Effect of swirling flow and particle-release pattern on drug delivery to human tracheobronchial airways

2021 ◽  
Author(s):  
Mohammad Hasan Taheri ◽  
Oveis Pourmehran ◽  
Mohammad Mohsen Sarafraz ◽  
Keveh Ahookhosh ◽  
Ali Farnoud ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Swirling Flow ◽  
Particle Release ◽  
Release Pattern

scholarly journals Deposition of bolus and continuously inhaled aerosols in rhythmically moving terminal alveoli

2018 ◽  
Vol 10 (4) ◽  
pp. 178-193 ◽  
Author(s):  
Jinxiang Xi ◽  
Khaled Talaat ◽  
Xiuhua April Si
Keyword(s):  
Drug Delivery ◽  
Release Time ◽  
Breath Holding ◽  
Measurement Instruments ◽  
Tidal Breathing ◽  
Particle Release ◽  
In Vivo Measurement ◽  
Tracking Model

The particle dynamics in an oscillating alveolus under tidal breathing can be dramatically different from those in a static alveolus. Despite its close relevance to pulmonary drug delivery and health risk from airborne exposure, quantifications of alveolar deposition are scarce due to its inaccessibility to in vivo measurement instruments, tiny size to replicate in vitro, and dynamic wall motions to model. The objective of this study is to introduce a numerical method to quantify alveolar deposition with continuous particle release in a rhythmically oscillating alveolus by integrating the deposition curves for bolus aerosols and use this method to develop correlations applicable in assessing alveolar drug delivery efficiency or dosimetry of inhaled toxicants. An idealized blind-end terminal alveolus model was developed with rhythmically moving alveolar boundary conditions in phase with tidal breathing. The dynamic wall expansion mode and magnitude were based on experimentally measured chest wall motions and tidal volumes. A well-validated Lagrangian tracking model was used to simulate the transport and deposition of inhaled micrometer particles. Large differences were observed between dynamic and static alveoli in particle motion, deposition onset, and final alveolar deposition fraction. Alveolar deposition of bolus aerosols is highly sensitive to breath-holding duration, particle release time, and alveolar dimension. For 1 µm particles, there exists a cut-off release time (zero bolus deposition), which decreases with alveolar size (i.e., 1.0 s in a 0.2-mm-diameter alveolus and 0.56 s in a 0.8-mm-diameter alveolus). The cumulative alveolar deposition was predicted to be 39% for a 0.2-mm-diameter alveolus, 22% for a 0.4-mm-diameter alveolus, and 10% for a 0.8-mm-diameter alveolus. A cumulative alveolar deposition correlation was developed for inhalation delivery with a prescribed period of drug release and the second correlation for the time variation of alveolar deposition of ambient aerosols, both of which captured the relative dependence of the particle release time and alveolar dimension.

Bentonite nanoclay-based drug-delivery systems for treating melanoma

Clay Minerals ◽  
2018 ◽  
Vol 53 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Faezeh Hosseini ◽  
Farzaneh Hosseini ◽  
Seyyed Mehdi Jafari ◽  
Azade Taheri
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Drug Delivery System ◽  
Delivery System ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Burst Release ◽  
Normal Tissues ◽  
Release Pattern

ABSTRACTLocal chemotherapy with biocompatible drug-delivery systems prolongs survival in patients. Due to the biocompatibility and high loading capacity, bentonite nanoclay is a good candidate for the fabrication of drug-delivery vehicles. In this study, doxorubicin-bentonite nanoclay complex (DOX-Bent complex) was prepared for the first time as a sustained-release drug-delivery system for intratumoural chemotherapy of melanoma. An efficient loading of DOX on 1 mg of bentonite nanoclay as high as 994.45 ± 4.9 µg was obtained at a 30:1 DOX:bentonite nanoclay mass ratio. The DOX-Bent complex showed a low initial burst release of DOX in the first 24 h of release, followed by a sustained-release pattern for 21 days. The cumulativein vitrorelease of DOX from the DOX-Bent complex at pHs 6.5 and 7.4 revealed that the DOX-Bent complex can distinguish between tumour and normal tissues and express specific drug release at the tumour site. The results of cytotoxicity experiments indicated that the release pattern of DOX can supply sufficient DOX to inhibit growth of the melanoma cancer cell with an IC50 of 0.29 ± 0.07 µg/mL. It is thus suggested that the DOX-Bent complex be introduced as a drug-delivery system for effective local cancer therapy.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

Nanotheranostic agents for neurodegenerative diseases

2020 ◽  
Vol 4 (6) ◽  
pp. 645-675
Author(s):  
Parasuraman Padmanabhan ◽  
Mathangi Palanivel ◽  
Ajay Kumar ◽  
Domokos Máthé ◽  
George K. Radda ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Neurodegenerative Diseases ◽  
Cell Types ◽  
Specific Cell ◽  
Ageing Population ◽  
Target Tissue ◽  
Therapeutic Approaches ◽  
Surface Receptors ◽  
Theranostic Agents ◽  
Preclinical Animal Models

Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD) and Parkinson's disease (PD), affect the ageing population worldwide and while severely impairing the quality of life of millions, they also cause a massive economic burden to countries with progressively ageing populations. Parallel with the search for biomarkers for early detection and prediction, the pursuit for therapeutic approaches has become growingly intensive in recent years. Various prospective therapeutic approaches have been explored with an emphasis on early prevention and protection, including, but not limited to, gene therapy, stem cell therapy, immunotherapy and radiotherapy. Many pharmacological interventions have proved to be promising novel avenues, but successful applications are often hampered by the poor delivery of the therapeutics across the blood-brain-barrier (BBB). To overcome this challenge, nanoparticle (NP)-mediated drug delivery has been considered as a promising option, as NP-based drug delivery systems can be functionalized to target specific cell surface receptors and to achieve controlled and long-term release of therapeutics to the target tissue. The usefulness of NPs for loading and delivering of drugs has been extensively studied in the context of NDDs, and their biological efficacy has been demonstrated in numerous preclinical animal models. Efforts have also been made towards the development of NPs which can be used for targeting the BBB and various cell types in the brain. The main focus of this review is to briefly discuss the advantages of functionalized NPs as promising theranostic agents for the diagnosis and therapy of NDDs. We also summarize the results of diverse studies that specifically investigated the usage of different NPs for the treatment of NDDs, with a specific emphasis on AD and PD, and the associated pathophysiological changes. Finally, we offer perspectives on the existing challenges of using NPs as theranostic agents and possible futuristic approaches to improve them.

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