Comparison of two kinds of nanomedicine for targeted gene therapy: premodified or postmodified gene delivery systems

Rising horizon in circumventing multidrug resistance in chemotherapy with nanotechnology

Multidrug resistance (MDR) is one of the key barriers in chemotherapy, leading to the generation of insensitive cancer cells towards administered therapy. Genetic and epigenetic alterations of the cells are the consequences of MDR, resulted in drug resistivity, which reflects in impaired delivery of cytotoxic agents to the cancer site. Nanotechnology-based nanocarriers have shown immense shreds of evidence in overcoming these problems, where these promising tools handle desired dosage load of hydrophobic chemotherapeutics to facilitate designing of safe, controlled and effective delivery to specifically at tumor microenvironment. Therefore, encapsulating drugs within the nano-architecture have shown to enhance solubility, bioavailability, drug targeting, where co-administered P-gp inhibitors have additionally combat against developed MDR. Moreover, recent advancement in the stimuli-sensitive delivery of nanocarriers facilitates a tumor-targeted release of the chemotherapeutics to reduce the associated toxicities of chemotherapeutic agents in normal cells. The present article is focused on MDR development strategies in the cancer cell and different nanocarrier-based approaches in circumventing this hurdle to establish an effective therapy against deadliest cancer disease.

Nanocarriers for spleen targeting: anatomo-physiological considerations, formulation strategies and therapeutic potential

There are several clinical advantages of spleen targeting of nanocarriers. For example, enhanced splenic concentration of active agents could provide therapeutic benefits in spleen resident infections and hematological disorders including malaria, hairy cell leukemia, idiopathic thrombocytopenic purpura, and autoimmune hemolytic anemia. Furthermore, spleen delivery of immunosuppressant agents using splenotropic carriers may reduce the chances of allograft rejection in organ transplantation. Enhanced concentration of radiopharmaceuticals in the spleen may improve visualization of the organ, which could provide benefit in the diagnosis of splenic disorders. Unique anatomical features of the spleen including specialized microvasculature environment and slow blood circulation rate enable it an ideal drug delivery site. Because there is a difference in blood flow between spleen and liver, splenic delivery is inversely proportional to the hepatic uptake. It is therefore desirable engineering of nanocarriers, which, upon intravenous administration, can avoid uptake by hepatic Kupffer cells to enhance splenic localization. Stealth and non-spherical nanocarriers have shown enhanced splenic delivery of active agents by avoiding hepatic uptake. The present review details the research in the field of splenotropy. Formulation strategies to design splenotropic drug delivery systems are discussed. The review also highlights the clinical relevance of spleen targeting of nanocarriers and application in diagnostics.

Design and evaluation of lidocaine- and prilocaine-coloaded nanoparticulate drug delivery systems for topical anesthetic analgesic therapy: a comparison between solid lipid nanoparticles and nanostructured lipid carriers

Purpose

Topical anesthesia analgesic therapy has diverse applicability in solving the barrier properties of skin and unfavorable physicochemical properties of drugs. Lidocaine (LID) combined with prilocaine (PRI) has been used as a topical preparation for dermal anesthesia for treatment of conditions such as paresthesia.

Materials and methods

In this study, for combination anesthesia and overcoming the drawbacks of LID and PRI, respectively, LID- and PRI-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) were prepared and characterized by determination of their particle size, drug loading capacity, stability, in vitro drug release behavior and in vitro cellular viability. Ex vivo skin permeation and in vivo anesthesia analgesic efficiency of these two systems were also evaluated and compared.

Results

Results revealed that combination delivery of the dual drugs exhibited more remarkable efficiency than signal drug-loaded systems. SLN systems have better ex vivo skin permeation ability than NLCs. NLC systems revealed a stronger in vivo anesthesia analgesic effect than SLN systems.

Conclusion

It can be concluded that SLNs and NLCs have different advantages, and that both carriers are promising dual drug delivery systems for topical anesthetic analgesic therapy.

Delivery of baicalein and paclitaxel using self-assembled nanoparticles: synergistic antitumor effect in vitro and in vivo

Purpose

Combination anticancer therapy is promising to generate synergistic anticancer effects to maximize the treatment effect and overcome multidrug resistance. The aim of the study reported here was to develop multifunctional, dual-ligand, modified, self-assembled nanoparticles (NPs) for the combination delivery of baicalein (BCL) and paclitaxel (PTX) prodrugs.

Methods

Prodrug of PTX and prodrug of BCL, containing dual-targeted ligands of folate (FA) and hyaluronic acid (HA), were synthesized. Multifunctional self-assembled NPs for combination delivery of PTX prodrug and BCL prodrug (PTX-BCL) were prepared and the synergistic antitumor effect was evaluated in vitro and in vivo. The in vitro transfection efficiency of the novel modified vectors was evaluated in human lung cancer A549 cells and drug-resistant lung cancer A549/PTX cells. The in vivo antitumor efficiency and systemic toxicity of different formulations were further investigated in mice bearing A549/PTX drug-resistant human lung cancer xenografts.

Results

The size of the PTX-BCL NPs was approximately 90 nm, with a positive zeta potential of +3.3. The PTX-BCL NPs displayed remarkably better antitumor activity over a wide range of drug concentrations, and showed an obvious synergism effect with CI₅₀ values of 0.707 and 0.513, indicating that double-ligand modification and the co-delivery of PTX and BCL prodrugs with self-assembled NPs had remarkable superiority over other formulations.

Conclusion

The prepared PTX-BCL NP drug-delivery system was proven efficient by its targeting of drug-resistant human lung cancer cells and delivering of BCL and PTX prodrugs. Enhanced synergistic anticancer effects were achieved by PTX-BCL NPs, and multidrug resistance of PTX was overcome by this promising targeted nanomedicine.

Targeted lung cancer therapy: preparation and optimization of transferrin-decorated nanostructured lipid carriers as novel nanomedicine for co-delivery of anticancer drugs and DNA

Purpose

Nanostructured lipid carriers (NLC) represent an improved generation of lipid nanoparticles. They have specific nanostructures to accommodate drugs/genes, and thus achieve higher loading capacity. The aim of this study was to develop transferrin (Tf)-decorated NLC as multifunctional nanomedicine for co-delivery of paclitaxel (PTX) and enhanced green fluorescence protein plasmid.

Methods

Firstly, Tf-conjugated ligands were synthesized. Secondly, PTX- and DNA-loaded NLC (PTX-DNA-NLC) was prepared. Finally, Tf-containing ligands were used for the surface decoration of NLC. Their average size, zeta potential, drug, and gene loading were evaluated. Human non-small cell lung carcinoma cell line (NCl-H460 cells) was used for the testing of in vitro transfection efficiency, and in vivo transfection efficiency of NLC was evaluated on mice bearing NCl-H460 cells.

Results

Tf-decorated PTX and DNA co-encapsulated NLC (Tf-PTX-DNA-NLC) were nano-sized particles with positive zeta potential. Tf-PTX-DNA-NLC displayed low cytotoxicity, high gene transfection efficiency, and enhanced antitumor activity in vitro and in vivo.

Conclusion

The results demonstrated that Tf-PTX-DNA-NLC can achieve impressive antitumor activity and gene transfection efficiency. Tf decoration also enhanced the active targeting ability of the carriers to NCl-H460 cells. The novel drug and gene delivery system offers a promising strategy for the treatment of lung cancer.

Study on the prostate cancer-targeting mechanism of aptamer-modified nanoparticles and their potential anticancer effect in vivo

Ligand-mediated prostate cancer (PCa)-targeting gene delivery is one of the focuses of research in recent years. Our previous study reported the successful preparation of aptamer-modified nanoparticles (APT-NPs) in our laboratory and demonstrated their PCa-targeting ability in vitro. However, the mechanism underlying this PCa-targeting effect and their anticancer ability in vivo have not yet been elucidated. The objective of this study was to assess the feasibility of using APT-NPs to deliver micro RNA (miRNA) systemically to PCa cells, to testify their tumor-targeting efficiency, and to observe their biodistribution after systemic administration to a xenograft mouse model of PCa. In addition, the effect of APT depletion and endocytosis inhibitors on cellular uptake was also evaluated quantitatively in LNCaP cells to explore the internalization mechanism of APT-NPs. Finally, blood chemistry, and renal and liver function parameters were measured in the xenograft mouse model of PCa to see whether APT-NPs had any demonstrable toxicity in mice in vivo. The results showed that APT-NPs prolonged the survival duration of the PCa tumor-bearing mice as compared with the unmodified NPs. In addition, they had a potential PCa-targeting effect in vivo. In conclusion, this research provides a prototype for the safe and efficient delivery of miRNA expression vectors to PCa cells, which may prove useful for preclinical and clinical studies on the treatment of PCa.

Development and characterization of a cationic lipid nanocarrier as non-viral vector for gene therapy

The aim of the present work was to produce a cationic solid lipid nanoparticle (SLN) as non-viral vector for protein delivery. Cationic SLN were produced by double emulsion method, composed of softisan(®) 100, cetyltrimethylammonium bromide (CTAB), Tween(®) 80, Span(®) 80, glycerol and lipoid(®) S75 loading insulin as model protein. The formulation was characterized in terms of mean hydrodynamic diameter (z-ave), polydispersity index (PI), zeta potential (ZP), stability during storage time, stability after lyophilization, effect of toxicity and transfection ability in HeLa cells, in vitro release profile and morphology. SLN were stable for 30days and showed minimal changes in their physicochemical properties after lyophilization. The particles exhibited a relatively slow release, spherical morphology and were able to transfect HeLa cells, but toxicity remained an obstacle. Results suggest that SLN are nevertheless promising for delivery of proteins or nucleic acids for gene therapy.

Transferrin-modified nanostructured lipid carriers as multifunctional nanomedicine for codelivery of DNA and doxorubicin

BACKGROUND

Nanostructured lipid carriers (NLC), composed of solid and liquid lipids, and surfactants are potentially good colloidal drug carriers. The aim of this study was to develop surface-modified NLC as multifunctional nanomedicine for codelivery of enhanced green fluorescence protein plasmid (pEGFP) and doxorubicin (DOX).

METHODS

TWO DIFFERENT NANOCARRIERS: pEGFP- and DOX-loaded NLC, and solid lipid nanoparticles (SLN) were prepared. Transferrin-containing ligands were used for the surface coating of the vectors. Their average size, zeta potential, and drug encapsulation capacity were evaluated. In vitro transfection efficiency of the modified vectors was evaluated in human alveolar adenocarcinoma cell line (A549 cells), and in vivo transfection efficiency of the modified vectors was evaluated in a mouse bearing A549 cells model.

RESULTS

Transferrin-modified DOX and pEGFP coencapsulated NLC (T-NLC) has a particle size of 198 nm and a +19 mV surface charge. The in vitro cell viabilities of the T-NLC formulations were over 80% compared with the control. T-NLC displayed remarkably greater gene transfection efficiency and enhanced antitumor activity than DOX- and pEGFP-coencapsulated SLN in vivo.

CONCLUSION

The results demonstrate that T-NLC noticeably enhanced antitumor activity through the combination of gene therapy with chemotherapy. Also coating of active transferrin improved the lung cancer cell-targeting of the carriers. In summary, the novel gene and drug delivery system offers a promising strategy for the treatment of lung cancer.

Folate-modified doxorubicin-loaded nanoparticles for tumor-targeted therapy

CONTEXT

Polymeric nanoparticles (NPs) have been used frequently as drug delivery vehicles. Surface modification of polymeric NPs with specific ligands defines a new biological identity, which assists in targeting of the nanocarriers to specific cancers cells.

OBJECTIVE

The aim of this study is to develop a kind of modified vector which could target the cancer cells through receptor-mediated pathways to increase the uptake of doxorubicin (DOX).

METHODS

Folate (FA)-conjugated PEG-PE (FA-PEG-PE) ligands were used to modify the polymeric NPs. The modification rate was optimized and the physical-chemical characteristics, in vitro release, and cytotoxicity of the vehicle were evaluated. The in vivo therapeutic effect of the vectors was evaluated in human nasopharyngeal carcinoma KB cells baring mice by giving each mouse 100 µl of 10 mg/kg different solutions.

RESULTS

FA-PEG-PE-modified NPs/DOX (FA-NPs/DOX) have a particle size of 229 nm, and 86% of drug loading quantity. FA-NPs/DOX displayed remarkably higher cytotoxicity (812 mm(3) tumor volume after 13 d of injection) than non-modified NPs/DOX (1290 mm(3)) and free DOX solution (1832 mm(3)) in vivo.

CONCLUSION

The results demonstrate that the modified drug delivery system (DDS) could function comprehensively to improve the efficacy of cancer therapy. Consequently, the system was shown to be a promising carrier for delivery of DOX, leading to the efficiency of antitumor therapy.

A promising targeted gene delivery system: folate-modified dexamethasone-conjugated solid lipid nanoparticles

CONTEXT

Non-viral gene delivery could deliver drugs/genes through cellular membranes and nuclear membranes by some modification of materials.

OBJECTIVE

This study develops a kind of vector to target the cells through receptor-mediated pathways. Nuclear localization signal (NLS) was also used to increase the nuclear uptake of genetic materials.

MATERIALS AND METHODS

A lipid containing dexamethasone (Dexa) was synthesized as the material of the preparation of solid lipid nanoparticles (SLNs) and folate (Fa)-conjugated PEG-PE (Fa-PEG-PE) ligands were used to modify the SLNs. The in vitro cytotoxicity of the carriers at various concentrations (10, 20, 50, 100, and 200 μg/ml) were evaluated in KB human carcinoma cells (KB cells). In vivo transfection efficiency of the novel modified vectors was evaluated in disseminated peritoneal tumors on mice bearing KB cells.

RESULTS

Fa-PEG-PE modified SLNs/enhanced green fluorescence protein plasmid (pEGFP) has a particle size of 258 nm, and the gene loading quantity of the vector was 90%. The in vitro cytotoxicity of Fa-PEG-PE-modified SLNs/pEGFP (Fa-SLNs/pEGFP) was low (cell viabilities were between 80% and 100% compared with controls). Fa-SLNs/pEGFP displayed remarkably higher transfection efficiency (40%) than non-modified SLNs/pEGFP (24%) and the vectors not containing Dexa (30%) in vivo.

CONCLUSION

The results demonstrate that Fa and Dexa could function as excellent active targeting ligands to improve the cell targeting and nuclear targeting ability of the carriers and the resulting vectors could be promising active targeting drug/gene delivery systems.

Inhaled gene therapy in lung cancer: proof-of-concept for nano-oncology and nanobiotechnology in the management of lung cancer

Lung cancer still remains one of the leading causes of death among cancer patients. Although novel targeted therapies have been established in everyday treatment practice, and conventional platinum-based doublets have demonstrated effective results regarding overall and progression-free survival, we have still failed to achieve long-term survival. Therefore, several strategies of applying locoregional therapy are under investigation. Aerosol chemotherapy is already under investigation and, taking this a step further, aerosol gene therapies with multiple delivery systems are being developed. Several efforts have demonstrated its efficiency and effectiveness, but there are still multiple factors that have to be considered and combined to achieve an overall more effective multifunctional treatment. In the current review, we present data regarding aerosol delivery systems, transporters, carriers, vectors, genes, toxicity, efficiency, specificity, lung microenvironment and delivery gene therapy systems. Finally, we present current studies and future perspectives.

Dual ligands modified double targeted nano-system for liver targeted gene delivery

CONTEXT

It is now well established that the surface of nanocarriers with specific ligands defines a new biological identity, which assist in targeting and internalization of the nanocarriers to specific cell populations, such as cancers and disease organs.

OBJECTIVE

The aim of this study is to develop systemically administrable dual ligands modified nano-system which could both target cancer cells and macrophages in the liver.

METHODS

Transferrin (Tf) and mannan (M) were linked onto polyethylene glycol-phosphatidylethanolamine (PEG-PE) and PE separately to get transferrin-PEG-PE (T-PEG-PE) and mannan-PE (M-PE) ligands for the surface modification of carriers. The in vivo transfection efficiency of the novel dual ligands modified (D-modified) vectors were evaluated in tumor bearing animal models.

RESULTS

D-modified solid lipid nanoparticles/enhanced green fluorescence protein plasmid (D-SLN/pEGFP) has a particle size of 198 nm and a gene loading quantity of 89%. D-SLN/pEGFP displayed over 25% higher transfection efficiency than M-PE modified SLN/pEGFP (M-SLN/pEGFP) in HepG2 cells and T-PEG-PE modified SLN/pEGFP (T-SLN/pEGFP) in Kupffer cells (KCs) isolated from mice.

CONCLUSION

It could be concluded that T-PEG-PE and M-PE could function as excellent active targeting ligands to improve the cell targeting ability of the carriers and the dual ligands modified vectors could be applied as a promising active targeting gene delivery system.

Vectors for inhaled gene therapy in lung cancer. Application for nano oncology and safety of bio nanotechnology

Novel aerosol therapeutic modalities have been investigated for lung cancer. Inhaled gene therapy has presented safety and effectiveness previously in cystic fibrosis. However, safety concerns have been raised regarding the safety of non-viral vectors for inhaled gene therapy in lung cancer, and therefore small steps have been made towards this multifunctional treatment modality. During the last decade, numerous new nanocomplexes have been created and investigated as a safe gene delivery nano-vehicle. These formulations are multifunctional; they can be used as either local therapy or carrier for an effective inhaled gene therapy for lung cancer. Herein, we present current and future perspectives of nanocomplexes for inhaled gene therapy treatment in lung cancer.

Transferrin-PEG-PE modified dexamethasone conjugated cationic lipid carrier mediated gene delivery system for tumor-targeted transfection

Background

The main barriers to non-viral gene delivery include cellular and nuclear membranes. As such, the aim of this study was to develop a type of vector that can target cells through receptor-mediated pathways and by using nuclear localization signal (NLS) to increase the nuclear uptake of genetic materials.

Methods

A dexamethasone (Dexa)-conjugated lipid was synthesized as the material of the solid lipid nanoparticles (SLNs), and transferrin (Tf) was linked onto polyethylene glycol-phosphatidylethanolamine (PEG-PE) to obtain Tf-PEG-PE ligands for the surface modification of the carriers. The in vitro transfection efficiency of the novel modified vectors was evaluated in human hepatoma carcinoma cell lines, and in vivo effects were observed in an animal model.

Results

Tf-PEG-PE modified SLNs/enhanced green fluorescence protein plasmid (pEGFP) had a particle size of 222 nm and a gene loading quantity of 90%. Tf-PEG-PE-modified SLNs/pEGFP (Tf-SLNs/pEGFP) displayed remarkably higher transfection efficiency than non-modified SLNs/pEGFP and the vectors not containing Dexa, both in vitro and in vivo.

Conclusion

It can be concluded that Tf and Dexa could function as an excellent active targeting ligand to improve the cell targeting and nuclear targeting ability of the carriers, and the resulting nanomedicine could be a promising active targeting drug/gene delivery system.