A Microfluidic Device as a Drug Carrier

The development of nanomedicine or medical nanotechnology, has brought important new ways to the development of medicines and biotechnology products. As a result of groundbreaking discoveries in the use of nanoscale materials significant commercialization initiatives have been launched and are at the forefront of the rapidly expanding field of nanotechnology by using smart particles. Microfluidic technologies use nano-and micro-scale manufacturing technologies to develop controlled and reproducible liquid microenvironments. Lead compounds with controlled physicochemical properties can be obtained using microfluidics, characterized by high productivity, and evaluated by biomimetic methods. Microfluidics, for example, can not only produce nanoparticles in a well-controlled, reproducible, and high-throughput manner, but it can also continuously create three-dimensional environments to mimic physiological and/or pathological processes. Materials with smart properties can be manipulated to respond in a controllable and reversible way, modifying some of their properties as a result of external stimuli such as mechanical stress or a certain temperature. All in all, microfluidic technology offers a potential platform for the rapid synthesis of various novel drug delivery systems. Therefore, these smart particles are equally necessary as the drug in drug delivery

Microfluidic Systems for Pathogen Sensing: A Review

Rapid pathogen sensing remains a pressing issue today since conventional identification methodsare tedious, cost intensive and time consuming, typically requiring from 48 to 72 h. In turn, chip based technologies, such as microarrays and microfluidic biochips, offer real alternatives capable of filling this technological gap. In particular microfluidic biochips make the development of fast, sensitive and portable diagnostic tools possible, thus promising rapid and accurate detection of a variety of pathogens. This paper will provide a broad overview of the novel achievements in the field of pathogen sensing by focusing on methods and devices that compliment microfluidics

Microfluidic fabrication of hydrocortisone nanocrystals coated with polymeric stabilisers

Hydrocortisone (HC) nanocrystals intended for parenteral administration of HC were produced by anti-solvent crystallisation within coaxial assemblies of pulled borosilicate glass capillaries using either co-current flow of aqueous and organic phases or counter-current flow focusing. The organic phase was composed of 7 mg/mL of HC in a 60:40 (v/v) mixture of ethanol and water and the anti-solvent was milli-Q water. The microfluidic mixers were fabricated with an orifice diameter of the inner capillary ranging from 50 µm to 400 µm and operated at the aqueous to organic phase flow rate ratio ranging from 5 to 25. The size of the nanocrystals decreased with increasing aqueous to organic flow rate ratio. The counter-current flow microfluidic mixers provided smaller nanocrystals than the co-current flow devices under the same conditions and for the same geometry, due to smaller diameter of the organic phase stream in the mixing zone. The Z-average particle size of the drug nanocrystals increased from 210–280 nm to 320–400 nm after coating the nanocrystals with 0.2 wt % aqueous solution of hydroxypropyl methylcellulose (HPMC) in a stirred vial. The differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) analyses carried out on the dried nanocrystals stabilized with HPMC, polyvinyl pyrrolidone (PVP), and sodium lauryl sulfate (SLS) were investigated and reported. The degree of crystallinity for the processed sample was lowest for the sample stabilised with HPMC and the highest for the raw HC powder

Microfluidic Platforms for Evaluation of Nanobiomaterials: a Review

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Microfluidic Platforms for Evaluation of Nanobiomaterials: A Review

Biomaterials, especially those based on nanomaterials, have emerged as critical tools in biomedical applications. The applications encompass a wide range such as implantable devices, tissue regeneration, drug delivery, diagnostic systems, and molecular printing. The type of materials used also covers a wide range: metals (permanent and degradable), polymers (permanent and degradable), carbon nanotubes, and lipid nanoparticles. This paper explores the use of microfluidic platforms as a high-throughput research tool for the evaluation of nanobiomaterials. Typical screening of such materials involves cell/tissue cultures to determine attributes such as cell adhesion, proliferation, differentiation, as well as biocompatibility. In addition to this, other areas such as drug delivery and toxicity can also be evaluated via microfluidics. Traditional approach for screening of such materials is very time-consuming, and a lot of animals should be sacrificed since it involves one material and a single composition or concentration for a single test. The microfluidics approach has the advantage of using multiple types of drugs and their concentration gradients to simultaneously study the effect on the nanobiomaterial and its interaction with cell/tissue. In addition to this, microfluidics provides a unique environment to study the effect of cell-to-extracellular interaction and cell-to-cell communication in the presence of the nanobiomaterials

Porous Silicon-Based On-Demand Nanohybrids for Biomedical Applications

Considerable efforts have been made to fabricate nano-sized drug delivery systems (DDS) with unique and advanced features in comparison to conventional DDS. Yet, challenges still lay ahead requesting for more controllable, even on-demand drug release profiles from the DDS. Moreover, the emerging concept of personalized treatment further urges the combining of therapy and imaging regimes into a single nanocarrier. Among all the nanomaterials studied so far, porous silicon (PSi) draws increasing interest for constructing DDS due to its good biocompatibility, non-immunogenicity, large pore size/surface area and easily changeable surface properties. Herein, the aim of this thesis was to explore PSi-based DDS for multiple biomedical applications, which were designed and synthesized with specific on-demand features. Moreover, simultaneous incorporation of imaging modalities and drugs enables real-time visualization of drug release and/or cellular/tissue level disease condition, which are expected to be beneficial for personalized treatment regime. First, the potential of PSi nanoparticles for hydrophilic drug loading and on-demand release were evaluated by adapting a dynamic non-covalent bonding method. Different ligands were synthesized and applied for modifying the PSi, and the hydrophilic anti-cancer drug doxorubicin (DOX) was sequentially loaded into the fabricated DDS for pH-responsive release profiles. Meanwhile, the fluorescence spectrum of DOX can be dynamically shifted or quenched, depending on the loading and releasing process, thus facilitating the in situ visualization of the drug releasing process. For hydrophobic drugs, a physical encapsulation method was applied to seal the pores of the PSi by a polymeric matrix. Microfluidic-assisted nanoprecipitation method was applied to synthesize batches of nanohybrids with identical PSi-core/polymer-shell structures, and the release behavior was feasibly tailored by the degradation behavior of the outer polymeric matrix. The first trial was set to fabricate a core/shell nanohybrid, with PSi and gold nanoparticles co-encapsulated in a pH-responsive polymer to simultaneously deliver hydrophobic drug and increase the computed tomography signal for acute liver failure theranostics. The newly established single-step co-encapsulation of different particles endowed a system with multi-functionalities, and the polymeric shell precisely tailored the drug release behavior in a pH-dependent manner. Similarly, an acid/oxidation dual-responsive polymer was designed and further applied in encapsulating atorvastatin-loaded PSi nanoparticles. The meticulously designed system not only obtained a dynamic drug release behavior, but also showed an orchestrated cascade that facilitated bio-mimetic diabetic wound healing. To better elucidate the biocompatibility of PSi for DDS fabrication, the biological effects and immunogenicity of different PSi nanoparticles were evaluated at pre-existing lesion sites, which provided insights for further applications of PSi in DDS fabrication. In conclusion, multiple PSi-based nanohybrids with different on-demand responses were fabricated and applied as DDSs for different diseases. The newly developed nanosystems tailored drug release and obtained multiple modalities, ranging from real-time bio-imaging to bio-mimetic/bio-response alteration, as such, represent promising platforms for future therapy regimes.Nanokokoisilla lääkeainekuljettimilla on ainutlaatuisia ja kehittyneempiä ominaisuuksia perinteisiin lääkeaineen kuljetusmenetelmiin verrattuna. Niiden kehittämiseksi on tehty paljon, siitä huolimatta niillä on edessä vieläkin useita haasteita, jotka vaativat täsmällistä ja erityisen hyvin säädeltyä lääkeaineenvapautumista. Lisäksi kiinnostus potilaslähtöiseen hoitoon vaatii terapian ja kuvantamismahdollisuuksien yhdistämistä yksittäiseen lääkeaineen nanokantajaan. Yksi kiinnostavimmista tähän mennessä tutkituista materiaaleista on huokoinen pii (PSi), mikä johtuu sen bioyhteensopivuudesta, vähäisestä immunogeenisyydestä, suuresta huokosten koosta ja pinta-alasta sekä helposti muunnettavista pinnan ominaisuuksista. Tämän väitöstyön tavoite oli tutkia huokoiseen piihin pohjautuvien räätälöityjen lääkeainekuljettimien soveltuvuutta erilaisiin biolääketieteellisiin sovelluksiin. Lääkeaineiden ja kuvantamisen mahdollistavien aineiden kuormaaminen samoihin nanohiukkasiin mahdollistaa tosiaikaisen lääkeaineenvapautumisen kuvantamisen sekä taudinkuvan määrittämisen solu- ja/tai kudostasolla, joiden molempien voi odottaa olevan hyödyllisiä potilaslähtöiseen terapiaan. Ensimmäiseksi tutkittiin PSi-nanohiukkasten soveltuvuutta hydrofiilisten lääkeaineiden kantajina. Hallittua lääkeaineenvapautumista tutkittiin soveltamalla dynaamista ei-kovalenttista sidosmenetelmää. Erilaisia ligandeja syntetisoitiin ja niitä kiinnitettiin PSi-nanohiukkasten pintaan. Tämän jälkeen hiukkasiin kuormattiin syöpälääke doksorubisiinia, jonka pH-vasteellinen vapautuminen määritettiin. Doksorubisiinin fluoresenssispektri voidaan dynaamisesti siirtää tai sammuttaa eri kuormaamis- ja vapautumismenetelmillä, mikä mahdollistaa lääkeaineenvapautumis-prosessin in situ-kuvantamisen. Hydrofobisille lääkeaineille sovellettiin mikrofluidiikkaan perustuvaa kapselointia, jossa lääke ensin kuormattiin PSi:n huokosiin, jotka sitten suljettiin polymeeri-matriisilla. Lääkeaineenvapautuminen määräytyi polymeerin hajoamisnopeudesta. Ensimmäisessä kokeessa valmistettiin kuori/ydin-nanohybridejä, joissa PSi, kultananohiukkaset sekä hydrofobinen lääkeaine kapseloitiin pH-vasteelliseen polymeeriin. Näin voitiin akuutin maksan vajaatoiminnan yhteydessä säädellä lääkeaineenvapautumista pH:n avulla sekä samanaikaisesti tomografiakuvantaa. Yksivaiheisella kerakapseloinnilla, jossa yhdistetään erilaisia partikkeleita, saatiin aikaan monitoiminnallinen kuljetin, jonka polymeerikuori kykenee täsmällisesti säätelemään lääkeaineenvapautumista eri pH-olosuhteissa. Seuraavassa kokeessa pH- ja hapettumis-vasteellisella polymeerillä kapseloitiin atorvastatiinilla kuormattuja PSi-nanohiukkasia. Nämä huolellisesti suunnitellut nanohiukkaset kykenivät aktiivisesti muuttamaan lääkeaineen vapautumista mutta myös vaikuttivat aktiivisesti, muistuttaen luonnollista prosessia, diabeteksesta johtuvan haavan paranemiseen. PSi-hiukkasten biologinen yhteensopivuus lääkeaineenkuljettimeksi varmistettiin tutkimalla erilaisten PSi-nanohiukkasten biologisia vaikutuksia ja immunogeenisyyttä leesio (haavauma) kohdissa. Näin saatiin lisätietoa jatkokehittelyyn. Väitöstyössä kehitettiin useita piihiukkasiin pohjautuvia nanoyhdistelmiä lääkeainekuljetukseen erilaisten tautien hoitamiseksi. Perinteisiin lääkeaineenkuljetus-menetelmiin verrattuna uusien nanosysteemien etuja ovat tarpeenmukainen lääkeaineenvapautuminen ja monikäyttöisyys – tosiaikaisesta kuvantamisesta luonnollista prosessia muistuttavaan tai biologista vastetta muuttavaan vaikutukseen. Sellaisena ne edustavat lupaavaa menetelmää tulevaisuuden hoidoill

Self-powered mobile sensor for in-pipe potable water quality monitoring

Traditional stationary sensors for potable-water quality monitoring in a wireless sensor network format allow for continuous data collection and transfer. These stationary sensors have played a key role in reporting contamination events in order to secure public health. We are developing a self-powered mobile sensor that can move with the water flow, allowing real-time detection of contamination in water distribution pipes, with a higher temporal resolution. Functionality of the mobile sensor was tested for detecting and monitoring pH, Ca2+, Mg2+, HCO3-/CO32-, NH4+, and Clions. Moreover, energy harvest and wireless data transmission capabilities are being designed for the mobile sensor

Valoaktivoituvien ICG-Doksorubisiini-liposomien valmistaminen ja Quasi-Vivo® -pohjaisen kaksisolumallin kehittäminen lääkkeiden teho- ja toksisuuskokeisiin

Perinteiset 2D-solunkasvatusmenetelmät ja kokeelliset alustat eivät usein pysty simuloimaan eri solutyyppien luonnollista kemiallista ja fysiologista ympäristöä. Tekijöitä, jotka voivat vaikuttaa merkittävästi solujen erilaistumiseen, kasvuun, solunsisäisiin rakenteisiin tai metaboliseen aktiivisuuteen ovat esimerkiksi hapen saatavuus, viestiaineet, kemialliset gradientit, paine, nesteen virtaus ja alustojen topografia. Modulaarisia bioreaktoreita, kuten Quasi-Vivo®-järjestelmää, voidaan käyttää simuloimaan näitä tekijöitä. Liposomit ovat fosfolipidikaksoiskerroksesta muodostuvia partikkeleja, joiden sisällä on vesitilavuus. Niitä voidaan muokata monin eri tavoin, lataamalla niitä kuljettamaan vesi- tai rasvaliukoisia molekyylejä, muokkaamalla niiden transitiolämpötilaa, tai päällystämällä niitä eri tarpeiden mukaan. Doksorubisiini on tehokas ja yhä laajassa käytössä oleva sytostaatti, jolla kuitenkin vapaana lääkeaineena annosteltuna on vakavia haittoja, erityisesti sydäntoksisuus. Tässä työssä tavoitteena on selvittää sopivat valmistusparametrit ja todeta riittävä säilyvyys valoaktivoituville ICG-Doksorubisiini-liposomeille, jotta niitä voidaan käyttää tulevissa in vitro kokeissa. Tämän lisäksi selvitetään HepG2 solulinjan selviäminen virtauksen alla Quasi-Vivo® -laitteistossa ja yhdistetään HepG2 ja A549 solulinjat yhdeksi kaksisolumalliksi. Lopuksi suoritetaan yksinkertainen valotuskoe aiemmin valmistetuilla liposomeilla tässä solumallissa, ja tarkastellaan, miten vaikutus näkyy koko systeemissä. Liposomien, joiden ICG- ja doksorubisiini-enkapsulaatio on yli 70%, valmistaminen onnistuu esitetyllä protokollalla luotettavasti ja toistettavasti, ja nämä liposomit säilyvät käyttökelpoisina ainakin 14 vuorokautta säilytettynä pimeässä, 4°C lämpotilassa. A549 ja HepG2 solulinjojen kasvattaminen ja yhdistäminen samaan laitteistoon yhteiseen kasvatusliuokseen virtauksen alle onnistuu, eikä kummankaan solulinjan kasvussa huomata eroa viljelyyn staattisissa olosuhteissa. Kun valotetaan laitteistoon annosteltuja liposomeja, huomataan alustavien tulosten perusteella merkittävää tehon lisäystä valotetussa järjestelmässä pimeään verrattuna, sekä valotetuissa kammiossa että niissä, jotka siihen on Quasi-Vivo® -putkiston kautta yhdistetty.Traditional 2D cell cultivating vessels and experimental models cannot often simulate natural chemical and physical environment of different cell types. For example, availability of oxygen, chemical gradients, messaging molecules, fluid pressure, flow and surface topography are factors that may affect significantly in cell differentiation, growth, cellular structure, and metabolism. Modular bioreactors like Quasi-Vivo® -system can be used to simulate these factors. Liposomes are particles of phospholipid bilayer with aqueous space enclosed within. They can be modified in numerous ways, like loading them with hydrophobic and hydrophilic molecules, changing their transition temperature or coating them according to different needs. Doxorubicin is effective and widely used cytostatic agent, but when administered as a free drug it has often severe side-effects, like cardiotoxicity. Goal of this thesis is to determine appropriate manufacturing parameters and verify adequate shelf-life of ICG-Doxorubicin liposomes, that they are applicable for future in vitro experiments. Then survival of HepG2 cell line under flow in Quasi-Vivo®-equipment is determined, after which A549 and HepG2 will be then combined into one two-cell model. Finally, a simple illumination experiment in this cell model with previously made liposomes is conducted, and the effect in whole system is examined. Using protocol presented in this thesis it is possible to produce successfully and repeatedly liposomes with both ICG and doxorubicin encapsulation over 70%. Their shelf-life was at least 14 days when stored in 4°C protected from light. This was determined to be sufficient for in vitro testing. Cultivating A549 and HepG2 cell lines combined in the same system with shared media and fluid flow conditions was successful. Neither of the cell lines show significant difference in viability when compared to static control. When light-activating liposomes are administered to the system and then illuminated, from preliminary results we can see significant difference in drug effect. Both illuminated chambers and off-target chambers connected via Quasi-Vivo® show increased suppression, which shows promise that this in vitro model would be useful for future experiments

BioMEMS

As technological advancements widen the scope of applications for biomicroelectromechanical systems (BioMEMS or biomicrosystems), the field continues to have an impact on many aspects of life science operations and functionalities. Because BioMEMS research and development require the input of experts who use different technical languages and come from varying disciplines and backgrounds, scientists and students can avoid potential difficulties in communication and understanding only if they possess a skill set and understanding that enables them to work at the interface of engineering and biosciences. Keeping this duality in mind throughout, BioMEMS: Science and Engineering Perspectives supports and expedites the multidisciplinary learning involved in the development of biomicrosystems. Divided into nine chapters, it starts with a balanced introduction of biological, engineering, application, and commercialization aspects of the field. With a focus on molecules of biological interest, the book explores the building blocks of cells and viruses, as well as molecules that form the self-assembled monolayers (SAMs), linkers, and hydrogels used for making different surfaces biocompatible through functionalization. The book also discusses: Different materials and platforms used to develop biomicrosystems Various biological entities and pathogens (in ascending order of complexity) The multidisciplinary aspects of engineering bioactive surfaces Engineering perspectives, including methods of manufacturing bioactive surfaces and devices Microfluidics modeling and experimentation Device level implementation of BioMEMS concepts for different applications. Because BioMEMS is an application-driven field, the book also highlights the concepts of lab-on-a-chip (LOC) and micro total analysis system (μTAS), along with their pertinence to the emerging point-of-care (POC) and point-of-need (PON) applications

Formulation and characterization of siRNA embedded nanoparticles for pulmonary delivery

Advancing existing or developing novel nanoparticle carrier systems is a crucial part of successful nucleic acid delivery for therapeutic purposes. The overall aim of nanoparticle formulations is to deliver their cargo to the site of action. During this procedure, nanoparticles need to show qualities to be internalized into the cell and release their cargo. Dependent on the application route and prior to cell uptake, nanoparticles can be transferred into a form of administration that improves conformation and leads to long-term storage stability. The aim of this thesis is to identify various small interfering RNA (siRNA)-nanoparticle formulations as drug delivery systems with potential to target the lungs (Chapter I + II). Nanoparticles carrier systems comprised of polymers, lipids or a hybrid combination encapsulating nucleic acids and were formed using the concept of microfluidic mixing. The thesis can be separated into two main parts. The first part addresses the common dilemma of the endosomal escape problem by improving existing polymers through chemical modification (Chapter III), synthesizing a novel amphiphilic polymer (Chapter IV) and forming hybrid lipid polyplex nanoparticles (Chapter V). The second section focuses on the development of a spray-drying approach (Chapter VI) and the long-term storage under various conditions (Chapter VI) for siRNA-lipid nanoparticles (LNPs) based on an adapted Onpattro® formulation. The endosomal release problem of polymeric nanoparticles was tackled looking at physicochemical nanoparticle characterization and in vitro performance assessment. Throughout Chapters III - V, sizes of 100 – 200 nm were reached, the zeta potential was kept neutral to positive, and the encapsulation efficiency of siRNA showed values > 90% resulting in an improved in vitro knockdown performance (> 50%) in comparison to polyethylene imine (PEI) polyplexes or triblock copolymer polyplexes cores. The establishment of a spray drying platform for LNPs (Chapter VI) and subsequent drying for storage stability (Chapter VII) resulted in spray dried powders that maintained LNP integrity and stability by loosing up to 15% of siRNA and lipid content. The aerodynamic properties showed ideal characteristics for pulmonary delivery with sizes of 3 μm. The in vitro performance reached knockdown levels of > 95% and a house keeping gene silencing of > 50% was established ex vivo in human precision cut lung slices. In conclusion, this thesis should give an overview of several non-viral siRNA nanoparticles as nucleic acid delivery systems that on the one hand improve the endosomal escape problem of polymeric nanoparticles, and on the other hand are established for pulmonary delivery through a spray drying method