Novel cationic SLN containing a synthesized single-tailed lipid as a modifier for gene delivery

Nanotechnology as a tool to overcome macromolecules delivery issues

Nanocarriers can deliver drugs to specific organs or cells, potentially bridging the gap between a drug's function and its interaction with biological systems such as human physiology. The untapped potential of nanotechnology stems from its ability to manipulate materials, allowing control over physical and chemical properties and overcoming drug-related problems, e.g., poor solubility or poor bioavailability. For example, most protein drugs are administered parenterally, each with challenges and peculiarities. Some problems faced by bioengineered macromolecule drugs leading to poor bioavailability are short biological half-life, large size and high molecular weight, low permeability through biological membranes, and structural instability. Nanotechnology emerges as a promising strategy to overcome these problems. Nevertheless, the delivery system should be carefully chosen considering loading efficiency, physicochemical properties, production conditions, toxicity, and regulations. Moving from the bench to the bedside is still one of the major bottlenecks in nanomedicine, and toxicological issues are the greatest challenges to overcome. This review provides an overview of biotech drug delivery approaches, associated nanotechnology novelty, toxicological issues, and regulations.

Prostate Cancer Therapy Using Docetaxel and Formononetin Combination: Hyaluronic Acid and Epidermal Growth Factor Receptor Targeted Peptide Dual Ligands Modified Binary Nanoparticles to Facilitate the in vivo Anti-Tumor Activity

Objective

To evaluate the prostate cancer therapy efficiency of the synergistic combination docetaxel (DTX) and formononetin (FMN) in one nano-sized drug delivery system. Hyaluronic acid (HA) and epidermal growth factor receptor-targeted peptide (GE11) dual ligands were applied to modify the nano-systems.

Methods

In this study, GE11-modified nanoparticles (GE-NPs) were applied for the loading of DTX, and HA-decorated NPs (HA-NPs) were used to encapsulate FMN. HA and GE11 dual ligand-modified binary nanoparticles (HAGE-DTX/FMN-NPs) were constructed by the self-assembling of GE-NPs and HA-NPs. The anti-PCa ability of the system was evaluated in vitro on PC-3 human prostate carcinoma cells (PC3 cells) and in vivo on PC3 tumor-bearing mice in comparison with single NPs and free drugs formulations.

Results

HA/GE-DTX/FMN-NPs were nano-sized particles with smaller particles coating on the inner core and achieved a size of 189.5 nm. HA/GE-DTX/FMN-NPs showed a cellular uptake efficiency of 59.6%, and a more efficient inhibition effect on PC3 cells compared with single ligand-modified NPs and free drugs. HA/GE-DTX/FMN-NPs showed significantly higher tumor inhibition efficiency than their single drug-loaded counterparts and free drugs.

Conclusion

HA/GE-DTX/FMN-NPs have a synergistic anti-tumor effect and also could the reduce unexpected side effects during the cancer therapy. It could be used as a promising anti-PCa system.

The Challenges and Opportunities in the Development of MicroRNA Therapeutics: A Multidisciplinary Viewpoint

microRNAs (miRs) are emerging as attractive therapeutic targets because of their small size, specific targetability, and critical role in disease pathogenesis. However, <20 miR targeting molecules have entered clinical trials, and none progressed to phase III. The difficulties in miR target identification, the moderate efficacy of miR inhibitors, cell type-specific delivery, and adverse outcomes have impeded the development of miR therapeutics. These hurdles are rooted in the functional complexity of miR's role in disease and sequence complementarity-dependent/-independent effects in nontarget tissues. The advances in understanding miR's role in disease, the development of efficient miR inhibitors, and innovative delivery approaches have helped resolve some of these hurdles. In this review, we provide a multidisciplinary viewpoint on the challenges and opportunities in the development of miR therapeutics.

Synergistic combination therapy of lung cancer using lipid-layered cisplatin and oridonin co-encapsulated nanoparticles

Lung cancer treatment using cisplatin (DDP) in combination with other drugs are effective for the treatment of non-small cell lung cancer (NSCLC). The aim of this study was to prepare a layer-by-layer nanoparticles (NPs) for the co-loading of DDP and oridonin (ORI) and to evaluate the antitumor activity of the system in vitro and in vivo. Novel DDP and ORI co-loaded layer-by-layer NPs (D/O-NPs) were constructed. The mean diameter, surface change stability and drug release behavior of NPs were evaluated. In vitro cytotoxicity of D/O-NPs was investigated against DDP resistant human lung cancer cell line (A549/DDP cells), and in vivo anti-tumor efficiency of D/O-NPs was tested on mice bearing A549/DDP cells xenografts. D/O-NPs have a diameter of 139.6 ± 4.4 nm, a zeta potential value of +13.8 ± 1.6 mV. D/O-NPs could significantly enhance in vitro cell toxicity and in vivo antitumor effect against A549/DDP cells and lung cancer animal model compared to the single drug loaded NPs and free drugs. The results demonstrated that the D/O-NPs could be used as a promising lung cancer treatment system.

Enhancement of Pancreatic Cancer Therapy Efficacy by Type-1 Matrix Metalloproteinase-Functionalized Nanoparticles for the Selective Delivery of Gemcitabine and Erlotinib

Purpose

Pancreatic cancer (PCa) is projected to become the second leading cause of cancer-related deaths by 2030. Gemcitabine (GEM) combined with erlotinib (ERL) have been approved by the FDA for locally advanced, unresectable or metastatic pancreatic cancer therapy since 2005. Type-1 matrix metalloproteinase (MT1-MMP) has been recognized as a critical mediator of several steps in PCa progression including activating TGF-β or releasing latent TGF-β from LTBP-1, resulting in increased collagen production and cleavage collagen.

Methods

In the present research, GEM and ERL co-loaded nanoparticles (GEM/ERL NPs) were prepared. A non-substrate MT1-MMP binding peptide was decorated onto the GEM/ERL NPs surface.

Results

M-M GEM/ERL NPs exhibited the highest uptake ability (67.65 ± 2.87%), longest half-life period, largest area under the curve, and the best tumor inhibition efficiency (69.81 ± 4.13%). The body weight, blood urine nitrogen (BUN), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) of the system were steady when tested in mice model.

Conclusion

In conclusion, M-M GEM/ERL NPs protected the drugs in the plasma, improved cellular uptake capacity, exhibited the most remarkable tumor cell inhibition ability, and showed the most efficient tumor growth inhibition capacity in vivo. M-M GEM/ERL NPs could be applied as an efficient and safe system for the synergistic combination chemotherapy of PCa.

Synergistic Effect of Tangeretin and Atorvastatin for Colon Cancer Combination Therapy: Targeted Delivery of These Dual Drugs Using RGD Peptide Decorated Nanocarriers

Purpose

Colorectal cancer (CRC) is the third most frequently diagnosed cancer and the fourth leading cause of cancer death over the world. Nano-sized drug delivery systems are used for the treatment of cancers. The aim of this study was to develop a tangeretin (TAGE) and atorvastatin (ATST) combined nano-system decorated with RGD (RGD-ATST/TAGE CNPs) for colon cancer combination therapy.

Materials and Methods

In this study, cyclized arginine-glycine-aspartic acid sequences (RGD) contained ligand was synthesized by conjugating cyclo (Arg-Gly-Asp-d-Phe-Lys) (cRGDfK) with D-α-tocopheryl succinate dichloromethane (TOSD) using polyethylene glycol (PEG) as a linker to obtain cRGDfK-PEG-TOSD. ATST and TAGE combined nano-systems: RGD-ATST/TAGE CNPs were prepared. The combination effects as well as antitumor effects of these two agents were evaluated on colon cancer cells and mice bearing cancer models.

Results

Drug entrapment efficiencies of nano-systems were high (around 90%), suggesting the good loading capacity. The release profiles of ATST or TAGE from RGD-ATST/TAGE CNPs followed Higuchi model. The RGD-decorated nano-system showed more obvious cytotoxicity on HT-29 cells than the undecorated nano-system, but no obvious difference was found on normal CCD-18 cells. The strongest synergism was observed when the weight ratio of ATST to TAGE was 1:1. In vivo biodistribution of RGD-ATST/TAGE CNPs in the tumor site is high and prominently inhibited the in vivo tumor growth.

Conclusion

The results demonstrated that RGD-ATST/TAGE CNPs showed the most significant synergistic therapeutic efficacy, exhibited no significant toxicity to major organs and tissues, and body weight of the treated mice was stable. Therefore, the combination nano-system is a promising platform for colon cancer therapy.

Novel Nanocomplexes Targeting STAT3 Demonstrate Promising Anti-Ovarian Cancer Effects in vivo

Background

Cationic solid lipid nanoparticles (SLN) have attracted intensive interest as an effective gene delivery system for its high biocompatibility, stability and low cytotoxicity. In our previous study, we successfully prepared SLN-STAT3 decoy ODN complexes and made a primary study on its antitumor behavior in ovarian cancer cells in vitro. However, there is little information available so far about the effect of SLN-STAT3 decoy ODN complexes on ovarian cancer in vivo, either little information about the pharmacological toxicology in vivo.

Material and Methods

We applied nanotechnology to improve the gene delivery system and synthesize SLN-STAT3 decoy ODN complexes. Xenograft mouse models were established to assess the antitumor effects of SLN-STAT3 decoy ODN on the tumor growth of ovarian cancer in vivo. To analyze the mechanisms of SLN-STAT3 decoy ODN, we investigated apoptosis, autophagy, epithelial–mesenchymal transition (EMT) in tumor tissues of nude mice and investigated the effects and toxicology of SLN-STAT3 decoy ODN complexes on the vital organs of nude mice.

Results

The results showed that SLN-STAT3 decoy ODN complexes markedly inhibited tumor growth in vivo. SLN-STAT3 decoy ODN complexes could induce cell apoptosis through downregulating Bcl-2, survivin and pro caspase 3, but upregulating Bax and cleaved caspase 3. These complexes could also regulate autophagy through upregulating LC3A-II, LC3B-II and beclin-1, but downregulating p-Akt and p-mTOR. Moreover, these complexes could inhibit cancer cell invasion through reversing EMT. Besides, SLN-STAT3 decoy ODN complexes showed no obvious toxicity on vital organs and hematological parameters of nude mice.

Conclusion

The molecular mechanisms that SLN-STAT3 decoy ODN complexes inhibit tumor growth involved activating the apoptotic cascade, regulating autophagy, and reversing EMT program; and these complexes showed no obvious toxicity on nude mice. Our study indicated that the nanocomplexes SLN-STAT3 decoy ODN might be a promising therapeutic approach for ovarian cancer treatment.

Hyaluronic Acid Capped, Irinotecan and Gene Co-Loaded Lipid-Polymer Hybrid Nanocarrier-Based Combination Therapy Platform for Colorectal Cancer

Background

The current approach for treating colorectal cancer favors the use of drug and gene combination therapy, and targeted nano-systems are gaining considerable attention for minimizing toxicity and improving the efficacy of anticancer treatment. The aim of this study was to develop ligand-modified, irinotecan and gene co-loaded lipid-polymer hybrid nanocarriers for targeted colorectal cancer combination therapy.

Methods

Hyaluronic acid modified, irinotecan and gene co-loaded LPNs (HA-I/D-LPNs) were prepared using a solvent-evaporation method. Their average size, zeta potential, drug and gene loading capacity were characterized. The in vitro and in vivo gene transfection and anti-tumor ability of this nano-system were evaluated on colorectal cancer cells and mice bearing colorectal cancer model.

Results

HA-I/D-LPNs had a size of 182.3 ± 5.1, over 80% drug encapsulation efficiency and over 90% of gene loading capacity. The peak plasma concentration (C_max) and half-life (T_1/2) achieved from HA-I/D-LPNs were 41.31 ± 1.58 μg/mL and 12.56 ± 0.67 h. HA-I/D-LPNs achieved the highest tumor growth inhibition efficacy and the most prominent transfection efficiency in vivo.

Conclusion

HA-I/D-LPNs exhibited the most remarkable tumor inhibition efficacy and best gene transfection efficiency in the tumor, which could prove the effects of the drug and gene combination therapy.

Therapy for myocardial infarction: In vitro and in vivo evaluation of puerarin-prodrug and tanshinone co-loaded lipid nanoparticulate system

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. Nanoparticle systems carrying drugs have already been developed to treat MI. To improve the efficiency of tanshinone (TAN), and to achieve the synergistic effect of TAN and puerarin (PUE), PUE-prodrug and TAN co-loaded solid lipid nanoparticles (SLN) was structured and utilized for MI treatment in the present research. PUE-prodrug was synthesized by an esterification reaction. PUE-prodrug and TAN co-loaded SLN (PUEp/TAN-SLN) were prepared by a single emulsification followed by a solvent evaporation method. The physicochemical properties of SLN were characterized and the in vivo infarct therapy effects were evaluated in MI rats. PUE-prodrug and TAN contained SLN showed a size of 112.6 ± 3.1 nm. The SLN encapsulation reduced the cytotoxicity of drugs and was a safer system. PUEp-SLN exhibited a 1.7-fold increase in comparison to PUE-SLN (21.2 ± 2.1 versus 12.5 ± 1.5 mg/L), in the mean time a 3.4-fold increase compared with free PUE in heart drug concentration (21.2 ± 2.1 versus 6.3 ± 0.9 mg/L). In vivo infarct therapy efficiency of double drugs loaded PUEp/TAN-SLN (17 ± 1.9%) was significantly better than the single drug loaded PUEp-SLN (31 ± 1.6%) and TAN-SLN (40 ± 2.2%). PUE-prodrug contained, double drugs co-loaded SLN can be utilized as promising candidate delivery system for cardioprotective drugs in treatment of myocardial infarction.

Topical anesthesia therapy using lidocaine-loaded nanostructured lipid carriers: tocopheryl polyethylene glycol 1000 succinate-modified transdermal delivery system

Purpose

Transdermal drug delivery of local anesthetics using lipid nanoparticles could enhance lipophilic drugs permeation through the stratum corneum, improve drug diffusion to deeper skin, and exert good therapeutic effects. The purpose of this study was to engineer a Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS)-modified cationic nanostructured lipid carriers (NLC) for the delivery of lidocaine (LID; TPGS/LID-NLC).

Materials and methods

TPGS/LID-NLC was prepared by solvent diffusion method. The particle size, polydispersity index, zeta potential, drug entrapment efficiency, drug loading, stability, drug release, and cytotoxicity were tested to evaluate the basic characters of NLC. In vitro skin permeation and in vivo anesthesia effect in an animal model were further investigated to determine the therapeutic efficiency of the system.

Results

TPGS/LID-NLC had a particle size of 167.6±4.3 nm, a zeta potential of +21.2±2.3 mV, an entrapment efficiency of 85.9%±3.1%, and a drug loading of 11.5%±0.9%. A sustained release pattern was achieved by TPGS/LID-NLC, with 81.2% of LID released at 72 hours. In vitro permeation study showed that the steady-state fluxes (J_ss), permeability coefficient (Kp), and cumulative drug permeation Q_n at 72 hours (Q₇₂) of TPGS/LID-NLC were 15.6±1.8 µg/cm²/hour, 10.3±0.9 cm/hour (×10⁻³), and 547.5±23.6 µg/cm², respectively, which were significantly higher than the nonmodified NLC and free drug groups. In vivo anesthesia effect of TPGS/LID-NLC was the most remarkable and long acting among the formulations tested, which could be concluded by the most considerable maximum possible effect from 10 to 120 minutes during the whole research.

Conclusion

The most prominent in vitro permeation efficiency and in vivo anesthetic effect of TPGS/LID-NLC could be the evidence that TPGS-modified NLC could function as a promising drug delivery system for prolonged and efficient local anesthetic therapy.

Colorectal cancer combination therapy using drug and gene co-delivered, targeted poly(ethylene glycol)-ε-poly(caprolactone) nanocarriers

Purpose

Combination therapy is a promising strategy to treat cancer due to the synergistic effects. The drug and gene co-delivered systems attract more attention in the field of combination therapy.

Materials and methods

In the present research, poly(ethylene glycol)-ε-poly(caprolactone) block copolymer was used for the co-loading of 5-fluorouracil (5-FU) and gene. The physicochemical characteristics, in vitro and in vivo anticancer, and gene transfection efficiency were tested on colon cancer cells and tumor-bearing mice.

Results

5-FU and gene co-loaded nanocarriers had a size of 145 nm. In vivo gene delivery results showed about 60% of gene-positive cells. Tumor volume of nanocarrier groups at day 21 was around 320 mm³, which is significantly smaller compared with free 5-FU group (852 mm³) and control group (1,059 mm³). The maximum 5-FU plasma concentration in nanocarrier groups (49 µg/mL) was significantly greater than free 5-FU (13 µg/mL). At 24 hours, drug level of nanocarrier groups was about 2.8 µg/mL compared with 0.02 µg/mL of free 5-FU.

Conclusion

The resulting nanocarriers co-loaded with the anticancer drugs and genes could be considered as a promising nanomedicine for colorectal cancer therapy.

Triphenylphosphonium and D-α-tocopheryl polyethylene glycol 1000 succinate-modified, tanshinone IIA-loaded lipid-polymeric nanocarriers for the targeted therapy of myocardial infarction

Background

Cardiovascular diseases (CVDs) are the leading causes of mortality worldwide. Currently, the best treatment options for myocardial infarction focus on the restoration of blood flow as soon as possible, which include reperfusion therapy, percutaneous coronary intervention, and therapeutic thrombolytic drugs.

Materials and methods

In the present study, we report the development of lipid-polymeric nanocarriers (LPNs) for mitochondria-targeted delivery of tanshinone IIA (TN). D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was linked to the triphenylphosphonium (TPP) cation. The LPNs were fabricated by nanoprecipitation method. LPNs were evaluated in vitro and in vivo in comparison with free drugs and other similar nanocarriers.

Results

The mean diameter of TN/nanoparticles (NPs) was 89.6 nm, while that of TN/LPNs was 121.3 nm. The zeta potential of TN/NPs and TN/LPNs was −33.6 and −22.3 mV, respectively. Compared with free TN and TN/NPs, TN/LPNs exhibited significantly improved compatibility and therapeutic efficiency. In addition, the in vivo pharmacokinetics, biodistribution, and infarct therapy studies in Sprague Dawley rats showed that TPP-TPGS/TN/LPNs had better efficiency than their nonmodified TN/LPNs counterparts in all respects.

Conclusion

These results indicated that the TPP-TPGS/TN/LPNs were promising nanocarriers for efficient delivery of cardiovascular drugs and other therapeutic agents for the treatment of CVDs.

Endothelial growth factor receptor-targeted and reactive oxygen species-responsive lung cancer therapy by docetaxel and resveratrol encapsulated lipid-polymer hybrid nanoparticles

Special targeted therapy like endothelial growth factor receptor (EGFR) targeted therapy is available for the treatment of advanced non-small cell lung cancer (NSCLC). Biodegradable core-shell lipid-polymer hybrid nanoparticles (LPNs) can combine the beneficial properties of lipid and polymeric NPs for controlled drug delivery. In the present study, epidermal growth factor (EGF) conjugated LPNs were fabricated to co-deliver docetaxel (DTX) and resveratrol (RSV). In vitro and in vivo studies demonstrated that EGF DTX/RSV LPNs have significant synergistic effects, best tumor inhibition ability and the lowest systemic toxicity. The results indicate that EGF DTX/RSV LPNs may be a promising strategy for treatment of NSCLC.

Protective effects on myocardial infarction model: delivery of schisandrin B using matrix metalloproteinase-sensitive peptide-modified, PEGylated lipid nanoparticles

Purpose

Schisandrin B (Sch B) is clinically applied for the treatment of hepatitis and ischemic disease. However, its clinical efficacy is limited due to the poor solubility and low bioavailability. This study aimed to develop matrix metalloproteinase (MMP)-sensitive peptide-modified, polyethylene glycol (PEG)-modified (PEGylated) solid lipid nanoparticles (SLNs) for loading Sch B (MMP-Sch B SLNs), and to evaluate the therapeutic effect in the myocardial infarction model.

Methods

PEG lipid and MMP-targeting peptide conjugate were synthesized. MMP-Sch B SLNs were prepared by solvent displacement technique. The physicochemical properties and pharmacokinetics of SLNs were investigated. In vivo effects on infarct size was evaluated in rats.

Results

The successful synthesis of lipid-peptide conjugate was confirmed. MMP-Sch B SLNs had a particle size of 130 nm, a zeta potential of 18.3 mV, and a sustained-release behavior. Higher heart drug concentration and longer blood circulation times were achieved by Sch B loaded SLNs than the drug solution according to the pharmacokinetic and biodistribution results. The best therapeutic efficacy was exhibited by MMP-Sch B SLNs by reducing the infarction size to the greatest extent.

Conclusion

The modified SLNs may be a good choice for delivery of Sch B for the treatment of myocardial infarction.

Topical delivery of TRPsiRNA-loaded solid lipid nanoparticles confer reduced pain sensation via TRPV1 silencing, in rats

Present work describes a novel composition for encapsulating TRPsiRNA (TRPV1-targeting siRNA) within lipid-matrix (4:1::glyceryl behnate:stearic acid) of SLNs, using suitably modified cold high-pressure homogenisation technique. Optimisation of the method and composition conducted using calf-thymus DNA (ctDNA), to avoid cost of TRPsiRNA molecules, resulted in small size (d₅₀ = 50-100 nm) and high entrapment (77.22-98.5%). Complete masking of extreme negative charge of both ctDNA (-34.50 mV) and TRPsiRNA (-23.98 mV) upon encapsulation in SLNs without employing cationic components is reported herein for the first time. Diffusion-controlled release (90.17% at 72 h) from a rigid matrix shifted to porous matrix (at 24 h) due to solubilisation of stearic acid at 37 °C. Efficient in vitro (HEK293 T cells) and in vivo transfection and expression established the proof-of-concept. PEG600 as supporting-surfactant and vitrifying agent promoted small size, effective transfection and rupture of endosomal membrane to affect endosomal escape. Physiological efficacy in terms of significant increase (p < .0001) in paw-withdrawal-latency, following topical and intradermal application of TRPsiRNA-loaded SLNs, in rats, exposed to thermal hyperalgesia (145 and 182%, respectively) and capsaicin-induced pain (155 and 182%, respectively) indicate effective silencing of skin TRPV1. Significant decrease in intensity and duration (one-fifth) of capsaicin-induced nocifensive behaviour was also observed. Naked TRPsiRNA, however, did not show any effect.

Lung cancer gene therapy: Transferrin and hyaluronic acid dual ligand-decorated novel lipid carriers for targeted gene delivery

To achieve lung cancer gene therapy, nanocarriers decorated with different ligands were used. Surface decoration and nanoparticulate system will assist in targeting the gene to specific cells and tissues, such as cancers and diseased organs. The aim of this research was to develop a dual ligand-decorated nanocarriers, which could target the tumor cells through receptor-mediated pathways to increase the uptake of genetic materials. Transferrin (Tf) and hyaluronic (HA) containing polyethylene glycol-distearoylphosphatidylethanolamine (Tf-PEG-DSPE and HA-PEG-DSPE) ligands were synthesized. Novel Tf and HA ligand-decorated, plasmid-enhanced green fluorescent protein loaded nanostructured lipid carriers (Tf/HA-pDNA NLC) was constructed. Physicochemical properties such as morphology, size, and ζ-potential as well as release properties were evaluated. The in vitro and in vivo gene transfection efficiency of Tf/HA-pDNA NLC was evaluated in lung adenocarcinoma A549 cells and lung cancer bearing animal models. Tf/HA-pDNA NLC displayed significantly higher transfection efficiency than undecorated DNA-NLCs and single ligand-decorated NLCs in vitro and in vivo. The newly constructed NLCs could successfully load gene; and Tf and HA functioned as excellent targeting ligands to improve the cell targeting ability of the gene-loaded nanocarriers. The resulting dual ligands decorated vectors could be a promising targeted gene delivery system for the lung cancer treatment.

Anti-tumor efficiency of paclitaxel and DNA when co-delivered by pH responsive ligand modified nanocarriers for breast cancer treatment

CONTEXT

Combination of chemotherapy and nucleic acid therapy generally take advantage of drugs anti-tumor activity together with DNA capacity to transfect cancer cells, showing great promise in cancer treatment. However, effective co-delivery of drugs and DNA in a single carrier for cancer treatment remains a challenge.

OBJECTIVE

This study aimed to design a tumor targeted, pH sensitive nanocarriers for the co-delivery of gene and drug.

MATERIALS AND METHODS

Hyaluronic acid - acid sensitive linker - 1,2-distearoyl phosphatideylethanolamine copolymers (HA-as-DSPE) were synthesized. HA-as-DSPE modified, paclitaxel and pDNA loaded solid lipid nanoparticles (HA-PTX/pDNA SLN) was prepared. The physicochemical properties like morphology, size, and zeta potential as well as release properties were evaluated. The ability and therapeutic effects of the novel system for the co-delivery of PTX and pDNA were demonstrated in vitro and in vivo.

RESULTS

In vitro experiments and in vivo animal studies both confirmed that the HA-PTX/pDNA SLN system could promote the inhibition of tumor, at the same time deliver and transfect gene into the cancer cells.

DISCUSSION AND CONCLUSION

Highest efficiency achieved by HA-PTX/pDNA SLN might result from the HA ligands that targeted the receptors on the cancer cells, the enhanced cellular uptake by the SLN formulations and also the pH sensitive bound of the carriers let the drug release more in the tumor cells. It could be concluded that HA-PTX/pDNA SLN could be used as a promising delivery system for drug and gene combination therapy.

Preclinical safety of solid lipid nanoparticles and nanostructured lipid carriers: Current evidence from in vitro and in vivo evaluation

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were designed as exceptionally safe colloidal carriers for the delivery of poorly soluble drugs. SLN/NLC have the particularity of being composed of excipientsalready approved for use in medicines for human use, which offers a great advantage over any other nanoparticulate system developed from novel materials. Despite this fact, any use of excipients in new route of administration or in new dosage form requires evidence of safety. After 25 years of research on SLN and NLC, enough evidence on their preclinical safety has been published. In the present work, published data on in vitro and in vivo compatibility of SLN/NLC have been surveyed, in order to provide evidence of high biocompatibility distinguished by intended administration route. We also identified critical factors and possible weak points in SLN/NLC formulations, such as the effect of surfactants on the cell viability in vitro, which should be considered for further development.

STAT3 Decoy Oligodeoxynucleotides-Loaded Solid Lipid Nanoparticles Induce Cell Death and Inhibit Invasion in Ovarian Cancer Cells

Recent advances in the synthesis of multi-functional nanoparticles have opened up tremendous opportunities for the targeted delivery of genes of interest. Cationic solid lipid nanoparticles (SLN) can efficiently bind nucleic acid molecules and transfect genes in vitro. Few reports have combined SLN with therapy using decoy oligodeoxynucleotides (ODN). In the present study, we prepared SLN to encapsulate STAT3 decoy ODN; then, the properties and in vitro behavior of SLN-STAT3 decoy ODN complexes were investigated. SLN-STAT3 decoy ODN complexes were efficiently taken up by human ovarian cancer cells and significantly suppressed cell growth. Blockage of the STAT3 pathway by SLN-STAT3 decoy ODN complexes resulted in an evident induction of cell death, including apoptotic and autophagic death. The mechanism involved the increased expression of cleaved caspase 3, Bax, Beclin-1 and LC3-II and reduced expression of Bcl-2, pro-caspase 3, Survivin, p-Akt and p-mTOR. In addition, SLN-STAT3 decoy ODN complexes inhibited cell invasion by up-regulating E-cadherin expression and down-regulating Snail and MMP-9 expression. These findings confirmed that SLN as STAT3 decoy ODN carriers can induce cell death and inhibit invasion of ovarian cancer cells. We propose that SLN represent a potential approach for targeted gene delivery in cancer therapy.

Polyelectrolyte-coated gold nanorods and their biomedical applications

Gold nanorods (GNRs) have been extensively used in biomedical applications, because of their favourable optical properties. Their longitudinal surface plasmon resonance can be tuned, providing a strong near-infrared (NIR) extinction coefficient peak within the tissue transparency window. However, the modification of the surface of GNRs is essential before they can be used for biomedical applications. The number of GNRs taken up by cells and their biodistribution depend on their surface modification. Here, we review the recent advances in modifying GNR surfaces with polyelectrolytes for biomedical applications. Major polyelectrolytes used to coat GNR surfaces over the past few years and the biocompatibility of polyelectrolyte-coated GNRs are discussed.

Analysis of the structure of nanocomposites of triglyceride platelets and DNA

DNA-complexes with platelet-like, cationically modified lipid nanoparticles (cLNPs) are studied with regard to the formation of nanocomposite structures with a sandwich-like arrangement of the DNA and platelets.

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.

Lipid nanoparticles as carriers for RNAi against viral infections: current status and future perspectives

The efforts made to develop RNAi-based therapies have led to productive research in the field of infections in humans, such as hepatitis C virus (HCV), hepatitis B virus (HBV), human immunodeficiency virus (HIV), human cytomegalovirus (HCMV), herpetic keratitis, human papillomavirus, or influenza virus. Naked RNAi molecules are rapidly digested by nucleases in the serum, and due to their negative surface charge, entry into the cell cytoplasm is also hampered, which makes necessary the use of delivery systems to exploit the full potential of RNAi therapeutics. Lipid nanoparticles (LNP) represent one of the most widely used delivery systems for in vivo application of RNAi due to their relative safety and simplicity of production, joint with the enhanced payload and protection of encapsulated RNAs. Moreover, LNP may be functionalized to reach target cells, and they may be used to combine RNAi molecules with conventional drug substances to reduce resistance or improve efficiency. This review features the current application of LNP in RNAi mediated therapy against viral infections and aims to explore possible future lines of action in this field.

Nanoparticle-mediated delivery of therapeutic genes: focus on miRNA therapeutics

INTRODUCTION

Micro RNAs (miRNA) are 21 - 23 nucleotides long and regulate the expression of coding genes by binding imperfectly with their 3' UTR region. The miRNA profile is altered in pathological processes, making miRNAs good targets for drug therapy. Restoration of down-regulated miRNA or inhibition of overexpressed miRNA to return miRNA to its normal state is the basis of miRNA-based therapy. This review focuses on nanocarriers used for the delivery of miRNA that confer physical stability to the unstable RNA structure, protect the RNA from nuclease degradation and aid in effective silencing of target genes.

AREAS COVERED

The necessity of the nanocarrier for the delivery of the miRNA is emphasized and the recent research on liposome-, metal- and polymer-mediated miRNA delivery for the inhibition or replacement of the disease-related miRNA is summarized.

EXPERT OPINION

The size, charge and surface properties of nanocarriers have to be tuned to ensure effective and safe delivery of the miRNA in clinical practice. The immune responses related to the nanocarriers and the double-stranded nucleotide delivery remain to be addressed. Also, the binding of miRNAs to non-specific targets has to be studied in more detail because miRNAs have multiple targets due to partial binding unlike siRNA.

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.

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

BACKGROUND

The applications of ligand-polyethylene glycol (PEG)-modified nanocarriers have now emerged, as well as recognized strategies to provide the vectors with active targeting properties. In this research, premodification and postmodification were compared using the same ligand, ie, a novel conjugated mannan-containing PEG and L-α-phosphatidylethanolamine (PE).

METHODS

Premodified and postmodified solid lipid nanoparticles were prepared and the characteristics of the two kinds of vehicles were evaluated. The modified vectors were then administered intravenously to rats and the in vivo targeting behavior of the complexes was investigated in liver macrophages.

RESULTS

By carefully formulating the carriers with an optimal ratio of mannan-containing PEG-PE, postmodified vehicles displayed more efficient gene expression in rat Kupffer cells both in vitro and in vivo.

CONCLUSION

Postmodified gene carriers are superior to premodified gene vectors, although the latter is also promising for targeted gene delivery. This discovery could guide our future research.

A pH-sensitive multifunctional gene carrier assembled via layer-by-layer technique for efficient gene delivery

Background

The success of gene therapy asks for the development of multifunctional vectors that could overcome various gene delivery barriers, such as the cell membrane, endosomal membrane, and nuclear membrane. Layer-by-layer technique is an efficient method with easy operation which can be used for the assembly of multifunctional gene carriers. This work describes a pH-sensitive multifunctional gene vector that offered long circulation property but avoided the inhibition of tumor cellular uptake of gene carriers associated with the use of polyethylene glycol.

Methods

Deoxyribonucleic acid (DNA) was firstly condensed with protamine into a cationic core which was used as assembly template. Then, additional layers of anionic DNA, cationic liposomes, and o-carboxymethyl-chitosan (CMCS) were alternately adsorbed onto the template via layer-by-layer technique and finally the multifunctional vector called CMCS-cationic liposome-coated DNA/protamine/DNA complexes (CLDPD) was constructed. For in vitro test, the cytotoxicity and transfection investigation was carried out on HepG2 cell line. For in vivo evaluation, CMCS-CLDPD was intratumorally injected into tumor-bearing mice and the tumor cells were isolated for fluorescence determination of transfection efficiency.

Results

CMCS-CLDPD had ellipsoidal shapes and showed “core-shell” structure which showed stabilization property in serum and effective protection of DNA from nuclease degradation. In vitro and in vivo transfection results demonstrated that CMCS-CLDPD had pH-sensitivity and the outermost layer of CMCS fell off in the tumor tissue, which could not only protect CMCS- CLDPD from serum interaction but also enhance gene transfection efficiency.

Conclusion

These results demonstrated that multifunctional CMCS-CLDPD had pH- sensitivity, which may provide a new approach for the antitumor gene delivery.

In vivo sustained release of siRNA from solid lipid nanoparticles

Small interfering RNA (siRNA) is a highly potent drug in gene-based therapy with a challenge of being delivered in a sustained manner. Nanoparticle drug delivery systems allow for incorporating and controlled release of therapeutic payloads. We demonstrate that solid lipid nanoparticles can incorporate and provide sustained release of siRNA. Tristearin solid lipid nanoparticles, made by nanoprecipitation, were loaded with siRNA (4.4-5.5 wt % loading ratio) using a hydrophobic ion pairing approach that employs the cationic lipid DOTAP. Intradermal injection of these nanocarriers in mouse footpads resulted in prolonged siRNA release over a period of 10-13 days. In vitro cell studies showed that the released siRNA retained its activity. Nanoparticles developed in this study offer an alternative approach to polymeric nanoparticles for encapsulation and sustained delivery of siRNA with the advantage of being prepared from physiologically well-tolerated materials.

Efficient nanoparticle mediated sustained RNA interference in human primary endothelial cells

Endothelium forms an important target for drug and/or gene therapy since endothelial cells play critical roles in angiogenesis and vascular functions and are associated with various pathophysiological conditions. RNA mediated gene silencing presents a new therapeutic approach to overcome many such diseases, but the major challenge of such an approach is to ensure minimal toxicity and effective transfection efficiency of short hairpin RNA (shRNA) to primary endothelial cells. In the present study, we formulated shAnnexin A2 loaded poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles which produced intracellular small interfering RNA (siRNA) against Annexin A2 and brought about the downregulation of Annexin A2. The per cent encapsulation of the plasmid within the nanoparticle was found to be 57.65%. We compared our nanoparticle based transfections with Lipofectamine mediated transfection, and our studies show that nanoparticle based transfection efficiency is very high (~97%) and is more sustained compared to conventional Lipofectamine mediated transfections in primary retinal microvascular endothelial cells and human cancer cell lines. Our findings also show that the shAnnexin A2 loaded PLGA nanoparticles had minimal toxicity with almost 95% of cells being viable 24 h post-transfection while Lipofectamine based transfections resulted in only 30% viable cells. Therefore, PLGA nanoparticle based transfection may be used for efficient siRNA transfection to human primary endothelial and cancer cells. This may serve as a potential adjuvant treatment option for diseases such as diabetic retinopathy, retinopathy of prematurity and age related macular degeneration besides various cancers.

A novel cationic liposome formulation for efficient gene delivery via a pulmonary route

The clinical success of gene therapy for lung cancer is not only dependent on efficient gene carriers but also on a suitable delivery route. A pulmonary delivery route can directly deliver gene vectors to the lung which is more efficient than a systemic delivery route. For gene carriers, cationic liposomes have recently emerged as leading non-viral vectors in worldwide gene therapy clinical trials. However, cytotoxic effects or apoptosis are often observed which is mostly dependent on the cationic lipid used. Therefore, an efficient and safe cationic lipid, 6-lauroxyhexyl lysinate (LHLN), previously synthesized by our group was first used to prepare cationic liposomes. Physicochemical and biological properties of LHLN-liposomes were investigated. LHLN-liposome/DNA complexes showed positive surface charge, spherical morphology, a relatively narrow particle size distribution and strong DNA binding capability. Compared with Lipofectamine2000, the new cationic liposome formulation using LHLN exhibited not only lower cytotoxicity (P < 0.05) but also similar transfection efficiency in A549 and HepG2 lung cancer cells for in vitro tests. When administered by intratracheal instillation into rat lungs for in vivo evaluation, LHLN-liposome/DNA complexes exhibited higher pulmonary gene transfection efficiency than Lipofectamine2000/DNA complexes (P < 0.05). These results suggested that LHLN-liposomes may have great potential for efficient pulmonary gene delivery.

Biodegradable tri-block copolymer poly(lactic acid)-poly(ethylene glycol)-poly(l-lysine)(PLA-PEG-PLL) as a non-viral vector to enhance gene transfection

Low cytotoxicity and high gene transfection efficiency are critical issues in designing current non-viral gene delivery vectors. The purpose of the present work was to synthesize the novel biodegradable poly (lactic acid)-poly(ethylene glycol)-poly(l-lysine) (PLA-PEG-PLL) copolymer, and explore its applicability and feasibility as a non-viral vector for gene transport. PLA-PEG-PLL was obtained by the ring-opening polymerization of Lys(Z)-NCA onto amine-terminated NH(2)-PEG-PLA, then acidolysis to remove benzyloxycarbonyl. The tri-block copolymer PLA-PEG-PLL combined the characters of cationic polymer PLL, PLA and PEG: the self-assembled nanoparticles (NPs) possessed a PEG loop structure to increase the stability, hydrophobic PLA segments as the core, and the primary ɛ-amine groups of lysine in PLL to electrostatically interact with negatively charged phosphate groups of DNA to deposit with the PLA core. The physicochemical properties (morphology, particle size and surface charge) and the biological properties (protection from nuclease degradation, plasma stability, in vitro cytotoxicity, and in vitro transfection ability in HeLa and HepG2 cells) of the gene-loaded PLA-PEG-PLL nanoparticles (PLA-PEG-PLL NPs) were evaluated, respectively. Agarose gel electrophoresis assay confirmed that the PLA-PEG-PLL NPs could condense DNA thoroughly and protect DNA from nuclease degradation. Initial experiments showed that PLA-PEG-PLL NPs/DNA complexes exhibited almost no toxicity and higher gene expression (up to 21.64% in HepG2 cells and 31.63% in HeLa cells) than PEI/DNA complexes (14.01% and 24.22%). These results revealed that the biodegradable tri-block copolymer PLA-PEG-PLL might be a very attractive candidate as a non-viral vector and might alleviate the drawbacks of the conventional cationic vectors/DNA complexes for gene delivery in vivo.

Simultaneous enhancement of photothermal stability and gene delivery efficacy of gold nanorods using polyelectrolytes

The propensity of nanoparticles to aggregate in aqueous media hinders their effective use in biomedical applications. Gold nanorods (GNRs) have been investigated as therapeutics, imaging agents, and diagnostics. We report that chemically generated gold nanorods rapidly aggregate in biologically relevant media. Depositing polyelectrolyte multilayers on gold nanorods enhanced the stability of these nanoparticles for at least up to 4 weeks. Dispersions of polyelectrolyte (PE)-gold nanorod assemblies (PE-GNRs) demonstrate a stable Arrhenius-like photothermal response, which was exploited for the hyperthermic ablation of prostate cancer cells in vitro. Subtoxic concentrations of PE-GNR assemblies were also employed for delivering exogenous plasmid DNA to prostate cancer cells. PE-GNRs based on a cationic polyelectrolyte recently synthesized in our laboratory demonstrated higher transfection efficacy and lower cytotoxicity compared to those based on polyethyleneimine, a current standard for polymer-mediated gene delivery. Our results indicate that judicious engineering of biocompatible polyelectrolytes leads to multifunctional gold nanorod-based assemblies that combine high stability and low cytotoxicity with photothermal ablation, gene delivery, and optical imaging capabilities on a single platform.