In vivo transfection study of chitosan-DNA-FAP-B nanoparticles as a new non viral vector for gene delivery to the lung

Mechanisms and challenges of nanocarriers as non-viral vectors of therapeutic genes for enhanced pulmonary delivery

With the rapid development of biopharmaceuticals and the outbreak of COVID-19, the world has ushered in a frenzy to develop gene therapy. Therefore, therapeutic genes have received enormous attention. However, due to the extreme instability and low intracellular gene expression of naked genes, specific vectors are required. Viral vectors are widely used attributed to their high transfection efficiency. However, due to the safety concerns of viral vectors, nanotechnology-based non-viral vectors have attracted extensive investigation. Still, issues of low transfection efficiency and poor tissue targeting of non-viral vectors need to be addressed. Especially, pulmonary gene delivery has obvious advantages for the treatment of inherited lung diseases, lung cancer, and viral pneumonia, which can not only enhance lung targeting and but also reduce enzymatic degradation. For systemic diseases therapy, pulmonary gene delivery can enhance vaccine efficacy via inducing not only cellular, humoral immunity but also mucosal immunity. This review provides a comprehensive overview of nanocarriers as non-viral vectors of therapeutic genes for enhanced pulmonary delivery. First of all, the characteristics and therapeutic mechanism of DNA, mRNA, and siRNA are provided. Thereafter, the advantages and challenges of pulmonary gene delivery in exerting local and systemic effects are discussed. Then, the inhalation dosage forms for nanoparticle-based drug delivery systems are introduced. Moreover, a series of materials used as nanocarriers for pulmonary gene delivery are presented, and the endosomal escape mechanisms of nanocarriers based on different materials are explored. The application of various non-viral vectors for pulmonary gene delivery are summarized in detail, with the perspectives of nano-vectors for pulmonary gene delivery.

Current Practices and Potential Nanotechnology Perspectives for Pain Related to Cystic Fibrosis

Pain is a complex, multidimensional process that negatively affects physical and mental functioning, clinical outcomes, quality of life, and productivity for cystic fibrosis (CF) patients. CF is an inherited multi-system disease that requires a complete approach in order to evaluate, monitor and treat patients. The landscape in CF care has changed significantly, with currently more adult patients than children worldwide. Despite the great advances in supportive care and in our understanding regarding its pathophysiology, there are still numerous aspects of CF pain that are not fully explained. This review aims to provide a critical overview of CF pain research that focuses on pain assessment, prevalence, characteristics, clinical association and the impact of pain in children and adults, along with innovative nanotechnology perspectives for CF management. Specifically, the paper evaluates the pain symptoms associated with CF and examines the relationship between pain symptoms and disease severity. The particularities of gastrointestinal, abdominal, musculoskeletal, pulmonary and chest pain, as well as pain associated with medical procedures are investigated in patients with CF. Disease-related pain is common for patients with CF, suggesting that pain assessment should be a routine part of their clinical care. A summary of the use of nanotechnology in CF and CF-related pain is also given. Further research is clearly needed to better understand the sources of pain and how to improve patients’ quality of life.

PEGylated Chitosan for Nonviral Aerosol and Mucosal Delivery of the CRISPR/Cas9 System in Vitro

Chitosan has been widely employed to deliver nucleic acids such as siRNA and plasmids. However, chitosan-mediated delivery of a gene-editing system has not been reported yet. In this study, poly(ethylene glycol) monomethyl ether (mPEG) was conjugated to chitosan with different molecular weights (low molecular weight and medium molecular weight chitosan) achieving a high degree of substitution as identified by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H NMR) spectra. PEGylated chitosan/pSpCas9-2A-GFP nanocomplexes were formed at different N/ P (amine group to phosphate group) ratios and characterized in terms of size and zeta potential. The nanocomplexes developed showed the capability to protect loaded nucleic acids from DNase I digestion and from the stresses of nebulization. In addition, we demonstrated that the PEG conjugation of chitosan improved the mucus-penetration capability of the formed nanocomplexes at N/ P ratios of 5, 10, 20, and 30. Finally, PEGylated low molecular weight chitosan nanocomplexes showed optimal transfection efficiency at an N/ P ratio of 20, while PEGylated medium molecular weight chitosan nanocomplexes showed an optimal transfection efficiency at an N/ P ratio of 5 at pH 6.5 and 6.8. This study established the basis for the delivery of a gene-editing system by PEGylated chitosan nanocomplexes.

Chitinase Induction Prior to Caspofungin Treatment of Experimental Invasive Aspergillosis in Neutropenic Rats Does Not Enhance Survival

Host chitinases, chitotriosidase and acidic mammalian chitinase (AMCase), improved the antifungal activity of caspofungin (CAS) against Aspergillus fumigatus in vitro These chitinases are not constitutively expressed in the lung. Here, we investigated whether chitosan derivatives were able to induce chitinase activity in the lungs of neutropenic rats and, if so, whether these chitinases were able to prolong survival of rats with invasive pulmonary aspergillosis (IPA) or of rats with IPA and treated with CAS. An oligosaccharide-lactate chitosan (OLC) derivative was instilled in the left lung of neutropenic rats to induce chitotriosidase and AMCase activities. Rats instilled with OLC or with phosphate-buffered saline (PBS) were subsequently infected with A. fumigatus and then treated with suboptimal doses of CAS. Survival, histopathology, and galactomannan indexes were determined. Instillation of OLC resulted in chitotriosidase and AMCase activities. However, instillation of OLC did not prolong rat survival when rats were subsequently challenged with A. fumigatus In 5 of 7 rats instilled with OLC, the fungal foci in the lungs were smaller than those in rats instilled with PBS. Instillation of OLC did not significantly enhance the survival of neutropenic rats challenged with A. fumigatus and treated with a suboptimal dosage of CAS. Chitotriosidase and AMCase activities can be induced with OLC, but the presence of active chitinases in the lung did not prevent the development of IPA or significantly enhance the therapeutic outcome of CAS treatment.

Preparation of astaxanthin-loaded DNA/chitosan nanoparticles for improved cellular uptake and antioxidation capability

DNA/chitosan co-assemblies were initially used as nanocarriers for efficient astaxanthin encapsulation and delivery. The obtained astaxanthin-loaded DNA/chitosan (ADC) colloidal system was transparent and homogenous, with astaxanthin content up to 65μg/ml. Compared to free astaxanthin, ADC nanoparticles with an astaxanthin concentration as low as 3.35nM still showed a more powerful cytoprotective effect on H₂O₂-induced oxidative cell damage, and improved cell viability from 49.9% to 61.9%. The ROS scavenging efficiency of ADC nanoparticles was as high as 54.3%, which was 2-fold higher than that of free astaxanthin. Besides this, ADC nanoparticles were easily engulfed by Caco-2 cells in a short time, indicating that the encapsulated astaxanthin could be absorbed through endocytosis by intestinal epithelial cells. The improved antioxidation capability and facilitated cellular uptake enabled the ADC nanoparticles to be good candidates for efficient delivery and absorption of astaxanthin.

Role of BmDredd during Apoptosis of Silk Gland in Silkworm, Bombyx mori

Silk glands (SGs) undergo massive apoptosis driven degeneration during the larval-pupal transformation. To better understand this event on molecular level, we investigated the expression of apoptosis-related genes across the developmental transition period that spans day 4 in the fifth instar Bombyx mori larvae to day 2 pupae. Increases in the expression of BmDredd (an initiator caspase homolog) closely followed the highest BmEcR expression and resembled the expression trend of BmIcE. Simultaneously, we found that BmDredd expression was significantly higher in SG compared to other tissues at 18 h post-spinning, but reduced following injection of the apoptosis inhibitor (Z-DEVD-fmk). Furthermore, BmDredd expression correlated with changes of caspase3-like activities in SG and RNAi-mediated knockdown of BmDredd delayed SG apoptosis. Moreover, caspase3-like activity was increased in SG by overexpression of BmDredd. Taken together, the results suggest that BmDredd plays a critical role in SG apoptosis.

Progresses towards safe and efficient gene therapy vectors

The emergence of genetic engineering at the beginning of the 1970′s opened the era of biomedical technologies, which aims to improve human health using genetic manipulation techniques in a clinical context. Gene therapy represents an innovating and appealing strategy for treatment of human diseases, which utilizes vehicles or vectors for delivering therapeutic genes into the patients' body. However, a few past unsuccessful events that negatively marked the beginning of gene therapy resulted in the need for further studies regarding the design and biology of gene therapy vectors, so that this innovating treatment approach can successfully move from bench to bedside. In this paper, we review the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors. At the end of the manuscript, we summarized the main advantages and disadvantages of common gene therapy vectors and we discuss possible future directions for potential therapeutic vectors.

Non-viral gene therapy: Gains and challenges of non-invasive administration methods

Gene therapy is becoming an influential part of the rapidly increasing armamentarium of biopharmaceuticals for improving health and combating diseases. Currently, three gene therapy treatments are approved by regulatory agencies. While these treatments utilize viral vectors, non-viral alternative technologies are also being developed to improve the safety profile and manufacturability of gene carrier formulations. We present an overview of gene-based therapies focusing on non-viral gene delivery systems and the genetic therapeutic tools that will further revolutionize medical treatment with primary focus on the range and development of non-invasive delivery systems for dermal, transdermal, ocular and pulmonary administrations and perspectives on other administration methods such as intranasal, oral, buccal, vaginal, rectal and otic delivery.

Nanotechnology approaches for inhalation treatment of lung diseases

Local administration of therapeutics by inhalation for treatment of lung diseases has the ability to deliver drugs, nucleic acids and peptides specifically to the site of their action and therefore enhance the efficacy of the treatment, limit the penetration of nebulized therapeutic agent(s) into the bloodstream and consequently decrease adverse systemic side effects of the treatment. Nanotechnology allows for a further enhancement of the treatment efficiency. The present review analyzes modern therapeutic approaches of inhaled nanoscale-based pharmaceutics for the detection and treatment of various lung diseases.

Chitosan aerosol inhalation alleviates lipopolysaccharide- induced pulmonary fibrosis in rats

PURPOSE

Pulmonary fibrosis (PF) is an insidiously progressive scarring disorder of the alveoli and is associated with high mortality. Currently, therapies available are associated with restricted efficacy and side effects. This study aimed to investigate the effect of chitosan aerosol inhalation on lipopolysaccharide (LPS)-induced pulmonary remodeling and fibrosis in rats.

METHODS

A rat model of PF was established by intratracheal injection of LPS (5 mg/kg). Chitosan was nebulized to rats from day 4 to 28 after LPS injection. We analyzed the effect of chitosan on LPS-induced pulmonary remodeling and fibrosis by hematoxylin-eosin staining (HE), Masson staining, and the determination of the hydroxyproline content. The expression intensities of matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were analyzed by western blots.

RESULTS

Histological assessments showed that chitosan aerosol inhalation attenuated the fibrotic changes in LPS-induced PF in rats. Compared with the LPS group, the fibrosis parameters were significantly improved in the LPS + chitosan group (LCh group), although not as good as those of the control group. The expressions of MMP-3 and TIMP-1 in the LCh group were markedly less than that of the LPS group on the 28th day.

CONCLUSIONS

Our findings show that chitosan aerosol inhalation inhibits the expression of MMP-3 and TIMP-1, and ameliorates LPS-induced pulmonary remodeling and fibrosis in rats.

Improving the efficacy of inhaled drugs in cystic fibrosis: challenges and emerging drug delivery strategies

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians associated with early death. Although the faulty gene is expressed in epithelia throughout the body, lung disease is still responsible for most of the morbidity and mortality of CF patients. As a local delivery route, pulmonary administration represents an ideal way to treat respiratory infections, excessive inflammation and other manifestations typical of CF lung disease. Nonetheless, important determinants of the clinical outcomes of inhaled drugs are the concentration/permanence at the lungs as well as the ability of the drug to overcome local extracellular and cellular barriers. This review focuses on emerging delivery strategies used for local treatment of CF pulmonary disease. After a brief description of the disease and formulation rules dictated by CF lung barriers, it describes current and future trends in inhaled drugs for CF. The most promising advanced formulations are discussed, highlighting the advantages along with the major challenges for researchers working in this field.

The absence of CpG in plasmid DNA-chitosan polyplexes enhances transfection efficiencies and reduces inflammatory responses in murine lungs

Chitosan polyplexes containing plasmid DNA (pDNA) have significant potential for pulmonary gene delivery applications. However, prior to using chitosan/pDNA polyplexes (CSpp) in clinical applications, their potential cytotoxicity needs to be investigated. In this study, we formulated 200–400 nm CSpp with amine to phosphate (N/P) ratios that ranged from 1 to 100. We compared two types of plasmids within CSpp: pDNA that was free of CpG sequences (CpG(−)) and pDNA that contained CpG sequences (CpG(+)). Both forms of CSpp showed low cytotoxicity when cultured with A549 and HEK293 cell lines in vitro. CSpp(CpG(−)) generated higher luciferase expression both in vitro, for A549 cells, and in vivo, compared with CSpp(CpG(+)). In addition, CSpp(CpG(−)) elicited milder inflammatory responses in mice one day subsequent to nasal instillation, as determined by proinflammatory cytokine levels within the bronchoalveolar lavage fluid. Our findings suggest that to achieve optimal gene expression with minimal cytotoxicity, inflammation, and oxidative stress, the N/P ratios and CpG sequences in the pDNA of CSpp need to be considered. These findings will inform the preclinical safety assessments of CSpp in pulmonary gene delivery systems.

Preparation of protamine cationic nanobubbles and experimental study of their physical properties and in vivo contrast enhancement

In this study, we aimed to prepare a novel type of microbubble (MB), protamine cationic nanobubble (NB), to provide a new vector for tumor gene therapy. We prepared cationic NBs with protamine and other lipid components using mechanical oscillation. The protamine cationic NBs had a mean diameter of 521.2 ± 37.57 nm, a zeta potential of +18.5 mV, and a gene-carrying capacity of 15.69 μg androgen receptor (AR) siRNA per 10(8) NBs. The cationic NBs exhibited superior contrast enhancement for in vivo imaging compared with SonoVue (Bracco, Geneva, Switzerland), and their physical properties did not change significantly after 1 wk; meanwhile, the transfection efficiency of the cationic NBs in androgen-independent prostate cancer cells mediated by ultrasound irradiation was better than that of liposomes (82.17 ± 7.4% vs. 55.04 ± 5.4%, p < 0.01). Therefore, the protamine cationic NB can be considered for use as a novel type of gene-loading MB for ultrasound imaging and MB-mediated gene therapy of tumors.

Exploring targeted pulmonary delivery for treatment of lung cancer

Lung cancer is the most malignant cancer today. The treatment of lung cancer continues to be a challenge for oncologists. The direct delivery of chemotherapeutic agents to the lungs could represent a novel therapeutic approach for patients with pulmonary metastases. The large alveolar surface area, the low thickness of the epithelial barrier, and an extensive vascularization make the pulmonary route an ideal route for administration of oncolytics. This paper reviews the research performed over the last and current decades on the delivery of various oncolytics for pulmonary delivery for the treatment of lung cancer. Inhaled drug delivery devices in cancer therapy are also discussed in the present manuscript.

A review of therapeutic prospects of non-viral gene therapy in the retinal pigment epithelium

Ocular gene therapy has been extensively explored in recent years as a therapeutic avenue to target diseases of the cornea, retina and retinal pigment epithelium (RPE). Adeno-associated virus (AAV)-mediated gene therapy has shown promise in several RPE clinical trials but AAVs have limited payload capacity and potential immunogenicity. Traditionally however, non-viral alternatives have been plagued by low transfection efficiency, short-term expression and low expression levels. Recently, these drawbacks have begun to be overcome by the use of specialty carriers such as polylysine, liposomes, or polyethyleneimines, and by inclusion of suitable DNA elements to enhance gene expression and longevity. Recent advancements in the field have yielded non-viral vectors that have favorable safety profiles, lack immunogenicity, exhibit long-term elevated gene expression, and show efficient transfection in the retina and RPE, making them poised to transition to clinical applications. Here we discuss the advancements in nanotechnology and vector engineering that have improved the prospects for clinical application of non-viral gene therapy in the RPE.

2-diethylaminoethyl-dextran methyl methacrylate copolymer nonviral vector: still a long way toward the safety of aerosol gene therapy

Revealing the lung tumor genome has directed the current treatment strategies toward targeted therapy. First line treatments targeting the genome of lung tumor cells have been approved and are on the market. However, they are limited by the small number of patients with the current investigated genetic mutations. Novel treatment administration modalities have been also investigated in an effort to increase the local drug deposition and disease control. In the current study, we investigated the safety of the new nonviral vector 2-diethylaminoethyl-dextran methyl methacrylate copolymer (DDMC; Ryujyu Science), which belongs to the 2-diethylaminoethyl-dextran family by aerosol administration. Thirty male BALBC mice, 2 month old, were included and divided into three groups. However, pathological findings indicated severe emphysema within three aerosol sessions. In addition, the CytoViva technique was applied for the first time to display the nonviral particles within the pulmonary tissue and emphysema lesions, and a spectral library of the nonviral vector was also established. Although our results in BALBC mice prevented us from further investigation of the DDMC nonviral vector as a vehicle for gene therapy, further investigation in animals with larger airways is warranted to properly evaluate the safety of the vector.

Stability studies of chitosan-DNA-FAP-B nanoparticles for gene delivery to lung epithelial cells

A successful gene delivery system requires efficiency and stability during storage. Stability studies are imperative for nanomedicines containing biotechnological products such as plasmids and targeting peptides. Chitosan-DNA-FAP-B nanoparticles are novel non-viral vectors for specific gene delivery to the lung epithelial cells. In this study, the storage stability of chitosan-DNA-FAP-B nanoparticles at -20, 5 and 24 °C was examined. Size, zeta potential and transfection efficiency of these nano-particles in storage were also evaluated. Stability studies showed that chitosan-DNA-FAP-B nanoparticles were stable after 1 month when stored at -20 °C and retained their initial size, zeta potential and transfection efficiency. However, their stability was not desirable at 5 and 24 °C. Based on these results, it can be concluded that chitosan-DNA-FAP-B nanoparticles can be a promising candidate for gene delivery to lung epithelial cells with good storage stability at -20 °C during 1 month.