This dissertation, "Drug Delivery Devices Fabricated by Microfluidic Method and Their Applications in Long-term Antimicrobial Therapy" by Jun, Wu, 吴隽, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Controlled drug delivery devices provide numerous advantages such as reduced side effects, higher therapeutic efficiency and improved patient compliance. Biodegradable polymer has become the most important material for controlled drug delivery device because of the excellent biocompatibility and tunable physicochemical properties. Biodegradable polymeric drug delivery devices are usually processed into various types of micro-particles due to the ease of fabrication and administration. However, controlling the drug release kinetics of these microparticles is still a challenge. One important reason is that drug release kinetics is significantly influenced by the microstructure of drug delivery devices, which is difficult to control. Microfluidic method is a group of technologies involved in the manipulation of fluids using channels in the scale of micrometers. Microfluidic method is particularly useful in controlling the structure of micro-droplets and generating homogeneous droplets. Therefore, microfluidics suggests great potential in controlling microstructures of drug delivery devices and drug release kinetics. In this study, biodegradable polymer based controlled drug delivery devices were fabricated using microfluidic method. Various types of microstructures were developed such as microspheres, core-shell microspheres, hollow microspheres and hydrogel microspheres. The results showed that microstructures were well controlled by fluid flow rates and geometries of capillary microfluidic devices. Both hydrophobic and hydrophilic drugs could be delivered by choosing drug delivery devices with suitable microstructures. Drug release kinetics of biodegradable polymeric microspheres has been studies a lot, yet complete understanding is still to be achieved. The diameter is an important factor which contributes to the drug release kinetics. However, the influence of diameter has not been systemically studied because monodisperse microspheres are difficult to obtain. Using microfluidic method, monodisperse PLGA microspheres with different diameters were fabricated to study the influence of diameter on drug release kinetics. It was found that diameter only influence the duration of the first phase (lag phase) in drug release process and smaller microspheres exhibited shorter lag phase. The relatively faster expansion of smaller microspheres was found to be responsible for the size effect by monitoring physicochemical changes during drug release. Rifampicin, a broad-spectrum antibiotic, was encapsulated by PLGA microspheres and PLGA-alginate core-shell microspheres. The long-term antimicrobial effects of drug loaded microspheres were investigated by drug release test and antimicrobial test against Staphylococcus aureus. The results showed that drug delivery devices could provide antimicrobial effect for more than one month. These drug delivery devices show potential in applications of controlled drug delivery and long-term antimicrobial therapy. In conclusion, drug delivery devices with different microstructures were fabricated using microfluidic method. The diameter of PLGA microspheres only influence the first phase of drug release profile (lag phase) and smaller microspheres exhibited shorter lag phase. The size effect is due to the relatively faster expansion rate of smaller microspheres. Rifampicin loaded PLGA microspheres and PLGA-alg

Microfluidics for Pharmaceutical Applications: From Nano/Micro Systems Fabrication to Controlled Drug Delivery is a concept-orientated reference that features case studies on utilizing microfluidics for drug delivery applications. It is a valuable learning reference on microfluidics for drug delivery applications and assists practitioners developing novel drug delivery platforms using microfluidics. It explores advances in microfluidics for drug delivery applications from different perspectives, covering device fabrication, fluid dynamics, cutting-edge microfluidic technology in the global drug delivery industry, lab-on-chip nano/micro fabrication and drug encapsulation, cell encapsulation and delivery, and cell- drug interaction screening. These microfluidic platforms have revolutionized the drug delivery field, but also show great potential for industrial applications. - Presents detailed coverage on the fabrication of novel drug delivery systems with desired characteristics, such as uniform size, Janus particles, and particular or combined responsiveness - Includes a variety of case studies that explain principles - Focuses on commercialization, cost, safety, society and educational issues of microfluidic applications, showing how microfluidics is used in the real world

Microfluidics or lab-on-a-chip (LOC) is an important technology suitable for numerous applications from drug delivery to tissue engineering. Microfluidic devices for biomedical applications discusses the fundamentals of microfluidics and explores in detail a wide range of medical applications.The first part of the book reviews the fundamentals of microfluidic technologies for biomedical applications with chapters focussing on the materials and methods for microfabrication, microfluidic actuation mechanisms and digital microfluidic technologies. Chapters in part two examine applications in drug discovery and controlled-delivery including micro needles. Part three considers applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and their role in developing tissue scaffolds and stem cell engineering. The final part of the book covers the applications of microfluidic devices in diagnostic sensing, including genetic analysis, low-cost bioassays, viral detection, and radio chemical synthesis.Microfluidic devices for biomedical applications is an essential reference for medical device manufacturers, scientists and researchers concerned with microfluidics in the field of biomedical applications and life-science industries. - Discusses the fundamentals of microfluidics or lab-on-a-chip (LOC) and explores in detail a wide range of medical applications - Considers materials and methods for microfabrication, microfluidic actuation mechanisms and digital microfluidic technologies - Considers applications of microfluidic devices in cellular analysis and manipulation, tissue engineering and their role in developing tissue scaffolds and stem cell engineering

This book provides an overview of various drug delivery systems at the cellular level including biological, chemical methods, and most importantly physical methods such as photoporation, electroporation, mechanoporation, and device-based techniques (e.g., microfluidics), as well as organism-level techniques including nanomaterials, biomaterials, and transdermal. Drug delivery (DD) can be defined as the method and route by which an active pharmaceutical ingredient (API) is administered to promote its desired pharmacological effect and/or convenience and/or to reduce adverse effects. Drug delivery systems are developed to maximize drug efficacy and minimize side effects. As drug delivery technologies improve, the drug becomes safer and more comfortable for patients to use. During the last seven decades, extraordinary progress has been made in drug delivery technologies, such as systems for long-term delivery for months and years, localized delivery, and targeted delivery. The advances, however, will face the next phase considering the future technologies that we need to overcome many physicochemical barriers for new formulation development and biological unknowns for treating various diseases. Thus, various technologies are built at a single-cell level as well as an organism level. This book is useful at the university level for graduate courses or research studies and biotechnology-based companies with research and development on cell-based analysis, diagnosis, or drug screening. This book is also very useful for researchers in drug delivery technologies, which came in frontier research for the past decade.

Drug Delivery Devices and Therapeutic Systems examines the current technology and innovations moving drug delivery systems (DDS) forward. The book provides an overview on the therapeutic use of drug delivery devices, including design, applications, and a description of the design of each device. While other books focus on the therapy, the primary emphasis in this book is on current technologies for DDS applications, including microfluidics, nanotechnology, biodegradable hydrogel and microneedles, with a special emphasis on wearable DDS. As part of the Developments in Biomedical Engineering and Bioelectronics series, this book is written by experts in the field and informed with information directly from manufacturers. Pharmaceutical scientists, medical researchers, biomedical engineers and clinical professionals will find this an essential reference. - Provides essential information on the most recent drug delivery systems available - Explains current technology and its applications to drug delivery - Contains contributions from biomedical engineers, pharmaceutical scientists and manufacturers

This book provides a comprehensive, state-of-the-art review of microfluidic approaches and applications in pharmatechnology. It is appropriate for students with an interdisciplinary interest in both the pharmaceutical and engineering fields, as well as process developers and scientists in the pharmaceutical industry. The authors cover new and advanced technologies for screening, production by micro reaction technology and micro bioreactors, small-scale processing of drug formulations, and drug delivery that will meet the need for fast and effective screening methods for drugs in different formulations, as well as the production of drugs in very small volumes. Readers will find detailed chapters on the materials and techniques for fabrication of microfluidic devices, microbioreactors, microsystems for emulsification, on-chip fabrication of drug delivery systems, respiratory drug delivery and delivery through microneedles, organs-on-chip, and more.