Pulmonary delivery of mucus-traversing PF127-modified silk fibroin nanoparticles loading with quercetin for lung cancer therapy

The mucosal barrier remains a major barrier in the pulmonary drug delivery system,as mucociliary clearance in the airway accelerates the removal of inhaled nanoparticles(NPs).Herein,we designed and developed the inhalable Pluronic F127-modified silk fibroin NPs loading with quercetin(marked as QR-SF(PF127)NPs),aiming to solve the airway mucus barrier and improve the cancer therapeutic effect of QR.The PF127 coating on the SF NPs could attenuate the interaction between NPs and mucin proteins,thus facilitating the diffusion of SF(PF127)NPs in the mucus layer.The QR-SF(PF127)NPs had particle sizes of approximately 200 nm with negatively charged surfaces and showed constant drug release properties.Fluorescence recovery after photobleaching(FRAP)assay and transepithelial transport test showed that QR-SF(PF127)NPs exhibited superior mucus-penetrating ability in artificial mucus and monolayer Calu-3 cell model.Notably,a large amount of QR-SF(PF127)NPs distributed uniformly in the mice airway section,indicating the good retention of NPs in the respiratory tract.Themicemelanoma lungmetastasismodel was established,and the therapeutic effect of QR-SF(PF127)NPs was significantly improved in vivo.PF127-modified SF NPs may be a promising strategy to attenuate the interaction with mucin proteins and enhancemucus penetration efficiency in the pulmonary drug delivery system.

Optimizing aerosolization of a high-dose L-arginine powder for pulmonary delivery

In this study a carrier-free dry powder inhalation(DPI)containing L-arginine(ARG)was developed.As such,it is proposed that ARG could be used for adjunctive treatment of cystic fibrosis and/or tuberculosis.Various processing methods were used to manufacture highdose formulation batches consisting various amounts of ARG and excipients.The formulations were evaluated using several analytical methods to assess suitability for further investigation.Several batches had enhanced in vitro aerolization properties.Significant future challenges include the highly hygroscopic nature of unformulated ARG powder and identifying the scale of dose of ARG required to achieve the response in lungs.

Reducing systemic absorption and macrophages clearance of genistein by lipid-coated nanocrystals for pulmonary delivery

Pulmonary delivery is an effective drug delivery strategy for the treatment of local respiratory diseases.However,the rapid systemic absorption through the lung due to the thin barrier and persistent lung clearances influence the drug retention in the lung.In this study,we designed a lipid-coated genistein nanocrystals(Lipo-NCs)formulation to achieve enhanced efficiency of local pulmonary delivery.The LipoNCs were fabricated by modifying genistein nanocrystals(NCs)with phospholipid membrane through thin film hydration following the homogenization method.The prepared Lipo-NCs exhibited a decreased drug release rate compared with the naked NCs.Our results demonstrated that intracellular uptake and transcellular transport of NCs by the Calu-3 epithelial layer were reduced after lipid coating.Furthermore,the macrophages clearance was also impeded by this Lipo-NCs formulation.In vivo lung retention and distribution revealed that more genistein was retained in the lung after intratracheal administration of Lipo-NCs.The pharmacokinetic study displayed that the AUC((0-t))values of Lipo-NCs were 1.59-fold lesser than those of the NCs group,indicating a reduced systemic absorption.In conclusion,this research indicated that Lipo-NCs could be a suitable formulation for reducing systemic absorption and macrophages clearance,and thus enhancing drug concentration in lung by pulmonary delivery.

Chitosan and β-cyclodextrin Microspheres as Pulmonary Sustained Delivery Systems

Chitosan and β-cyclodextrin were used to prepare microspheres with theophylline for pulmonary delivery by spray drying method. The characteristics, mucociliotoxicity, permeation rate and drug release were studied. The drug entrapments of microspheres Ⅰ, Ⅱ and Ⅲ were from 35.70% to 21.09% and 13.33%, while yields and encapsulation efficiencies were higher than 45% and about 90% respectively. The microspheres possessed low tap densities （0.34-0.48 g/cm^3）, appropriate diameters （3.35-3.94 μm） and theoretical aerodynamics diameters （2.20-3.04 μm）. SEM images showed the microspheres were spherical with smooth or wrinkled surface surfaces. FT-IR demonstrated theophylline had formed hydrogen bonds with chitosan and fl-cyclodextrin. The microspheres could effectively reduce the ciliotoxicity and easy to penetrate the memberine. The in vitro release of the microspheres was related to the ratio of drug/polymer and microspheres Ⅱ had a prolong release, providing the release of 72.00% in 12 h. The results suggestes that chitosan/β-cyclodextrin microspheres Ⅱ are a promising carrier as sustained release for pulmonary delivery.

Anti-tumor effects of combined doxorubicin and siRNA for pulmonary delivery

Direct administration of drugs and genes to the lungs by pulmonary delivery offers a potential effective therapy for lung cancers.In this study,combined doxorubicin（DOX） and Bcl2 siRNA was employed for cancer therapy using polyethylenimine（PEI） as the carrier of Bcl2 siRNA.Most of the DOX and siRNA possessed high cellular uptake efficiency in B16F10 cells,which was proved by FCM and CLSM analysis.Real-time PCR showed that PEI/Bcl2 siRNA exhibited high gene silencing efficiency with 70%Bcl2 mRNA being knocked down.The combination of DOX and siRNA could enhance the cell proliferation inhibition and the cell apoptosis against B16F10 cells compared to free DOX or PEI/Bcl2 siRNA.Furthermore,the biodistribution of DOX and siRNA via pulmonary administration was studied in mice with B16F10 metastatic lung cancer.The results showed that most of the DOX and siRNA were accumulated in lungs and lasted at least for 3 days,which suggested that combined DOX and siRNA by pulmonary administration may have high anti-tumor effects for metastatic lung cancer treatment in vivo.

Inhalation Devices and Pulmonary Drug Delivery

Inhaled drug delivery is mainly used to treat pulmonary airway disorders by transporting the drug directly to its targeted location for action.This decreases the dose required to exert a therapeutic effect and minimizes any potential adverse effects.Direct drug delivery to air passages facilitates a faster onset of action;it also minimizes irritation to the stomach,which frequently occurs with oral medications,and prevents the exposure of drugs to pre-systemic metabolism that takes place in the intestine and liver.In addition to that,the lung is regarded as a route for transporting medications throughout the entire body's blood circulation.The type of medication and the device used to deliver it are both important elements in carrying the drug to its target in the lungs.Different types of inhalation methods are used in inhaled delivery.They differ in the dose delivered,inhalation technique,and other factors.This paper will discuss these factors in more detail.

Liposomal remdesivir inhalation solution for targeted lung delivery as a novel therapeutic approach for COVID-19

Strong infectivity enables coronavirus disease 2019(COVID-19)to rage throughout the world.Moreover,the lack of drugs with definite therapeutic effects further aggravates the spread of the pandemic.Remdesivir is one of the most promising anti-severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)drugs.However,the limited clinical effects make its therapeutic effect controversial,which may result from the poor accumulation and activation of remdesivir in the lung.Therefore,we developed lyophilized remdesivir liposomes(Rdv-lips)which can be reconstituted as liposomal aerosol for pulmonary delivery to improve the in vivo behavior of existing remdesivir cyclodextrin conclusion compound(Rdv-cyc)injections.Liposome encapsulation endowed remdesivir with much higher solubility and better biocompatibility.The in vitro liposomal aerosol characterization demonstrated that Rdv-lips possessed a mass median aerodynamic diameter of 4.118μm and fine particle fraction(<5μm)higher than 50%,indicating good pulmonary delivery properties.Compared to the Rdv-cyc intravenous injection group,the Rdv-lips inhalation group displayed a nearly 100-fold increase in the remdesivir-active metabolite nucleotide triphosphate(NTP)concentration and better NTP accumulation in the lung than the Rdv-cyc inhalation group.A faster transition from remdesivir to NTP of Rdv-lips(inhalation)could also be observed due to better cell uptake.Compared to other preparations,the superiority of Rdv-lips was further evidenced by the results of an in vivo safety study,with little possibility of inducing inflammation.In conclusion,Rdv-lips for pulmonary delivery will be a potent formulation to improve the in vivo behavior of remdesivir and exert better therapeutic effects in COVID-19 treatment.

Novel approach for real-time monitoring of carrier-based DPIs delivery process via pulmonary route based on modular modified Sympatec HELOS

An explicit illustration of pulmonary delivery processes(PDPs)was a prerequisite for the formulation design and optimization of carrier-based DPIs.However,the current evaluation approaches for DPIs could not provide precise investigation of each PDP separately,or the approaches merely used a simplified and idealized model.In the present study,a novel modular modified Sympatec HELOS Real-time monitoring;Modular modification;Carrier;Air flow rate;Mechanism of drug delivery(MMSH)was developed to fully investigate the mechanism of each PDP separately in real-time.An inhaler device,artificial throat and pre-separator were separately integrated with a Sympatec HELOS.The dispersion and fluidization,transportation,detachment and deposition processes of pulmonary delivery for model DPIs were explored under different flow rates.Moreover,time-sliced measurements were used to monitor the PDPs in real-time.The Next Generation Impactor(NGI)was applied to determine the aerosolization performance of the model DPIs.The release profiles of the drug particles,drug aggregations and carriers were obtained by MMSH in real-time.Each PDP of the DPIs was analyzed in detail.Moreover,a positive correlation was established between the total release amount of drug particles and the fine particle fraction(FPF)values(R^2=0.9898).The innovative MMSH was successfully developed and was capable of illustrating the PDPs and the mechanism of carrier-based DPIs,providing a theoretical basis for the design and optimization of carrier-based DPIs.

Sericin microparticles enveloped with metal-organic networks as a pulmonary targeting delivery system for intra-tracheally treating metastatic lung cancer

Chemotherapy is one of the major approaches for the treatment of metastatic lung cancer.However,systemic chemotherapy is limited by poor therapeutic efficiency and severe toxic side effects,due to the extremely low delivery efficacy and non-specificity of anticancer drugs.Herein,we report a sericin microparticles enveloped with metal-organic networks as a pulmonary delivery system for treating lung metastasis of breast cancer in an animal model.The sericin microparticles(SMPs)were prepared using water in oil(w/o)emulsification method.After doxorubicin(DOX)loading,tannic acid(TA)/ferric irons(Fe3+)based metal organic networks(MON)were coated on the particles to obtain DOX-loaded microparticles(DOX@SMPs-MON).The SMPs-MON with good biocompatibility could effectively encapsulate DOX and sustainably unload cargos in a pH-dependent manner.The DOX-loaded microparticles could be uptaken by 4T1 cells,and effectively kill the cancer cells.In vivo,DOX@SMPs-MON was deposited in the lungs and remained for over 5 days after pulmonary administration.In contrast to conventional DOX treatment that did not show significantly inhibitory effects on lung metastatic tumor,DOX@SMPs-MON markedly decreased the number and size of metastatic nodules in lungs,and the lung weight and appearance were similar to those of healthy mice.In summary,the sericin microparticles with MON wrapping might be a promising pulmonary delivery system for treating lung metastatic cancer.

Pulmonary Drugs and Genes Delivery Systems for Lung Disease Treatment

Pulmonary drugs and genes delivery systems have become an attractive approach in the treatment of lung diseases with the advantages of minimal drug loss,precise quantization,high local drugs concentration and low side effects.However,special attention should be paid to the biological barriers of the lung.The delivery systems need to be designed carefully in order to overcome these biological barriers and maximize the drugs and genes deposition to the lungs.Pulmonary drugs and genes delivery systems can offer some encouraging results for delivering drugs and genes to the lungs.Specifically,some lipid-based and polymer-based delivery systems could control and sustain the release of drugs and genes with minimal or negligible toxicity.This review focuses on the latest development of pulmonary delivery of drugs and genes for the treatment of various lung diseases.The barriers to the lung,the delivery devices,the route of the administration and the delivery systems for drugs and genes pulmonary delivery are described.Based on the rapid development of clinical requirement,novel approaches using delivery systems for pulmonary delivery drugs and genes need to be constructed,which is believed to play an important role in the therapy of lung diseases in the future.

Dry powder platform for pulmonary drug delivery

The phenomenon of particle interaction involved in pulmonary drug delivery belongs to a wide variety of disciplines of particle technology, in particular, fluidization. This paper reviews the basic concepts of pulmonary drug delivery with references to fluidization research, in particular, studies on Geldart group C powders. Dry powder inhaler device-formulation combination has been shown to be an effective method for delivering drugs to the lung for treatment of asthma, chronic obstructive pulmonary disease and cystic fibrosis. Even with advanced designs, however, delivery efficiency is still poor mainly due to powder dispersion problems which cause poor lung deposition and high dose variability. Drug particles used in current inhalers must be 1–5 μm in diameter for effective deposition in small-diameter airways and alveoli. These powders are very cohesive, have poor flowability, and are difficult to disperse into aerosol due to cohesion arising from van der Waals attraction. These problems are well known in fluidization research, much of which is highly relevant to pulmonary drug delivery.

A homogenous nanoporous pulmonary drug delivery system based on metal-organic frameworks with fine aerosolization performance and good compatibility

Pulmonary drug delivery has attracted increasing attention in biomedicine,and porous particles can effectively enhance the aerosolization performance and bioavailability of drugs.However,the existing methods for preparing porous particles using porogens have several drawbacks,such as the inhomogeneous and uncontrollable pores,drug leakage,and high risk of fragmentation.In this study,a series of cyclodextrin-based metal-organic framework(CD-MOF)particles containing homogenous nanopores were delicately engineered without porogens.Compared with commercial inhalation carrier,CDMOF showed excellent aerosolization performance because of the homogenous nanoporous structure.The great biocompatibility of CD-MOF in pulmonary delivery was also confirmed by a series of experiments,including cytotoxicity assay,hemolysis ratio test,lung function evaluation,in vivo lung injury markers measurement,and histological analysis.The results of ex vivo fluorescence imaging showed the high deposition rate of CD-MOF in lungs.Therefore,all results demonstrated that CD-MOF was a promising carrier for pulmonary drug delivery.This study may throw light on the nanoporous particles for effective pulmonary administration.

Protein microspheres for pulmonary drug delivery

A new supercritical fluid(SCF)technique was developed for the preparation of microspheres for pulmonary drug delivery(PDD).This technique,based on the anti-solvent process,has incorporated advanced engineering design features to enable improved control of the particle formation process.Human recombinant insulin(HRI)was used as a model compound to evaluate the efficiency of this SCF process.An aqueous solution of HRI with a co-solvent was sprayed into high pressure carbon dioxide that extracted the solvent and water,leading to a dry fine powder with good particle size distribution and near ideal morphology for pulmonary drug delivery.

In vitro - in vivo - in silico approach in the development of inhaled drug products: Nanocrystal-based formulations with budesonide as a model drug

This study aims to understand the absorption patterns of three different kinds of inhaled formulations via in silico modeling using budesonide(BUD)as a model drug.The formulations investigated in this study are:(i)commercially available micronized BUD mixed with lactose(BUD-PT),(ii)BUD nanocrystal suspension(BUD-NC),(iii)BUD nanocrystals embedded hyaluronic acid microparticles(BUD-NEM).The deposition patterns of the three inhaled formulations in the rats’lungs were determined in vivo and in silico predicted,which were used as inputs in GastroPlus TM software to predict drug absorption following aerosolization of the tested formulations.BUD pharmacokinetics,estimated based on intravenous data in rats,was used to establish a drug-specific in silico absorption model.The BUD-specific in silico model revealed that drug pulmonary solubility and absorption rate constant were the key factors affecting pulmonary absorption of BUD-NC and BUD-NEM,respectively.In the case of BUD-PT,the in silico model revealed significant gastrointestinal absorption of BUD,which could be overlooked by traditional in vivo experimental observation.This study demonstrated that in vitro-in vivo-in silico approach was able to identify the key factors that influence the absorption of different inhaled formulations,which may facilitate the development of orally inhaled formulations with different drug release/absorption rates.

Drug/polymer nanoparticles prepared using unique spray nozzles and recent progress of inhaled formulation

Inhaled formulations are promising for pulmonary and systemic non-pulmonary diseases.Functional engineered particles including drugs and drug-loaded nanocarriers have been anticipated because they can improve drug delivery efficacy against target sites in the lungs or blood.In this review,unique spray nozzles(e.g.,four-fluid spray nozzle and twosolution mixing type nozzle)for the preparation of nanocomposite particles which mean microparticles containing drug nanoparticles are described.These nozzles can produce nanocomposite particles in one-step and their spray drying system is suitable for scalingup.Nanocomposite particles are useful in improving drug absorption and delivery efficacy against alveolar macrophages.In addition,recent studies on several pulmonary diseases(tuberculosis,lung cancer,cystic fibrosis,pneumonia,vaccine and others)and related inhaled formulations were also reviewed.

Increasing stiffness promotes pulmonary retention of ligand-directed dexamethasone-loaded nanoparticle for enhanced acute lung inflammation therapy

Inhaled nanoparticles(NPs)need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local therapy.However,the bronchial mucociliary barrier eliminates NPs rapidly,which considerably limits their mucosal penetration.In this study,we find that surface ligand modification and stiffness adjustment of NPs contribute to the significantly enhanced bronchial mucosal absorption and pulmonary retention of inhaled drugs.We utilize neonatal Fc receptor ligand(FcBP)to modify the rationally designed low stiffness NPs(Soft-NP)and high stiffness NPs(Stiff-NP)to target bronchial mucosa.In an acute lung inflammation rat model,after intranasal administration with dexamethasone-loaded NPs,Stiff-NP endowed with FcBP displays superior therapeutic effects.The in vitro data demonstrate that the promotion effect of FcBP to bronchial mucosal absorption of Stiff-NP dominates over Soft-NP.This could be attributed to the higher affinity between ligand-receptor when incorporating FcBP on the Stiff-NP surface.Meanwhile,high stiffness modulates more actin filaments aggregation to mediate endocytosis,along with strengthened Ca2+signal to enhance exocytosis.Conclusively,we highlight that FcBP-modified NPs with higher stiffness would be a potential pulmonary drug delivery system.

Inhalable iron redox cycling powered nanoreactor for amplified ferroptosis-apoptosis synergetic therapy of lung cancer

Fenton reaction centered ferroptosis-apoptosis synergetic therapy has emerged as a promising tumor elimination strategy.However,the low intracellular Fenton level and accumulation of therapeutics at the lesion site greatly limit the efficacy of ferroptosis therapy.To overcome these two bottlenecks,an inhalable metal polyphenol network(MPN)-hybrid liposome,encoded as LDG,was proposed for enhancing the intracellular Fenton reaction level by co-delivering the ferroptosis inducer dihydroartemisinin(DHA)and the ferrous ion(Fe2+)donor MPN.The synthesized LDG had excellent nebulization performance which significantly improved the accumulation in the lungs,about 8.2 times of intravenous injection.In terms of anticancer mechanisms,MPN raised the intracellular level of Fe2+by constructing iron cycling in the weakly acidic environment of tumors.Triggered by Fe2+,DHA with peroxide-bridge structure underwent a high level of Fenton-like reaction,promoted the production of intracellular reactive oxygen species(ROS)and induced strong ferroptosis while cooperating with apoptosis.LDG exhibited extraordinary antitumor ability in an orthotopic lung tumor model,whose tumor inhibition efficiency was 1.53(P=0.0014)and 1.32(P=0.0183)times of the LG group(liposomes coated with gallic acid(GA)-Fe MPN)and LD group(liposomes loaded with DHA),respectively,showing the strongest anticancer effect.In conclusion,the constructed MPN-hybrid liposomes could be a potent custom nanoplatform for pulmonary delivery and underscored the great potential of ferroptosis-apoptosis synergetic therapy.

Pharmaceutical strategies to extend pulmonary exposure of inhaled medicines

Pulmonary administration route has been extensively exploited for the treatment of local lung diseases such as asthma,chronic obstructive pulmonary diseases and respiratory infections,and systemic diseases such as diabetes.Most inhaled medicines could be cleared rapidly from the lungs and their therapeutic effects are transit.The inhaled medicines with extended pulmonary exposure may not only improve the patient compliance by reducing the frequency of drug administration,but also enhance the clinical benefits to the patients with improved therapeutic outcomes.This article systematically reviews the physical and chemical strategies to extend the pulmonary exposure of the inhaled medicines.It starts with an introduction of various physiological and pathophysiological barriers for designing inhaled medicines with extended lung exposure,which is followed by recent advances in various strategies to overcome these barriers.Finally,the applications of the inhaled medicines with extended lung exposure for the treatment of various diseases and the safety concerns associated to various strategies to extend the pulmonary exposure of the inhaled medicines are summarized.

Inhalation treatment of primary lung cancer using liposomal curcumin dry powder inhalers

Lung cancer is the leading cause of cancer-related deaths. Traditional chemotherapy causes serious toxicity due to the wide bodily distribution of these drugs. Curcumin is a potential anticancer agent but its low water solubility, poor bioavailability and rapid metabolism significantly limits clinical applications. Here we developed a liposomal curcumin dry powder inhaler(LCD) for inhalation treatment of primary lung cancer. LCDs were obtained from curcumin liposomes after freeze-drying. The LCDs had a mass mean aerodynamic diameter of 5.81 μm and a fine particle fraction of 46.71%, suitable for pulmonary delivery. The uptake of curcumin liposomes by human lung cancer A549 cells was markedly greater and faster than that of free curcumin. The high cytotoxicity on A549 cells and the low cytotoxicity of curcumin liposomes on normal human bronchial BEAS-2B epithelial cells yielded a high selection index partly due to increased cell apoptosis. Curcumin powders, LCDs and gemcitabine were directly sprayed into the lungs of rats with lung cancer through the trachea. LCDs showed higher anticancer effects than the other two medications with regard to pathology and the expression of many cancer-related markers including VEGF, malondialdehyde, TNF-α, caspase-3 and BCL-2. LCDs are a promising medication for inhalation treatment of lung cancer with high therapeutic efficiency.

Inhalable oridonin-loaded poly(lactic-co-glycolic)acid large porous microparticles for in situ treatment of primary non-small cell lung cancer

Non-small cell lung cancer(NSCLC) accounts for about 85% of all lung cancers. Traditional chemotherapy for this disease leads to serious side effects. Here we prepared an inhalable oridonin-loaded poly(lactic-co-glycolic)acid(PLGA) large porous microparticle(LPMP) for in situ treatment of NSCLC with the emulsion/solvent evaporation/freeze-drying method. The LPMPs were smooth spheres with many internal pores. Despite a geometric diameter of 10 mm, the aerodynamic diameter of the spheres was only 2.72 mm, leading to highly efficient lung deposition. In vitro studies showed that most of oridonin was released after 1 h, whereas the alveolar macrophage uptake of LPMPs occurred after 8 h, so that most of oridonin would enter the surroundings without undergoing phagocytosis. Rat primary NSCLC models were built and administered with saline, oridonin powder, gemcitabine, and oridonin-loaded LPMPs via airway, respectively. The LPMPs showed strong anticancer effects. Oridonin showed strong angiogenesis inhibition and apoptosis. Relevant mechanisms are thought to include oridonin-induced mitochondrial dysfunction accompanied by low mitochondrial membrane potentials, downregulation of BCL-2 expressions, upregulation of expressions of BAX, caspase-3 and caspase-9. The oridonin-loaded PLGALPMPs showed high anti-NSCLC effects after pulmonary delivery. In conclusion, LPMPs are promising dry powder inhalations for in situ treatment of lung cancer.