Intranasal administration of CpG DNA lipoplex prevents pulmonary metastasis in mice

Lipid-nanoparticle-enabled nucleic acid therapeutics for liver disorders

Inherited genetic disorders of the liver pose a significant public health burden. Liver transplantation is often limited by the availability of donor livers and the exorbitant costs of immunosuppressive therapy. To overcome these limitations, nucleic acid therapy provides a hopeful alternative that enables gene repair, gene supplementation, and gene silencing with suitable vectors. Though viral vectors are the most efficient and preferred for gene therapy, pre-existing immunity debilitating immune responses limit their use. As a potential alternative, lipid nanoparticle-mediated vectors are being explored to deliver multiple nucleic acid forms, including pDNA, mRNA, siRNA, and proteins. Herein, we discuss the broader applications of lipid nanoparticles, from protein replacement therapy to restoring the disease mechanism through nucleic acid delivery and gene editing, as well as multiple preclinical and clinical studies as a potential alternative to liver transplantation.

Recent Advances in Intranasal Liposomes for Drug, Gene, and Vaccine Delivery

Liposomes are safe, biocompatible, and biodegradable spherical nanosized vesicles produced from cholesterol and phospholipids. Recently, liposomes have been widely administered intranasally for systemic and brain delivery. From the nasal cavity, liposome-encapsulated drugs and genes enter the systemic circulation primarily via absorption in the respiratory region, whereas they can be directly transported to the brain via the olfactory pathway. Liposomes can protect drugs and genes from enzymatic degradation, increase drug absorption across the nasal epithelium, and prolong the residence time in the nasal cavity. Intranasal liposomes are also a potential approach for vaccine delivery. Liposomes can be used as a platform to load antigens and as vaccine adjuvants to induce a robust immune response. With the recent interest in intranasal liposome formulations, this review discusses various aspects of liposomes that make them suitable for intranasal administration. We have summarized the latest advancements and applications of liposomes and evaluated their performance in the systemic and brain delivery of drugs and genes administered intranasally. We have also reviewed recent advances in intranasal liposome vaccine development and proposed perspectives on the future of intranasal liposomes.

Nanoimmunoengineering strategies in cancer diagnosis and therapy

Cancer immunotherapy strategies in combination with engineered nanosystems have yielded beneficial results in the treatment of cancer and their application is increasing day by day. The pivotal role of stimuli-responsive nanosystems and nanomedicine-based cancer immunotherapy, as a subsidiary discipline in the field of immunology, cannot be ignored. Today, rapid advances in nanomedicine are used as a platform for exploring new therapeutic applications and modern smart healthcare management strategies. The progress of nanomedicine in cancer treatment has confirmed the findings of immunotherapy in the medical research phase. This study concentrates on approaches connected to the efficacy of nanoimmunoengineering strategies for cancer immunotherapies and their applications. By assessing improved approaches, different aspects of the nanoimmunoengineering strategies for cancer therapies are discussed in this study.

Delivery of genome-editing biomacromolecules for treatment of lung genetic disorders

Genome-editing systems based on clustered, regularly interspaced, short palindromic repeat (CRISPR)/associated protein (CRISPR/Cas), are emerging as a revolutionary technology for the treatment of various genetic diseases. To date, the delivery of genome-editing biomacromolecules by viral or non-viral vectors have been proposed as new therapeutic options for lung genetic disorders, such as cystic fibrosis (CF) and α-1 antitrypsin deficiency (AATD), and it has been accepted that these delivery vectors can introduce CRISPR/Cas9 machineries into target cells or tissues in vitro, ex vivo and in vivo. However, the efficient local or systemic delivery of CRISPR/Cas9 elements to the lung, enabled by either viral or by non-viral carriers, still remains elusive. Herein, we first introduce lung genetic disorders and their current treatment options, and then summarize CRISPR/Cas9-based strategies for the therapeutic genome editing of these disorders. We further summarize the pros and cons of different routes of administration for lung genetic disorders. In particular, the potentials of aerosol delivery for therapeutic CRISPR/Cas9 biomacromolecules for lung genome editing are discussed and highlighted. Finally, current challenges and future outlooks in this emerging area are briefly discussed.

The genetic script of metastasis

Metastasis is a pivotal event that changes the course of cancers from benign and treatable to malignant and difficult to treat, resulting in the demise of patients. Understanding the genetic control of metastasis is thus crucial to develop efficient and sustainable targeted therapies. Here we discuss the alterations in epigenetic mechanisms, transcription, chromosomal instability, chromosome imprinting, non-coding RNAs, coding RNAs, mutant RNAs, enhancers, G-quadruplexes, and copy number variation to dissect the genetic control of metastasis. We conclude that the genetic control of metastasis is predominantly executed through epithelial to mesenchymal transition and evasion of cell death. We discuss how genetic regulatory mechanisms can be harnessed for therapeutic purposes to achieve sustainable control over cancer metastasis.

Nanoparticles for Immune Stimulation Against Infection, Cancer, and Autoimmunity

Vaccination using nanocarrier-based delivery systems has recently emerged as a promising approach for meeting the continued challenge posed by infectious diseases and cancer. A diverse portfolio of nanocarriers of various sizes, compositions, and physical parameters have now been developed, and this diversity provides an opportunity for the rational design of vaccines that can mediate targeted delivery of various antigens and adjuvants or immune regulatory agents in ways unachievable with classical vaccination approaches. This flexibility allows control over the characteristics of vaccine-elicited immune responses such that they can be tailored to be effective in circumstances where classical vaccines have failed. Furthermore, the utility of nanocarrier-based immune modulation extends to the treatment of autoimmune disease where precisely targeted inhibition of immune responses is desirable. Clearly, the selection of appropriate nanocarriers, antigens, adjuvants, and other components underpins the efficacy of these nanoimmune interventions. Herein, we provide an overview of currently available nanocarriers of various types and their physical and pharmacological properties with the goal of providing a resource for researchers exploring nanomaterial-based approaches for immune modulation and identify some information gaps and unexplored questions to help guide future investigation.

Nanomedicine approaches to improve cancer immunotherapy

Significant advances have been made in the field of cancer immunotherapy by orchestrating the body's immune system to eradicate cancer cells. However, safety and efficacy concerns stemming from the systemic delivery of immunomodulatory compounds limits cancer immunotherapies expansion and application. In this context, nanotechnology presents a number of advantages, such as targeted delivery to immune cells, enhanced clinical outcomes, and reduced adverse events, which may aid in the delivery of cancer vaccines and immunomodulatory agents. With this in mind, a diverse range of nanomaterials with different physicochemical characteristics have been developed to stimulate the immune system and battle cancer. In this review, we will focus on some recent developments and the potential advantages of utilizing nanotechnology within the field of cancer immunotherapy. WIREs Nanomed Nanobiotechnol 2017, 9:e1456. doi: 10.1002/wnan.1456 For further resources related to this article, please visit the WIREs website.

Airway administration of a highly versatile peptide-based liposomal construct for local and distant antitumoral vaccination

With the discovery of tumor-associated antigens such as ErbB2, vaccination is considered as a promising strategy to prevent the development of cancer or treat the existing disease. Among routes of immunization, the respiratory route provides the opportunity to develop non-invasive approach for vaccine delivery. In the current study, this administration route was used in order to investigate the potency of a highly versatile di-epitopic liposomal construct to exhibit local or distant antitumoral efficiency after prophylactic or therapeutic vaccination in mice. Well-characterized liposomes, containing the ErbB2 (p63-71) TCD8(+) and HA (p307-319) TCD4(+) peptide epitopes and the Pam2CAG adjuvant, were formulated and administered into the airway of naïve BALB/c mice. The nanoparticle vaccine candidate induced local and specific systemic immune response, as measured by immune cell infiltration and chemokine and cytokine production in BALF or lung tissue, and by spleen T-cell activation ex vivo, respectively. This potent immune response resulted in an efficient antitumor activity against both lung and solid s.c. tumors. Interestingly, the antitumor efficacy was observed after both prophylactic and therapeutic vaccinations, which are the most judicious ones to fight cancer. Our data showed an undeniable interest of liposomal peptide-based vaccines in antitumor vaccination by the respiratory route, opening new perspectives for cancer treatment.

Preparation of immunostimulatory single-walled carbon nanotube/CpG DNA complexes and evaluation of their potential in cancer immunotherapy

Carbon nanotubes (CNTs) have many interesting properties. In particular, their photohyperthermic effect by near-infrared (NIR) irradiation could be used to kill cancer cells, and could thus be applied in photohyperthermic therapy. However, the solubility of CNTs must be improved before they can be used in biological applications. As DNA is reported to disperse the CNTs in aqueous solution with π-π interactions, we hypothesis that immunostimulatory CpG DNA may also disperse the CNTs in aqueous solution. In this study, we used CpG DNA to disperse single-walled CNTs (SWCNTs) in aqueous solution, in order to combine photohyperthermic effect and immunoactivation together to achieve a more effective cancer therapy. As expected, CpG DNA effectively dispersed the SWCNTs in aqueous solution via the formation of SWCNT/CpG DNA complexes. Moreover, the immunoreactivity of the SWCNT/CpG DNA complexes was investigated. The results showed that intratumoral administration of the SWCNT/CpG DNA complexes in mice enhanced the production level of inflammatory cytokines in tumor tissues. Finally, we evaluated the antitumor effects of the SWCNT/CpG DNA complexes in tumor-bearing mice. The result indicated that intratumoral administration of the SWCNT/CpG DNA complexes combined with NIR irradiation was a more effective approach to prevent the proliferation of tumor growth.

Applications of nanotechnology for immunology

Nanotechnology uses the unique properties of objects that function as a unit within the overall size range of 1-1,000 nanometres. The engineering of nanostructure materials, including nanoparticles, nanoemulsions or nanotubules, holds great promise for the development of new immunomodulatory agents, as such nanostructures can be used to more effectively manipulate or deliver immunologically active components to target sites. Successful applications of nanotechnology in the field of immunology will enable new generations of vaccines, adjuvants and immunomodulatory drugs that aim to improve clinical outcomes in response to a range of infectious and non-infectious diseases.

Effect of molecular weight of polyethyleneimine on loading of CpG oligodeoxynucleotides onto flake-shell silica nanoparticles for enhanced TLR9-mediated induction of interferon-α

BACKGROUND

Class B CpG oligodeoxynucleotides primarily interact with Toll-like receptor 9 (TLR9) in B cells and enhance the immune system through induction of various interleukins including interleukin-6 in these immune cells. Although free class B CpG oligodeoxynucleotides do not induce interferon (IFN)-α production, CpG oligodeoxynucleotide molecules have been reported to induce IFN-α when loaded onto nanoparticles. Here, we investigated the in vitro induction of IFN-α by a nanocarrier delivery system for class B CpG oligodeoxynucleotide molecules.

METHODS

For improving the capacity to load CpG oligodeoxynucleotide molecules, flake-shell SiO(2) nanoparticles with a specific surface area approximately 83-fold higher than that of smooth-surfaced SiO(2) nanoparticles were prepared by coating SiO(2) nanoparticles with polyethyleneimine (PEI) of three different number-average molecular weights (Mns 600, 1800, and 10,000 Da).

RESULTS

The capacity of the flake-shell SiO(2) nanoparticles to load CpG oligodeoxynucleotides was observed to be 5.8-fold to 6.7-fold higher than that of smooth-surfaced SiO(2) nanoparticles and was found to increase with an increase in the Mn of the PEI because the Mn contributed to the positive surface charge density of the nanoparticles. Further, the flake-shell SiO(2) nanoparticles showed much higher levels of IFN-α induction than the smooth-surfaced SiO(2) nanoparticles. The highest IFN-α induction potential was observed for CpG oligodeoxynucleotide molecules loaded onto flake-shell SiO(2) nanoparticles coated with PEI of Mn 600 Da, although the CpG oligodeoxynucleotide density was lower than that on flake-shell SiO(2) nanoparticles coated with PEI of Mns 1800 and 10,000 Da. Even with the same density of CpG oligodeoxynucleotides on flake-shell SiO(2) nanoparticles, PEI with an Mn of 600 Da caused a markedly higher level of IFN-α induction than that with Mns of 1800 Da and 10,000 Da. The higher TLR9-mediated IFN-α induction by CpG oligodeoxynucleotides on flake-shell SiO(2) nanoparticles coated with a PEI of Mn 600 Da is attributed to residence of the CpG oligodeoxynucleotide molecules in endolysosomes.

Heat shock proteins and cancer vaccines: developments in the past decade and chaperoning in the decade to come

Molecular chaperone-peptide complexes extracted from tumors (heat shock protein [HSP] vaccines) have been intensively studied in the preceding two decades, proving to be safe and effective in treating a number of malignant diseases. They offer personalized therapy and target a cross-section of antigens expressed in patients' tumors. Future advances may rely on understanding the molecular underpinnings of this approach to immunotherapy. One property common to HSP vaccines is the ability to stimulate antigen uptake by scavenger receptors on the antigen-presenting cell surface and trigger T-lymphocyte activation. HSPs can also induce signaling through Toll-Like receptors in a range of immune cells and this may mediate the effectiveness of vaccines.

The involvement of NK cell activation following intranasal administration of CpG DNA lipoplex in the prevention of pulmonary metastasis and peritoneal dissemination in mice

Synthetic oligodeoxynucleotides containing CpG motifs (CpG DNA) can activate immunocompetent cells, which may possess antitumor activity. Previously, we found that when the cationic liposomes complexes formed with CpG DNA (CpG DNA lipoplex) were administered intranasally, they could prevent pulmonary metastasis in mice. However, the mechanisms underlying this process are unknown. In the present study, we show that natural killer (NK) cells play an important role in preventing pulmonary metastasis and peritoneal dissemination in a mouse model of metastatic disease. Further, in vitro, the NK cells obtained from mice treated with CpG DNA lipoplex showed higher cytotoxicity compared with untreated mice and in vivo, depletion of NK cells (achieved through injection of rabbit anti-asialo GM1 serum), abolished the inhibitory effect of CpG DNA lipoplex on pulmonary metastasis and peritoneal dissemination. In contrast, macrophage elimination did not disrupt the effects of the CpG DNA lipoplex. These results suggest that intranasal administration of CpG DNA lipoplex could prevent pulmonary metastasis and peritoneal dissemination by activating NK cells.

Enhanced tumor localization and retention of chlorin e6 in cationic nanolipoplexes potentiate the tumor ablation effects of photodynamic therapy

Here we report the tumor ablation effects of the negatively charged photosensitizer chlorin e6 (Ce6) in nanocomplexes. Ce6 was complexed to cationic 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine-based liposomes, forming cationic nanolipoplexes. The loading efficiency of Ce6 to cationic nanolipoplexes was greater than 90%. The degree of enhancement of cellular uptake of Ce6 by treatment in cationic nanolipoplexes increased with the concentration of Ce6, showing 18.3-fold higher uptake than free Ce6 at 15 µM. Molecular imaging revealed the preferential distribution and retention of Ce6 in SCC7 tumor tissues after intravenous administration of Ce6 in cationic nanolipoplexes. Moreover, localized illumination of mice receiving Ce6 in cationic nanolipoplexes resulted in the formation of thick scabs over tumor regions, and complete ablation of tumors after scab detachment. In contrast, continuous growth of tumors was observed in the group treated with free Ce6. Our results suggest that the cationic nanolipoplexes of Ce6 improve the therapeutic effects of photodynamic cancer therapy as compared to free Ce6.

Cationic liposomes as vaccine adjuvants

The application of cationic liposomes as vaccine delivery systems and adjuvants has been investigated extensively over the last few decades. However, cationic liposomes are, in general, not sufficiently immunostimulatory, which is why the combination of liposomes with immunostimulating ligands has arisen as a strategy in the development of novel adjuvant systems. Within the last 5 years, two novel adjuvant systems based on cationic liposomes incorporating Toll-like receptor or non-Toll-like receptor immunostimulating ligands have progressed from preclinical testing in smaller animal species to clinical testing in humans. The immune responses that these clinical candidates induce are primarily of the Th1 type for which there is a profound unmet need. Furthermore, a number of new cationic liposome-forming surfactants with notable immunostimulatory properties have been discovered. In this article we review the recent progress on the application of cationic liposomes as vaccine delivery systems/adjuvants.

Enhancing effect of natural borneol on the absorption of geniposide in rat via intranasal administration

Both geniposide (Ge) and natural borneol (NB) are bioactive substances derived from traditional Chinese herbs. The effect of NB on the pharmacokinetics of Ge in rat via intranasal administration was investigated. The concentrations of Ge in plasma were determined by reversed-phase high-performance liquid chromatography (HPLC) after intranasal administration of Ge (4 mg/kg) alone and combined with different doses (0.08, 0.8, and 8 mg/kg) of NB. The intravenous administration was given as a reference (4 mg/kg of Ge and 8 mg/kg of NB). Compared with the intravenous administration, the absolute bioavailability of Ge was 76.14% through intranasal administration combined with NB. Compared with the intranasal administration of Ge alone, Ge could be absorbed rapidly in the nasal cavity combined with NB; the peak time of Ge in the plasma became shorter (3-5 min vs. 40 min); the peak concentration became higher (1.32-4.25 μg/ml vs. 0.67 μg/ml); and, the relative bioavailability of Ge combined with NB was 90.3%-237.8%. The enhancing effect was attenuated as the dose of NB decreased. The results indicated that NB can accelerate the absorption of Ge dose-dependently in the nasal cavity.

A non-invasive intranasal inoculation technique using isoflurane anesthesia to infect the brain of mice with rabies virus

Methods for intranasal inoculation of viruses are often described poorly and the effects of variations in the technique on the outcome are unknown. Standardization of protocols is key to compare studies and minimize animal use. The clinical and virological outcome of infection with rabies virus (genotypes 1 and 5) upon administration of different inoculum volumes (25, 50 and 100μl) and different anesthetic regimens were examined. Administration of 25μl of virus as a drop on both nostrils under brief superficial isoflurane anesthesia (92μl/dm(3), recovery after 85 ± 1 0s) was the most effective to infect the brain and induced 100% lethal infection 9 days later. Increasing the inoculum volume reduced infectivity significantly, with decreased viral loads in the brain and only 40% mortality. Increasing the depth of isoflurane anesthesia (230μl/dm(3)) improved the infectivity of the large-volume inoculum (90% mortality), probably because of suppression of swallow and sneeze reflexes. Compared to isoflurane anesthesia, xylazine-ketamine anesthesia reduced the infectivity of the inoculum significantly. Thus, administration of a small volume of virus on the nostrils under brief gas anesthesia is a safe and reproducible technique to induce infection of the brain. Since needles are not required, this helps to preserve the integrity of the physical barriers, animal welfare and the manipulator's safety.

Liposomes as delivery systems for nasal vaccination: strategies and outcomes

IMPORTANCE OF THE FIELD

Among the particulate systems that have been envisaged in vaccine delivery, liposomes are very attractive. These phospholipid vesicles can indeed deliver a wide range of molecules. They have been shown to enhance considerably the immunogenicity of weak protein antigens or synthetic peptides. Also, they offer a wide range of pharmaceutical options for the design of vaccines. In the past decade, the nasal mucosa has emerged as an effective route for vaccine delivery, together with the opportunity to develop non-invasive approaches in vaccination.

AREAS COVERED IN THIS REVIEW

This review focuses on the recent strategies and outcomes that have been developed around the use of liposomes in nasal vaccination.

WHAT THE READER WILL GAIN

The various formulation parameters, including lipid composition, size, charge and mucoadhesiveness, that have been investigated in the design of liposomal vaccine candidates dedicated to nasal vaccination are outlined. Also, an overview of the immunological and protective responses obtained with the developed formulations is presented.

TAKE HOME MESSAGE

This review illustrates the high potential of liposomes as nasal vaccine delivery systems.