Intrinsic bio-signature of gene delivery nanocarriers may impair gene therapy goals

Pleiotropic Properties of Amphiphilic Dihydropyridines, Dihydropyridones, and Aminovinylcarbonyl Compounds

Three groups of synthetic lipids are chosen for studies: (1) 1,4-dihydropyridines (1,4-DHPs) containing two cationic moieties and their analogues; (2) 3,4-dihydro-2(1H)-pyridones containing a cationic moiety; and (3) acyclic, open-chain analogues, i.e., 2-amino-3-alkoxycarbonylalkylammonium derivatives. 1,4-DHPs possessing dodecyl alkyl chains in the ester groups in positions 3 and 5 and cationic nitrogen-containing groups in positions 2 and 6 have high cytotoxicity in cancer cells HT-1080 (human lung fibrosarcoma) and MH-22A (mouse hepatoma), but low cytotoxicity in the noncancerous NIH3T3 cells (mouse embryonic fibroblast). On the contrary, similar compounds having short (methyl, ethyl, or propoxyethyl) chains in the ester groups in positions 3 and 5 lack cytotoxicity in the cancer cells HT-1080 and MH-22A even at high doses. Inclusion of fluorine atoms in the alkyl chains in positions 3 and 5 of the DHP cycle decreases the cytotoxicity of the mentioned compounds. Structurally related dihydropyridones with a polar head group are substantially more toxic to normal and cancerous cells than the DHP analogues. Open-chain analogues of DHP lipids comprise the same conjugated aminovinylcarbonyl moiety and possess anticancer activity, but they also have high basal cytotoxicity. Electrochemical oxidation data demonstrate that oxidation potentials of selected compounds are in the range of 1.6-1.7 V for cationic 1,4-DHP, 2.0-2.4 V for cationic 3,4-dihydropyridones, and 1.2-1.5 V for 2-amino-3-alkoxycarbonylalkylammonium derivatives. Furthermore, the tested cationic 1,4-DHP amphiphiles possess antiradical activity. Molecular topological polar surface area values for the tested compounds were defined in accordance with the main fragments of compound structures. The determined logP values were highest for dodecyl ester groups in positions 3 and 5 of the 1,4-DHP and lowest for short alkyl chain-containing amphiphiles.

Effect of PEGylation on assembly morphology and cellular uptake of poly ethyleneimine-cholesterol conjugates for delivery of sorafenib tosylate in hepatocellular carcinoma

Introduction: Sorafenib (SFB) is an FDA-approved chemotherapeutic agent with a high partition coefficient (log P = 4.34) for monotherapy of hepatocellular carcinoma (HCC). The oral bioavailability is low and variable, so it was aimed to study the application of the polymeric nanoassembly of cholesterol conjugates of branched polyethyleneimine (PEI) for micellar solubilization of SFB and to investigate the impact of the polymer PEGylation on the physicochemical and cellular characteristics of the lipopolymeric dispersions. Methods: Successful synthesis of cholesterol-PEI lipopolymers, either native or PEGylated, was confirmed by FTIR, ¹H-NMR, pyrene assay methods. The nanoassemblies were also characterized in terms of morphology, particle size distribution and zeta-potential by TEM and dynamic light scattering (DLS). The SFB loading was optimized using general factorial design. Finally, the effect of particle characteristics on cellular uptake and specific cytotoxicity was investigated by flow cytometry and MTT assay in HepG2 cells. Results: Transmission electron microscopy (TEM) showed that PEGylation of the lipopolymers reduces the size and changes the morphology of the nanoassembly from rod-like to spherical shape. However, PEGylation of the lipopolymer increased critical micelle concentration (CMC) and reduced the drug loading. Moreover, the particle shape changes from large rods to small spheres promoted the cellular uptake and SFB-related cytotoxicity. Conclusion: The combinatory effects of enhanced cellular uptake and reduced general cytotoxicity can present PEGylated PEI-cholesterol conjugates as a potential carrier for delivery of poorly soluble chemotherapeutic agents such as SFB in HCC that certainly requires further investigations in vitro and in vivo.

Stimuli-responsive chitosan-based nanocarriers for cancer therapy

Introduction: Stimuli-responsive nanocarriers offer unique advantages over the traditional drug delivery systems (DDSs) in terms of targeted drug delivery and on-demand release of cargo drug molecules. Of these, chitosan (CS)-based DDSs offer several advantages such as high compatibility with biological settings. Methods: In this study, we surveyed the literature in terms of the stimuli-responsive nanocarriers and discussed the most recent advancements in terms of CS-based nanosystems and their applications in cancer therapy and diagnosis. Results: These advanced DDSs are able to release the entrapped drugs in response to a specific endogenous stimulus (e.g., pH, glutathione concentration or certain enzymes) or exogenous stimulus (e.g., temperature, light, ultrasound, and magnetic field) at the desired time and target site. Dual-responsive nanocarriers by the combination of different stimuli have also been developed as efficient and improved DDSs. Among the stimuli-responsive nanocarriers, CS-based DDSs offer several advantages, including biocompatibility and biodegradability, antibacterial activity, ease of modification and functionalization, and non-immunogenicity. They are as one of the most ideal smart multifunction DDSs. Conclusion: The CS-based stimuli-responsive multifunctional nanosystems (NSs) offer unique potential for the targeted delivery of anticancer agents and provide great potential for on-demand and controlled-release of anticancer agents in response to diverse external/internal stimuli.

Bioimpacts of nanoparticle size: why it matters?

During the last two decades, applications of nanotechnology are delivered to benefit the human society. The fact is that various nanomaterials are able to be tailor made to achieve desired properties. In biomedical field, nanotechnology has created great excitements to advance both diagnosis and therapy areas – the field so-called nanomedicines in different forms of nanoparticles (NPs) and nanosystems (NSs). It is noteworthy to mention NPs/NSs do not act similarly in the biological milieu, in which their biological behaviors/ impacts varies with size, morphology, and physicochemical characteristics. On the other hand, nanomedicines impacts on biological systems seem to be influenced by its possible interaction(s) with different bioelements of cell membrane, in particular the endocytic pathway(s) by which NPs/NSs can be internalized and localized. This latter phenomenon is influenced by membrane viscoelastic property, polymerization/depolymerization of cytoskeletal system, and the particle specification itself. Among all other properties of NPs/NSs, as shown by various researchers, the size is an important parameter in the fate of the particle. Accordingly, in-depth efforts to unravel the size dependent effects of nanomedicins can provide insights to design and develop more efficacious NSs with greater benefits and lower side effects. This editorial aims to highlight some important aspects of size dependent impacts NPs/NSs.

A prospective highlight on exosomal nanoshuttles and cancer immunotherapy and vaccination

Introduction: Exosomes (EXOs) and ectosomes (ECTOs) are nanoscale membranous extracellular vesicles (EVs) derived from different cells mediating various cellular communications. EXOs are liberated based on the exocytosis of multivesicular bodies, while ECTOs are ubiquitously released from the plasma membranes.

Methods: Here, in this paper, we go over the extracellular vesicular machineries and concisely highlight their clinical importance in solid tumors and their possible applications in cancer immunotherapy/vaccination.

Results: In various types of cancers, these vesicles play central roles delivering cancer cell messages to the target cells, as a result both of them seem to provide a novel useful means for diagnosis and therapy of malignancies. Dendritic cell-derived exosomes (DEXOs) are able to activate the tumor antigen-specific CD8⁺ cytotoxic T-lymphocytes (CTLs) and hence induce antitumor responses in vivo. Within the tumor microenvironment (TME), however, tumor cells seem to generate exosomes (the so-called oncosoems) that may act in favor of tumor progression.

Conclusions: As complex systems, these vesicular micro-/nano-machines convey important cellular messages dependent upon the cells/tissue setting(s). In addition to their potential in diagnosis of cancers, they have been exploited for cancer immunotherapy/vaccination. However, such treatment strategies need to be carefully designed to attain desired clinical outcomes.

Personalized cell-mediated immunotherapy and vaccination: combating detrimental uprisings of malignancies

A large number of researchers worldwide have conducted various investigations to advance the cell-based immunotherapies and to examine their clinical benefits as an ultimate prevention and/or treatment modalities against life-threatening malignancies. This dominion needs integration of science and technology to change the face of treatment of diseases towards much more personalized medicines. It is now plausible to reprogram the human cells for the prevention and treatment of diseases through various mechanisms such as modulation of immune system, nonetheless we should understand the complexity of biological functions of the cells in a holistic way to be able to manipulate the central dogma of the life to prevent any inadvertent mistake. We should, if not must, comprehend the interrelations of the cellular components (e.g., transport machineries) in the developmental processes of diseases. Still, we do not have a complete image of life, perhaps as expressive barcodes, and many pieces are missing. While completing this puzzle to picture the whole image and examine new treatment modalities, we should take extra caution upon unknown/little-known biological phenomena because trifling modulation/ alteration in the complex systems of the life may result in tremendous impacts. In short, it seems we need to consider malignancies as complex systems and treat them in a holistic manner by targeting its hallmarks. Taken all, the immune system reinforcement would be one of the main foundations in combating detrimental malignancy uprising.

Multifunctional mitoxantrone-conjugated magnetic nanosystem for targeted therapy of folate receptor-overexpressing malignant cells

Background

Targeted delivery of anticancer chemotherapeutics such as mitoxantrone (MTX) can significantly intensify their cytotoxic effects selectively in solid tumors such as breast cancer. In the current study, folic acid (FA)-armed and MTX-conjugated magnetic nanoparticles (MNPs) were engineered for targeted eradication of folate receptor (FR)-positive cancerous cells. Polyethylene glycol (PEG), FA and MTX were covalently conjugated onto the MNPs to engineer the PEGylated FA-MTX-MNPs. The internalization studies were performed using fluorescein isothiocyanate (FITC)-labeled FA-decorated MNPs (FA-FITC-MNPs) in both FR-positive MCF-7 cells and FR-negative A549 cells by means of fluorescence microscopy and flow cytometry. The cellular and molecular impacts of FA-MTX-MNPs were examined using trypan blue cell viability and FITC-labeled annexin V apoptosis assays and 4′,6-diamidino-2-phenylindole (DAPI) staining, DNA ladder and quantitative polymerase chain reaction (qPCR) assays.

Results

The FR-positive MCF-7 cells showed significant internalization of the FA-FITC-MNPs, but not the FR-negative A549 cells. The FR-positive cells treated with the PEGylated FA-MTX-MNPs exhibited the IC₅₀ values of 3 μg/mL and 1.7 μg/mL, 24 h and 48 h post-treatment, respectively. DAPI staining and DNA ladder assays revealed significant condensation of nucleus and fragmentation of genomic DNA in the FR-positive MCF-7 cells treated with the PEGylated FA-MTX-MNPs as compared to the FR-negative A549 cells. The FITC-labeled annexin V assay confirmed emergence of late apoptosis (>80%) in the FR-positive MCF-7 cells treated with the PEGylated FA-MTX-MNPs, but not in the FR-negative A549 cells. The qPCR analysis confirmed profound cytotoxic impacts via alterations of apoptosis-related genes induced by MTX-FA-MNPs in MCF-7 cells, but not in the A549 cells.

Conclusion

Our findings evince that the engineered PEGylated FA-MTX-MNPs can be specifically taken up by the FR-positive malignant cells and effectively demolish them through up-regulation of Bcl-2–associated X protein (Bax) and Caspase 9 and down-regulation of AKt. Hence, the engineered nanosystem is proposed for simultaneous targeted imaging and therapy of various cancers overexpressing FRs.

Impacts of quantum dots in molecular detection and bioimaging of cancer

Introduction: A number of assays have so far been exploited for detection of cancer biomarkers in various malignancies. However, the expression of cancer biomarker(s) appears to be extremely low, therefore accurate detection demands sensitive optical imaging probes. While optical detection using conventional fluorophores often fail due to photobleaching problems, quantum dots (QDs) offer stable optical imaging in vitro and in vivo.

Methods: In this review, we briefly overview the impacts of QDs in biology and its applications in bioimaging of malignancies. We will also delineate the existing obstacles for early detection of cancer and the intensifying use of QDs in advancement of diagnostic devices.

Results: Of the QDs, unlike the II-VI type QDs (e.g., cadmium (Cd), selenium (Se) or tellurium (Te)) that possess inherent cytotoxicity, the I-III-VI 2 type QDs (e.g., AgInS₂, CuInS₂, ZnS-AgInS₂) appear to be less toxic bioimaging agents with better control of band-gap energies. As highly-sensitive bioimaging probes, advanced hybrid QDs (e.g., QD-QD, fluorochrome-QD conjugates used for sensing through fluorescence resonance energy transfer (FRET), quenching, and barcoding techniques) have also been harnessed for the detection of biomarkers and the monitoring of delivery of drugs/genes to the target sites. Antibody-QD (Ab-QD) and aptamer- QD (Ap-QD) bioconjugates, once target the relevant biomarker, can provide highly stable photoluminescence (PL) at the target sites. In addition to their potential as nanobiosensors, the bioconjugates of QDs with homing devices have successfully been used for the development of smart nanosystems (NSs) providing targeted bioimaging and photodynamic therapy (PDT).

Conclusion: Having possessed great deal of photonic characteristics, QDs can be used for development of seamless multifunctional nanomedicines, theranostics and nanobiosensors.

Targeting tumor microenvironment: crossing tumor interstitial fluid by multifunctional nanomedicines

Introduction: The genesis of cancer appears to be a complex matter, which is not simply based upon few genetic abnormalities/alteration. In fact, irregular microvasculature and aberrant interstitium of solid tumors impose significant pathophysiologic barrier functions against cancer treatment modalities, hence novel strategies should holistically target bioelements of tumor microenvironment (TME). In this study, we provide some overview and insights on TME and important strategies used to control the impacts of such pathophysiologic barriers.

Methods: We reviewed all relevant literature for the impacts of tumor interstitium and microvasculature within the TME as well as the significance of the implemented strategies.

Results: While tumorigenesis initiation seems to be in close relation with an emergence of hypoxia and alterations in epigenetic/genetic materials, large panoplies of molecular events emerge as intricate networks during oncogenesis to form unique lenient TME in favor of tumor progression. Within such irregular interstitium, immune system displays defective surveillance functionalities against malignant cells. Solid tumors show multifacial traits with coadaptation and self-regulation potentials, which bestow profound resistance against the currently used conventional chemotherapy and immunotherapy agents that target solely one face of the disease.

Conclusion: The cancerous cells attain unique abilities to form its permissive microenvironment, wherein (a) extracellular pH is dysregulated towards acidification, (b) extracellular matrix (ECM) is deformed, (c) stromal cells are cooperative with cancer cells, (d) immune system mechanisms are defective, (e) non-integrated irregular microvasculature with pores (120-1200 nm) are formed, and (h) interstitial fluid pressure is high. All these phenomena are against cancer treatment modalities. As a result, to control such abnormal pathophysiologic traits, novel cancer therapy strategies need to be devised using multifunctional nanomedicines and theranostics.

Shikonin-loaded antibody-armed nanoparticles for targeted therapy of ovarian cancer

Conventional chemotherapy of ovarian cancer often fails because of initiation of drug resistance and/or side effects and trace of untouched remaining cancerous cells. This highlights an urgent need for advanced targeted therapies for effective remediation of the disease using a cytotoxic agent with immunomodulatory effects, such as shikonin (SHK). Based on preliminary experiments, we found SHK to be profoundly toxic in ovarian epithelial cancer cells (OVCAR-5 and ID8 cells) as well as in normal ovarian IOSE-398 cells, endothelial MS1 cells, and lymphocytes. To limit its cytotoxic impact solely to tumor cells within the tumor microenvironment (TME), we aimed to engineer SHK as polymeric nanoparticles (NPs) with targeting moiety toward tumor microvasculature. To this end, using single/double emulsion solvent evaporation/diffusion technique with sonication, we formulated biodegradable NPs of poly(lactic-co-glycolic acid) (PLGA) loaded with SHK. The surface of NPs was further decorated with solubilizing agent polyethylene glycol (PEG) and tumor endothelial marker 1 (TEM1)/endosialin-targeting antibody (Ab) through carbodiimide/N-hydroxysuccinimide chemistry. Having characterized the physicochemical and morphological properties of NPs, we studied their drug-release profiles using various kinetic models. The biological impact of NPs was also evaluated in tumor-associated endothelial MS1 cells, primary lymphocytes, and epithelial ovarian cancer OVCAR-5 cells. Based on particle size analysis and electron microscopy, the engineered NPs showed a smooth spherical shape with size range of 120 to 250 nm and zeta potential value of -30 to -40 mV. Drug entrapment efficiency was ~80%-90%, which was reduced to ~50%-60% upon surface decoration with PEG and Ab. The liberation of SHK from NPs showed a sustained-release profile that was best fitted with Wagner log-probability model. Fluorescence microscopy and flow cytometry analysis showed active interaction of Ab-armed NPs with TEM1-positive MS1 cells, but not with TEM1-negative MS1 cells. While exposure of the PEGylated NPs for 2 hours was not toxic to lymphocytes, long-term exposure of the Ab-armed and PEGylated NPs was significantly toxic to TEM1-positive MS1 cells and OVCAR-5 cells. Based on these findings, we propose SHK-loaded Ab-armed PEGylated PLGA NPs as a novel nanomedicine for targeted therapy of solid tumors.

Surface modified multifunctional nanomedicines for simultaneous imaging and therapy of cancer

INTRODUCTION

To date, a growing number of advanced anticancer nanomedicines (e.g., Doxil(®), Lipoxal(®), DepoCyte(®)) have entered into different phases of clinical trials. However, most of these medicaments fail to differentiate between diseased and normal cells. They also do not have capability of real time monitoring of disease status trough on-demand imaging/sensing of target molecule(s). Multifunctional nanomedicines and theranostics can resolve such limitations, while formulation of these advanced seamless systems appear to involve various sophisticated process, exploiting several bioconjugations.

METHODS

Recent works upon multifunctional nanomedicines for simultaneous imaging and therapy of cancer have been systematically reviewed, focusing on surface modification and application of advanced nanobiomaterials.

RESULTS

Ultimate therapy of malignancies, as complex systems, demands implementation of seamless nanosystems (NSs) that can specifically target the cancerous cells and smartly deliver the anticancer agent(s) into the desired target site. Engineering of such NSs requires in-situ coordination of various technologies (e.g., synthesis, surface modification and bioconjugation) in order to achieve improved pharmacokinetics and pharmacodynamics outcomes.

CONCLUSION

Seamless multimodal NSs have potential to simultaneously target and monitor the tumor cells through homing and imaging/sensing devices and deliver the therapeutic agents. However, to achieve superior pharmacokinetics with maximal efficacy and minimal side effects, these advanced NSs need to become much more intelligent to sense the disease condition and liberate therapeutics on demand.

Dysregulated pH in Tumor Microenvironment Checkmates Cancer Therapy

INTRODUCTION

The dysregulation of pH by cancerous cells of solid tumors is able to create a unique milieu that is in favor of progression, invasion and metastasis as well as chemo-/immuno-resistance traits of solid tumors. Bioelements involved in pH dysregulation provide new set of oncotargets, inhibition of which may result in better clinical outcome.

METHODS

To study the impacts of pH dysregulation, we investigated the tumor development and progression in relation with Warburg effect, glycolysis and formation of aberrant tumor microenvironment.

RESULTS

The upregulation of glucose transporter GLUT-1 and several enzymes involve in glycolysis exacerbates this phenomenon. The accumulation of lactic acids in cancer cells provokes upregulation of several transport machineries (MCT-1, NHE-1, CA IX and H(+) pump V-ATPase) resulting in reinforced efflux of proton into extracellular fluid. This deviant event makes pH to be settled at 7.4 and 6.6 respectively in cancer cells cytoplasm and extracellular fluid within the tumor microenvironment, which in return triggers secretion of lysosomal components (various enzymes in acidic milieu with pH 5) into cytoplasm. All these anomalous phenomena make tumor microenvironment (TME) to be exposed to cocktail of various enzymes with acidic pH, upon which extracellular matrix (ECM) can be remodeled and even deformed, resulting in emergence of a complex viscose TME with high interstitial fluid pressure.

CONCLUSION

It seems that pH dysregulation is able to remodel various physiologic functions and make solid tumors to become much more invasive and metastatic. It also can cause undesired resistance to chemotherapy and immunotherapy. Hence, cancer therapy needs to be reinforced using specific inhibitors of bioelements involved in pH dysregulation of TME in solid tumors.