit, and maghemite nanoparticles coated with citrate (Magh-Cit), used as control, was evaluated by tumor volume reduction, histology, and morphometric analysis. Magh-Rh2Cit and Magh-Cit promoted a significant decrease in tumor area, and no experimental groups presented hematotoxic effects or increased levels of serum ALT and creatinine. This observation was corroborated by the histopathological examination of the liver and kidney of mice. Furthermore, the presence of nanoparticles was verified in lung tissue with no morphological changes, supporting the idea that our nanoformulations did not induce toxicity effects. No studies about the systemic action of rhodium (II) citrate-loaded maghemite nanoparticles have been carried out, making this report a suitable starting point for exploring the therapeutic potential of these compounds in treating breast cancer.

The beneficial effect of melatonin in brain endothelial cells against oxygen-glucose deprivation followed by reperfusion-induced injury

Melatonin has a cellular protective effect in cerebrovascular and neurodegenerative diseases. Protection of brain endothelial cells against hypoxia and oxidative stress is important for treatment of central nervous system (CNS) diseases, since brain endothelial cells constitute the blood brain barrier (BBB). In the present study, we investigated the protective effect of melatonin against oxygen-glucose deprivation, followed by reperfusion- (OGD/R-) induced injury, in bEnd.3 cells. The effect of melatonin was examined by western blot analysis, cell viability assays, measurement of intracellular reactive oxygen species (ROS), and immunocytochemistry (ICC). Our results showed that treatment with melatonin prevents cell death and degradation of tight junction protein in the setting of OGD/R-induced injury. In response to OGD/R injury of bEnd.3 cells, melatonin activates Akt, which promotes cell survival, and attenuates phosphorylation of JNK, which triggers apoptosis. Thus, melatonin protects bEnd.3 cells against OGD/R-induced injury.

High glucose increases LPS-induced DC apoptosis through modulation of ERK1/2, AKT and Bax/Bcl-2

Background

This study investigates the effect of glucose on the LPS-induced apoptosis of dendritic cells in the intestinal tract of mice and the dendritic cell line DC2.4.

Methods

Flow cytometry was used to detect dendritic cell apoptosis both in vivo and in vitro. Hoechst 33258 staining was used to detect the morphological changes characteristic of apoptotic nuclei. Expression of apoptosis related proteins was investigated by western blot analysis and immunohistochemistry.

Results

Pretreatment with a high concentration of glucose increased apoptosis of LPS-treated dendritic cells both in vivo and in vitro at 24 h. No effect was evident at the earlier time points of 15 min and 6 h in vitro. Furthermore, at 24 hours the expression of the survival proteins AKT, ERK and Bcl-2 was decreased, while the expression of the proapoptotic protein Bax was increased. AKT, ERK, Bcl-2 and Bax were mainly located in the cytoplasm by immunohistochemistry.

Conclusions

These results suggest that high glucose concentrations might prime dendritic cells for apoptosis induced by LPS in the intestinal tract through upregulating the expression of Bax and downregulating the expression of AKT, ERK and Bcl-2. Therefore, this study may give clues to understanding the immunological mechanism behind gastrointestinal complications in diabetes mellitus.

Synthesis, characterization and in vitro studies of doxorubicin-loaded magnetic nanoparticles grafted to smart copolymers on A549 lung cancer cell line

Background

The aim of present study was to develop the novel methods for chemical and physical modification of superparamagnetic iron oxide nanoparticles (SPIONs) with polymers via covalent bonding entrapment. These modified SPIONs were used for encapsulation of anticancer drug doxorubicin.

Method

At first approach silane–grafted magnetic nanoparticles was prepared and used as a template for polymerization of the N-isopropylacrylamide (NIPAAm) and methacrylic acid (MAA) via radical polymerization. This temperature/pH-sensitive copolymer was used for preparation of DOX–loaded magnetic nanocomposites. At second approach Vinyltriethoxysilane-grafted magnetic nanoparticles were used as a template to polymerize PNIPAAm-MAA in 1, 4 dioxan and methylene-bis-acrylamide (BIS) was used as a cross-linking agent. Chemical composition and magnetic properties of Dox–loaded magnetic hydrogel nanocomposites were analyzed by FT-IR, XRD, and VSM.

Results

The results demonstrate the feasibility of drug encapsulation of the magnetic nanoparticles with NIPAAm–MAA copolymer via covalent bonding. The key factors for the successful prepardtion of magnetic nanocomposites were the structure of copolymer (linear or cross-linked), concentration of copolymer and concentration of drug. The influence of pH and temperature on the release profile of doxorubicin was examined. The in vitro cytotoxicity test (MTT assay) of both magnetic DOx–loaded nanoparticles was examined. The in vitro tests showed that these systems are no toxicity and are biocompatible.

Conclusion

IC50 of DOx–loaded Fe₃O₄ nanoparticles on A549 lung cancer cell line showed that systems could be useful in treatment of lung cancer.

Polymeric nanoparticles conjugate a novel heptapeptide as an epidermal growth factor receptor-active targeting ligand for doxorubicin

Background

This study was performed to develop a functional poly(D,L-lactide-co-glycolide)- poly(ethylene glycol) (PLGA-PEG)-bearing amino-active end group for peptide conjugation.

Methods and results

PLGA was preactivated following by copolymerization with PEG diamine. The resulting amphiphilic PLGA-PEG copolymer bearing 97.0% of amino end groups had a critical micelle concentration of 3.0 × 10⁻⁸ mol/L, and the half-effective inhibition concentration (IC₅₀) of the prepared PLGA-PEG nanoparticles was >100 mg/mL, which was much higher than that of PLGA nanoparticles (1.02 ± 0.37 mg/mL). The amphiphilic properties of PLGA-PEG spontaneously formed a core-shell conformation in the aqueous environment, and this special feature provided the amino group on the PEG chain scattered on the surface of PLGA-PEG nanoparticles for efficient peptide conjugation. The peptide-conjugated PLGA-PEG nanoparticles showed three-fold higher uptake than peptide-free PLGA-PEG nanoparticles in a SKOV3 cell line with high expression of epidermal growth factor receptor. Both peptide-conjugated and peptide-free PLGA-PEG nanoparticles were used as nanocarriers for delivery of doxorubicin. Although the rate of release of doxorubicin from both nanoparticles was similar, drug release at pH 4.0 (500 U lipase) was faster than at pH 7.4. The IC₅₀ of doxorubicin-loaded peptide-conjugated PLGA-PEG nanoparticles in SKOV3 cells (0.05 ± 0.03 μg/mL) was much lower (by 62.4-fold) than that of peptide-free PLGA-PEG nanoparticles (3.12 ± 1.44 μg/mL).

Conclusion

This in vivo biodistribution study in SKOV3 tumor-bearing mice was further promising in that accumulation of doxorubicin in tumor tissue was in the order of peptide-conjugated PLGA-PEG nanoparticles > peptide-free PLGA-PEG nanoparticles > doxorubicin solution.

The immunopharmacologic potential of Semaxanib and new generation directed therapeutic drugs: Receptor tyrosine kinase regulation with anti-tumorigenensis/angiogenesis properties

Molecular signaling of messages emanating from cellular membranes through receptor tyrosine kinases (RTKs) is a major mechanism for intercellular communication and transduction during development and metabolism, as well as in disease-associated processes. The phosphorylation status and signaling activity of RTKs are determined by a dynamic equilibrium of the activity of both RTKs and protein tyrosine phosphatases (PTPs). RTKs are essentially a class of cell-surface receptors for growth factors and other extracellular ligands, the most conspicuous perhaps are members of the vascular endothelial growth factor (VEGF) gene family, which plays a fundamental role in the growth and differentiation of vascular, as well as lymphatic endothelial cells. In particular, VEGF is a major regulator of normal (physiologic) and abnormal (cancerous) angiogenesis, including that associated with tumors and cancer. Blockers/inhibitors and regulators of RTKs are indeed promising cancer interventions, their specific mechanisms are yet to be unraveled. In this cutting-edge synopsis, I elaborate on breakthroughs/advances and current concepts of RTK regulation, further shedding light on exploring the role of potential regulators, particularly the RTK inhibitor Semaxanib, and the mechanisms associated with tumorigenesis in an effort to understand a potentially alleviating pharmacologic therapeutic intervention. This survey also tackles the loopholes and shortcomings of the aforementioned inhibitory role of Semaxanib, especially its inefficacy and ultimate discontinuation of relevant clinical trials.

Preparation and in vitro evaluation of doxorubicin-loaded Fe₃O₄ magnetic nanoparticles modified with biocompatible copolymers

BACKGROUND

Superparamagnetic iron oxide nanoparticles are attractive materials that have been widely used in medicine for drug delivery, diagnostic imaging, and therapeutic applications. In our study, superparamagnetic iron oxide nanoparticles and the anticancer drug, doxorubicin hydrochloride, were encapsulated into poly (D, L-lactic-co-glycolic acid) poly (ethylene glycol) (PLGA-PEG) nanoparticles for local treatment. The magnetic properties conferred by superparamagnetic iron oxide nanoparticles could help to maintain the nanoparticles in the joint with an external magnet.

METHODS

A series of PLGA:PEG triblock copolymers were synthesized by ring-opening polymerization of D, L-lactide and glycolide with different molecular weights of polyethylene glycol (PEG(2000), PEG(3000), and PEG(4000)) as an initiator. The bulk properties of these copolymers were characterized using (1)H nuclear magnetic resonance spectroscopy, gel permeation chromatography, Fourier transform infrared spectroscopy, and differential scanning calorimetry. In addition, the resulting particles were characterized by x-ray powder diffraction, scanning electron microscopy, and vibrating sample magnetometry.

RESULTS

The doxorubicin encapsulation amount was reduced for PLGA:PEG(2000) and PLGA:PEG(3000) triblock copolymers, but increased to a great extent for PLGA:PEG(4000) triblock copolymer. This is due to the increased water uptake capacity of the blended triblock copolymer, which encapsulated more doxorubicin molecules into a swollen copolymer matrix. The drug encapsulation efficiency achieved for Fe(3)O(4) magnetic nanoparticles modified with PLGA:PEG(2000), PLGA:PEG(3000), and PLGA:PEG(4000) copolymers was 69.5%, 73%, and 78%, respectively, and the release kinetics were controlled. The in vitro cytotoxicity test showed that the Fe(3)O(4)-PLGA:PEG(4000) magnetic nanoparticles had no cytotoxicity and were biocompatible.

CONCLUSION

There is potential for use of these nanoparticles for biomedical application. Future work includes in vivo investigation of the targeting capability and effectiveness of these nanoparticles in the treatment of lung cancer.

Block ionomer complex micelles based on the self-assembly of poly(ethylene glycol)-block-poly(acrylic acid) and CdCl₂ for anti-tumor drug delivery

A novel block ionomer complex micelles as drug carrier is developed utilizing self-assemble of poly(ethylene glycol)-block-poly(acrylic acid) (PEG-b-PAA) and cadmium chloride. This micelles are characterized to be have good bio-compatibility, hydrophilicity, passive targeting and sustained slow release property which shows great potential for liver cancer therapy. Block ionomer complex micelles based on PEG-b-PAA and cadmium chloride can self-assemble in distilled water, and Cd(²+) agent is entrapped into the core stabilized by PEG shells. Results showed the block ionomer complex micelles to be spherically shaped. Cadmium was incorporated easily into the ionic core with remarkably high efficiency (34.25% weight (wt)/wt). The cadmium-loaded polymeric micelles exhibited sustained and slow release behavior of cadmium and a potent cytotoxicity against SMMC-7721 in vitro. This novel block ionomer complex micelles with cores of metal antitumor drug indicates to be potential carriers for effective drug delivery.

Bis-(3',5')-cyclic dimeric adenosine monophosphate: strong Th1/Th2/Th17 promoting mucosal adjuvant

New effective adjuvants are required to improve the performance of subunit vaccines. Here, we showed that bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP), a second messenger molecule in bacteria and archaea, exerts strong adjuvant activities when delivered by mucosal route. In vitro studies showed that c-di-AMP was able to both stimulate pre-activated murine macrophages and promote the activation and maturation of dendritic cells of murine and human origin. Co-administration of c-di-AMP with β-galactosidase (β-Gal) by intranasal route to BALB/c mice resulted in the elicitation of significantly higher serum antigen-specific IgG titres than in controls. The induction of local immune responses was shown by the production of antigen-specific secretory IgA in different mucosal territories. In addition, strong cellular immune responses were observed against both the β-Gal protein and a peptide encompassing its MHC class I-restricted epitope. The ratio of β-Gal-specific antibodies and the secreted cytokine profiles by in vitro re-stimulated splenocytes suggested that a balanced Th1/Th2/Th17 response pattern is promoted by c-di-AMP. When C57BL/6 mice were immunized with OVA and c-di-AMP, vigorous in vivo CTL responses were also observed. These results indicated that c-di-AMP exhibits a high potential as adjuvant for the development of mucosal vaccines, in particular when cellular immunity is needed.

Targets and mechanisms of photodynamic therapy in lung cancer cells: a brief overview

Lung cancer remains one of the most common cancer-related causes of death. This type of cancer typically develops over a period of many years, and if detected at an early enough stage can be eliminated by a variety of treatments including photodynamic therapy (PDT). A critical discussion on the clinical applications of PDT in lung cancer is well outside the scope of the present report, which, in turn focuses on mechanistic and other aspects of the photodynamic action at a molecular and cellular level. The knowledge of these issues at pre-clinical levels is necessary to develop, check and adopt appropriate clinical protocols in the future. This report, besides providing general information, includes a brief overview of present experimental PDT and provides some non-exhaustive information on current strategies aimed at further improving the efficacy, especially in regard to lung cancer cells.

Preparation of new 5-fluorouracil-loaded zein nanoparticles for liver targeting

This study proposes a new zein nanoparticle (ZP) encapsulated 5-fluorouracil (5-FU) that target liver through intravenous delivery. The ZPs were prepared by phase separation process and optimized using uniform experimental design. The physical properties, in vitro drug release and stability of optimal drug-loaded ZPs were studied. The biodistribution and the target efficiency of the particles were investigated in a mouse model. The highest drug loading was obtained using zein: 5-FU, 3:1 (v/v); zein concentration, 12.5mg/ml, pH 9.18, mixing time, 3h and ethanol concentration, 40%. The encapsulation efficiency and the drug loading were 60.7 ± 1.74 and 9.17 ± 0.11 respectively. The size of ZPs and zeta potential were 114.9 ± 59.4 nm and -45 ± 0.3 mV respectively. Differential scanning calorimetry (DSC) demonstrated that the drug was encapsulated within the ZPs. A sustained release profile of 5-FU was observed from ZPs. The more stable storage condition of ZPs was at a temperature of 4 °C. In vivo, ZPs was mostly accumulated in liver following intravenous injection, and the targeting efficiency increased 31.33%. The relative uptake rate of liver was 2.79. Also, nano-sized ZPs were beneficial for prolonged blood residence (7.2-fold increase). These demonstrated that the drug-loaded ZPs could be efficiently targeted at the liver by intravenous delivery.

Synthesis and in vitro release of adriamycin from star-shaped poly(lactide-co-glycolide) nano- and microparticles

The star-shaped poly(lactide-co-glycolide (PLGA)-beta-cyclodextrin (PLGA-beta-CD) copolymer was synthesized by reacting L-lactide, glycolide, and beta-cyclodextrin in the presence of stannous octoate as a catalyst. The structure of PLGA-beta-CD copolymer was confirmed with (1)H-NMR, (13)C-NMR, and FT-IR spectra. Adriamycin (ADR), which is an antitumor antibiotic, was encapsulated within micro- and nanoparticles made of PLGA-beta-CD with a modified double emulsion method. Relatively low amount of beta-CD and catalyst were used in order to obtain high molecular weight polymers. Differential scanning calorimetry (DSC) was used to determine the thermal properties of star-shaped copolymers. The reduction of interactions between the star-shaped polyester molecules is due to their branched structure lowered T(g) and T(m) compared to linear PLGA copolymers. Effects of the experimental parameters, such as copolymer composition, ADR concentration, copolymer concentration, and poly(vinyl alcohol) concentration, on particular size and encapsulation efficiency were investigated. An increase in the internal aqueous phase volume led to a decrease in particles average size. A decrease in the polymer concentration resulted in increasing the particle average size from 135.5 to 325.6 nm. The high entrapment efficiency (EE) (about 65%) was obtained for 220 microm particles. All of the release profiles indicated a close relationship between each formulation variable and the amount of ADR released.

Nanoparticles in photodynamic therapy: an emerging paradigm

Photodynamic therapy (PDT) has emerged as one of the important therapeutic options in management of cancer and other diseases [M. Triesscheijn, P. Baas, J.H. Schellens, F.A. Stewart, Photodynamic therapy in oncology, Oncologist 11 (2006) 1034-1044]. Most photosensitizers are highly hydrophobic and require delivery systems. Previous classification of delivery systems was based on presence or absence of a targeting molecule on the surface [Y.N. Konan, R. Gurny, E. Allemann, State of the art in the delivery of photosensitizers for photodynamic therapy, J. Photochem. Photobiol., B 66 (2002) 89-106]. Recent reports have described carrier nanoparticles with additional active complementary and supplementary roles in PDT. We introduce a functional classification for nanoparticles in PDT to divide them into passive carriers and active participants in photosensitizer excitation. Active nanoparticles are distinguished from non-biodegradable carriers with extraneous functions, and sub-classified mechanistically into photosensitizer nanoparticles, [A.C. Samia, X. Chen, C. Burda, Semiconductor quantum dots for photodynamic therapy, J. Am. Chem. Soc. 125 (2003) 15736-15737, R. Bakalova, H. Ohba, Z. Zhelev, M. Ishikawa, Y. Baba, Quantum dots as photosensitizers? Nat. Biotechnol. 22 (2004) 1360-1361] self-illuminating nanoparticles [W. Chen, J. Zhang, Using nanoparticles to enable simultaneous radiation and photodynamic therapies for cancer treatment, J. Nanosci. Nanotechnology 6 (2006) 1159-1166] and upconverting nanoparticles [P. Zhang, W. Steelant, M. Kumar, M. Scholfield, Versatile photosensitizers for photodynamic therapy at infrared excitation, J. Am. Chem. Soc. 129 (2007) 4526-4527]. Although several challenges remain before they can be adopted for clinical use, these active or second-generation PDT nanoparticles probably offer the best hope for extending the reach of PDT to regions deep in the body.

A pegylated derivative of alpha-galactosylceramide exhibits improved biological properties

The glycolipid alpha-galactosylceramide (alphaGalCer) has immunomodulatory properties, which have been exploited to combat cancer, chronic inflammatory diseases, and infections. However, its poor solubility makes alphaGalCer a suboptimal compound for in vivo applications. In this study, a pegylated derivative of alphaGalCer is characterized, which exhibits improved physical and biological properties. The new compound, alphaGalCerMPEG, is water-soluble and retains the specificity for the CD1d receptor of alphaGalCer. The in vitro stimulatory properties on immune cells (e.g., dendritic cells and splenocytes) are maintained intact, even when tested at a 33-fold lower concentration of the active moiety than alphaGalCer. NK cells isolated from mice treated with alphaGalCerMPEG also had stronger cytotoxic activity on YAC-1 cells than those obtained from animals receiving either alphaGalCer or CpG. Intranasal immunization studies performed in mice showed that alphaGalCerMPEG exerts stronger adjuvant activities than the parental compound alphaGalCer when tested at 0.35 vs 11.7 nM/dose. Coadministration of beta-galactosidase with alphaGalCerMPEG resulted not only in high titers of Ag-specific Abs in serum (i.e., 1:512,000), but also in the stimulation of stronger Th2 and secretory IgA responses, both at local and remote mucosal effector sites (i.e., nose, lung, and vagina). The new synthetic derivative alphaGalCerMPEG represents a promising tool for the development of immune interventions against infectious and noninfectious diseases.

Adriamycin release from poly(lactide-coglycolide)-polyethylene glycol nanoparticles: synthesis, and in vitro characterization

The preparation, properties, and application in adriamycin delivery ofbiocompatible and biodegradable poly(lactide-co-glycolide)-polyethylene glycol (PLGA-PEG) nanoparticles are discussed. PLGA-PEG copolymers were synthesized by ring opening polymerization of the dl-lactide and glycolide in the presence of PEG1000. 1H-NMR and FT-IR spectrum were consistent with the structure of PLGA-PEG copolymers. The adriamycin-loaded nanoparticles could be prepared using a precipitation-solvent evaporation technique. The nanoparticles have been produced by a precipitation-solvent evaporation technique. The physical characteristics and drug loading efficiency of the PLGA-PEG nanoparticles were influenced by the composition of the PLGA-PEG copolymers used to prepare the nanoparticles. Particle sizes were between 65 and 100 nm for different compositions of PLGA-PEG copolymers. PLGA-PEG nanoparticles prepared from copolymers having relatively high PLGA/PEG ratios were smaller. Entrapment efficiency was 25%-33%. Adriamycin release from the nanoparticles at pH 7.4 showed an initial burst release and then sustained release phase. These results showed that PLGA-PEG nanoparticles could be an effective carrier for cancer therapy.

The bacterial second messenger cdiGMP exhibits promising activity as a mucosal adjuvant

The development of mucosal adjuvants is still a critical need in vaccinology. In the present work, we show that bis(3',5')-cyclic dimeric GMP (cdiGMP), a second messenger that modulates cell surface properties of several microorganisms, exerts potent activity as a mucosal adjuvant. BALB/c mice were immunized intranasally with the model antigen beta-galactosidase (beta-Gal) coadministered with cdiGMP. Animals receiving cdiGMP as an adjuvant showed significantly higher anti-beta-Gal immunoglobulin G (IgG) titers in sera than controls (i.e., 512-fold [P < 0.05]). Coadministration of cdiGMP also stimulated efficient beta-Gal-specific secretory IgA production in the lung (P < 0.016) and vagina (P < 0.036). Cellular immune responses were observed in response to both the beta-Gal protein and a peptide encompassing its major histocompatibility complex class I-restricted epitope. The IgG1-to-IgG2a ratio of anti-beta-Gal antibodies and the observed profiles of secreted cytokines suggest that a dominant Th1 response pattern is promoted by mucosal coadministration of cdiGMP. Finally, the use of cdiGMP as a mucosal adjuvant also led to the stimulation of in vivo cytotoxic T-lymphocyte responses in C57BL/6 mice intranasally immunized with ovalbumin and cdiGMP (up to 30% of specific lysis). The results obtained indicate that cdiGMP is a promising tool for the development of mucosal vaccines.

The bacterial second messenger cyclic diGMP exhibits potent adjuvant properties

The identification of new adjuvants is a critical need in vaccinology. In this work, it is demonstrated that bis-(3',5')-cyclic dimeric guanosine monophosphate (cdiGMP) exhibits potent adjuvant properties. Subcutaneous co-administration of cdiGMP with beta-galactosidase (beta-Gal) to mice resulted in the elicitation of significantly higher antigen-specific serum IgG titres than in animals receiving beta-Gal alone. Strong cellular immune responses, which were characterized by a balanced Th1/Th2 pattern, were also observed in response to the beta-Gal protein and a peptide encompassing its MHC class I-restricted epitope in immunized animals. These results suggest that cdiGMP represents a promising adjuvant for vaccine development.

Nanoparticle and targeted systems for cancer therapy

This review explores recent work directed towards more targeted treatment of cancer, whether through more specific anti-cancer agents or through methods of delivery. These areas include delivery by avoiding the reticuloendothelial system, utilizing the enhanced permeability and retention effect and tumor-specific targeting. Treatment opportunities using antibody-targeted therapies are summarized. The ability to treat cancer by targeting delivery through angiogenesis is also discussed and antiangiogenic drugs in clinical trials are presented. Delivery methods that specifically use nanoparticles are also highlighted, including both degradable and nondegradable polymers.

cDNA Technologies and their application to drug resistance research: power, potential and problems

The effectiveness of systemic chemotherapy is dramatically limited by both intrinsic and acquired drug resistance. Several new technologies have been developed over the last decade to more rapidly identify underlying genetic alterations that impart a drug-resistant phenotype. Techniques such as cDNA-based subtraction technologies, SAGE analysis, and most recently cDNA array and high-density micro-array technologies have rapidly expanded our ability to detect changes in RNA transcription in drug-resistant tumors. These technologies are currently being applied to generate a large number of new hypotheses regarding the regulatory molecules underlying the drug-resistance phenotype. These techniques suggest that there is a large number of transcriptional changes which occur in the drug-resistance phenotype and future work will need to focus on dissecting which of these transcriptional changes are central to the drug resistance phenotype, both in vitro, and more importantly within clinical neoplasia. Copyright 2000 Harcourt Publishers Ltd.