In vivo targeted gene delivery by cationic nanoparticles for treatment of hepatocellular carcinoma

Nano-based drug delivery systems in hepatocellular carcinoma

The high recurrence rate of hepatocellular carcinoma (HCC) and poor prognosis after medical treatment reflects the necessity to improve the current chemotherapy protocols, particularly drug delivery methods. Development of targeted and efficient drug delivery systems (DDSs), in all active, passive and stimuli-responsive forms for selective delivery of therapeutic drugs to the tumour site has been extended to improve efficacy and reduce the severe side effects. Recent advances in nanotechnology offer promising breakthroughs in the diagnosis, treatment and monitoring of cancer cells. In this review, the specific design of DDSs based on the different nano-particles and their surface engineering is discussed. In addition, the innovative clinical studies in which nano-based DDS was used in the treatment of HCC were highlighted.

Revitalizing Cytokine-Based Cancer Immunotherapy through Advanced Delivery Systems

Cytokines can coordinate robust immune responses, holding great promise as therapeutics against infections, autoimmune diseases, and cancers. In cancer treatment, numerous pro-inflammatory cytokines have displayed promising efficacy in preclinical studies. However, their clinical application is hindered by poor pharmacokinetics, significant toxicity and unsatisfactory anticancer efficacy. Thus, while IFN-α and IL-2 are approved for specific cancer treatments, other cytokines still remain subject of intense investigation. To accelerate the application of cytokines as cancer immunotherapeutics, strategies need to be directed to improve their safety and anticancer performance. In this regard, delivery systems could be used to generate innovative therapies by targeting the cytokines or nucleic acids, such as DNA and mRNA, encoding the cytokines to tumor tissues. This review centers on these innovative delivery strategies for cytokines, summarizing key approaches, such as gene delivery and protein delivery, and critically examining their potential and challenges for clinical translation.

Non-Viral Gene Delivery to Hepatocellular Carcinoma via Intra-Arterial Injection

Purpose

Hepatocellular carcinoma (HCC) has limited treatment options, and modest survival after systemic chemotherapy or procedures such as transarterial chemoembolization (TACE). There is therefore a need to develop targeted therapies to address HCC. Gene therapies hold immense promise in treating a variety of diseases, including HCC, though delivery remains a critical hurdle. This study investigated a new approach of local delivery of polymeric nanoparticles (NPs) via intra-arterial injection for targeted local gene delivery to HCC tumors in an orthotopic rat liver tumor model.

Methods

Poly(beta-amino ester) (PBAE) nanoparticles were formulated and assessed for GFP transfection in N1-S1 rat HCC cells in vitro. Optimized PBAE NPs were next administered to rats via intra-arterial injection with and without orthotopic HCC tumors, and both biodistribution and transfection were assessed.

Results

In vitro transfection of PBAE NPs led to >50% transfected cells in adherent and suspension culture at a variety of doses and weight ratios. Administration of NPs via intra-arterial or intravenous injection demonstrated no transfection of healthy liver, while intra-arterial NP injection led to transfection of tumors in an orthotopic rat HCC model.

Conclusion

Hepatic artery injection is a promising delivery approach for PBAE NPs and demonstrates increased targeted transfection of HCC tumors compared to intravenous administration, and offers a potential alternative to standard chemotherapies and TACE. This work demonstrates proof of concept for administration of polymeric PBAE nanoparticles via intra-arterial injection for gene delivery in rats.

Efficacy of Sirna-Loaded Nanoparticles in the Treatment of k-ras Mutant Lung Cancer in vitro

AIM

To design and develop K-RAS silencing small interfering RNA (siRNA)-loaded poly (D, L-lactic-co-glycolic acid) nanoparticles and evaluate their efficacy in the treatment of K-RAS mutant lung cancer.

METHODS

The nanoparticles prepared by the double emulsion solvent evaporation method were characterized by TEM, FTIR and XPS analyzes and evaluated in vitro by XTT, PCR, ELISA, and Western-Blot. Metabolomic analyzes were performed to evaluate the changes in metabolic profiles of the cells after nanoparticles treatment.

RESULTS

The nanoparticles were obtained with a particle size less than 250 nm, a polydispersity index around 0.1, a surface charge of (-12) - (+14) mV, and 80% of the siRNA encapsulation. The nanoparticles didn't affect cell viability of the cells after 72 hours. In cancer cells, KRAS expression was decreased by up to 50%, protein levels were decreased by more than 90%.

CONCLUSION

The formulated siRNA delivery nanoparticles can be promising treatment in lung cancer.

Applications of Nanobiomaterials in the Therapy and Imaging of Acute Liver Failure

This review focuses on the therapeutic mechanisms, targeting strategies of various nanomaterials in acute liver failure, and recent advances of diverse nanomaterials for acute liver failure therapy, diagnosis, and imaging. This review provides an outlook on the applications of nanomaterials, especially on the new horizons in acute liver failure therapy, and inspires broader interests across various disciplines. Acute liver failure (ALF), a fatal clinical disease featured with overwhelming hepatocyte necrosis, is a grand challenge in global health. However, a satisfactory therapeutic option for curing ALF is still absent, other than liver transplantation. Nanobiomaterials are currently being developed for the diagnosis and treatment of ALF. The liver can sequester most of nanoparticles from blood circulation, which becomes an intrinsic superiority for nanobiomaterials targeting hepatic diseases. Nanobiomaterials can enhance the bioavailability of free drugs, thereby significantly improving the therapeutic effects in ALF. Nanobiomaterials can also increase the liver accumulation of therapeutic agents and enable more effective targeting of the liver or specific liver cells. In addition, stimuli-responsive, optical, or magnetic nanomaterials exhibit great potential in the therapeutical, diagnostic, and imaging applications in ALF. Therefore, therapeutic agents in combination with nanobiomaterials increase the specificity of ALF therapy, diminish adverse systemic effects, and offer a multifunctional theranostic platform. Nanobiomaterial holds excellent significance and prospects in ALF theranostics. In this review, we summarize the therapeutic mechanisms and targeting strategies of various nanobiomaterials in ALF. We highlight recent developments of diverse nanomedicines for ALF therapy, diagnosis, and imaging. Furthermore, the challenges and future perspectives in the theranostics of ALF are also discussed.

Localized Interleukin-12 for Cancer Immunotherapy

Interleukin-12 (IL-12) is a potent, pro-inflammatory type 1 cytokine that has long been studied as a potential immunotherapy for cancer. Unfortunately, IL-12's remarkable antitumor efficacy in preclinical models has yet to be replicated in humans. Early clinical trials in the mid-1990's showed that systemic delivery of IL-12 incurred dose-limiting toxicities. Nevertheless, IL-12's pleiotropic activity, i.e., its ability to engage multiple effector mechanisms and reverse tumor-induced immunosuppression, continues to entice cancer researchers. The development of strategies which maximize IL-12 delivery to the tumor microenvironment while minimizing systemic exposure are of increasing interest. Diverse IL-12 delivery systems, from immunocytokine fusions to polymeric nanoparticles, have demonstrated robust antitumor immunity with reduced adverse events in preclinical studies. Several localized IL-12 delivery approaches have recently reached the clinical stage with several more at the precipice of translation. Taken together, localized delivery systems are supporting an IL-12 renaissance which may finally allow this potent cytokine to fulfill its considerable clinical potential. This review begins with a brief historical account of cytokine monotherapies and describes how IL-12 went from promising new cure to ostracized black sheep following multiple on-study deaths. The bulk of this comprehensive review focuses on developments in diverse localized delivery strategies for IL-12-based cancer immunotherapies. Advantages and limitations of different delivery technologies are highlighted. Finally, perspectives on how IL-12-based immunotherapies may be utilized for widespread clinical application in the very near future are offered.

In vivo gene delivery mediated by non-viral vectors for cancer therapy

Gene therapy by expression constructs or down-regulation of certain genes has shown great potential for the treatment of various diseases. The wide clinical application of nucleic acid materials dependents on the development of biocompatible gene carriers. There are enormous various compounds widely investigated to be used as non-viral gene carriers including lipids, polymers, carbon materials, and inorganic structures. In this review, we will discuss the recent discoveries on non-viral gene delivery systems. We will also highlight the in vivo gene delivery mediated by non-viral vectors to treat cancer in different tissue and organs including brain, breast, lung, liver, stomach, and prostate. Finally, we will delineate the state-of-the-art and promising perspective of in vivo gene editing using non-viral nano-vectors.

Microfluidic Synthesis of Rifampicin Loaded PLGA Nanoparticles and the Effect of Formulation on their Physical and Antibacterial Properties

The encapsulation of drugs in nanoparticles serves as an effective way to modify pharmacokinetics and therapeutic efficacy. Nanoparticles comprised of poly(d,l-lactide-co-glycolide) (PLGA) are well suited for this purpose; they are accessible using multiple synthesis methods, are highly biocompatible and biodegradable, and possess desirable drug release properties. In the present study, we have explored the effects of various formulation parameters on the physical properties of PLGA nanoparticles synthesised using a microfluidic assisted nanoprecipitation method and loaded with a model drug. PLGA nanoparticles, with diameters ranging from 165–364nm, were produced using three alternate stabilisers; poly(vinyl alcohol) (PVA), d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and didodecyldimethylammonium bromide (DMAB). Three additional formulations used PVA in addition to 20wt-% 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA), and oleic acid. Spectrophotometric analysis demonstrated that the use of PVA increased the loading efficiency over that of TPGS and DMAB formulations, while the inclusion of oleic acid in the PVA formulation resulted in a further 3-fold increase in loading efficiency. Invitro release studies demonstrate that the inclusion of lipid additives significantly alters release kinetics; release was most rapid and complete in the formulation containing oleic acid, while the addition of DOTAP and DOTMA significantly reduced release rates. Finally, the antimicrobial activity of each formulation was tested against Staphylococcus aureus and Bacillus cereus, with minimum inhibitory concentrations nearing or exceeding that of free rifampicin.

Cationic micelle-based siRNA delivery for efficient colon cancer gene therapy

Small interfering RNA (siRNA)-based gene therapy has provided an alternative strategy for cancer therapy. One of the key components within gene therapy process is the delivery system. As a novel non-viral gene vector, DMP, prepared by modifying mPEG-PCL micelle with cationic DOTAP lipid, has been prepared and successfully applied in plasmid DNA-based colon cancer gene therapy study. However, its potential in siRNA delivery is unknown. In this study, the preparation process of DMP was optimized and the anti-cancer efficacies of the DMP/siMcl1 and DMP/siBcl-xl complexes were studied on a mouse colon cancer model. Our results demonstrated that DMP cationic micelle-delivered siRNAs could effectively inhibit the growth of C26 colon cancer cells in vitro. Meanwhile, intratumoral administration of DMP/siMcl1 and DMP/siBcl-xl complexes obviously suppressed subcutaneous tumor model in vivo. These results suggest the DMP/siRNA complex to be a potential candidate for cancer gene therapy.

Systemic RALA/iNOS Nanoparticles: A Potent Gene Therapy for Metastatic Breast Cancer Coupled as a Biomarker of Treatment

This study aimed to determine the therapeutic benefit of a nanoparticular formulation for the delivery of inducible nitric oxide synthase (iNOS) gene therapy in a model of breast cancer metastasis. Nanoparticles comprising a cationic peptide vector, RALA, and plasmid DNA were formulated and characterized using a range of physiochemical analyses. Nanoparticles complexed using iNOS plasmids and RALA approximated 60 nm in diameter with a charge of 25 mV. A vector neutralization assay, performed to determine the immunogenicity of nanoparticles in immunocompetent C57BL/6 mice, revealed that no vector neutralization was evident. Nanoparticles harboring iNOS plasmids (constitutively active cytomegalovirus [CMV]-driven or transcriptionally regulated human osteocalcin [hOC]-driven) evoked iNOS protein expression and nitrite accumulation and impaired clonogenicity in the highly aggressive MDA-MB-231 human breast cancer model. Micrometastases of MDA-MB-231-luc-D3H1 cells were established in female BALB/c SCID mice by intracardiac delivery. Nanoparticulate RALA/CMV-iNOS or RALA/hOC-iNOS increased median survival in mice bearing micrometastases by 27% compared with controls and also provoked elevated blood nitrite levels. Additionally, iNOS gene therapy sensitized MDA-MB-231-luc-D3H1 tumors to docetaxel treatment. Studies demonstrated that systemically delivered RALA-iNOS nanoparticles have therapeutic potential for the treatment of metastatic breast cancer. Furthermore, detection of nitrite levels in the blood serves as a reliable biomarker of treatment.

Decorin-loaded poly lactic-co-glycolic acid nanoparticles modified by anti-alpha fetoprotein antibody: preparation, proliferation inhibition and induced apoptosis effects on HepG2 cells in vitro

OBJECTIVES

Decorin (DCN) is a negative regulatory factor for the growth of cancer cells and can inhibit the proliferation, metastasis of cancer cells and angiogenesis in cancer tissues. The aims of this study were to prepare the nanoparticles consisting of DCN and poly lactic-co-glycolic acid (PLGA) modified by anti-alpha fetoprotein (AFP) monoclonal antibody (mAb) and to examine the conventional physical properties, the in-vitro release of DCN and the targeting effect of these nanoparticles on HepG2 cells.

KEY FINDINGS

The encapsulated plasmid was slowly and steadily released from the nanoparticles. The targeted PLGA nanoparticles were initiatively taken in HepG2 cells high-efficiently. According to the results of RT-PCR, DCN gene in AFPmAb-PLGA-rhDCN nanoparticles can be expressed in HepG2 cells successfully. These nanoparticles significantly inhibited the proliferation of HepG2 cells and induced apoptosis. The mRNA expression of Bcl-2 gene in the AFPmAb-PLGA-rhDCN-treated groups appeared significantly to decrease and the caspase-3 gene had the opposite trend as compared with that of control group (P < 0.01).

CONCLUSION

These studies revealed that these nanoparticles were capable of specifically targeting the HepG2 cells and inhibiting the proliferation and they induce apoptosis of HepG2 cells in vitro, which was in a dose- and time-dependent manner.

Nanoparticle passage through porcine jejunal mucus: Microfluidics and rheology

A micro-slide chamber was used to screen and rank sixteen functionalized fluorescent silica nanoparticles (SiNP) of different sizes (10, 50, 100 and 200 nm) and surface coatings (aminated, carboxylated, methyl-PEG₁₀₀₀ylated, and methyl-PEG₂₀₀₀ylated) according to their capacity to permeate porcine jejunal mucus. Variables investigated were influence of particle size, surface charge and methyl-PEGylation. The anionic SiNP showed higher transport through mucus whereas the cationic SiNP exhibited higher binding with lower transport. A size-dependence in transport was identified - 10 and 50 nm anionic (uncoated or methyl-PEGylated) SiNP showed higher transport compared to the larger 100 and 200 nm SiNP. The cationic SiNP of all sizes interacted with the mucus, making it more viscous and less capable of swelling. In contrast, the anionic SiNP (uncoated or methyl-PEGylated) caused minimal changes in the viscoelasticity of mucus. The data provide insights into mucus-NP interactions and suggest a rationale for designing oral nanomedicines with improved mucopermeability.

Iron-Oxide-Based Nanovector for Tumor Targeted siRNA Delivery in an Orthotopic Hepatocellular Carcinoma Xenograft Mouse Model

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide. Small interfering RNA (siRNA) holds promise as a new class of therapeutics for HCC, as it can achieve sequence-specific gene knockdown with low cytotoxicity. However, the main challenge in the clinical application of siRNA lies in the lack of effective delivery approaches that need to be highly specific and thus incur low or no systemic toxicity. Here, a nonviral nanoparticle-based gene carrier is presented that can specifically deliver siRNA to HCC. The nanovector (NP-siRNA-GPC3 Ab) is made of an iron oxide core coated with chitosan-polyethylene glycol (PEG) grafted polyethyleneimine copolymer, which is further functionalized with siRNA and conjugated with a monoclonal antibody (Ab) against human glypican-3 (GPC3) receptor highly expressed in HCC. A rat RH7777 HCC cell line that coexpresses human GPC3 and firefly luciferase (Luc) is established to evaluate the nanovector. The nanoparticle-mediated delivery of siRNA against Luc effectively suppresses Luc expression in vitro without notable cytotoxicity. Significantly, NP-siLuc-GPC3 Ab administered intravenously in an orthotopic model of HCC is able to specifically bound to tumor and induce remarkable inhibition of Luc expression. The findings demonstrate the potential of using this nanovector for targeted delivery of therapeutic siRNA to HCC.

Gene therapy approaches against cancer using in vivo and ex vivo gene transfer of interleukin-12

IL-12 is an immunostimulatory cytokine with strong antitumor properties. Systemic administration of IL-12 in cancer patients led to severe toxic effects, prompting the development of gene therapy vectors able to express this cytokine locally in tumors. Both nonviral and viral vectors have demonstrated a high antitumor efficacy in preclinical tumor models. Some of these vectors, including DNA electroporation, adenovirus and ex vivo transduced dendritic cells, were tested in patients, showing low toxicity and moderate antitumor efficacy. IL-12 activity can be potentiated by molecules with immunostimulatory, antiangiogenic or cytotoxic activity. These combination therapies are of clinical interest because they could lower the threshold for IL-12 efficacy, increasing the therapeutic potential of gene therapy and preventing the toxicity mediated by this cytokine.

Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles

Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(DL-lactic-co-glycolic acid) (PLGA) nanocarriers modified with the cationic lipid dioleoyltrimethyl-ammoniumpropane (DOTAP). A library of siRNA-loaded LPNs was prepared by systematically varying the nitrogen-to-phosphate (N/P) ratio. Atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM) combined with small angle X-ray scattering (SAXS) and confocal laser scanning microscopy (CLSM) studies suggested that the siRNA-loaded LPNs are characterized by a core-shell structure consisting of a PLGA matrix core coated with lamellar DOTAP structures with siRNA localized both in the core and in the shell. Release studies in buffer and serum-containing medium combined with in vitro gene silencing and quantification of intracellular siRNA suggested that this self-assembling core-shell structure influences the siRNA release kinetics and the delivery dynamics. A main delivery mechanism appears to be mediated via the release of transfection-competent siRNA-DOTAP lipoplexes from the LPNs. Based on these results, we suggest a model for the nanostructural characteristics of the LPNs, in which the siRNA is organized in lamellar superficial assemblies and/or as complexes entrapped in the polymeric matrix.

Small RNA- and DNA-based gene therapy for the treatment of liver cirrhosis, where we are?

Chronic liver diseases with different aetiologies rely on the chronic activation of liver injuries which result in a fibrogenesis progression to the end stage of cirrhosis and liver failure. Based on the underlying cellular and molecular mechanisms of a liver fibrosis, there has been proposed several kinds of approaches for the treatment of liver fibrosis. Recently, liver gene therapy has been developed as an alternative way to liver transplantation, which is the only effective therapy for chronic liver diseases. The activation of hepatic stellate cells, a subsequent release of inflammatory cytokines and an accumulation of extracellular matrix during the liver fibrogenesis are the major obstacles to the treatment of liver fibrosis. Several targeted strategies have been developed, such as antisense oligodeoxynucleotides, RNA interference and decoy oligodeoxynucleotides to overcome this barriers. With this report an overview will be provided of targeted strategies for the treatment of liver cirrhosis, and particularly, of the targeted gene therapy using short RNA and DNA segments.

Phosphorothioate-modified CpG oligodeoxynucleotide (CpG ODN) induces apoptosis of human hepatocellular carcinoma cells independent of TLR9

Toll-like receptors (TLRs) expressed on cancer cells are closely associated with tumor development. In this study, we investigated the biological functions of the TLR9 ligand, CpG oligodeoxynucleotide (CpG ODN), on TLR9 expressed in the cytoplasm of hepatocellular carcinoma (HCC) cells. In vitro, human HCC cell lines were transfected with phosphorothioate-modified oligodeoxynucleotides TLR9 agonist OND M362 and its negative control ODN M362 ctrl, which inhibited the proliferation of HCC cells by inducing apoptosis without altering the cell cycle. Interestingly, ODN M362 and ODN M362 Ctrl displayed a similar proapoptotic effect on HCC, possibly related to phosphorothioate modification of the structure of CpG ODN. Although both of them resulted in the upregulation of the TLR9 receptor, their effect on HCC apoptosis was independent of TLR9. They also upregulated inflammatory cytokines, but did not activate the NF-κB signaling pathway. Finally, the activities of ODN M362 and ODN M362 Ctrl were demonstrated in nude mice inoculated with HCC cells. These findings suggest that the phosphorothioate-modified TLR9 agonist ODN M362, and its control, elicit antitumor activity in HCC cells and may serve as a novel therapeutic target for HCC therapy.

Homo-Roche ester derivatives by asymmetric hydrogenation and organocatalysis

Asymmetric hydrogenation routes to homologues of The Roche ester tend to be restricted to hydrogenations of itaconic acid derivatives, that is, substrates that contain a relatively unhindered, 1,1-disubstituted alkene. This is because in hydrogenations mediated by RhP2 complexes, the typical catalysts, it is difficult to obtain high conversions using the alternative substrate for the same product, the isomeric trisubstituted alkenes (D in the text). However, chemoselective modification of the identical functional groups in itaconic acid derivatives are difficult; hence, it would be favorable to use the trisubstituted alkene. Trisubstituted alkene substrates can be hydrogenated with high conversions using chiral analogs of Crabtree's catalyst of the type IrN(carbene). This paper demonstrates that such reactions are scalable (tens of grams) and can be manipulated to give optically pure homo-Roche ester chirons. Organocatalytic fluorination, chlorination, and amination of the homo-Roche building blocks was performed to demonstrate that they could easily be transformed into functionalized materials with two chiral centers and α,ω-groups that provide extensive scope for modifications. A synthesis of (S,S)- and (R,S)-γ-hydroxyvaline was performed to illustrate one application of the amination product.

Efficient hepatic delivery of drugs: novel strategies and their significance

Liver is a vital organ responsible for plethora of functions including detoxification, protein synthesis, and the production of biochemicals necessary for the sustenance of life. Therefore, patients with chronic liver diseases such as viral hepatitis, liver cirrhosis, and hepatocellular carcinoma need immediate attention to sustain life and as a result are often exposed to the prolonged treatment with drugs/herbal medications. Lack of site-specific delivery of these medications to the hepatocytes/nonparenchymal cells and adverse effects associated with their off-target interactions limit their continuous use. This calls for the development and fabrication of targeted delivery systems which can deliver the drug payload at the desired site of action for defined period of time. The primary aim of drug targeting is to manipulate the whole body distribution of drugs, that is, to prevent distribution to non-target cells and concomitantly increase the drug concentration at the targeted site. Carrier molecules are designed for their selective cellular uptake, taking advantage of specific receptors or binding sites present on the surface membrane of the target cell. In this review, various aspects of liver targeting of drug molecules and herbal medications have been discussed which elucidate the importance of delivering the drugs/herbal medications at their desired site of action.

Intravenous infusion of phage-displayed antibody library in human cancer patients: enrichment and cancer-specificity of tumor-homing phage-antibodies

Phage display is a powerful method for target discovery and selection of ligands for cancer treatment and diagnosis. Our goal was to select tumor-binding antibodies in cancer patients. Eligibility criteria included absence of preexisting anti-phage-antibodies and a Stage IV cancer status. All patients were intravenously administered 1 × 10(11) TUs/kg of an scFv library 1 to 4 h before surgical resection of their tumors. No significant adverse events related to the phage library infusion were observed. Phage were successfully recovered from all tumors. Individual clones from each patient were assessed for binding to the tumor from which clones were recovered. Multiple tumor-binding phage-antibodies were identified. Soluble scFv antibodies were produced from the phage clones showing higher tumor binding. The tumor-homing phage-antibodies and derived soluble scFvs were found to bind varying numbers (0-5) of 8 tested normal human tissues (breast, cervix, colon, kidney, liver, spleen, skin, and uterus). The clones that showed high tumor-specificity were found to bind corresponding tumors from other patients also. Clone enrichment was observed based on tumor binding and DNA sequence data. Clone sequences of multiple variable regions showed significant matches to certain cancer-related antibodies. One of the clones (07-2,355) that was found to share a 12-amino-acid-long motif with a reported IL-17A antibody was further studied for competitive binding for possible antigen target identification. We conclude that these outcomes support the safety and utility of phage display library panning in cancer patients for ligand selection and target discovery for cancer treatment and diagnosis.

Topical delivery of anti-TNFα siRNA and capsaicin via novel lipid-polymer hybrid nanoparticles efficiently inhibits skin inflammation in vivo

The barrier properties of the skin pose a significant but not insurmountable obstacle for development of new effective anti-inflammatory therapies. The objective of this study was to design and evaluate therapeutic efficacy of anti-nociception agent Capsaicin (Cap) and anti-TNFα siRNA (siTNFα) encapsulated cyclic cationic head lipid-polymer hybrid nanocarriers (CyLiPns) against chronic skin inflammatory diseases. Physico-chemical characterizations including hydrodynamic size, surface potential and entrapment efficacies of CyLiPns were found to be 163±9nm, 35.14±8.23mV and 92% for Cap, respectively. In vitro skin distribution studies revealed that CyLiPns could effectively deliver FITC-siRNA up to 360μm skin depth. Further, enhanced (p<0.001) Cap permeation from CyLiPns was observed compared to Capsaicin-Solution and Capzasin-HP. Therapeutic efficacies of CyLiPns were assessed using imiquamod-induced psoriatic plaque like model. CyLiPns carrying both Cap and siTNFα showed significant reduced expression of TNFα, NF-κB, IL-17, IL-23 and Ki-67 genes compared to either drugs alone (p<0.05) and were in close comparison with Topgraf®. Collectively these findings support our notion that novel cationic lipid-polymer hybrid nanoparticles can efficiently carry siTNFα and Cap into deeper dermal milieu and Cap with a combination of siTNFα shows synergism in treating skin inflammation.

Delivering instilled hydrophobic drug to the bladder by a cationic nanoparticle and thermo-sensitive hydrogel composite system

Some bladder disease therapies can benefit from intravesical drug delivery, which involves direct instillation of drug into the bladder via a catheter, to attain high local concentrations of the drug with minimal systemic effects. Deguelin is a potential anticancer agent, however, its poor water solubility and neurotoxicity restrict its clinical application. To address these challenges, we investigated the promising application of deguelin in the intravesical therapy of bladder cancer by designing a novel intravesical drug delivery system for deguelin. It was found that deguelin could efficiently kill bladder cancer cells and inhibit angiogenesis. Intravesically administrated deguelin had better tolerance than systemically applied deguelin. Encapsulation of deguelin in cationic DOTAP and monomethoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL) hybrid nanoparticles (DMP) created the deguelin loaded DMP nanoparticles (D/DMP). They had a mean particle size of 35 nm and zeta potential of 21 mV, rendering deguelin completely dispersible in aqueous media. Encapsulation of deguelin in cationic DMP nanoparticles enhanced the anticancer activity of deguelin in vitro. In addition, D/DMP nanoparticles were incorporated into a thermo-sensitive Pluronic F127 hydrogel, forming a novel D/DMP-F system, which remained in a flowing liquid state at lower than 25 °C, but underwent gelation at higher temperatures. The DMP nanoparticles in the F127 hydrogel system (DMP-F) could significantly extend the hydrophobic drug residence time and increase the drug concentration within the bladder. These results suggested that DMP-F was a good intravesical drug delivery system and D/DMP-F may have promising applications in intravesical therapy of bladder cancer.

In vivo gene delivery by nonviral vectors: overcoming hurdles?

The promise of cancer gene therapeutics is hampered by difficulties in the in vivo delivery to the targeted tumor cells, and systemic delivery remains to be the biggest challenge to be overcome. Here, we concentrate on systemic in vivo gene delivery for cancer therapy using nonviral vectors. In this review, we summarize the existing delivery barriers together with the requirements and strategies to overcome these problems. We will also introduce the current progress in the design of nonviral vectors, and briefly discuss their safety issues.

Polycationic amphiphilic cyclodextrin-based nanoparticles for therapeutic gene delivery

Aim: In this study, a set of polycationic amphiphilic cyclodextrins featuring self-assembling capabilities in the presence of nucleic acids have been evaluated as therapeutic gene vectors for in vivo purposes. Materials & Methods: A tetradecacationic structure incorporating 14 primary amino groups and 7 thioureido groups in the primary face of the cyclooligosaccharide core and 14 hexanoyl chains in the secondary face was judged to be optimal for therapeutic gene delivery. Results & Conclusion: This compound efficiently mediated serum-resistant transfection in HeLa and HepG2 cells, comparing favorably with branched poly(ethyleneimine), with a low associated toxicity. Further transfection experiments using an encoding therapeutic gene plasmid (pCMVIL-12) were effected to report expression levels of IL-12. Finally, in vivo gene delivery experiments by systemic injection in mice indicated relatively high transfection levels in the liver, overcoming trapping of the nanoparticles in lung cells, with low toxicity.

Influence of lipid components on gene delivery by polycation liposomes: Transfection efficiency, intracellular kinetics and in vivo tumor inhibition

Transfection efficiency of non-viral gene vectors is influenced by many factors, including chemical makeup, cellular uptake pathway and intracellular delivery. To investigate the effect of lipid saturation on transfection efficiency of polycation liposomes (PCLs), a soybean phospholipids (SPL), egg phospholipids (EPL) and hydrogenated soybean phosphatidylcholine (HSPC) series was used to prepare PCLs. Testing these PCLs in a luciferase assay indicated that with increasing saturation (SPL<EPL<HSPC), the ability to confer gene expression decreased. The effect of protamine combined with these PCLs was also studied in different cell lines. Improved transfection because of protamine incorporation was dependent on lipid saturation and on the cell line tested. The kinetics of cellular uptake and intracellular distribution was studied using flow cytometry and laser scanning confocal microscope, which showed that naked oligonucleotide (ODN) and PCLs/ODN complexes became equilibrium after 4h incubation. PCLs containing SPL (PCLs-S) and 1,2-dieleoyl-sn-glycero-3-phosphoethanolamine (PCLs-D) increased uptake rates by 2.20- and 5.45-fold, respectively. Furthermore, pCMV-IL-12 transfection mediated by PCLs-D showed excellent tumor inhibition efficiency compared with control and naked pCMV-IL-12 treatments in vivo.

Enhanced delivery of monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly l-lysine nanoparticles loading platelet-derived growth factor BB small interfering RNA by ultrasound and/or microbubbles to rat retinal pigment epithelium cells

BACKGROUND

A novel small interfering RNA (siRNA) delivery method based on the combined use of nanoparticles (NPs) with ultrasound (US) and/or microbubbles (MBs) was introduced in the present study. We investigated the efficacy and safety of US and/or MBs-enhanced delivery of monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly l-lysine (mPEG-PLGA-PLL) NPs loading platelet-derived growth factor BB (PDGF-BB) siRNA to rat retinal pigment epithelium (RPE)-J cells.

METHODS

The effect of US and/or MBs on the delivery of NPs containing Cy3-labeled siRNA was evaluated by fluorescence microscopy and flow cytometry. Potential toxicity of NPs and cell viability under different conditions of US and/or MBs were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method.

RESULTS

The results obtained showed that low intensity US or 15-20% MBs could increase the delivery efficiency of a lower concentration of mPEG-PLGA-PLL NPs loading siRNA to RPE-J cells, whereas the combination of US with MBs under the optimal conditions for the enhancement of NPs delivery did not further increase the cellular uptake of NPs compared to either US or MBs alone (p = 0.072 and p = 0.488, respectively). Under the optimal condition for US-enhanced NPs delivery, the enhanced PDGF-BB gene silencing with a combination of US and NPs encapsulating siRNA resulted in a significant decrease of mRNA and protein expression levels compared to NPs alone.

CONCLUSIONS

US and/or MBs could be used safely to enhance the delivery of NPs loading siRNA to rat RPE-J cells. A combination of the chemical (mPEG-PLGA-PLL NPs loading siRNA) and physical (US) approaches could more effectively downregulate the mRNA and protein expression of PDGF-BB.

Targeted novel surface-modified nanoparticles for interferon delivery for the treatment of hepatitis B

The purpose of the present work was to develop hepatitis B surface antigen (HBsAg) surface-adsorbed cationic poly (d,l-lactic-co-glycolic acid) PLGA nanoparticles for interferon alpha (IFNα) delivery targeted to hepatocytes. Cationic PLGA nanoparticles loaded with IFNα were prepared using the double emulsification technique. Delipidated HBsAg was passively adsorbed on the surface of nanoparticles by using the simple dipping and drying method. Surface morphology and size distribution of nanoparticles were analyzed by scanning electron microscopy and dynamic light-scattering method, respectively. The biodistribution behavior of plain and HBsAg-coated (99m)Tc-tagged PLGA nanoparticles was also examined followed by intravenous injection. The results revealed that ∼75% of the radioactivity was recovered in the liver after 4 h of injection that was nearly 3-fold greater in magnitude than the plain PLGA nanoparticles. These data demonstrated that the novel formulation of nanoparticles has potential application in hepatic-targeted drug delivery.

Design of an inhalable dry powder formulation of DOTAP-modified PLGA nanoparticles loaded with siRNA

Matrix systems based on biocompatible and biodegradable polymers like the United States Food and Drug Administration (FDA)-approved polymer poly(DL-lactide-co-glycolide acid) (PLGA) are promising for the delivery of small interfering RNA (siRNA) due to favorable safety profiles, sustained release properties and improved colloidal stability, as compared to polyplexes. The purpose of this study was to design a dry powder formulation based on cationic lipid-modified PLGA nanoparticles intended for treatment of severe lung diseases by pulmonary delivery of siRNA. The cationic lipid dioleoyltrimethylammoniumpropane (DOTAP) was incorporated into the PLGA matrix to potentiate the gene silencing efficiency. The gene knock-down level in vitro was positively correlated to the weight ratio of DOTAP in the particles, and 73% silencing was achieved in the presence of 10% (v/v) serum at 25% (w/w) DOTAP. Optimal properties were found for nanoparticles modified with 15% (w/w) DOTAP, which reduced the gene expression with 54%. This formulation was spray-dried with mannitol into nanocomposite microparticles of an aerodynamic size appropriate for lung deposition. The spray-drying process did not affect the physicochemical properties of the readily re-dispersible nanoparticles, and most importantly, the in vitro gene silencing activity was preserved during spray-drying. The siRNA content in the powder was similar to the theoretical loading and the siRNA was intact, suggesting that the siRNA is preserved during the spray-drying process. Finally, X-ray powder diffraction analysis demonstrated that mannitol remained in a crystalline state upon spray-drying with PLGA nanoparticles suggesting that the sugar excipient might exert its stabilizing effect by sterical inhibition of the interactions between adjacent nanoparticles. This study demonstrates that spray-drying is an excellent technique for engineering dry powder formulations of siRNA nanoparticles, which might enable the local delivery of biologically active siRNA directly to the lung tissue.

Role of weakly polarized nanoparticles in electroporation

In this study, we present a role for weakly polarized nanoparticles as engineered gene transporters that can enhance electromediated gene delivery. To validate this proof-of-concept, fluorescent poly(ethylene glycol) (PEG)-coated silica nanoparticles (SiNPs) with opposite polarities, SiNPs(RITC)-PEG/PTMA(+) and SiNPs(RITC)-PEG/PMP(-), are used. To investigate the electroporative uptake direction of the nanoparticles-gene complex, we employ microscale electroporation to generate more symmetric and uniform electric fields. The effect of the polarity of the nanoparticles on EGFP gene transfection efficiency in HeLa cells is measured by flow cytometry analysis. The results show that, compared to cationic nanoparticles, anionic nanoparticles have potential as electromediated gene transporters at a low gene concentration. Furthermore, we believe that this finding can be useful for developing a platform that enables electroporation-based gene/drug delivery associated with functional nanoparticles.

PLGA nanoparticles containing various anticancer agents and tumour delivery by EPR effect

As mortality due to cancer continues to rise, advances in nanotechnology have significantly become an effective approach for achieving efficient drug targeting to tumour tissues by circumventing all the shortcomings of conventional chemotherapy. During the past decade, the importance of polymeric drug-delivery systems in oncology has grown exponentially. In this context, poly(lactic-co-glycolic acid) (PLGA) is a widely used polymer for fabricating 'nanoparticles' because of biocompatibility, long-standing track record in biomedical applications and well-documented utility for sustained drug release, and hence has been the centre of focus for developing drug-loaded nanoparticles for cancer therapy. Such PLGA nanoparticles have also been used to develop proteins and peptides for nanomedicine, and nanovaccines, as well as a nanoparticle-based drug- and gene-delivery system for cancer therapy, and nanoantigens and growth factors. These drug-loaded nanoparticles extravasate through the tumour vasculature, delivering their payload into the cells by the enhanced permeability and retention (EPR) effect, thereby increasing their therapeutic effect. Ongoing research about drug-loaded nanoparticles and their delivery by the EPR effect to the tumour tissues has been elucidated in this review with clarity.

Surface functionalisation of PLGA nanoparticles for gene silencing

This work presents a method for decorating the surface of poly (lactide-co-glycolide) (PLGA) nanoparticles with polyethyleneimine (PEI) utilising a cetyl derivative to improve surface functionalisation and siRNA delivery. Sub-micron particles were produced by an emulsion-diffusion method using benzyl alcohol. We demonstrate by x-ray photoelectron spectroscopy (XPS), 2.6 times higher surface presentation of amines using the cetyl derivative compared to non-cetylated-PEI formulations (6.5 and 2.5% surface nitrogen, respectively). The modified particles were shown by spectroscopy, fluorescent microscopy and flow cytometry to bind and mediate siRNA delivery into the human osteosarcoma cell line U2OS and the murine macrophage cell line J774.1. Specific reduction in the anti-apoptotic oncogene BCL-w in U2OS cells was achieved with particles containing cetylated-PEI (53%) with no cellular toxicity. In addition, particles containing cetylated-PEI achieved 64% silencing of TNFalpha in J774.1 cells. This rapid method for surface modification of PLGA nanoparticles promotes its application for alternative cetylated functional derivatives as a strategy to control specific biological properties of nanoparticles.

Scope of nanotechnology in ovarian cancer therapeutics

This review describes the use of polymer micelle nanotechnology based chemotherapies for ovarian cancer. While various chemotherapeutic agents can be utilized to improve the survival rate of patients with ovarian cancer, their distribution throughout the entire body results in high normal organ toxicity. Polymer micelle nanotechnology aims to improve the therapeutic efficacy of anti-cancer drugs while minimizing the side effects. Herein, different types of polymer micelle technology based nanotherapies such as PLGA, polymerosomes, acid cleavable, thermosensitive, pH sensitive, and cross-linked micelles are introduced and structural differences are explained. Additionally, production methods, stability, sustainability, drug incorporation and drug release profiles of various polymer micelle based nanoformulations are discussed. An important feature of polymer micelle nanotechnology is the small size (10-100 nm) of particles which improves circulation and enables superior accumulation of the therapeutic drugs at the tumor sites. This review provides a comprehensive evaluation of different types of polymer micelles and their implications in ovarian cancer therapeutics.

Shell cross-linked and hepatocyte-targeting nanoparticles containing doxorubicin via acid-cleavable linkage

Hepatocyte-targeting and shell cross-linked nanoparticles with lactose moiety on the surface and doxorubicin (DOX) in the core were prepared from lactose-PEG-DOX conjugate. The process consists of the synthesis of a novel α-hydrazine-ω-propargyl poly(ethylene glycol) (PEG) with a double bond in the PEG backbone, followed by the bonding of a lactose molecule containing an azide group to the ω-end of PEG via "click" chemistry, and finally, the conjugation of DOX to the α-end of PEG via an acid-labile, hydrazone linkage. The resultant conjugate can be self-assembled into nanoparticles. Thiolated tri(ethylene glycol) was introduced into the shell of nanoparticles as a cross-linking agent. The release of DOX is more rapid from lactose-PEG-DOX at pH 5.0 than at pH 7.4. Fluorescent microscope studies suggest that the lactose-DOX nanoparticles are internalized by hepatoma cells through a lactose receptor-mediated mechanism, whereas the lactose-free nanoparticles are not endocytosed as rapidly as lactose-DOX nanoparticles. MTT assay also shows that lactose-DOX nanoparticles have a stronger inhibition against hepatoma cells than DOX nanoparticles and pure DOX.

FROM THE CLINICAL EDITOR

In this basic science study, a highly efficient targeted doxorubicin delivery method to hepatocytes is presented.

Bio and nanotechnological strategies for tumor-targeted gene therapy

Gene therapy is a new medical approach for the treatment of tumors. For safe and efficient gene therapy, therapeutic genes need to be delivered efficiently into the target tumor cells. Development of gene delivery systems to specifically recognize and target tumor cells and to distinguish them from normal cells, especially in the same tissue or organ, is one of the most important issues regarding the present gene delivery methodologies. The enhanced permeability and retention (EPR) effect using the characteristics of angiogenic tumor blood vessels, as well as gene delivery systems recognizing hyperactivated receptors or intracellular signals, is broadly applied to tumor-targeted gene therapy. In addition, bacterial vectors can be a useful means for targeting hypoxic or anoxic regions of a tumor.

Engineering gas-foamed large porous particles for efficient local delivery of macromolecules to the lung

Gas-foamed large porous particles (gfLPP) based on poly(lactic-co-glycolic) acid (PLGA) have been recently suggested as potential carriers for pulmonary drug delivery. In this work, we attempt to engineer gfLPP for efficient local delivery of macromolecules in the lungs. Particles were fabricated by the double emulsion-solvent evaporation technique using ammonium bicarbonate as porogen. To improve particle technological properties, two lipid aid excipients, namely dipalmitoylphosphatidylcholine (DPPC) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), were tested. Preliminary technological studies performed on unloaded gfLPP showed that the addition of an appropriate amount of NH(4)(HCO(3)), which spontaneously produces CO(2) and NH(3) during solvent evaporation, is essential to achieve a homogeneous population of highly porous particles with optimal aerodynamic properties. Then, the effect of the presence of DPPC or DOTAP upon the properties of gfLPP containing a model hydrophilic macromolecule, rhodamine B isothiocyanate-dextran (Rhod-dex), was assessed. We found that in the case of hydrophilic macromolecules unable to interact with PLGA end-groups, such as Rhod-dex, excipient addition is essential to increase the amount of drug entrapped within gfLPP, being as high as 80% only for DPPC- or DOTAP-engineered gfLPP. Also Rhod-dex release profile from gfLPP was strongly affected by excipient addition in the initial formulation, with lipid-engineered gfLPP allowing for a more prolonged release of Rhod-dex as compared to excipient-free gfLPP. A further modulation of Rhod-dex initial release rate could be achieved when DOTAP was used, likely due to the electrostatic interactions occurring between macromolecule and cationic phospholipid. Conceiving the developed gfLPP for drug inhalation, DPPC- and DOTAP-engineered gfLPP displayed optimal MMAD(exp) values falling within the range 6.1-7.6 microm and very low geometric standard deviations (GSD) varying between 1.2 and 1.3. In vivo deposition studies performed after intra-tracheal administration of gfLPP in rats confirmed the ability of the developed dry powders to deposit along bronchia and bronchioles. In perspective, lipid-engineered gfLPP represent a viable alternative to LPP developed so far to achieve local and prolonged release of hydrophilic macromolecules, such as nucleic acids, in the lungs.

Optimization of DNA delivery by three classes of hybrid nanoparticle/DNA complexes

Plasmid DNA encoding a luciferase reporter gene was complexed with each of six different hybrid nanoparticles (NPs) synthesized from mixtures of poly (D, L-lactide-co-glycolide acid) (PLGA 50:50) and the cationic lipids DOTAP (1, 2-Dioleoyl-3-Trimethyammonium-Propane) or DC-Chol {3β-[N-(N', N'-Dimethylaminoethane)-carbamyl] Cholesterol}. Particles were 100-400 nm in diameter and the resulting complexes had DNA adsorbed on the surface (out), encapsulated (in), or DNA adsorbed and encapsulated (both). A luciferase reporter assay was used to quantify DNA expression in 293 cells for the uptake of six different NP/DNA complexes. Optimal DNA delivery occurred for 10⁵ cells over a range of 500 ng - 10 μg of NPs containing 20-30 μg DNA per 1 mg of NPs. Uptake of DNA from NP/DNA complexes was found to be 500-600 times as efficient as unbound DNA. Regression analysis was performed and lines were drawn for DNA uptake over a four week interval. NP/DNA complexes with adsorbed NPs (out) showed a large initial uptake followed by a steep slope of DNA decline and large angle of declination; lines from uptake of adsorbed and encapsulated NPs (both) also exhibited a large initial uptake but was followed by a gradual slope of DNA decline and small angle of declination, indicating longer times of luciferase expression in 293 cells. NPs with encapsulated DNA only (in), gave an intermediate activity. The latter two effects were best seen with DOTAP-NPs while the former was best seen with DC-Chol-NPs. These results provide optimal conditions for using different hybrid NP/DNA complexes in vitro and in the future, will be tested in vivo.