Biodistribution and elimination pathways of PEGylated recombinant human deoxyribonuclease I after pulmonary delivery in mice

Functional 2D Nanoplatforms Alleviate Eosinophilic Chronic Rhinosinusitis by Modulating Eosinophil Extracellular Trap Formation

The therapeutic outcomes of patients with eosinophilic chronic rhinosinusitis (ECRS) remain unsatisfactory, largely because the underlying mechanisms of eosinophilic inflammation are uncertain. Here, it is shown that the nasal secretions of ECRS patients have high eosinophil extracellular trap (EET) and cell-free DNA (cfDNA) levels. Moreover, the cfDNA induced EET formation by activating toll-like receptor 9 (TLR9) signaling. After demonstrating that DNase I reduced eosinophilic inflammation by modulating EET formation, linear polyglycerol-amine (LPGA)-coated TiS2 nanosheets (TLPGA) as functional 2D nanoplatforms with low cytotoxicity, mild protein adsorption, and increased degradation rate is developed. Due to the more flexible linear architecture, TLPGA exhibited higher cfDNA affinity than the TiS2 nanosheets coated with dendritic polyglycerol-amine (TDPGA). TLPGA reduced cfDNA levels in the nasal secretions of ECRS patients while suppressing cfDNA-induced TLR9 activation and EET formation in vitro. TLPGA displayed exceptional biocompatibility, preferential nasal localization, and potent inflammation modulation in mice with eosinophilic inflammation. These results highlight the pivotal feature of the linear molecular architecture and 2D sheet-like nanostructure in the development of anti-inflammation nanoplatforms, which can be exploited for ECRS treatment.

Research progress on the PEGylation of therapeutic proteins and peptides (TPPs)

With the rapid advancement of genetic and protein engineering, proteins and peptides have emerged as promising drug molecules for therapeutic applications. Consequently, there has been a growing interest in the field of chemical modification technology to address challenges associated with their clinical use, including rapid clearance from circulation, immunogenicity, physical and chemical instabilities (such as aggregation, adsorption, deamination, clipping, oxidation, etc.), and enzymatic degradation. Polyethylene glycol (PEG) modification offers an effective solution to these issues due to its favorable properties. This review presents recent progress in the development and application of PEGylated therapeutic proteins and peptides (TPPs). For this purpose, firstly, the physical and chemical properties as well as classification of PEG and its derivatives are described. Subsequently, a detailed summary is provided on the main sites of PEGylated TPPs and the factors that influence their PEGylation. Furthermore, notable instances of PEG-modified TPPs (including antimicrobial peptides (AMPs), interferon, asparaginase and antibodies) are highlighted. Finally, we propose the chemical modification of TPPs with PEG, followed by an analysis of the current development status and future prospects of PEGylated TPPs. This work provides a comprehensive literature review in this promising field while facilitating researchers in utilizing PEG polymers to modify TPPs for disease treatment.

Tackling Severe Neutrophilic Inflammation in Airway Disorders with Functionalized Nanosheets

Severe airway inflammatory disorders impose a significant societal burden, and the available treatments are unsatisfactory. High levels of neutrophil extracellular trap (NET) and cell-free DNA (cfDNA) were detected in the inflammatory microenvironment of these diseases, which are closely associated with persistent uncontrolled neutrophilic inflammation. Although DNase has proven to be effective in mitigating neutrophilic airway inflammation in mice by reducing cfDNA and NET levels, its clinical use is hindered by severe side effects. Here, we synthesized polyglycerol-amine (PGA) with a series of hydroxyl/amine ratios and covered them with black phosphorus (BP) nanosheets. The BP nanosheets functionalized with polyglycerol-50% amine (BP-PGA50) efficiently lowered cfDNA levels, suppressed toll-like receptor 9 (TLR9) activation and inhibited NET formation in vitro. Importantly, BP-PGA50 nanosheets demonstrated substantial accumulation in inflamed airway tissues, excellent biocompatibility, and potent inflammation modulation ability in model mice. The 2D sheet-like structure of BP-PGA50 was identified as a crucial factor for the therapeutic efficacy, and the hydroxyl/amine ratio was revealed as a significant parameter to regulate the protein resistance, cfDNA-binding efficacy, and cytotoxicity. This study shows the promise of the BP-PGA50 nanosheet for tackling uncontrolled airway inflammation, which is also significant for the treatment of other neutrophilic inflammatory diseases. In addition, our work also highlights the importance of proper surface functionalization, such as hydroxyl/amine ratio, in therapeutic nanoplatform construction for inflammation modulation.

Inhalation Lenalidomide-Loaded Liposome for Bleomycin-Induced Pulmonary Fibrosis Improvement

Idiopathic pulmonary fibrosis (IPF) is a progressive, fibrotic interstitial lung disease with unclear etiology and increasing prevalence. Pulmonary administration can make the drug directly reach the lung lesion location and reduce systemic toxic and side effects. The effectiveness of lenalidomide (Len) liposomal lung delivery in idiopathic pulmonary fibrosis was investigated. Len liposomes (Len-Lip) were prepared from soybean lecithin, cholesterol (Chol), and medicine in different weight ratios by thin film hydration method. The Len-Lip were spherical in shape with an average size of 226.7 ± 1.389 nm. The liposomes with a higher negative zeta potential of around - 34 mV, which was conducive to improving stability by repelling each other. The drug loading and encapsulation rate were 2.42 ± 0.07% and 85.47 ± 2.42%. Len-Lip had little toxicity at the cellular level and were well taken up by cells. At bleomycin-induced pulmonary fibrosis model mice, inhalation Len-Lip could improve lung function and decrease lung hydroxyproline contents, and alleviate pulmonary fibrosis state. Inhalation Len-Lip provided a reference for the treatment of idiopathic pulmonary fibrosis.

Nebulization of PEGylated recombinant human deoxyribonuclease I using vibrating membrane nebulizers: A technical feasibility study

Recombinant human deoxyribonuclease I (rhDNase, Pulmozyme®) is the most frequently used mucolytic agent for the symptomatic treatment of cystic fibrosis (CF) lung disease. Conjugation of rhDNase to polyethylene glycol (PEG) has been shown to greatly prolong its residence time in the lungs and improve its therapeutic efficacy in mice. To present an added value over current rhDNase treatment, PEGylated rhDNase needs to be efficiently and less frequently administrated by aerosolization and possibly at higher concentrations than existing rhDNase. In this study, the effects of PEGylation on the thermodynamic stability of rhDNase was investigated using linear 20 kDa, linear 30 kDa and 2-armed 40 kDa PEGs. The suitability of PEG30-rhDNase to electrohydrodynamic atomization (electrospraying) as well as the feasibility of using two vibrating mesh nebulizers, the optimized eFlow® Technology nebulizer (eFlow) and Innospire Go, at varying protein concentrations were investigated. PEGylation was shown to destabilize rhDNase upon chemical-induced denaturation and ethanol exposure. Yet, PEG30-rhDNase was stable enough to withstand aerosolization stresses using the eFlow and Innospire Go nebulizers even at higher concentrations (5 mg of protein per ml) than conventional rhDNase formulation (1 mg/ml). High aerosol output (up to 1.5 ml per min) and excellent aerosol characteristics (up to 83% fine particle fraction) were achieved while preserving protein integrity and enzymatic activity. This work demonstrates the technical feasibility of PEG-rhDNase nebulization with advanced vibrating membrane nebulizers, encouraging further pharmaceutical and clinical developments of a long-acting PEGylated alternative to rhDNase for treating patients with CF.

Self-Propelled Proteomotors with Active Cell-Free mtDNA Clearance for Enhanced Therapy of Sepsis-Associated Acute Lung Injury

Acute lung injury (ALI) is a frequent and serious complication of sepsis with limited therapeutic options. Gaining insights into the inflammatory dysregulation that causes sepsis-associated ALI can help develop new therapeutic strategies. Herein, the crucial role of cell-free mitochondrial DNA (cf-mtDNA) in the regulation of alveolar macrophage activation during sepsis-associated ALI is identified. Most importantly, a biocompatible hybrid protein nanomotor (NM) composed of recombinant deoxyribonuclease I (DNase-I) and human serum albumin (HSA) via glutaraldehyde-mediated crosslinking is prepared to obtain an inhalable nanotherapeutic platform targeting pulmonary cf-mtDNA clearance. The synthesized DNase-I/HSA NMs are endowed with self-propulsive capability and demonstrate superior performances in stability, DNA hydrolysis, and biosafety. Pulmonary delivery of DNase-I/HSA NMs effectively eliminates cf-mtDNAs in the lungs, and also improves sepsis survival by attenuating pulmonary inflammation and lung injury. Therefore, pulmonary cf-mtDNA clearance strategy using DNase-I/HSA NMs is considered to be an attractive approach for sepsis-associated ALI.

Colistin-loaded aerosolizable particles for the treatment of bacterial respiratory infections

Compared to parenteral administration of colistin, its direct pulmonary administration can maximize lung drug deposition while reducing systemic adverse side effects and derived nephrotoxicity. Current pulmonary administration of colistin is carried out by the aerosolization of a prodrug, colistin methanesulfonate (CMS), which must be hydrolized to colistin in the lung to produce its bactericidal effect. However, this conversion is slow relative to the rate of absorption of CMS, and thus only 1.4 % (w/w) of the CMS dose is converted to colistin in the lungs of patients receiving inhaled CMS. We synthesized several aerosolizable nanoparticle carriers loaded with colistin using different techniques and selected particles with sufficient drug loading and adequate aerodynamic behavior to efficiently deliver colistin to the entire lung. Specifically, we carried out (i) the encapsulation of colistin by single emulsion-solvent evaporation with immiscible solvents using polylactic-co-glycolic (PLGA) nanoparticles; (ii) its encapsulation using nanoprecipitation with miscible solvents using poly(lactide-co-glycolide)-block-poly(ethylene glycol) as encapsulating matrix; (iii) colistin nanoprecipitation using the antisolvent precipitation method and its subsequent encapsulation within PLGA nanoparticles; and (iv) colistin encapsulation within PLGA-based microparticles using electrospraying. Nanoprecipitation of pure colistin using antisolvent precipitation showed the highest drug loading (55.0 ± 4.8 wt%) and spontaneously formed aggregates with adequate aerodynamic diameter (between 3 and 5 μm) to potentially reach the entire lung. These nanoparticles were able to completely eradicate Pseudomonas aeruginosa in an in vitro lung biofilm model at 10 µg/mL (MBC). This formulation could be a promising alternative for the treatment of pulmonary infections improving lung deposition and, therefore, the efficacy of aerosolized antibiotics.

Novel drug delivery systems and disease models for pulmonary fibrosis

Pulmonary fibrosis (PF) is a serious and progressive lung disease which is possibly life-threatening. It causes lung scarring and affects lung functions including epithelial cell injury, massive recruitment of immune cells and abnormal accumulation of extracellular matrix (ECM). There is currently no cure for PF. Treatment for PF is aimed at slowing the course of the disease and relieving symptoms. Pirfenidone (PFD) and nintedanib (NDNB) are currently the only two FDA-approved oral medicines to slow down the progress of idiopathic pulmonary fibrosis, a specific type of PF. Novel drug delivery systems and therapies have been developed to improve the prognosis of the disease, as well as reduce or minimize the toxicities during drug treatment. The drug delivery routes for these therapies are various including oral, intravenous, nasal, inhalant, intratracheal and transdermal; although this is dependent on specific treatment mechanisms. In addition, researchers have also expanded current animal models that could not fully restore the clinicopathology, and developed a series of in vitro models such as organoids to study the pathogenesis and treatment of PF. This review describes recent advances on pathogenesis exploration, classifies and specifies the progress of drug delivery systems by their delivery routes, as well as an overview on the in vitro and in vivo models for PF research.

Optimization of a Liposomal DNase I Formulation with an Extended Circulating Half-Life

Drug delivery systems such as liposomes are widely used to stabilize and increase the plasma half-life of therapeutics. In this article, we have investigated two strategies to increase the half-life of deoxyribonuclease I, an FDA-approved enzyme used for the treatment of cystic fibrosis, and a potential candidate for the reduction of uncontrolled inflammation induced by neutrophil extracellular traps. We demonstrate that our optimized preparation procedure resulted in nanoparticles with improved plasma half-life and total exposure relative to native protein, while maintaining enzymatic activity.

Emerging trends in pulmonary delivery of biopharmaceuticals

Over the years, a tendency toward biopharmaceutical products as therapeutics has been witnessed compared with small molecular drugs. Biopharmaceuticals possess greater specificity, selectivity and potency with fewer side effects. The pulmonary route is a potential noninvasive route studied for the delivery of various molecules, including biopharmaceuticals. It directly delivers drugs to the lungs in higher concentrations and provides greater bioavailability than other noninvasive routes. This review focuses on the pulmonary route for the delivery of biopharmaceuticals. We have covered various biopharmaceuticals, including peptides, recombinant proteins, enzymes, monoclonal antibodies and nucleic acids, administered via a pulmonary route and discussed their rewards and drawbacks.

Actin-Resistant DNase1L2 as a Potential Therapeutics for CF Lung Disease

In cystic fibrosis (CF), the accumulation of viscous lung secretions rich in DNA and actin is a major cause of chronic inflammation and recurrent infections leading to airway obstruction. Mucolytic therapy based on recombinant human DNase1 reduces CF mucus viscosity and promotes airway clearance. However, the marked susceptibility to actin inhibition of this enzyme prompts the research of alternative treatments that could overcome this limitation. Within the human DNase repertoire, DNase1L2 is ideally suited for this purpose because it exhibits metal-dependent endonuclease activity on plasmid DNA in a broad range of pH with acidic optimum and is minimally inhibited by actin. When tested on CF artificial mucus enriched with actin, submicromolar concentrations of DNase1L2 reduces mucus viscosity by 50% in a few seconds. Inspection of superimposed model structures of DNase1 and DNase1L2 highlights differences at the actin-binding interface that justify the increased resistance of DNase1L2 toward actin inhibition. Furthermore, a PEGylated form of the enzyme with preserved enzymatic activity was obtained, showing interesting results in terms of activity. This work represents an effort toward the exploitation of natural DNase variants as promising alternatives to DNase1 for the treatment of CF lung disease.

PEGylation of recombinant human deoxyribonuclease I decreases its transport across lung epithelial cells and uptake by macrophages

Conjugation to high molecular weight (MW ≥ 20 kDa) polyethylene glycol (PEG) was previously shown to largely prolong the lung residence time of recombinant human deoxyribonuclease I (rhDNase) and improve its therapeutic efficacy following pulmonary delivery in mice. In this paper, we investigated the mechanisms promoting the extended lung retention of PEG-rhDNase conjugates using cell culture models and lung biological media. Uptake by alveolar macrophages was also assessed in vivo. Transport experiments showed that PEGylation reduced the uptake and transport of rhDNase across monolayers of Calu-3 cells cultured at an air-liquid interface. PEGylation also decreased the uptake of rhDNase by macrophages in vitro whatever the PEG size as well as in vivo 4 h following intratracheal instillation in mice. However, the reverse was observed in vivo at 24 h due to the higher availability of PEGylated rhDNase in lung airways at 24 h compared with rhDNase, which is cleared faster. The uptake of rhDNase by macrophages was dependent on energy, time, and concentration and occurred at rates indicative of adsorptive endocytosis. The diffusion of PEGylated rhDNase in porcine tracheal mucus and cystic fibrosis sputa was slower compared with that of rhDNase. Nevertheless, no significant binding of PEGylated rhDNase to both media was observed. In conclusion, decreased transport across lung epithelial cells and uptake by macrophages appear to contribute to the longer retention of PEGylated rhDNase in the lungs.