Comprehensive Physicochemical Characterization, In Vitro Membrane Permeation, and In Vitro Human Skin Cell Culture of a Novel TOPK Inhibitor, HI-TOPK-032

Nonmelanoma skin cancers (NMSC) are the most common skin cancers, and about 5.4 million people are diagnosed each year in the United States. A newly developed T-lymphokine-activated killer cell-originated protein kinase (TOPK) inhibitor, HI-TOPK-032, is effective in suppressing colon cancer cell growth, inducing the apoptosis of colon cancer cells and ultraviolet (UV) light-induced squamous cell carcinoma (SCC). This study aimed to investigate the physicochemical properties, permeation behavior, and cytotoxicity potential of HI-TOPK-032 prior to the development of a suitable topical formulation for targeted skin drug delivery. Techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, differential scanning calorimetry (DSC), hot-stage microscopy (HSM), X-ray powder diffraction (XRPD), Karl Fisher (KF) coulometric titration, Raman spectrometry, confocal Raman microscopy (CRM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and Fourier transform infrared microscopy were used to characterize HI-TOPK-032. The dose effect of HI-TOPK-032 on in vitro cell viability was evaluated using a 2D cell culture of the human skin keratinocyte cell line (HaCaT) and primary normal human epidermal keratinocytes (NHEKs). Transepithelial electrical resistance (TEER) at the air-liquid interface as a function of dose and time was measured on the HaCAT human skin cell line. The membrane permeation behavior of HI-TOPK-032 was tested using the Strat-M® synthetic biomimetic membrane with an in vitro Franz cell diffusion system. The physicochemical evaluation results confirmed the amorphous nature of the drug and the homogeneity of the sample with all characteristic chemical peaks. The in vitro cell viability assay results confirmed 100% cell viability up to 10 µM of HI-TOPK-032. Further, a rapid, specific, precise, and validated reverse phase-high performance liquid chromatography (RP-HPLC) method for the quantitative estimation of HI-TOPK-032 was developed. This is the first systematic and comprehensive characterization of HI-TOPK-032 and a report of these findings.

Innovative Rocuronium Bromide Topical Formulation for Targeted Skin Drug Delivery: Design, Comprehensive Characterization, In Vitro 2D/3D Human Cell Culture and Permeation

Cutaneous squamous cell carcinoma (cSCC) is the second-most common type of non-melanoma skin cancer and is linked to long-term exposure to ultraviolet (UV) radiation from the sun. Rocuronium bromide (RocBr) is an FDA-approved drug that targets p53-related protein kinase (PRPK) that inhibits the development of UV-induced cSCC. This study aimed to investigate the physicochemical properties and in vitro behavior of RocBr. Techniques such as thermal analysis, electron microscopy, spectroscopy and in vitro assays were used to characterize RocBr. A topical oil/water emulsion lotion formulation of RocBr was successfully developed and evaluated. The in vitro permeation behavior of RocBr from its lotion formulation was quantified with Strat-M^® synthetic biomimetic membrane and EpiDerm™ 3D human skin tissue. Significant membrane retention of RocBr drug was evident and more retention was obtained with the lotion formulation compared with the solution. This is the first systematic and comprehensive study to report these findings.

Kidney targeting of formoterol containing polymeric nanoparticles improves recovery from ischemia reperfusion-induced acute kidney injury in mice

The β₂ adrenergic receptor agonist, formoterol, is an inducer of mitochondrial biogenesis and restorer of mitochondrial and kidney function in acute and chronic models of kidney injury. Unfortunately, systemic administration of formoterol has the potential for adverse cardiovascular effects, increased heart rate, and decreased blood pressure. To minimize these effects, we developed biodegradable and biocompatible polymeric nanoparticles containing formoterol that target the kidney, thereby decreasing the effective dose, and lessen cardiovascular effects while restoring kidney function after injury. Male C57Bl/6 mice, treated with these nanoparticles daily, had reduced ischemia-reperfusion-induced serum creatinine and kidney cortex kidney injury molecule-1 levels by 78% and 73% respectively, compared to control mice six days after injury. With nanoparticle therapy, kidney cortical mitochondrial number and proteins reduced by ischemic injury, recovered to levels of sham-operated mice. Tubular necrosis was reduced 69% with nanoparticles treatment. Nanoparticles improved kidney recovery even when the dosing frequency was reduced from daily to two days per week. Finally, compared to treatment with formoterol-free drug alone, these nanoparticles did not increase heart rate nor decrease blood pressure. Thus, targeted kidney delivery of formoterol-containing nanoparticles is an improvement in standard formoterol therapy for ischemia-reperfusion-induced acute kidney injuries by decreasing the dose, dosing frequency, and cardiac side effects.

Therapeutic Cancer Vaccines—Antigen Discovery and Adjuvant Delivery Platforms

For decades, vaccines have played a significant role in protecting public and personal health against infectious diseases and proved their great potential in battling cancers as well. This review focused on the current progress of therapeutic subunit vaccines for cancer immunotherapy. Antigens and adjuvants are key components of vaccine formulations. We summarized several classes of tumor antigens and bioinformatic approaches of identification of tumor neoantigens. Pattern recognition receptor (PRR)-targeting adjuvants and their targeted delivery platforms have been extensively discussed. In addition, we emphasized the interplay between multiple adjuvants and their combined delivery for cancer immunotherapy.

Design, Physicochemical Characterization, and In Vitro Permeation of Innovative Resatorvid Topical Formulations for Targeted Skin Drug Delivery

Nonmelanoma skin cancers (NMSCs) are the most common malignancies worldwide and affect more than 5 million people in the United States every year. NMSC is directly linked to the excessive exposure of the skin to solar ultraviolet (UV) rays. The toll-like receptor 4 (TLR4) antagonist, resatorvid (TAK-242), is a novel prototype chemo preventive agent that suppresses the production of inflammation mediators induced by UV exposure. This study aimed to design and develop TAK-242 into topical formulations using FDA-approved excipients, including DermaBase^TM, PENcream^TM, polyethylene glycol (PEG)-400, propylene glycol (PG), carbomer gel, hyaluronic acid (HA) gel, and Pluronic^® F-127 poloxamer triblock copolymer gel for the prevention of skin cancer. The physicochemical properties of raw TAK-242, which influence the compatibility and solubility in the selected base materials, were confirmed using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), hot-stage microscopy (HSM), Raman spectroscopy, and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopic analysis. The permeation behavior of TAK-242 from the prepared formulations was determined using Strat-M^® transdermal diffusion membranes, and 3D cultured primary human-derived epidermal keratinocytes (EpiDerm^TM). Despite TAK-242′s high molecular weight and hydrophobicity, it can permeate through reconstructed human epidermis from all formulations. The findings, reported for the first time in this study, emphasize the capabilities of the topical application of TAK-242 via these multiple innovative topical drug delivery formulation platforms.

Glycosylated Ang-(1-7) MasR Agonist Peptide Poly Lactic-co-Glycolic Acid (PLGA) Nanoparticles and Microparticles in Cognitive Impairment: Design, Particle Preparation, Physicochemical Characterization, and In Vitro Release

Heart failure (HF) causes decreased brain perfusion in older adults, and increased brain and systemic inflammation increases the risk of cognitive impairment and Alzheimer’s disease (AD). Glycosylated Ang-(1-7) MasR agonists (PNA5) has shown improved bioavailability, stability, and brain penetration compared to Ang-(1-7) native peptide. Despite promising results and numerous potential applications, clinical applications of PNA5 glycopeptide are limited by its short half-life, and frequent injections are required to ensure adequate treatment for cognitive impairment. Therefore, sustained-release injectable formulations of PNA5 glycopeptide are needed to improve its bioavailability, protect the peptide from degradation, and provide sustained drug release over a prolonged time to reduce injection administration frequency. Two types of poly(D,L-lactic-co-glycolic acid) (PLGA) were used in the synthesis to produce nanoparticles (≈0.769−0.35 µm) and microparticles (≈3.7−2.4 µm) loaded with PNA5 (ester and acid-end capped). Comprehensive physicochemical characterization including scanning electron microscopy, thermal analysis, molecular fingerprinting spectroscopy, particle sizing, drug loading, encapsulation efficiency, and in vitro drug release were conducted. The data shows that despite the differences in the size of the particles, sustained release of PNA5 was successfully achieved using PLGA R503H polymer with high drug loading (% DL) and high encapsulation efficiency (% EE) of >8% and >40%, respectively. While using the ester-end PLGA, NPs showed poor sustained release as after 72 h, nearly 100% of the peptide was released. Also, lower % EE and % DL values were observed (10.8 and 3.4, respectively). This is the first systematic and comprehensive study to report on the successful design, particle synthesis, physicochemical characterization, and in vitro glycopeptide drug release of PNA5 in PLGA nanoparticles and microparticles.

Advanced Microparticulate/Nanoparticulate Respirable Dry Powders of a Selective RhoA/Rho Kinase (Rock) Inhibitor for Targeted Pulmonary Inhalation Aerosol Delivery

Pulmonary hypertension (PH) is a progressive disease that eventually leads to heart failure and potentially death for some patients. There are many unique advantages to treating pulmonary diseases directly and non-invasively by inhalation aerosols and dry powder inhalers (DPIs) possess additional unique advantages. There continues to be significant unmet medical needs in the effective treatment of PH that target the underlying mechanisms. To date, there is no FDA-approved DPI indicated for the treatment of PH. Fasudil is a novel RhoA/Rho kinase (ROCK) inhibitor that has shown great potential in effectively treating pulmonary hypertension. This systematic study is the first to report on the design and development of DPI formulations comprised of respirable nanoparticles/microparticles using particle engineering design by advanced spray drying. In addition, comprehensive physicochemical characterization, in vitro aerosol aerosol dispersion performance with different types of human DPI devices, in vitro cell-drug dose response cell viability of different human respiratory cells from distinct lung regions, and in vitro transepithelial electrical resistance (TEER) as air-interface culture (AIC) demonstrated that these innovative DPI fasudil formulations are safe on human lung cells and have high aerosol dispersion performance properties.

Neurofilament light: a possible prognostic biomarker for treatment of vascular contributions to cognitive impairment and dementia

Background

Decreased cerebral blood flow and systemic inflammation during heart failure (HF) increase the risk for vascular contributions to cognitive impairment and dementia (VCID) and Alzheimer disease-related dementias (ADRD). We previously demonstrated that PNA5, a novel glycosylated angiotensin 1–7 (Ang-(1–7)) Mas receptor (MasR) agonist peptide, is an effective therapy to rescue cognitive impairment in our preclinical model of VCID. Neurofilament light (NfL) protein concentration is correlated with cognitive impairment and elevated in neurodegenerative diseases, hypoxic brain injury, and cardiac disease. The goal of the present study was to determine (1) if treatment with Ang-(1–7)/MasR agonists can rescue cognitive impairment and decrease VCID-induced increases in NfL levels as compared to HF-saline treated mice and, (2) if NfL levels correlate with measures of cognitive function and brain cytokines in our VCID model.

Methods

VCID was induced in C57BL/6 male mice via myocardial infarction (MI). At 5 weeks post-MI, mice were treated with daily subcutaneous injections for 24 days, 5 weeks after MI, with PNA5 or angiotensin 1–7 (500 microg/kg/day or 50 microg/kg/day) or saline (n = 15/group). Following the 24-day treatment protocol, cognitive function was assessed using the Novel Object Recognition (NOR) test. Cardiac function was measured by echocardiography and plasma concentrations of NfL were quantified using a Quanterix Simoa assay. Brain and circulating cytokine levels were determined with a MILLIPLEX MAP Mouse High Sensitivity Multiplex Immunoassay. Treatment groups were compared via ANOVA, significance was set at p < 0.05.

Results

Treatment with Ang-(1–7)/MasR agonists reversed VCID-induced cognitive impairment and significantly decreased NfL levels in our mouse model of VCID as compared to HF-saline treated mice. Further, NfL levels were significantly negatively correlated with cognitive scores and the concentrations of multiple pleiotropic cytokines in the brain.

Conclusions

These data show that treatment with Ang-(1–7)/MasR agonists rescues cognitive impairment and decreases plasma NfL relative to HF-saline-treated animals in our VCID mouse model. Further, levels of NfL are significantly negatively correlated with cognitive function and with several brain cytokine concentrations. Based on these preclinical findings, we propose that circulating NfL might be a candidate for a prognostic biomarker for VCID and may also serve as a pharmacodynamic/response biomarker for therapeutic target engagement.

Inhalation Delivery for the Treatment and Prevention of COVID-19 Infection

Coronavirus disease-2019 (COVID-19) is caused by coronavirus-2 (SARS-CoV-2) and has produced a global pandemic. As of 22 June 2021, 178 million people have been affected worldwide, and 3.87 million people have died from COVID-19. According to the Centers for Disease Control and Prevention (CDC) of the United States, COVID-19 virus is primarily transmitted between people through respiratory droplets and contact routes. Since the location of initial infection and disease progression is primarily through the lungs, the inhalation delivery of drugs directly to the lungs may be the most appropriate route of administration for treating COVID-19. This review article aims to present possible inhalation therapeutics and vaccines for the treatment of COVID-19 symptoms. This review covers the comparison between SARS-CoV-2 and other coronaviruses such as SARS-CoV/MERS, inhalation therapeutics for the treatment of COVID-19 symptoms, and vaccines for preventing infection, as well as the current clinical status of inhaled therapeutics and vaccines.

Matrix metalloproteinase-9 as a messenger in the cross talk between obstructive sleep apnea and comorbid systemic hypertension, cardiac remodeling, and ischemic stroke: a literature review

STUDY OBJECTIVES

OSA is a common sleep disorder. There is a strong link between sleep-related breathing disorders and cardiovascular and cerebrovascular diseases. Matrix metalloproteinase-9 (MMP-9) is a biological marker for extracellular matrix degradation, which plays a significant role in systemic hypertension, myocardial infarction and postmyocardial infarction heart failure, and ischemic stroke. This article reviews MMP-9 as an inflammatory mediator and a potential messenger between OSA and OSA-induced comorbidities.

METHODS

We reviewed the MEDLINE database (PubMed) for publications on MMP-9, OSA, and cardiovascular disease, identifying 1,592 studies and including and reviewing 50 articles for this work.

RESULTS

There is strong evidence that MMP-9 and tissue inhibitor of metalloproteinase-1 levels are elevated in patients with OSA (mainly MMP-9), systemic hypertension, myocardial infarction, and postmyocardial infarction heart failure. Our study showed variable results that could be related to the sample size or to laboratory methodology.

CONCLUSIONS

MMP-9 and its endogenous inhibitor, tissue inhibitor of metalloproteinase-1, are a common denominator in OSA, systemic hypertension, myocardial infarction, and heart failure. This characterization makes MMP-9 a target for developing novel selective inhibitors that can serve as adjuvant therapy in patients with OSA, which may ameliorate the cardiovascular and cerebrovascular mortality associated with OSA.

Formoterol PLGA-PEG Nanoparticles Induce Mitochondrial Biogenesis in Renal Proximal Tubules

Formoterol is a long-acting β₂ agonist (LABA). Agonism of the β₂-adrenergic receptor by formoterol is known to stimulate mitochondrial biogenesis (MB) in renal proximal tubules and recover kidney function. However, formoterol has a number of cardiovascular side effects that limits its usage. The goal of this study was to design and develop an intravenous biodegradable and biocompatible polymeric nanoparticle delivery system that targets formoterol to the kidney. Poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) nanoparticles containing encapsulated formoterol were synthesized by a modified single-emulsion solvent evaporation technique resulting in nanoparticles with a median hydrodynamic diameter of 442 + 17 nm. Using primary cell cultures of rabbit renal proximal tubular cells (RPTCs), free formoterol, encapsulated formoterol polymeric nanoparticles, and drug-free polymeric nanoparticles were biocompatible and not cytotoxic over a wide concentration range. In healthy male mice, polymeric nanoparticles were shown to localize in tubules of the renal cortex and improved the renal localization of encapsulated formoterol compared to the free formoterol. At a lower total formoterol dose, the nanoparticle localization resulted in increased expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), the master regulator of MB, and increased electron transport chain proteins, markers of MB. This was confirmed by direct visual quantification of mitochondria and occurred with both free formoterol and the encapsulated formoterol polymeric nanoparticles. At the same time, localization of nanoparticles to the kidneys resulted in reduced induction of MB markers in the heart. These new nanoparticles effectively target formoterol to the kidney and successfully produce MB in the kidney.

Spray-Dried Inhalable Powder Formulations of Therapeutic Proteins and Peptides

Respiratory diseases are among the leading causes of morbidity and mortality worldwide. Innovations in biochemical engineering and understanding of the pathophysiology of respiratory diseases resulted in the development of many therapeutic proteins and peptide drugs with high specificity and potency. Currently, protein and peptide drugs are mostly administered by injections due to their large molecular size, poor oral absorption, and labile physicochemical properties. However, parenteral administration has several limitations such as frequent dosing due to the short half-life of protein and peptide in blood, pain on administration, sterility requirement, and poor patient compliance. Among various noninvasive routes of administrations, the pulmonary route has received a great deal of attention and is a better alternative to deliver protein and peptide drugs for treating respiratory diseases and systemic diseases. Among the various aerosol dosage forms, dry powder inhaler (DPI) systems appear to be promising for inhalation delivery of proteins and peptides due to their improved stability in solid state. This review focuses on the development of DPI formulations of protein and peptide drugs using advanced spray drying. An overview of the challenges in maintaining protein stability during the drying process and stabilizing excipients used in spray drying of proteins and peptide drugs is discussed. Finally, a summary of spray-dried DPI formulations of protein and peptide drugs, their characterization, various DPI devices used to deliver protein and peptide drugs, and current clinical status are discussed.

To treat or not to treat: CFTR modulators after lung transplantation

Evidence for the extrapulmonary benefits of (CFTR) modulators is rapidly expanding. The use of CFTR modulators in CF patients who have undergone lung transplantation is not clear without guidance published in the medical literature to assist clinicians in the care of these patients. We discuss the potential benefits of CFTR modulators and provide insight into their use based on our experience in a small cohort of CF LTx recipients. We present pros and cons of CFTR modulator therapy for LTx recipients with CF. CFTR modulators should be considered in CF patients after lung transplantation for the time being until further research defines how to best use these therapies in transplant recipients.

Design and Comprehensive Characterization of Tetramethylpyrazine (TMP) for Targeted Lung Delivery as Inhalation Aerosols in Pulmonary Hypertension (PH): In Vitro Human Lung Cell Culture and In Vivo Efficacy

This is the first study reporting on the design and development innovative inhaled formulations of the novel natural product antioxidant therapeutic, tetramethylpyrazine (TMP), also known as ligustrazine. TMP is obtained from Chinese herbs belonging to the class of Ligusticum. It is known to have antioxidant properties. It can act as a Nrf2/ARE activator and a Rho/ROCK inhibitor. The present study reports for the first time on the comprehensive characterization of raw TMP (non-spray dried) and spray dried TMP in a systematic manner using thermal analysis, electron microscopy, optical microscopy, and Raman spectroscopy. The in vitro aerosol dispersion performance of spray dried TMP was tested using three different FDA-approved unit-dose capsule-based human dry powder inhaler devices. In vitro human cellular studies were conducted on pulmonary cells from different regions of the human lung to examine the biocompatibility and non-cytotoxicity of TMP. Furthermore, the efficacy of inhaled TMP as both liquid and dry powder inhalation aerosols was tested in vivo using the monocrotaline (MCT)-induced PH rat model.

Advanced therapeutic inhalation aerosols of a Nrf2 activator and RhoA/Rho kinase (ROCK) inhibitor for targeted pulmonary drug delivery in pulmonary hypertension: design, characterization, aerosolization, in vitro 2D/3D human lung cell cultures, and in vivo efficacy

Inhalable nanostructured microparticles of simvastatin, a Nrf2 activator and RhoA/Rho kinase (ROCK) inhibitor, were rationally designed for targeted pulmonary delivery as dry powder inhalers (DPIs) for the treatment of pulmonary hypertension (PH). Advanced particle engineering design technology was employed to develop inhalable dry powders using different dilute feed concentrations and spray drying pump rates. Several analytical techniques were used comprehensively to characterize the physicochemical properties of the resulting powders. Scanning electron microscopy (SEM) was used to visualize particle morphology (shape), surface structure, size, and size distribution. Karl Fischer titration (KFT) was employed to quantify the residual water content in the powders. X-ray powder diffraction (XRPD) was used to determine crystallinity. Hot-stage microscopy (HSM) under cross-polarizing lens was used to observe the presence or absence of birefringence characteristic of crystallinity. Differential scanning calorimetry (DSC) was employed to quantify thermotropic phase behavior. Attenuated total reflectance (ATR)-Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy were used to determine the molecular fingerprint of simvastatin powders before and after particle engineering design. In vitro aerosol dispersion performance was performed with three different Food and Drug Administration (FDA)-approved human DPI devices. Cell viability and transepithelial electrical resistance (TEER) were demonstrated using different in vitro human pulmonary cell two and three-dimensional models at the air-liquid interface, and in vivo safety in healthy rats by inhalation. Efficacy was demonstrated in the in vivo lamb model of PH. Four different inhalable powders of simvastatin were successfully produced. They possessed nanostructured surfaces and were in the inhalable size range. Simvastatin retained its crystallinity following particle engineering design. The more dilute feed concentration spray dried at the lower pump rate produced the smallest particles. All powders successfully aerosolized with all three DPI human devices. Inhaled simvastatin as an aerosol restored the endothelial function in the shunt lamb model of PH, as demonstrated by the reduction of pulmonary vascular resistance (PVR) in response to the endothelium-dependent vasodilator acetylcholine.The reviews of this paper are available via the supplemental material section.

Organic Solution Advanced Spray-Dried Microparticulate/Nanoparticulate Dry Powders of Lactomorphin for Respiratory Delivery: Physicochemical Characterization, In Vitro Aerosol Dispersion, and Cellular Studies

The purpose of this study was to formulate Lactomorphin (MMP2200) in its pure state as spray-dried(SD) powders, and with the excipient Trehalose as co-spray-dried(co-SD) powders; for intranasal and deep lung administration with Dry Powder Inhalers (DPI). Lactomorphin is a glycopeptide which was developed for the control of moderate to severe pain. Particles were rationally designed and produced by advanced spray drying particle engineering in a closed mode from a dilute organic solution. Comprehensive physicochemical characterization using different analytical techniques was carried out to analyze the particle size, particle morphology, particle surface morphology, solid-state transitions, crystallinity/non-crystallinity, and residual water content. The particle chemical composition was confirmed using attenuated total reflectance-Fourier-transform infrared (ATR-FTIR), and Confocal Raman Microscopy (CRM) confirmed the particles' chemical homogeneity. The solubility and Partition coefficient (LogP) of Lactomorphin were determined by the analytical and computational methodology and revealed the hydrophilicity of Lactomorphin. A thermal degradation study was performed by exposing samples of solid-state Lactomorphin to a high temperature (62 °C) combined with zero relative humidity (RH) and to a high temperature (62 °C) combined with a high RH (75%) to evaluate the stability of Lactomorphin under these two different conditions. The solid-state processed particles exhibited excellent aerosol dispersion performance with an FDA-approved human DPI device to reach lower airways. The cell viability resazurin assay showed that Lactomorphin is safe up to 1000 μg/mL on nasal epithelium cells, lung cells, endothelial, and astrocyte brain cells.

Inhalable Nanoparticles/Microparticles of an AMPK and Nrf2 Activator for Targeted Pulmonary Drug Delivery as Dry Powder Inhalers

Metformin is an activator of the AMPK and Nrf2 pathways which are important in the pathology of several complex pulmonary diseases with unmet medical needs. Organic solution advanced spray drying in the absence of water in closed-mode was used to design and develop respirable dry powders. Following comprehensive characterization, the influence of physicochemical properties was correlated with performance as aerosols using inertial impaction and three different human dry powder inhaler (DPI) devices varying in device properties. In vitro cell assays were conducted to test safety in 2D human pulmonary cell lines and in 3D small airway epithelia comprising primary cells at the air-liquid interface (ALI). In addition, in vitro transepithelial electrical resistance (TEER) was carried out. Metformin remained crystalline following advanced spray drying under these conditions. All SD powders consisted of nanoparticles/microparticles in the solid state. In vitro aerosol dispersion performance showed high aerosolization for all SD metformin powders with all DPI devices tested. High emitted dose for all powders with all three DPI devices was measured. Differences in other aerosol performance parameters and the interplay between the properties of different formulations produced at specific pump rates and the three different DPI devices were correlated with spray drying pump rate and device properties. Safety over a wide metformin dose range was also demonstrated in vitro. Aerosol delivery of metformin nanoparticles/microparticles has the potential to be a new "first-in-class" therapeutic for the treatment of a number of pulmonary diseases including pulmonary vascular diseases such as pulmonary hypertension.

Design and development of innovative microparticulate/nanoparticulate inhalable dry powders of a novel synthetic trifluorinated chalcone derivative and Nrf2 agonist

Chalcone derivatives are shown to possess excellent anti-inflammatory and anti-oxidant properties which are of great interest in treating respiratory diseases such as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF). This study successfully designed and developed dry powder inhaler (DPI) formulations of TMC (2-trifluoromethyl-2'-methoxychalone), a new synthetic trifluorinated chalcone and Nrf2 agonist, for targeted pulmonary inhalation aerosol drug delivery. An advanced co-spray drying particle engineering technique was used to design and produce microparticulate/nanoparticulate formulations of TMC with a suitable excipient (mannitol) as inhalable particles with tailored particle properties for inhalation. Raw TMC and co-spray dried TMC formulations were comprehensively characterized for the first time using scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) spectroscopy, thermal analysis, X-ray powder diffraction (XRPD), and molecular fingerprinting as dry powders by ATR-FTIR spectroscopy and Raman spectroscopy. Further, biocompatibility and suitability of formulations were tested with in vitro cellular transepithelial electrical resistance (TEER) in air-interface culture (AIC) using a human pulmonary airway cell line. The ability of these TMC formulations to perform as aerosolized dry powders was systematically evaluated by design of experiments (DOEs) using three different FDA-approved human inhaler devices followed by interaction parameter analyses. Multiple spray drying pump rates (25%, 75%, and 100%) successfully produced co-spray dried TMC:mannitol powders. Raw TMC exhibited a first-order phase transition temperature at 58.15 ± 0.38 °C. Furthermore, the results demonstrate that these innovative TMC dry powder particles are suitable for targeted delivery to the airways by inhalation.

Advanced spray dried proliposomes of amphotericin B lung surfactant-mimic phospholipid microparticles/nanoparticles as dry powder inhalers for targeted pulmonary drug delivery

The purpose of this study was to design, develop and characterize inhalable proliposomal microparticles/nanoparticles of Amphotericin B (AmB) with synthetic phospholipids, dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG) which are lung surfactant-mimic phospholipids. Organic solutions of AmB and phospholipids, were co-spray dried using an advanced closed-mode system and a high performance cyclone. Scanning electron microscopy (SEM) was employed to visualize the surface structure, morphology, and particles size. The residual water content of the proliposomes was quantified by Karl Fisher coulometric titration (KFT). Degree of crystallinity/non-crystallinity was measured by X-ray powder diffraction (XRPD). Phase behavior was measured by differential scanning calorimetry. The chemical composition by molecular fingerprinting was established using attenuated total reflectance (ATR)-Fourier-transform infrared (FTIR) spectroscopy. The amount of AmB loaded into the proliposomes was quantified using UV-VIS spectroscopy. The in vitro aerosol dispersion performance was conducted using the Next Generation Impactor (NGI) and the human dry powder inhaler (DPI) (Handihaler®) that is FDA-approved. Different human lung cell lines were employed to demonstrate in vitro safety as a function of dose and formulation. Smooth, spherical microparticles/nanoparticles were formed at medium and high spray drying pump rates and had low residual water content. A characteristic peak in the XRPD diffraction pattern as well as an endotherm in DSC confirmed the presence of the lipid bilayer structure characteristic in the DPPC/DPPG proliposomal systems. Superior in vitro aerosol performance was achieved with engineered microparticles/nanoparticles demonstrating suitability for targeted pulmonary drug delivery as inhalable dry powders. The in vitro cellular studies demonstrated that the formulated proliposomes are safe. These AmB proliposomes can be a better option for targeted treatment of severe pulmonary fungal infections.

Advanced design and development of nanoparticle/microparticle dual-drug combination lactose carrier-free dry powder inhalation aerosols

Rationale: lactose is the only FDA-approved carrier for dry powder inhaler (DPI) formulations in the US. Lactose carrier-based DPI products are contraindicated in patients with a known lactose allergy. Hence, inhaler formulations without lactose will benefit lactose allergic asthmatics. Objectives: to rationally design and develop lactose carrier-free dry powder inhaler formulations of fluticasone propionate and salmeterol xinafoate that will benefit people with known lactose allergy. The study also aims at improving the aerosol deposition of the dry powder formulation through advanced particle engineering design technologies to create inhalable powders consisting of nanoparticles/microparticles. Methods: advanced DPI nanoparticle/microparticle formulations were designed, developed and optimized using organic solution advanced closed-mode spray drying. The co-spray dried (co-SD) powders were comprehensively characterized in solid-state and in vitro comparative analysis of the aerodynamic performance of these molecularly mixed formulations was conducted with the marketed formulation of Advair® Diskus® interactive physical mixture. Measurements and main results: comprehensive solid-state physicochemical characterization of the powders showed that the engineered co-SD particles were small and spherical within the size range of 450 nm to 7.25 μm. Improved fine particle fraction and lower mass median aerodynamic diameter were achieved by these DPI nanoparticles/microparticles. Conclusions: this study has successfully produced a lactose-free dry powder formulation containing fluticasone propionate and salmeterol xinafoate with mannitol as excipient engineered as inhalable DPI nanoparticles/microparticles by advanced spray drying. Further, co-spray drying with mannitol and using Handihaler® device can generate higher fine particle mass of fluticasone/salmeterol. Mannitol, a mucolytic agent and aerosol performance enhancer, is a suitable excipient that can enhance aerosol dispersion of DPIs.

Risks associated with lung transplantation in cystic fibrosis patients

INTRODUCTION

Survival after lung transplantation lags behind outcomes of other solid organ transplants, and complications from lung transplant are the second most common cause of death in cystic fibrosis. Evolving surgical techniques, therapeutics, and perioperative management have improved short-term survival after lung transplantation, yet have not translated into significant improvement in long-term mortality. Areas covered: We review risk factors for poor long-term outcomes among patients with cystic fibrosis undergoing lung transplantation to highlight areas for improvement. This includes reasons for organ dysfunction, complications of immunosuppression, further exacerbation of extrapulmonary complications of cystic fibrosis, and quality of life. A literature search was performed using PubMed-indexed journals. Expert commentary: There are multiple medical and socioeconomic barriers that threaten long-term survival following lung transplant for patients with cystic fibrosis. An understanding of the causes of each could elucidate treatment options. There is a lack of prospective, multicenter, randomized control trials due to cost, complexity, and feasibility. Ongoing prospective studies should be reserved for the most promising interventions identified in retrospective studies in order to improve long-term outcomes.

Transfusion with packed red blood cells while awaiting lung transplantation is associated with reduced survival after lung transplantation

BACKGROUND

The effect of pretransplant transfusion of red blood cells on survival after lung transplantation (LTx) has not been studied.

METHODS

The UNOS database was queried from 2005 to 2013 to compare survival in recipients receiving a transfusion while on the LTx wait list.

RESULTS

Of 12 283 adult patients undergoing single or bilateral LTx from May 2005 onwards, 11 801 met inclusion criteria, among whom 512 required transfusion while on the LTx wait list. Transfusion was associated with a higher mortality hazard in unadjusted Cox proportional hazards analysis (HR=1.296; 95% CI: 1.124, 1.494; P<.001), and in a multivariable Cox model (HR=1.178; 95% CI: 1.013, 1.369; P=.033) after multiple imputation was used to complete data on covariates. Propensity score matching was used to match transfusion recipients to nonrecipients on the likelihood of having received transfusions on the wait list, calculated from characteristics at the time of listing. Unadjusted Cox regression stratified on the matched pairs also demonstrated an association between transfusion receipt on the wait list and higher post-transplant mortality hazard (HR=1.494; 95% CI: 1.127, 1.979; P=.005).

CONCLUSIONS

Blood transfusion while on the LTx wait list was associated with diminished patient survival after transplantation.

Impact of Donor Arterial Partial Pressure of Oxygen on Outcomes After Lung Transplantation in Adult Cystic Fibrosis Recipients

INTRODUCTION

Donor PaO2 levels are used for assessing organs for lung transplantation (LTx), but survival implications of PaO2 levels in adult cystic fibrosis (CF) patients receiving LTx are unclear.

METHODS

UNOS registry data spanning 2005-2013 were used to test for associations of donor PaO2 with patient survival and bronchiolitis obliterans syndrome (BOS) in adult (age ≥ 18 years) first-time LTx recipients diagnosed with CF.

RESULTS

The analysis included 1587 patients, of whom 1420 had complete data for multivariable Cox models. No statistically significant differences among donor PaO2 categories of ≤200, 201-300, 301-400, or >400 mmHg were found in univariate survival analysis (log-rank test p = 0.290). BOS onset did not significantly differ across donor PaO2 categories (Chi-square p = 0.480). Multivariable Cox models of patient survival supported the lack of difference across donor PaO2 categories. Interaction analysis found a modest difference in survival between the two top categories of donor PaO2 when examining patients with body mass index (BMI) in the lowest decile (≤16.5 kg/m(2)).

CONCLUSIONS

Donor PaO2 was not associated with survival or BOS onset in adult CF patients undergoing LTx. Notwithstanding statistically significant interactions between donor PaO2 and BMI, there was no evidence of post-LTx survival risk associated with donor PaO2 below conventional thresholds in any subgroup of adults with CF.

Role of Nrf2 and Autophagy in Acute Lung Injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are the clinical manifestations of severe lung damage and respiratory failure. Characterized by severe inflammation and compromised lung function, ALI/ARDS result in very high mortality of affected individuals. Currently, there are no effective treatments for ALI/ARDS, and ironically, therapies intended to aid patients (specifically mechanical ventilation, MV) may aggravate the symptoms. Key events contributing to the development of ALI/ARDS are: increased oxidative and proteotoxic stresses, unresolved inflammation, and compromised alveolar-capillary barrier function. Since the airways and lung tissues are constantly exposed to gaseous oxygen and airborne toxicants, the bronchial and alveolar epithelial cells are under higher oxidative stress than other tissues. Cellular protection against oxidative stress and xenobiotics is mainly conferred by Nrf2, a transcription factor that promotes the expression of genes that regulate oxidative stress, xenobiotic metabolism and excretion, inflammation, apoptosis, autophagy, and cellular bioenergetics. Numerous studies have demonstrated the importance of Nrf2 activation in the protection against ALI/ARDS, as pharmacological activation of Nrf2 prevents the occurrence or mitigates the severity of ALI/ARDS. Another promising new therapeutic strategy in the prevention and treatment of ALI/ARDS is the activation of autophagy, a bulk protein and organelle degradation pathway. In this review, we will discuss the strategy of concerted activation of Nrf2 and autophagy as a preventive and therapeutic intervention to ameliorate ALI/ARDS.

Development of three-dimensional lung multicellular spheroids in air- and liquid-interface culture for the evaluation of anticancer therapeutics

Three-dimensional (3D) lung multicellular spheroids (MCS) in liquid-covered culture (LCC) and air-interface culture (AIC) conditions have both been developed for the evaluation of aerosol anticancer therapeutics in solution and aerosols, respectively. The MCS were formed by seeding lung cancer cells on top of collagen where they formed spheroids due to the prevalence of cell-to-cell interactions. LCC MCS were exposed to paclitaxel (PTX) in media whereas AIC MCS were exposed to dry powder PEGylated phospholipid aerosol microparticles containing paclitaxel. The difference in viability for 2D versus 3D culture for both LCC and AIC was evaluated along with the effects of the particles on lung epithelium via transepithelial electrical resistance (TEER) measurements. For LCC and AIC conditions, the 3D spheroids were more resistant to treatment with higher IC50 values for A549 and H358 cell lines. TEER results initially indicated a decrease in resistance upon drug or particle exposure, however, these values increased over the course of several days indicating the ability of the cells to recover. Overall, these studies offer a comprehensive in vitro evaluation of aerosol particles used in the treatment of lung cancer while introducing a new method for culturing lung cancer MCS in both LCC and AIC conditions.

Microparticulate/Nanoparticulate Powders of a Novel Nrf2 Activator and an Aerosol Performance Enhancer for Pulmonary Delivery Targeting the Lung Nrf2/Keap-1 Pathway

This systematic and comprehensive study reports for the first time on the successful rational design of advanced inhalable therapeutic dry powders containing dimethyl fumarate, a first-in-class Nrf2 activator drug to treat pulmonary inflammation, using particle engineering design technology for targeted delivery to the lungs as advanced spray dried (SD) one-component DPIs. In addition, two-component co-spray dried (co-SD) DMF:D-Man DPIs with high drug loading were successfully designed for targeted lung delivery as advanced DPIs using organic solution advanced spray drying in closed mode. Regional targeted deposition using design of experiments (DoE) for in vitro predictive lung modeling based on aerodynamic properties was tailored based on composition and spray drying parameters. These findings indicate the significant potential of using D-Man in spray drying to improve particle formation and aerosol performance of small molecule with a relatively low melting point. These respirable microparticles/nanoparticles in the solid-state exhibited excellent aerosol dispersion performance with an FDA-approved human DPI device. Using in vitro predictive lung deposition modeling, the aerosol deposition patterns of these particles show the capability to reach lower airways to treat inflammation in this region in pulmonary diseases such as acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH), and pulmonary endothelial disease.

Prevalence of Pulmonary Hypertension and its Influence on Survival in Patients With Advanced Chronic Obstructive Pulmonary Disease Prior to Lung Transplantation

INTRODUCTION

Prevalence of pulmonary hypertension (PH) and its influence on survival in chronic obstructive pulmonary disease (COPD) are not well studied in the lung allocation score (LAS) era.

METHODS

The UNOS database was queried from 2005 to 2013 to identify first-time adult lung transplant candidates with COPD who were tracked from wait list entry date until death or censoring to determine both prevalence and influence of PH. Using right heart catheterization measurements, mild PH was defined as mean pulmonary artery pressure (mPAP) ≥ 25 mmHg and severe ≥ 35 mmHg.

RESULTS

Of 1315 COPD candidates not transplanted, 1243 were used for survival analysis using Cox proportional hazards models, and 1010 (mild PH) and 244 (severe PH) were used for propensity score matching, respectively. A total of 52% (652) of subjects had PH mPAP ≥ 25 mmHg. Univariate analysis revealed significant differences in survival for mild PH (HR = 1.769; 95% CI: 1.331, 2.351; p < 0.001) and severe PH (HR = 3.271; 95% CI: 2.311, 4.630; p < 0.001). Kaplan-Meier survival function demonstrated significant disparities for mild PH (Log-rank test: Chi-square1: 15.87, p < 0.0001) and severe PH (Log-rank test: Chi-square1: 50.13, p < 0.0001). Multivariate Cox models identified significant risk for death for mild PH (HR = 1.987; 95% CI: 1.484, 2.662; p < 0.001) and severe PH (HR = 3.432; 95% CI: 2.410, 4.888; p < 0.001). Propensity score matching confirmed increased mortality hazard associated with mild PH (HR = 2.280; 95% CI: 1.425, 3.649; p = 0.001) and severe PH (HR = 7.000; 95% CI: 2.455, 19.957; p < 0.001).

CONCLUSIONS

PH is highly prevalent in advanced COPD and associated with a significantly higher risk for mortality.

Influence of Pulmonary Hypertension on Patients With Idiopathic Pulmonary Fibrosis Awaiting Lung Transplantation

BACKGROUND

The influence of varying levels of pulmonary hypertension (PH) on survival in idiopathic pulmonary fibrosis is not well defined.

METHODS

The United Network for Organ Sharing database was queried from 2005 to 2013 to identify first-time lung transplant candidates listed for lung transplantation who were tracked from waitlist entry date until death or censoring to determine the influence of PH on patients with advanced lung disease. Using data for right heart catheterization measurements, mild PH was defined as mean pulmonary artery pressure of 25 mm Hg or more, and severe as 35 mm Hg or more.

RESULTS

Of 6,657 idiopathic pulmonary fibrosis patients, 6,651 were used for univariate analysis, 6,126 for Kaplan-Meier survival function, 6,013 for multivariate Cox models, and 5,186 (mild PH) and 2,014 (severe PH) for propensity score matching, respectively. Univariate Cox proportional hazards analysis found significant differences in survival for mild PH (hazard ratio [HR] 1.689, 95% confidence interval [CI]: 1.434 to 1.988, p < 0.001) and severe PH (HR 2.068, 95% CI: 1.715 to 2.493, p < 0.001). Further assessment by multivariate Cox models identified significant risk for death for mild PH (HR 1.433, 95% CI: 1.203 to 1.706, p < 0.001) and severe PH (HR 1.597, 95% CI: 1.308 to 1.949, p < 0.001). Propensity score matching confirmed the risk for death for mild PH (HR 1.530, 95% CI: 1.189 to 1.969, p = 0.001) and severe PH (HR 2.103, 95% CI: 1.436 to 3.078, p < 0.001).

CONCLUSIONS

The manifestation of PH, even with mild severity, is associated with significantly increased risk for death among patients with idiopathic pulmonary fibrosis awaiting lung transplantation, so referral should be considered early in the disease course.

Human leukocyte antigen mismatching and survival after lung transplantation in adult and pediatric patients with cystic fibrosis

INTRODUCTION

The influence of human leukocyte antigen (HLA) mismatching on survival in adult and pediatric patients with cystic fibrosis (CF) after lung transplantation (LTx) is unknown.

METHODS

The United Network for Organ Sharing database was queried from 1987 to 2013 to determine the influence of HLA mismatching on survival in adult and pediatric CF LTx recipients by assessing the association of HLA mismatching with survival in first-time adult (aged ≥ 18 years) and pediatric (aged <18 years) recipients.

RESULTS

Of 3149 adult and 489 pediatric patients with CF, 3145 and 489 were used for univariate Cox analysis, 2687 and 363 for Kaplan-Meier survival analysis, and 2073 and 257 for multivariate Cox analysis, respectively. Univariate analyses in adult and pediatric patients with CF demonstrated conflicting associations between HLA mismatching and survival (adult hazard ratio [HR], 1.0; 95% confidence interval [CI], 0.97-1.1; P = .45 vs pediatric HR, 0.87; 95% CI, 0.77-0.99; P = .032). Multivariate Cox models including both pediatric and adult patients confirmed that HLA mismatching had an initially protective effect at young ages (HR, 0.85; 95% CI, 0.73-0.99; P = .044) and that this protective effect diminished at older ages and was no longer associated with survival at P < .05 beyond age 10 years.

CONCLUSIONS

HLA mismatching has significantly different implications for survival after LTx in adult compared with pediatric patients with CF.

Survival in Adult Lung Transplant Recipients Receiving Pediatric Versus Adult Donor Allografts

BACKGROUND

Recent evidence showed that pediatric donor lungs increased rates of allograft failure in adult lung transplant recipients; however, the influence on survival is unclear.

METHODS

The United Network for Organ Sharing (UNOS) database was queried from 2005 to 2013 for adult lung transplant recipients (≥18 years) to assess survival differences among donor age categories (<18 years, 18 to 29 years, 30 to 59 years, ≥60 years).

RESULTS

Of 12,297 adult lung transplants, 12,209 were used for univariate Cox models and Kaplan-Meier (KM) analysis and 11,602 for multivariate Cox models. A total of 1,187 adult recipients received pediatric donor lungs compared with 11,110 receiving adult donor organs. Univariate and multivariate Cox models found no difference in survival between donor ages 0 to 17 and donor ages 18 to 29, whereas donor ages 60 and older were significantly associated with increased mortality hazard, relative to the modal category of donor ages 30 to 59 (adjusted hazard ratio = 1.381; 95% confidence interval = 1.188% to 1.606%; p < 0.001). Interactions between recipient and donor age range found that the oldest donor age range was negatively associated with survival among middle-aged (30 to 59) and older (≥60) lung transplant recipients.

CONCLUSIONS

Pediatric donor lung allografts were not negatively associated with survival in adult lung transplant recipients; however, the oldest donor age range was associated with increased mortality hazard for adult lung transplant recipients.

Mortality Risk and Pulmonary Function in Adults With Cystic Fibrosis at Time of Wait Listing for Lung Transplantation

BACKGROUND

Lung transplantation (LTx) benefit for survival in cystic fibrosis (CF) patients placed on the wait list is not well studied.

METHODS

To predict the relationship between initial forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) and the hazard ratio (HR) associated with LTx in CF patients, the United Network for Organ Sharing database was queried from 2005 to 2006 for adult patients with CF. Survival was assessed from wait list entry time until death on wait list, death after LTx, or censoring. Multivariate Cox proportional hazards models were used to assess the effect of LTx. The first model estimated the HR of LTx with adjustment for FEV1 or FVC and other covariates, and the second model estimated the HR of LTx conditional on FEV1 or FVC at listing.

RESULTS

Two hundred seventy-eight patients with CF were included in the cohort, and 277 were used for survival analysis. Lung transplantation reduced the risk for death controlling for FEV1 (HR, 0.601; 95% confidence interval, 0.375 to 0.964; p = 0.035) or controlling for FVC (HR, 0.547; 95% confidence interval, 0.336 to 0.889; p = 0.015). Interaction models found that the HR of LTx varied significantly across initial FEV1 and FVC, with the predicted LTx HR and 95% confidence interval being protective (HR < 1) at FEV1 of 25% or less and FVC of 40% or less, respectively.

CONCLUSIONS

The benefit of LTx in adults with CF was significant at a lower baseline FEV1 than expected. A threshold for baseline FVC was established below which LTx was protective.

Autophagy in neonatal hypoxia ischemic brain is associated with oxidative stress

Autophagy is activated when the neonatal brain exposed to hypoxia ischemia (HI), but the mechanisms underlying its activation and its role in the neuronal cell death associated with HI is unclear. We have previously shown that reactive oxygen species (ROS) derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase play an important role in HI-mediated neuronal cell death. Thus, the aim of this study was to determine if ROS is involved in the activation of autophagy in HI-mediated neonatal brain injury and to determine if this is a protective or deleterious pathway. Initial electron microscopy data demonstrated that autophagosome formation is elevated in P7 hippocampal slice cultures exposed to oxygen-glucose deprivation (OGD). This corresponded with increased levels of LC3II mRNA and protein. The autophagy inhibitor, 3-methyladenine (3-MA) effectively reduced LC3II levels and autophagosome formation in hippocampal slice cultures exposed to OGD. Neuronal cell death was significantly attenuated. Finally, we found that the pharmacologic inhibition of NADPH oxidase using apocynin or gp91ds-tat decreased autophagy in hippocampal slice cultures and the rat brain respectively. Thus, our results suggest that an activation of autophagy contributes to neonatal HI brain injury this is oxidative stress dependent.

High-risk age window for mortality in children with cystic fibrosis after lung transplantation

LTx in children with CF remains controversial. The UNOS database was queried from 1987 to 2013 for CF patients <18 yr of age at time of transplant. PCHR model was used to quantify hazard of mortality. 489 recipients were included in the survival analysis. The hazard function of post-transplant mortality was plotted over attained age to identify age window of highest risk, which was 16-20 yr. Unadjusted PCHR model revealed ages immediately after the high-risk window were characterized by lower hazard of mortality (HR = 0.472; 95% CI = 0.302, 0.738; p = 0.001). After adjusting for potential confounders, the decline in mortality hazard immediately after the high-risk window remained statistically significant (HR = 0.394; 95% CI: 0.211, 0.737; p = 0.004). Hazard of mortality in children with CF after LTx was highest between 16 and 20 yr of attained age and declined thereafter.

Formulation and characterization of inhalable magnetic nanocomposite microparticles (MnMs) for targeted pulmonary delivery via spray drying

Targeted pulmonary delivery facilitates the direct application of bioactive materials to the lungs in a controlled manner and provides an exciting platform for targeting magnetic nanoparticles (MNPs) to the lungs. Iron oxide MNPs remotely heat in the presence of an alternating magnetic field (AMF) providing unique opportunities for therapeutic applications such as hyperthermia. In this study, spray drying was used to formulate magnetic nanocomposite microparticles (MnMs) consisting of iron oxide MNPs and d-mannitol. The physicochemical properties of these MnMs were evaluated and the in vitro aerosol dispersion performance of the dry powders was measured by the Next Generation Impactor(®). For all powders, the mass median aerosol diameter (MMAD) was <5μm and deposition patterns revealed that MnMs could deposit throughout the lungs. Heating studies with a custom AMF showed that MNPs retain excellent thermal properties after spray drying into composite dry powders, with specific absorption ratios (SAR)>200W/g, and in vitro studies on a human lung cell line indicated moderate cytotoxicity of these materials. These inhalable composites present a class of materials with many potential applications and pose a promising approach for thermal treatment of the lungs through targeted pulmonary administration of MNPs.

High-performing dry powder inhalers of paclitaxel DPPC/DPPG lung surfactant-mimic multifunctional particles in lung cancer: physicochemical characterization, in vitro aerosol dispersion, and cellular studies

Inhalable lung surfactant-based carriers composed of synthetic phospholipids, dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG), along with paclitaxel (PTX), were designed and optimized as respirable dry powders using organic solution co-spray-drying particle engineering design. These materials can be used to deliver and treat a wide variety of pulmonary diseases with this current work focusing on lung cancer. In particular, this is the first time dry powder lung surfactant-based particles have been developed and characterized for this purpose. Comprehensive physicochemical characterization was carried out to analyze the particle morphology, surface structure, solid-state transitions, amorphous character, residual water content, and phospholipid bilayer structure. The particle chemical composition was confirmed using attenuated total reflectance-Fourier-transform infrared (ATR-FTIR) spectroscopy. PTX loading was high, as quantified using UV-VIS spectroscopy, and sustained PTX release was measured over weeks. In vitro cellular characterization on lung cancer cells demonstrated the enhanced chemotherapeutic cytotoxic activity of paclitaxel from co-spray-dried DPPC/DPPG (co-SD DPPC/DPPG) lung surfactant-based carrier particles and the cytotoxicity of the particles via pulmonary cell viability analysis, fluorescent microscopy imaging, and transepithelial electrical resistance (TEER) testing at air-interface conditions. In vitro aerosol performance using a Next Generation Impactor™ (NGI™) showed measurable powder deposition on all stages of the NGI and was relatively high on the lower stages (nanometer aerodynamic size). Aerosol dispersion analysis of these high-performing DPIs showed mass median diameters (MMADs) that ranged from 1.9 to 2.3 μm with excellent aerosol dispersion performance as exemplified by high values of emitted dose, fine particle fractions, and respirable fractions.

Dry powder inhalers in COPD, lung inflammation and pulmonary infections

INTRODUCTION

The number of pulmonary diseases that are effectively treated by aerosolized medicine continues to grow.

AREAS COVERED

These diseases include chronic obstructive pulmonary disease (COPD), lung inflammatory diseases (e.g., asthma) and pulmonary infections. Dry powder inhalers (DPIs) exhibit many unique advantages that have contributed to the incredible growth in the number of DPI pharmaceutical products. To improve the performance, there are a relatively large number of DPI devices available for different inhalable powder formulations. The relationship between formulation and inhaler device features on performance of the drug-device combination product is critical. Aerosol medicine products are drug-device combination products. Device design and compatibility with the formulation are key drug-device combination product aspects in delivering drugs to the lungs as inhaled powders. In addition to discussing pulmonary diseases, this review discusses DPI devices, respirable powder formulation and their interactions in the context of currently marketed DPI products used in the treatment of COPD, asthma and pulmonary infections.

EXPERT OPINION

There is a growing line of product options available for patients in choosing inhalers for treatment of respiratory diseases. Looking ahead, combining nanotechnology with optimized DPI formulation and enhancing device design presents a promising future for DPI development.

Inhalable PEGylated Phospholipid Nanocarriers and PEGylated Therapeutics for Respiratory Delivery as Aerosolized Colloidal Dispersions and Dry Powder Inhalers

Nanomedicine is making groundbreaking achievements in drug delivery. The versatility of nanoparticles has given rise to its use in respiratory delivery that includes inhalation aerosol delivery by the nasal route and the pulmonary route. Due to the unique features of the respiratory route, research in exploring the respiratory route for delivery of poorly absorbed and systemically unstable drugs has been increasing. The respiratory route has been successfully used for the delivery of macromolecules like proteins, peptides, and vaccines, and continues to be examined for use with small molecules, DNA, siRNA, and gene therapy. Phospholipid nanocarriers are an attractive drug delivery system for inhalation aerosol delivery in particular. Protecting these phospholipid nanocarriers from pulmonary immune system attack by surface modification by polyethylene glycol (PEG)ylation, enhancing mucopenetration by PEGylation, and sustaining drug release for controlled drug delivery are some of the advantages of PEGylated liposomal and proliposomal inhalation aerosol delivery. This review discusses the advantages of using PEGylated phospholipid nanocarriers and PEGylated therapeutics for respiratory delivery through the nasal and pulmonary routes as inhalation aerosols.

Design, characterization, and aerosol dispersion performance modeling of advanced co-spray dried antibiotics with mannitol as respirable microparticles/nanoparticles for targeted pulmonary delivery as dry powder inhalers

Dry powder inhalation aerosols of antibiotic drugs (a first-line aminoglycoside, tobramycin, and a first-line macrolide, azithromycin) and a sugar alcohol mucolytic agent (mannitol) as co-spray dried (co-SD) particles at various molar ratios of drug:mannitol were successfully produced by organic solution advanced co-spray drying from dilute solute concentration. These microparticulate/nanoparticulate aerosols consisting of various antibiotic drug:mannitol molar ratios were rationally designed with a narrow and unimodal primary particle size distribution, spherical particle shape, relatively smooth particle surface, and very low residual water content to minimize the interparticulate interactions and enhance in vitro aerosolization. These microparticulate/nanoparticulate inhalation powders were high-performing aerosols as reflected in the aerosol dispersion performance parameters of emitted dose, fine particle fraction (FPF), respirable fraction (RF), and mass median aerodynamic diameter (MMAD). The glass transition temperature (Tg) values were significantly above room temperature, which indicated that the co-SD powders were all in the amorphous glassy state. The Tg values for co-SD tobramycin:mannitol powders were significantly lower than those for co-SD azithromycin:mannitol powders. The interplay between aerosol dispersion performance parameters and Tg was modeled where higher Tg values (i.e., more ordered glass) were correlated with higher values in FPF and RF and lower values in MMAD.

Alternative tacrolimus and sirolimus regimen associated with rapid resolution of posterior reversible encephalopathy syndrome after lung transplantation

BACKGROUND

Neurotoxicity is a significant complication of calcineurin inhibitor use, and posterior reversible encephalopathy syndrome has been reported. Limited data exist on the use of alternative immunosuppression regimens in the management of posterior reversible encephalopathy syndrome in transplant recipients.

METHODS

We present the immunosuppression management strategy of a girl who underwent bilateral lung transplantation for cystic fibrosis 6 months earlier, then suddenly developed a grand mal seizure due to posterior reversible encephalopathy syndrome diagnosed by magnetic resonance imaging of the brain. In an effort to reduce her tacrolimus dose, an alternative immunosuppressant regimen combining tacrolimus and sirolimus was used.

RESULTS

After the modification of her immunosuppressant regimen, there was rapid clinical improvement with no further seizures. Her brain findings had resolved on magnetic resonance imaging 2 months later. Over the next 6 months, allograft function remained stable and surveillance transbronchial biopsies found no allograft rejection on the combined sirolimus and tacrolimus therapy.

CONCLUSIONS

Tacrolimus-associated neurotoxicity resolved in a lung transplant recipient with a combined tacrolimus and sirolimus regimen. This combined therapy appears to be an effective alternative for lung transplant recipients that allow them to receive the benefits of both drugs but at lower doses, which reduces the risk for adverse effects.

Design, characterization, and aerosol dispersion performance modeling of advanced spray-dried microparticulate/nanoparticulate mannitol powders for targeted pulmonary delivery as dry powder inhalers

BACKGROUND

The purpose was to design and characterize inhalable microparticulate/nanoparticulate dry powders of mannitol with essential particle properties for targeted dry powder delivery for cystic fibrosis mucolytic treatment by dilute organic solution spray drying, and, in addition, to tailor and correlate aerosol dispersion performance delivered as dry powder inhalers based on spray-drying conditions and solid-state physicochemical properties.

METHODS

Organic solution advanced spray drying from dilute solution followed by comprehensive solid-state physicochemical characterization and in vitro dry powder aerosolization were used.

RESULTS

The particle size distribution of the spray-dried (SD) powders was narrow, unimodal, and in the range of ∼500 nm to 2.0 μm. The particles possessed spherical particle morphology, relatively smooth surface morphology, low water content and vapor sorption (crystallization occurred at exposure above 65% relative humidity), and retention of crystallinity by polymorphic interconversion. The emitted dose, fine particle fraction (FPF), and respirable fraction (RF) were all relatively high. The mass median aerodynamic diameters were below 4 μm for all SD mannitol aerosols.

CONCLUSION

The in vitro aerosol deposition stage patterns could be tailored based on spray-drying pump rate. Positive linear correlation was observed between both FPF and RF values with spray-drying pump rates. The interplay between various spray-drying conditions, particle physicochemical properties, and aerosol dispersion performance was observed and examined, which enabled tailoring and modeling of high aerosol deposition patterns.

Influence of the carboxymethyl chitosan anti-adhesion solution on the TGF-β1 in a postoperative peritoneal adhesion rat

The aim of this paper was to investigate the effect of carboxymethyl chitosan anti-adhesion solution on prevention of postsurgical adhesion. Forty adult male Wistar rats were randomly divided into three groups: 0.9% normal saline solution (group A), hyaluronic acid gels (group B) and carboxymethyl chitosan anti-adhesion solution (group C). The animals were treated with normal saline, hyaluronic acid gels or carboxymethyl chitosan anti-adhesion solution at the time of surgery. After 2 or 3 weeks, the degree of adhesions and histological effects were determined. The adhesions in groups B and C were significantly decreased, and the levels of TGF-β1 and hydroxyproline in group C were significantly lower than that in group A (P < 0.05). The histopathology in group C showed fewer inflammatory cells and fibroblasts. Carboxymethyl chitosan anti-adhesion solution can effectively prevent postoperative adhesion which is a promising drug delivery system in the context of postsurgical anti-adhesion.