David Humen käsitys passioista, tahdosta sekä tahdonvapaudesta ja moraalisesta vastuusta

Tässä tutkielmassa perehdyn skottiempiristi David Humen käsitykseen passioista, tahdosta sekä tahdonvapaudesta ja moraalisesta vastuusta. Lähteeni on teoksen A Treatise of Human Nature toinen kirja Of the Passions mutta tutkielmassa viitataan myös teoksen muihin kirjoihin sekä Humen muihin teoksiin. Metodini on systemaattinen analyysi. Tutkielmani aiheesta ei ole julkaistu aikaisemmin suomenkielistä tutkimusta. Tutkimuksen ensimmäinen pääluku on katsaus Humen filosofiaan. Varsinaisia tutkimuskysymyksiä käsittelen luvuissa 2-4. Toisessa luvussa vastaan kysymyksiin siitä, mitä passiot ovat ja mikä on niiden tehtävä. Passiot ovat Humen mukaan sekundaarisia vaikutelmia ja hän jakaa ne epäsuoriin ja suoriin passioihin. Suorat passiot, kuten ilo, suru, halu ja pelko, syntyvät suoraan kivun tai nautinnon kokemuksesta. Epäsuorat passiot, kuten ylpeys, nöyryys, viha ja rakkaus, vaativat syntyäkseen sekä kohteen että aiheuttajan sekä assosiaatiota näiden välillä. Hume luokittelee passioita myös niiden tyyneyden ja rajuuden perusteella. Luokittelu perustuu passioiden häiriönasteeseen sielussa. Kumpikin voi yhtälailla toimia toiminnan motivaattorina. Kolmannessa luvussa kysyn ja vastaan, mitä Hume tarkoittaa tahdolla ja minkälainen kyky se on sekä mikä on passioiden suhde tahtoon. Hume määrittelee tahdon sisäiseksi vaikutelmaksi, jonka tunnemme ja josta olemme tietoisia, kun tieten tahtoen saamme aikaan minkä tahansa uuden liikkeen ruumiissamme tai uuden havainnon mielessämme. Tahto on passioiden kaltainen, mutta niistä erotettava sielun kyky. Tahto on Humen mukaan itsessään toimintaa ja passiot taas toimivat toimintaa aikaansaavina voimina. Humen määritelmä ei anna selkeää kuvaa siitä, mitä hän tarkoittaa tahdolla ja miten se toimii. Neljännessä luvussa kysyn, mistä tahto on vapaa, miten tahto ja passiot liittyvät moraaliseen vastuuseen ja miten Hume määrittelee moraalisen vastuun. Humen mukaan tahto on vapaa silloin, kun sille ei ole ulkoista estettä tai pakotetta. Hume uskoo siihen, että kaikella maailmassa on syynsä ja seurauksensa, jolloin myös kaikki toiminta ja ajattelu on aiheutunut jostain aikaisemmasta. Hume on kompatibilisti eli hän katsoo, että vapaa tahto on yhteen sovitettavissa determinismin kanssa. Klassisessa tulkintatavassa Humen kompatibilismia tarkastellaan Humen vapaudelle antaman määritelmän ja maailmassa ilmenevän välttämättömyyden kautta. Klassisessa tulkintatavassa Humen mukaan ihmistä voi pitää vastuullisena vain sellaisista teoista, jotka ovat johdettavissa häneen ja jotka ovat aiheutettuja. Tulkinnassa keskitytään perustelemaan miten aiheutettu toiminta voi olla vapaata. ja sen mukaan moraalinen vastuu edellyttää determinismiä. Naturalistisessa tulkintatavassa otetaan huomioon Humen passioteoria. Humen mukaan moraalinen vastuu koetaan sisäisinä moraalitunteina, jotka ovat passioita. Toisen toimintaa eli tahdon toteuttamista seuratessa siitä koetaan joko hyväksyntää tai paheksuntaa ja toista pidetään sen perusteella vastuullisena toiminnastaan. Mikäli hyväksynnän tai paheksunnan tuntemuksia ei synny, toisen ei katsota olevan vastuussa teostaan. Merkitystä ei ole sillä, voidaanko toiminta johdonmukaisesti määritellä vapaaksi, vaan sillä, saako se aikaan moraalitunteita

Coassembly Generates Peptide Hydrogel with Wound Dressing Material Properties

Multicomponent self-assembly of peptides is a powerful strategy to fabricate novel functional materials with synergetic properties that can be used for several nanobiotechnological applications. In the present study, we used a coassembly strategy to generate an injectable ultrashort bioactive peptide hydrogel formed by mixing a dipeptide hydrogelator with a macrophage attracting short chemotactic peptide ligand. Coassembly does not impede hydrogelation as shown by cryo-transmission electron microscopy (cryo-TEM), scanning electron microscopy, and rheology. Biocompatibility was shown by cytotoxicity assays and confocal microscopy. The hydrogels release the entrapped skin antibiotic ciprofloxacin, among others, in a slow and continuous manner. Such bioinspired advanced functional materials can find applications as wound dressing materials to treat chronic wound conditions like diabetic foot ulcer

In vitro vascularization of hydrogel-based tissue constructs via a combined approach of cell sheet engineering and dynamic perfusion cell culture

The bioengineering of artificial tissue constructs requires special attention to their fast vascularization to provide cells with sufficient nutrients and oxygen. We addressed the challenge of in vitro vascularization by employing a combined approach of cell sheet engineering, 3D printing, and cellular self-organization in dynamic maturation culture. A confluent cell sheet of human umbilical vein endothelial cells (HUVECs) was detached from a thermoresponsive cell culture substrate and transferred onto a 3D-printed, perfusable tubular scaffold using a custom-made cell sheet rolling device. Under indirect co-culture conditions with human dermal fibroblasts (HDFs), the cell sheet-covered vessel mimic embedded in a collagen gel together with additional singularized HUVECs started sprouting into the surrounding gel, while the suspended cells around the tube self-organized and formed a dense lumen-containing 3D vascular network throughout the gel. The HDFs cultured below the HUVEC-containing cell culture insert provided angiogenic support to the HUVECs via molecular crosstalk without competing for space with the HUVECs or inducing rapid collagen matrix remodeling. The resulting vascular network remained viable under these conditions throughout the 3 week cell culture period. This static indirect co-culture setup was further transferred to dynamic flow conditions, where the medium perfusion was enabled via two independently addressable perfusion circuits equipped with two different cell culture chambers, one hosting the HDFs and the other hosting the HUVEC-laden collagen gel. Using this system, we successfully connected the collagen-embedded HUVEC culture to a dynamic medium flow, and within 1 week of the dynamic cell culture, we detected angiogenic sprouting and dense microvascular network formation via HUVEC self-organization in the hydrogel. Our approach of combining a 3D-printed and cell sheet-covered vascular precursor that retained its sprouting capacity together with the self-assembling HUVECs in a dynamic perfusion culture resulted in a vascular-like 3D network, which is a critical step toward the long-term vascularization of bioengineered in vitro tissue constructs

Flow-induced glycocalyx formation and cell alignment of HUVECs compared to iPSC-derived ECs for tissue engineering applications

The relevance of cellular in vitro models highly depends on their ability to mimic the physiological environment of the respective tissue or cell niche. Static culture conditions are often unsuitable, especially for endothelial models, since they completely neglect the physiological surface shear stress and corresponding reactions of endothelial cells (ECs) such as alignment in the direction of flow. Furthermore, formation and maturation of the glycocalyx, the essential polysaccharide layer covering all endothelial surfaces and regulating diverse processes, is highly dependent on applied fluid flow. This fragile but utterly important macromolecular layer is hard to analyze, its importance is often underestimated and accordingly neglected in many endothelial models. Therefore, we exposed human umbilical vein ECs (HUVECs) and human induced pluripotent stem cell-derived ECs (iPSC-ECs) as two relevant EC models in a side-by-side comparison to static and physiological dynamic (6.6 dyn cm−2) culture conditions. Both cell types demonstrated an elongation and alignment along the flow direction, some distinct changes in glycocalyx composition on the surface regarding the main glycosaminoglycan components heparan sulfate, chondroitin sulfate or hyaluronic acid as well as an increased and thereby improved glycocalyx thickness and functionality when cultured under homogeneous fluid flow. Thus, we were able to demonstrate the maturity of the employed iPSC-EC model regarding its ability to sense fluid flow along with the general importance of physiological shear stress for glycocalyx formation. Additionally, we investigated EC monolayer integrity with and without application of surface shear stress, revealing a comparable existence of tight junctions for all conditions and a reorganization of the cytoskeleton upon dynamic culture leading to an increased formation of focal adhesions. We then fabricated cell sheets of EC monolayers after static and dynamic culture via non-enzymatic detachment using thermoresponsive polymer coatings as culture substrates. In a first proof-of-concept we were able to transfer an aligned iPSC-EC sheet to a 3D-printed scaffold thereby making a step in the direction of vascular modelling. We envision these results to be a valuable contribution to improvements of in vitro endothelial models and vascular engineering in the future

Rise of tissue- and species-specific 3D bioprinting based on decellularized extracellular matrix-derived bioinks and bioresins

Thanks to its natural complexity and functionality, decellularized extracellular matrix (dECM) serves as an excellent foundation for creating highly cell-compatible bioinks and bioresins. This enables the bioprinted cells to thrive in an environment that closely mimics their native ECM composition and offers customizable biomechanical properties. To formulate dECM bioinks and bioresins, one must first pulverize and/or solubilize the dECM into non-crosslinked fragments, which can then be chemically modified as needed. In bioprinting, the solubilized dECM-derived material is typically deposited and/or crosslinked in a layer-by-layer fashion to build 3D hydrogel structures. Since the introduction of the first liver-derived dECM-based bioinks, a wide variety of decellularized tissue have been employed in bioprinting, including kidney, heart, cartilage, and adipose tissue among others. This review aims to summarize the critical steps involved in tissue-derived dECM bioprinting, starting from the decellularization of the ECM to the standardized formulation of bioinks and bioresins, ultimately leading to the reproducible bioprinting of tissue constructs. Notably, this discussion also covers photocrosslinkable dECM bioresins, which are particularly attractive due to their ability to provide precise spatiotemporal control over the gelation in bioprinting. Both in extrusion printing and vat photopolymerization, there is a need for more standardized protocols to fully harness the unique properties of dECM-derived materials. In addition to mammalian tissues, the most recent bioprinting approaches involve the use of microbial extracellular polymeric substances in bioprinting of bacteria. This presents similar challenges as those encountered in mammalian cell printing and represents a fascinating frontier in bioprinting technology

3D-Cultured Vascular-Like Networks Enable Validation of Vascular Disruption Properties of Drugs In Vitro

Vascular-disrupting agents are an interesting class of anticancer compounds because of their combined mode of action in preventing new blood vessel formation and disruption of already existing vasculature in the immediate microenvironment of solid tumors. The validation of vascular disruption properties of these drugs in vitro is rarely addressed due to the lack of proper in vitro angiogenesis models comprising mature and long-lived vascular-like networks. We herein report an indirect coculture model of human umbilical vein endothelial cells (HUVECs) and human dermal fibroblasts (HDFs) to form three-dimensional profuse vascular-like networks. HUVECs embedded and sandwiched in the collagen scaffold were cocultured with HDFs located outside the scaffold. The indirect coculture approach with the vascular endothelial growth factor (VEGF) producing HDFs triggered the formation of progressively maturing lumenized vascular-like networks of endothelial cells within less than 7 days, which have proven to be viably maintained in culture beyond day 21. Molecular weight-dependent Texas red-dextran permeability studies indicated high vascular barrier function of the generated networks. Their longevity allowed us to study the dose-dependent response upon treatment with the three known antiangiogenic and/or vascular disrupting agents brivanib, combretastatin A4 phosphate (CA4P), and 6´-sialylgalactose (SG) via semi-quantitative brightfield and qualitative confocal laser scanning microscopic (CLSM) image analysis. Compared to the reported data on in vivo efficacy of these drugs in terms of antiangiogenic and vascular disrupting effects, we observed similar trends with our 3D model, which are not reflected in conventional in vitro angiogenesis assays. High-vascular disruption under continuous treatment of the matured vascular-like network was observed at concentrations ≥3.5 ng·ml−1 for CA4P and ≥300 nM for brivanib. In contrast, SG failed to induce any significant vascular disruption in vitro. This advanced model of a 3D vascular-like network allows for testing single and combinational antiangiogenic and vascular disrupting effects with optimized dosing and may thus bridge the gap between the in vitro and in vivo experiments in validating hits from high-throughput screening. Moreover, the physiological 3D environment mimicking in vitro assay is not only highly relevant to in vivo studies linked to cancer but also to the field of tissue regeneration. Copyright © 2022 Yavvari, Laporte, Elomaa, Schraufstetter, Pacharzina, Daberkow, Hoppensack and Weinhart

Bioprinted Multi-Cell Type Lung Model for the Study of Viral Inhibitors

Influenza A virus (IAV) continuously causes epidemics and claims numerous lives every year. The available treatment options are insufficient and the limited pertinence of animal models for human IAV infections is hampering the development of new therapeutics. Bioprinted tissue models support studying pathogenic mechanisms and pathogen-host interactions in a human micro tissue environment. Here, we describe a human lung model, which consisted of a bioprinted base of primary human lung fibroblasts together with monocytic THP-1 cells, on top of which alveolar epithelial A549 cells were printed. Cells were embedded in a hydrogel consisting of alginate, gelatin and collagen. These constructs were kept in long-term culture for 35 days and their viability, expression of specific cell markers and general rheological parameters were analyzed. When the models were challenged with a combination of the bacterial toxins LPS and ATP, a release of the proinflammatory cytokines IL-1β and IL-8 was observed, confirming that the model can generate an immune response. In virus inhibition assays with the bioprinted lung model, the replication of a seasonal IAV strain was restricted by treatment with an antiviral agent in a dose-dependent manner. The printed lung construct provides an alveolar model to investigate pulmonary pathogenic biology and to support development of new therapeutics not only for IAV, but also for other viruses

An observational study of technical and non-technical skills in advanced life support in the clinical setting

ObjectiveTechnical skills (TS) and non-technical skills (NTS) are the primary elements ensuring patient safety during advanced life support (ALS) and effective crisis resource management (CRM). Both skills are needed to perform high-quality ALS, though they are traditionally practiced separately. The evidence of the association between NTS and TS in high-quality ALS performance is insufficient. Hence, we aimed to evaluate the association between the skills in real-life in-hospital ALS situations.MethodsWe video recorded real-life in-hospital ALS situations, analyzed TS and NTS demonstrated in them with an instrument measuring TS and NTS, and tested the linear association between NTS and TS using a linear mixed model.ResultsAmong 50 real-life in-hospital ALS situations that we recorded, 20 had adequate data for analysis. NTS and TS total scores were associated with one another (slope 0.48, P P chest compression quality, ventilation quality, rhythm control and defibrillation quality) were associated with one another (slopes ranging from 0.37 to 0.56, P ConclusionsThe resuscitation teams who demonstrated good NTS also performed the technical aspects of ALS better. The results suggest that NTS and TS have an association with one another in real-life in-hospital ALS situations. NTS performance had the most evident association with chest compression quality and rhythm control and defibrillation quality; these are considered the most crucial elements affecting outcomes of ALS. The findings of the study present novel information of what and why to emphasize in ALS training.Clinical trial registration. ClinicalTrials.gov, NCT03017144.</p

Papain-Based Solubilization of Decellularized Extracellular Matrix for the Preparation of Bioactive, Thermosensitive Pregels

Solubilized, gel-forming decellularized extracellular matrix (dECM) is used in a wide range of basic and translational research and due to its inherent bioactivity can promote structural and functional tissue remodeling. The animal-derived protease pepsin has become the standard proteolytic enzyme for the solubilization of almost all types of collagen-based dECM. In this study, pepsin was compared with papain, α-amylase, and collagenase for their potential to solubilize porcine liver dECM. Maximum preservation of bioactive components and native dECM properties was used as a decisive criterion for further application of the enzymes, with emphasis on minimal destruction of the protein structure and maintained capacity for physical thermogelation at neutral pH. The solubilized dECM digests, and/or their physically gelled hydrogels were characterized for their rheological properties, gelation kinetics, GAG content, proteomic composition, and growth factor profile. This study highlights papain as a plant-derived enzyme that can serve as a cost-effective alternative to animal-derived pepsin for the efficient solubilization of dECM. The resulting homogeneous papain-digested dECM preserved its thermally triggered gelation properties similar to pepsin digests, and the corresponding dECM hydrogels demonstrated their enhanced bioadhesiveness in single-cell force spectroscopy experiments with fibroblasts. The viability and proliferation of human HepaRG cells on dECM gels were similar to those on pure rat tail collagen type I gels. Papain is not only highly effective and economically attractive for dECM solubilization but also particularly interesting when digesting human-tissue-derived dECM for regenerative applications, where animal-derived materials are to be avoided

Optimization of cell-laden bioinks for 3D bioprinting and efficient infection with influenza A virus

Bioprinting is a new technology, which arranges cells with high spatial resolution, but its potential to create models for viral infection studies has not yet been fully realized. The present study describes the optimization of a bioink composition for extrusion printing. The bioinks were biophysically characterized by rheological and electron micrographic measurements. Hydrogels consisting of alginate, gelatin and Matrigel were used to provide a scaffold for a 3D arrangement of human alveolar A549 cells. A blend containing 20% Matrigel provided the optimal conditions for spatial distribution and viability of the printed cells. Infection of the 3D model with a seasonal influenza A strain resulted in widespread distribution of the virus and a clustered infection pattern that is also observed in the natural lung but not in two-dimensional (2D) cell culture, which demonstrates the advantage of 3D printed constructs over conventional culture conditions. The bioink supported viral replication and proinflammatory interferon release of the infected cells. We consider our strategy to be paradigmatic for the generation of humanized 3D tissue models by bioprinting to study infections and develop new antiviral strategies.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität Berli