CEACAM7 expression contributes to early events of pancreatic cancer.

BACKGROUND: The trends of pancreatic cancer (PanCa) incidence and mortality are on rising pattern, and it will be a second leading cause of cancer related deaths by 2030. Pancreatic ductal adenocarcinoma (PDAC), major form of PanCa, exhibits a grim prognosis as mortality rate is very close to the incidence rate, due to lack of early detection methods and effective therapeutic regimen. Considering this alarming unmet clinic need, our team has identified a novel oncogenic protein, carcinoembryonic antigen-related cell adhesion molecule 7 (CEACAM7), that can be useful for spotting early events of PDAC. METHODOLOGY: This study includes bioinformatics pre-screening using publicly available cancer databases followed by molecular biology techniques in PDAC progressive cell line panel and human tissues to evaluate CEACAM7 expression in early events of pancreatic cancer. RESULTS: PanCa gene and protein expression analysis demonstrated the significantly higher expression of CEACAM7 in PDAC, compared to other cancers and normal pancreas. Overall survival analysis demonstrated an association between the higher expression of CEACAM7 and poor patients' prognosis with high hazard ratio. Additionally, in a performance comparison analysis CEACAM7 outperformed S100A4 in relation to PDAC. We also observed an increase of CEACAM7 in PDAC cell line panel model. However, poorly differentiated, and normal cell lines did not show any expression. Human tissue analysis also strengthened our data by showing strong and positive IHC staining in early-stage tumors. CONCLUSION: Our observations clearly cite that CEACAM7 can serve as a potential early diagnostic and/or prognostic marker of PDAC and may also potentiate the sensitivity of the existing biomarker panel of PDAC. However, further studies are warranted to determine its clinical significance.

Transferrin-Bearing, Zein-Based Hybrid Lipid Nanoparticles for Drug and Gene Delivery to Prostate Cancer Cells.

Gene therapy holds great promise for treating prostate cancer unresponsive to conventional therapies. However, the lack of delivery systems that can transport therapeutic DNA and drugs while targeting tumors without harming healthy tissues presents a significant challenge. This study aimed to explore the potential of novel hybrid lipid nanoparticles, composed of biocompatible zein and conjugated to the cancer-targeting ligand transferrin. These nanoparticles were designed to entrap the anti-cancer drug docetaxel and carry plasmid DNA, with the objective of improving the delivery of therapeutic payloads to prostate cancer cells, thereby enhancing their anti-proliferative efficacy and gene expression levels. These transferrin-bearing, zein-based hybrid lipid nanoparticles efficiently entrapped docetaxel, leading to increased uptake by PC-3 and LNCaP cancer cells and significantly enhancing anti-proliferative efficacy at docetaxel concentrations exceeding 1 µg/mL. Furthermore, they demonstrated proficient DNA condensation, exceeding 80% at polymer-DNA weight ratios of 1500:1 and 2000:1. This resulted in increased gene expression across all tested cell lines, with the highest transfection levels up to 11-fold higher than those observed with controls, in LNCaP cells. These novel transferrin-bearing, zein-based hybrid lipid nanoparticles therefore exhibit promising potential as drug and gene delivery systems for prostate cancer therapy.

Glutathione-Responsive Tannic Acid-Assisted FRET Nanomedicine for Cancer Therapy.

In cancer combination therapy, a multimodal delivery vector is used to improve the bioavailability of multiple anti-cancer hydrophobic drugs. Further, targeted delivery of therapeutics along with simultaneous monitoring of the drug release at the tumor site without normal organ toxicity is an emerging and effective strategy for cancer treatment. However, the lack of a smart nano-delivery system limits the application of this therapeutic strategy. To overcome this issue, a PEGylated dual drug, conjugated amphiphilic polymer (CPT-S-S-PEG-CUR), has been successfully synthesized by conjugating two hydrophobic fluorescent anti-cancer drugs, curcumin (CUR) and camptothecin (CPT), through an ester and a redox-sensitive disulfide (-S-S-) linkage, respectively, with a PEG chain via in situ two-step reactions. CPT-S-S-PEG-CUR is spontaneously self-assembled in the presence of tannic acid (TA, a physical crosslinker) into anionic, comparatively smaller-sized (~100 nm), stable nano-assemblies in water in comparison to only polymer due to stronger H-bond formation between polymer and TA. Further, due to the spectral overlap between CPT and CUR and a stable, smaller nano-assembly formation by the pro-drug polymer in water in presence of TA, a successful Fluorescence Resonance Energy Transfer (FRET) signal was generated between the conjugated CPT (FRET donor) and conjugated CUR (FRET acceptor). Interestingly, these stable nano-assemblies showed a preferential breakdown and release of CPT in a tumor-relevant redox environment (in the presence of 50 mM glutathione), leading to the disappearance of the FRET signal. These nano-assemblies exhibited a successful cellular uptake by the cancer cells and an enhanced antiproliferative effect in comparison to the individual drugs in cancer cells (AsPC1 and SW480). Such promising in vitro results with a novel redox-responsive, dual-drug conjugated, FRET pair-based nanosized multimodal delivery vector can be highly useful as an advanced theranostic system towards effective cancer treatment.

Biomolecule-functionalized nanoformulations for prostate cancer theranostics.

BACKGROUND: Even with the advancement in the areas of cancer nanotechnology, prostate cancer still poses a major threat to men's health. Nanomaterials and nanomaterial-derived theranostic systems have been explored for diagnosis, imaging, and therapy for different types of cancer still, for prostate cancer they have not delivered at full potential because of the limitations like in vivo biocompatibility, immune responses, precise targetability, and therapeutic outcome associated with the nanostructured system. AIM OF REVIEW: Functionalizing nanomaterials with different biomolecules and bioactive agents provides advantages like specificity towards cancerous tumors, improved circulation time, and modulation of the immune response leading to early diagnosis and targeted delivery of cargo at the site of action. KEY SCIENTIFIC CONCEPTS OF REVIEW: In this review, we have emphasized the classification and comparison of various nanomaterials based on biofunctionalization strategy and source of biomolecules such that it can be used for possible translation in clinical settings and future developments. This review highlighted the opportunities for embedding highly specific biological targeting moieties (antibody, aptamer, oligonucleotides, biopolymer, peptides, etc.) on nanoparticles which can improve the detection of prostate cancer-associated biomarkers at a very low limit of detection, direct visualization of prostate tumors and lastly for its therapy. Lastly, special emphasis was given to biomimetic nanomaterials which include functionalization with extracellular vesicles, exosomes and viral particles and their application for prostate cancer early detection and drug delivery. The present review paves a new pathway for next-generation biofunctionalized nanomaterials for prostate cancer theranostic application and their possibility in clinical translation.

Current status of biopsy markers for the breast in clinical settings.

INTRODUCTION: A breast biopsy marker is a very small object that is introduced into the breast to serve as a tissue marker. The placement of a breast marker following a biopsy or to mark an abnormality in the breast has become standard practice in the clinical setting. Breast biopsy markers offer a wide range of benefits which includes the prevention of re-biopsy of a benign tumor, differentiating multiple lesions within the breast, evaluation of the extent of a tumor, and increased precision during surgery. AREAS COVERED: This review article presents a range of breast biopsy markers used in clinical practice. First, an overview of the necessity of breast markers in healthy breast management. Second, it summarizes the diversity in composition, shape, unique properties and features, and bio-absorbable carriers of breast biopsy markers. Finally, it also discusses the possible use of clinically approved breast biopsy markers in various scenarios and their implications. EXPERT OPINION: This review serves as a guide in the selection of an appropriate breast marker. We believe that some of the common drawbacks associated with current breast biopsy markers can be overcome by developing novel polymer-metal and composite-based breast biopsy markers.

Preparation of Zein-Based Nanoparticles: Nanoprecipitation versus Microfluidic-Assisted Manufacture, Effects of PEGylation on Nanoparticle Characteristics and Cellular Uptake by Melanoma Cells.

Background: The manufacture of nanoparticles using manual methods is hampered by its challenging scale-up and poor reproducibility. To overcome this issue, the production of zein nanoparticles entrapping a lipophilic drug model, coumarin-6, by using a microfluidic system was assessed in this study. The influence of PEG density and chain length on zein nanoparticle characteristics, as well as their uptake efficacy in melanoma cancer cells, was also evaluated. Methods: Zein nanoparticles were prepared by both manual and microfluidic approaches to allow comparison between the two processes. PEGylated zein nanoparticles with various PEG densities and chain lengths were produced by nanoprecipitation and characterized. Their cellular uptake was evaluated on B16F10 melanoma cancer cells in vitro. Results: Zein nanoparticles have successfully been produced by both manual and microfluidic approaches. Parameters such as total flow rate and flow rate ratio of the aqueous and organic phases in microfluidic process, as well as the method preparation and aqueous to organic phase volume ratio during nanoprecipitation, have been shown to strongly influence the characteristics of the resulting nanoparticles. Continuous microfluidics led to the production of nanoparticles with low yield and drug entrapment, unlike nanoprecipitation, which resulted in zein nanoparticles with an appropriate size and an optimal drug entrapment efficiency of 64%. The surface modification of the nanoparticles produced by nanoprecipitation, with lower PEG density and shorter PEG chain length made mPEG5K-zein (0.5:1) the most favorable formulation in our study, resulting in enhanced stability and higher coumarin-6 uptake by melanoma cancer cells. Conclusion: mPEG5K-zein (0.5:1) nanoparticles prepared by nanoprecipitation were the most promising formulation in our study, exhibiting increased stability and enhancing coumarin-6 uptake by melanoma cancer cells.

Lactoferrin- and Dendrimer-Bearing Gold Nanocages for Stimulus-Free DNA Delivery to Prostate Cancer Cells.

Background: The use of gene therapy to treat prostate cancer is hampered by the lack of effective nanocarriers that can selectively deliver therapeutic genes to cancer cells. To overcome this, we hypothesize that conjugating lactoferrin, a tumor-targeting ligand, and the diaminobutyric polypropylenimine dendrimer into gold nanocages, followed by complexation with a plasmid DNA, would enhance gene expression and anti-proliferation activity in prostate cancer cells without the use of external stimuli. Methods: Novel gold nanocages bearing lactoferrin and conjugated to diaminobutyric polypropylenimine dendrimer (AuNCs-DAB-Lf) were synthesized and characterized. Following complexation with a plasmid DNA, their gene expression, cellular uptake and anti-proliferative efficacies were evaluated on PC-3 prostate cancer cells. Results: AuNCs-DAB-Lf was able to complex DNA at conjugate: DNA weight ratios 5:1 onwards. Gene expression was at its highest after treatment with AuNCs-DAB-Lf at a weight ratio of 10:1, as a result of a significant increase in DNA uptake mediated by the conjugate at that ratio in PC-3 cells. Consequently, the anti-proliferative activity of AuNCs-DAB-Lf-DNA encoding TNFα was significantly improved by up to 9-fold compared with DAB dendriplex encoding TNFα. Conclusion: Lactoferrin-bearing dendrimer-conjugated gold nanocages are highly promising gene delivery systems for the treatment of prostate cancer.

Limited Impact of the Protein Corona on the Cellular Uptake of PEGylated Zein Micelles by Melanoma Cancer Cells.

The formation of a protein layer "corona" on the nanoparticle surface upon entry into a biological environment was shown to strongly influence the interactions with cells, especially affecting the uptake of nanomedicines. In this work, we present the impact of the protein corona on the uptake of PEGylated zein micelles by cancer cells, macrophages, and dendritic cells. Zein was successfully conjugated with poly(ethylene glycol) (PEG) of varying chain lengths (5K and 10K) and assembled into micelles. Our results demonstrate that PEGylation conferred stealth effects to the zein micelles. The presence of human plasma did not impact the uptake levels of the micelles by melanoma cancer cells, regardless of the PEG chain length used. In contrast, it decreased the uptake by macrophages and dendritic cells. These results therefore make PEGylated zein micelles promising as potential drug delivery systems for cancer therapy.

A topography of immunotherapies against gastrointestinal malignancies.

Gastrointestinal (GI) cancers are one of the leading causes of death worldwide. Although various approaches are implemented to improve the health condition of GI patients, none of the treatment protocols promise for eradicating cancer. However, a treatment mechanism against any kind of disease condition is already existing executing inside the human body. The 'immune system' is highly efficient to detect and destroy the unfavorable events of the body including tumor cells. The immune system can restrict the growth and proliferation of cancer. Cancer cells behave much smarter and adopt new mechanisms for hiding from the immune cells. Thus, cancer immunotherapy might play a decisive role to train the immune system against cancer. In this review, we have discussed the immunotherapy permitted for the treatment of GI cancers. We have discussed various methods and mechanisms, periodic development of cancer immunotherapies, approved biologicals, completed and ongoing clinical trials, role of various biopharmaceuticals, and epigenetic factors involved in GI cancer immunotherapies.

Emergence of cationic polyamine dendrimersomes: design, stimuli sensitivity and potential biomedical applications.

For decades, self-assembled lipid vesicles have been widely used in clinics as nanoscale delivery systems for various biomedical applications, including treatment of various diseases. Due to their core-shell architecture and versatile nature, they have been successfully used as carriers for the delivery of a wide range of therapeutic cargos, including drugs and nucleic acids, in cancer treatment. Recently, surface-modified polyamine dendrimer-based vesicles, or dendrimersomes, have emerged as promising alternatives to lipid vesicles for various biomedical applications, due to their ease of synthesis, non-immunogenicity, stability in circulation and lower size polydispersity. This mini-review provides an overview of the recent advances resulting from the use of biomimetic hydrophobically-modified polyamine-based dendrimersomes towards biomedical applications, focusing mainly on the two most widely used polyamine dendrimers, namely polyamidoamine (PAMAM) and poly(propylene imine) (PPI) dendrimers.

Lactoferrin-Bearing Gold Nanocages for Gene Delivery in Prostate Cancer Cells in vitro.

BACKGROUND: Gold nanocages have been widely used as multifunctional platforms for drug and gene delivery, as well as photothermal agents for cancer therapy. However, their potential as gene delivery systems for cancer treatment has been reported in combination with chemotherapeutics and photothermal therapy, but not in isolation so far. The purpose of this work was to investigate whether the conjugation of gold nanocages with the cancer targeting ligand lactoferrin, polyethylene glycol and polyethylenimine could lead to enhanced transfection efficiency on prostate cancer cells in vitro, without assistance of external stimulation. METHODS: Novel lactoferrin-bearing gold nanocages conjugated to polyethylenimine and polyethylene glycol have been synthesized and characterized. Their transfection efficacy and cytotoxicity were assessed on PC-3 prostate cancer cell line following complexation with a plasmid DNA. RESULTS: Lactoferrin-bearing gold nanocages, alone or conjugated with polyethylenimine and polyethylene glycol, were able to condense DNA at conjugate:DNA weight ratios 5:1 and higher. Among all gold conjugates, the highest gene expression was obtained following treatment with gold complex conjugated with polyethylenimine and lactoferrin, at weight ratio 40:1, which was 1.71-fold higher than with polyethylenimine. This might be due to the increased DNA cellular uptake observed with this conjugate, by up to 8.65-fold in comparison with naked DNA. CONCLUSION: Lactoferrin-bearing gold nanocages conjugates are highly promising gene delivery systems to prostate cancer cells.

Regression of Melanoma Following Intravenous Injection of Plumbagin Entrapped in Transferrin-Conjugated, Lipid-Polymer Hybrid Nanoparticles.

BACKGROUND: Plumbagin, a naphthoquinone extracted from the officinal leadwort presenting promising anti-cancer properties, has its therapeutic potential limited by its inability to reach tumors in a specific way at a therapeutic concentration following systemic injection. The purpose of this study is to assess whether a novel tumor-targeted, lipid-polymer hybrid nanoparticle formulation of plumbagin would suppress the growth of B16-F10 melanoma in vitro and in vivo. METHODS: Novel lipid-polymer hybrid nanoparticles entrapping plumbagin and conjugated with transferrin, whose receptors are present in abundance on many cancer cells, have been developed. Their cellular uptake, anti-proliferative and apoptosis efficacy were assessed on various cancer cell lines in vitro. Their therapeutic efficacy was evaluated in vivo after tail vein injection to mice bearing B16-F10 melanoma tumors. RESULTS: The transferrin-bearing lipid-polymer hybrid nanoparticles loaded with plumbagin resulted in the disappearance of 40% of B16-F10 tumors and regression of 10% of the tumors following intravenous administration. They were well tolerated by the mice. CONCLUSION: These therapeutic effects, therefore, make transferrin-bearing lipid-polymer hybrid nanoparticles entrapping plumbagin a highly promising anti-cancer nanomedicine.

Nanotechnology synergized immunoengineering for cancer.

Novel strategies modulating the immune system yielded enhanced anticancer responses and improved cancer survival. Nevertheless, the success rate of immunotherapy in cancer treatment has been below expectation(s) due to unpredictable efficacy and off-target effects from systemic dosing of immunotherapeutic(s). As a result, there is an unmet clinical need for improving conventional immunotherapy. Nanotechnology offers several new strategies, multimodality, and multiplex biological targeting advantage to overcome many of these challenges. These efforts enable programming the pharmacodynamics, pharmacokinetics, and delivery of immunomodulatory agents/co-delivery of compounds to prime at the tumor sites for improved therapeutic benefits. This review provides an overview of the design and clinical principles of biomaterials driven nanotechnology and their potential use in personalized nanomedicines, vaccines, localized tumor modulation, and delivery strategies for cancer immunotherapy. In this review, we also summarize the latest highlights and recent advances in combinatorial therapies availed in the treatment of cold and complicated tumors. It also presents key steps and parameters implemented for clinical success. Finally, we analyse, discuss, and provide clinical perspectives on the integrated opportunities of nanotechnology and immunology to achieve synergistic and durable responses in cancer treatment.

Octadecyl chain-bearing PEGylated poly(propyleneimine)-based dendrimersomes: physicochemical studies, redox-responsiveness, DNA condensation, cytotoxicity and gene delivery to cancer cells.

Stimuli-responsive nanocarriers have become increasingly important for nucleic acid and drug delivery in cancer therapy. Here, we report the synthesis, characterization and evaluation of disulphide-linked, octadecyl (C18 alkyl) chain-bearing PEGylated generation 3-diaminobutyric polypropylenimine dendrimer-based vesicles (or dendrimersomes) for gene delivery. The lipid-bearing PEGylated dendrimer was successfully synthesized through in situ two-step reaction. It was able to spontaneously self-assemble into stable, cationic, nanosized vesicles, with low critical aggregation concentration value, and also showed redox-responsiveness in presence of a glutathione concentration similar to that of the cytosolic reducing environment. In addition, it was able to condense more than 70% of DNA at dendrimer: DNA weight ratios of 5 : 1 and higher. This dendriplex resulted in an enhanced cellular uptake of DNA at dendrimer: DNA weight ratios of 10 : 1 and 20 : 1, by up to 16-fold and by up to 28-fold compared with naked DNA in PC-3 and DU145 prostate cancer cell lines respectively. At a dendrimer: DNA weight ratio of 20 : 1, it led to an increase in gene expression in PC-3 and DU145 cells, compared with DAB dendriplex. These octadecyl chain-bearing, PEGylated dendrimer-based vesicles are therefore promising redox-sensitive drug and gene delivery systems for potential applications in combination cancer therapy.

"Tomorrow Never Dies": Recent Advances in Diagnosis, Treatment, and Prevention Modalities against Coronavirus (COVID-19) amid Controversies.

The outbreak of novel coronavirus disease (2019-nCoV or COVID-19) is responsible for severe health emergency throughout the world. The attack of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is found to be responsible for COVID-19. The World Health Organization has declared the ongoing global public health emergency as a pandemic. The whole world fights against this invincible enemy in various capacities to restore economy, lifestyle, and safe life. Enormous amount of scientific research work(s), administrative strategies, and economic measurements are in place to create a successful step against COVID-19. Furthermore, differences in opinion, facts, and implementation methods laid additional layers of complexities in this battle against survival. Thus, a timely overview of the recent, important, and overall inclusive developments against this pandemic is a pressing need for better understanding and dealing with COVID-19. In this review, we have systematically summarized the epidemiological studies, clinical features, biological properties, diagnostic methods, treatment modalities, and preventive measurements related to COVID-19.

Anti-Tumor Activity of Intravenously Administered Plumbagin Entrapped in Targeted Nanoparticles.

Plumbagin, a natural naphthoquinone from the officinal leadwort, has recently been shown to exert promising anti-cancer effects. However, its therapeutic use is hampered by its failure to specifically reach tumors after intravenous administration, without secondary effects on normal tissues. Its poor solubility in water and rapid elimination following in vivo administration further limit its potential use. We hypothesize that the entrapment of plumbagin within PEGylated PLGA nanoparticles conjugated with transferrin, whose receptors are overexpressed on many types of cancer cells, could lead to a selective delivery of the drug to tumors following intravenous administration and enhance its chemotherapeutic effects. The objectives of this study were therefore to prepare and characterize transferrin-conjugated, PEGylated PLGA nanoparticles entrapping plumbagin, and to assess their anti-cancer efficacy in vitro as well as in tumor-bearing mice. The intravenous administration of transferrin-conjugated PEGylated PLGA nanoparticles resulted in the complete suppression of 10% of B16-F10 tumors and regression of 30% of the tumors, with improvement of the animal survival compared to controls. The treatment was well tolerated by the animals. Transferrin-bearing PEGylated PLGA nanoparticles entrapping plumbagin are therefore highly promising therapeutic systems, able to lead to tumor regression and even suppression after intravenous administration without visible toxicity.

Camptothecin-based dendrimersomes for gene delivery and redox-responsive drug delivery to cancer cells.

Combination therapy involving chemotherapeutic drugs and genes is emerging as a promising strategy to provide a synergistic therapeutic effect, to overcome drug resistance while reducing the severe side effects associated with conventional chemotherapeutic drugs. However, the lack of nanomedicines able to simultaneously carry anti-cancer drugs and nucleic acids limits the application of this therapeutic strategy. To overcome this issue, we proposed to synthesize a pro-drug dendrimer by conjugating the PEGylated, positively charged generation 3-diaminobutyric polypropylenimine dendrimer to the anti-cancer drug camptothecin with a redox-sensitive disulphide linkage, and evaluate its efficacy to co-deliver the complexed DNA and camptothecin to cancer cells. This PEGylated pro-drug dendrimer was found to spontaneously self-assemble into cationic (∼3-5 mV) vesicles at pH 7.4, at a critical aggregation concentration of about 200 µg mL-1. These vesicles (dendrimersomes) became smaller (150-200 nm) with increasing dendrimer concentration and remained stable over 7 days. They were able to release about 70% of the conjugated camptothecin in presence of 50 mM glutathione (equivalent to the intracellular environment of tumor tissue). They could also condense more than 85% of the DNA at dendrimer : DNA weight ratios of 5 : 1 and higher. DNA condensation occurred instantly and was found to be stable for at least 24 h. This led to an enhanced cellular uptake of DNA (by up to 1.6-fold) and increased gene transfection (by up to 2.4-fold) in prostate cancer cells in comparison with the unmodified dendrimer. These novel dendrimersomes are therefore promising for single carrier-based combination cancer therapy.

Transferrin-bearing liposomes entrapping plumbagin for targeted cancer therapy.

The therapeutic potential of plumbagin, a naphthoquinone extracted from the officinal leadwort with anticancer properties, is hampered by its failure to specifically reach tumours at a therapeutic concentration after intravenous administration, without secondary effects on normal tissues. Its use in clinic is further limited by its poor aqueous solubility, its spontaneous sublimation, and its rapid elimination in vivo. We hypothesize that the entrapment of plumbagin within liposomes grafted with transferrin, whose receptors are overexpressed on many cancer cells, could result in a selective delivery to tumours after intravenous administration. The objectives of this study were therefore to prepare and characterize transferrin-targeted liposomes entrapping plumbagin and to evaluate their therapeutic efficacy in vitro and in vivo. The entrapment of plumbagin in transferrin-bearing liposomes led to an increase in plumbagin uptake by cancer cells and improved antiproliferative efficacy and apoptosis activity in B16-F10, A431, and T98G cell lines compared with that observed with the drug solution. In vivo, the intravenous injection of transferrin-bearing liposomes entrapping plumbagin led to tumour suppression for 10% of B16-F10 tumours and tumour regression for a further 10% of the tumours. By contrast, all the tumours treated with plumbagin solution or left untreated were progressive. The animals did not show any signs of toxicity. Transferrin-bearing liposomes entrapping plumbagin are therefore highly promising therapeutic systems that should be further optimized as a therapeutic tool for cancer treatment.

Redox-sensitive, cholesterol-bearing PEGylated poly(propylene imine)-based dendrimersomes for drug and gene delivery to cancer cells.

Stimuli-responsive nanocarriers have attracted increased attention as materials that can facilitate drug and gene delivery in cancer therapy. The present study reports the development of redox-sensitive dendrimersomes comprising disulfide-linked cholesterol-bearing PEGylated dendrimers, which can be used as drug and gene delivery systems. Two disulfide-linked cholesterol-bearing PEGylated generation 3 diaminobutyric polypropylenimine dendrimers have been successfully synthesized via an in situ two-step reaction. They were able to spontaneously self-assemble into stable, cationic, nanosized vesicles (or dendrimersomes) with lower critical aggregation concentration values for high-cholesterol-bearing vesicles. These dendrimersomes were able to entrap both hydrophilic and hydrophobic dyes, and they also showed a redox-responsive sustained release of the entrapped guests in the presence of a glutathione concentration similar to that of a cytosolic reducing environment. The high-cholesterol-bearing dendrimersomes were found to have a higher melting enthalpy, increased adsorption tendency on mica surface, entrapping ability for a larger amount of hydrophobic drugs, and increased resistance to redox-responsive environments in comparison with their low-cholesterol counterpart. In addition, both dendrimersomes were able to condense more than 85% of the DNA at all the tested ratios for the low-cholesterol vesicles, and at dendrimer : DNA weight ratios of 1 : 1 and higher for the high-cholesterol vesicles. These vesicles resulted in an enhanced cellular uptake of DNA, by up to 15-fold when compared with naked DNA with low-cholesterol vesicles. As a result, they increased the gene transfection on the PC-3 prostate cancer cell line, with the highest transfection being obtained with low-cholesterol vesicle complexes at a dendrimer : DNA weight ratio of 5 : 1 and high-cholesterol vesicle complexes at a dendrimer : DNA weight ratio of 10 : 1. These transfection levels were about 5-fold higher than those observed when treated with naked DNA. These cholesterol-bearing PEGylated dendrimer-based vesicles are, therefore, promising as redox-sensitive drugs and gene delivery systems for potential applications in combination cancer therapies.

PEGylation of polypropylenimine dendrimers: effects on cytotoxicity, DNA condensation, gene delivery and expression in cancer cells.

Diaminobutyric polypropylenimine (DAB) dendrimers have been shown to be highly efficient non-viral gene delivery systems for cancer therapy. However, their cytotoxicity currently limits their applications. To overcome this issue, PEGylation of DAB dendrimer, using various PEG molecular weights and dendrimer generations, has been attempted to decrease the cytotoxicity and enhance the DNA condensation, size and zeta potential, cellular uptake and transfection efficacy of these dendriplexes. Among all the PEGylated dendrimers synthesized, generation 3- and generation 4-DAB conjugated to low molecular weight PEG (2 kDa) at a dendrimer: DNA ratio of 20:1 and 10:1 resulted in an increase in gene expression on almost all tested cancer cells lines (by up to 3.2-fold compared to unmodified dendrimer in A431 cells). The highest level of ß-galactosidase gene expression (10.07 × 10-3 ± 0.09 × 10-3 U/mL) was obtained following treatment of B16F10-Luc cells with G4-dendrimer PEGylated with PEG2K at a dendrimer: DNA ratio of 20:1. These delivery systems significantly decreased cytotoxicity on B16F10-Luc cells, by more than 3.4-fold compared to unmodified dendrimer. PEGylated generations 3- and 4-DAB dendrimers are therefore promising gene delivery systems for cancer therapy, combining low cytotoxicity and high transfection efficacy.