Refine
Has Fulltext
- yes (82)
Is part of the Bibliography
- yes (82)
Year of publication
Document Type
- Journal article (82) (remove)
Language
- English (82) (remove)
Keywords
- melt electrowriting (10)
- 3D printing (9)
- additive manufacturing (8)
- biofabrication (7)
- melt electrospinning writing (7)
- bioprinting (6)
- hyaluronic acid (6)
- bioink (4)
- polycaprolactone (4)
- breast cancer (3)
- calcium phosphate cement (3)
- chondrogenic differentiation (3)
- electrohydrodynamics (3)
- extracellular matrix (3)
- hydrogels (3)
- magnesium phosphate cement (3)
- melt electrowriting (MEW) (3)
- phytic acid (3)
- tissue engineering (3)
- MSC (2)
- angiogenesis (2)
- arteriovenous loop (2)
- baghdadite (2)
- biocompatibility (2)
- bone (2)
- bone cement (2)
- calcium phosphate (2)
- cortical neurons (2)
- dual-stage crosslinking (2)
- electrohydrodynamic (2)
- in vitro (2)
- inflammation (2)
- printability (2)
- rheology (2)
- scaffold (2)
- shape fidelity (2)
- therapy (2)
- (AB)\(_{n}\) segmented copolymers (1)
- 316L stainless-steel (1)
- 3D electrophysiology (1)
- 3D microfiber (1)
- 3D model systems (1)
- 3D neuronal networks (1)
- 3D powder printing (1)
- 3D scaffolds (1)
- 3D tumor model (1)
- ACPC (1)
- ALI culture (1)
- Adenovirus (1)
- Bone marrow (1)
- Breast cancer (1)
- Ca\(^{2+}\)-Imaging (1)
- Cartilage (1)
- Chondrogenesis (1)
- ECM (1)
- FluidFM technology (1)
- Fluorescence Microscopy (1)
- Gene therapy (1)
- HA modifiedCNF membranes (1)
- HEMA (1)
- Hypertrophy (1)
- Janus fibers (1)
- MPI (1)
- MPS (1)
- Mesenchymal stem cell (1)
- NLRP3 (1)
- Normal breast (1)
- PTEN (1)
- Primary cell lines (1)
- QCM (1)
- RHO (1)
- ROCK (1)
- SOX9 (1)
- Schiff base chemistry (1)
- Staphylococcus aureus / drug effects (1)
- Stem cells plasticity (1)
- Tissue engineering (1)
- Vancomycin / administration & dosage (1)
- Vancomycin / chemistry (1)
- Vancomycin / pharmacology (1)
- WST test (1)
- acrylate-endcapped urethane-based polymer (AUP) (1)
- actin (1)
- acute myeloid leukaemia (1)
- adhesion dynamics (1)
- adipose tissue (1)
- adipose-derived stromal cells (1)
- agarose (1)
- alginate (1)
- alveolar‐capillary barrier (1)
- amoeboid cell migration (1)
- animal model (1)
- anisotropic porous structures (1)
- anti-bacterial agents / administration & dosage (1)
- anti-bacterial agents / chemistry (1)
- anti-bacterial agents / pharmacology (1)
- arthritis (1)
- artificial bones (1)
- astrocytes (1)
- atomic force microscopy (1)
- axial vascularization (1)
- azlactone (1)
- balloon kyphoplasty (1)
- bending strength (1)
- bio-printability (1)
- bioceramic (1)
- biocompatible Materials (1)
- biodegradable polymers (1)
- biofabricated vascular graft (1)
- bioinorganic (1)
- bioinspired interface (1)
- bioinspired membrane (1)
- biological models (1)
- biomaterial ink (1)
- biomaterials (1)
- biomechanical evaluation (1)
- biomechanics (1)
- biomedical materials (1)
- biophysics (1)
- biosensor (1)
- biosensors (1)
- blood-plasma (1)
- bone adhesive (1)
- bone and cartilage tissue engineering (1)
- bone critical size defect (1)
- bone graft substitutes (1)
- bone wires (1)
- brain cancer (1)
- breast cancer model (1)
- brushite cement (1)
- calcaneus (1)
- calcium phosphate cements (1)
- calcium-phosphate (1)
- carbon fiber reinforcement (1)
- cardiovascular pharmacology (1)
- cartilage (1)
- cartilage repair (1)
- cell coagulation (1)
- cell counting (1)
- cell elongation (1)
- cell guidance (1)
- cell migration (1)
- cell morphology (1)
- cell printing (1)
- cell self-assembled monolayers (1)
- cell transplantation (1)
- cell viability (1)
- cement (1)
- ceramics (1)
- chemokines (1)
- chondrocyte (1)
- chondrocytes (1)
- chondroprogenitors (1)
- click chemistry (1)
- co-culture (1)
- coatings (1)
- cochlea (1)
- collagen sponge (1)
- combination of physical vapor deposition and electrochemical etching (1)
- composite material (1)
- compressive strength (1)
- connective tissue (1)
- crosslinked coating (1)
- cryostructured scaffolds (1)
- cyclic mechanical stretch (1)
- cyclic stretch (1)
- cyclic testing (1)
- cyto-compatibility (1)
- cytotoxicity (1)
- damage tolerant cement (1)
- deafness (1)
- defects (1)
- defined humanized test system (1)
- definition (1)
- degradable bone substitutes (1)
- degradable implant (1)
- detachment force quantification (1)
- dicalcium phosphate cement (1)
- differentation (1)
- digitization (1)
- dihydrate cement (1)
- disease models (1)
- drillable bone cement (1)
- drop on demand (1)
- drug delivery (1)
- drug liberation (1)
- dual setting (1)
- dual setting system (1)
- durotaxis (1)
- electroactive (1)
- electroactive polymers (1)
- electron microscopy (1)
- electrospinning (1)
- eletrhydrodynamic (1)
- embedded templating (1)
- endothelial progenitor cells (1)
- expression (1)
- extrusion of hiMPC-containing bioinks alginate + collagen type I (1)
- extrusion-based 3D printing (1)
- factor-I (1)
- farringtonite (1)
- fiber (1)
- fiber reinforcement (1)
- fibers (1)
- fiber–matrix interaction (1)
- fixation (1)
- focal adhesions (1)
- force (1)
- fracture (1)
- free radical polymerization (1)
- functionalization (1)
- gels (1)
- gentamicin-loaded poly (methyl methacrylate) bone cement (1)
- granules (1)
- growth (1)
- guided bone regeneration (1)
- heart-failure (1)
- hemocompatibility (1)
- heterotypic scaffold design (1)
- human iPSC-derived mesodermal cells (hiMPCs) (1)
- human macrophages (1)
- human neutrophil elastase (HNE) (1)
- hybrid fabrication (1)
- hybrid materials (1)
- hybrid polymers (1)
- hydraulic reactivity (1)
- hydrogel (1)
- hydrogel formation (1)
- hydroxyapatite (1)
- hypoxia (1)
- imaging agents (1)
- immunomodulation (1)
- implants (1)
- in vitro cell‐stretch model (1)
- in-vivo Micro-Computed Tomography (1)
- inflammatory response (1)
- inner ear (1)
- inositol hexaphosphate (1)
- intercellular adhesion (1)
- interface control (1)
- iron release (1)
- lectin (1)
- left-ventricular function (1)
- load to failure testing (1)
- lung cell model (1)
- macrophage polarization (1)
- macrophages (1)
- magnetic properties (1)
- magnetoactive materials (1)
- materials testing (1)
- mature cell-cell contacts (1)
- mechanical activation (1)
- mechanical performance (1)
- mechanical properties (1)
- medical-grade poly(ε-caprolactone) (1)
- medicine (1)
- melanoma (1)
- melt electrowriting (1)
- melt electrofibrillation (1)
- microfibers (1)
- microfibres (1)
- microfluidics (1)
- microstructures (1)
- microvasculature (1)
- migration (1)
- minipig (1)
- modelling (1)
- morphology controls (1)
- mucin (1)
- multilayered vessel wall with intimate, media and adventitia (1)
- nanofibers (1)
- nanostructures (1)
- nanotopographical surfaces (1)
- networks (1)
- neurite growth (1)
- organ-on-a-chip (1)
- organoids (1)
- osseointegration (1)
- osteoblasts (1)
- osteochondral defect (1)
- osteoporosis (1)
- oxidation (1)
- particle study (1)
- peptide conjugation (1)
- peptide immobilization (1)
- phase conversion (1)
- photo-crosslinking (1)
- photopolymerization (1)
- physicochemical characterization (1)
- plasticizers (1)
- platelet-adhesion (1)
- poly(2-ethyl-2-oxazoline) (1)
- poly(ethylene glycol) (1)
- poly(lactide-co-glycolide) (1)
- polyacrylic acid (1)
- polyethylene glycol (1)
- polymer processing (1)
- polymer-analogue functionalization (1)
- polymeric matrix (1)
- polymers (1)
- polyoxazoline (1)
- polyoxazolines (1)
- porosity (1)
- pre-crosslinking (1)
- primary vascular smooth muscle‐like cells (vSMCs) (1)
- proliferation (1)
- prostheses and implants (1)
- protein adsorption (1)
- radiopacity (1)
- rat model (1)
- recruitment (1)
- remodelling (1)
- repair (1)
- rhBMP–2 (1)
- sacrificial printing (1)
- sanders (1)
- scaffolds (1)
- screw (1)
- self-assembled monolayers (1)
- serial block face EM (1)
- setting reaction (1)
- shear stress (1)
- shear thinning (1)
- silicones (1)
- sodium alginate (1)
- solution electrospinning (1)
- spheroids (1)
- spinning (1)
- stanfieldite (1)
- starPEG hydrogel (1)
- stem cells (1)
- stimulation (1)
- stress (1)
- sugar glass printing (1)
- surface coating (1)
- surfaces (1)
- sutures (1)
- synbones (1)
- synergistic reinforcement (1)
- synthetic hydrogels (1)
- systematic investigations (1)
- tension (1)
- tethering (1)
- thermoresponsive hydrogel (1)
- thiol-ene (1)
- tibial head depression fracture (1)
- tissue morphogenesis (1)
- topotaxis (1)
- total joint arthroplasty (1)
- total knee arthroplasty (1)
- traction (1)
- tranexamic acid (1)
- transforming growth factor-beta 1 (1)
- transplantation (1)
- tubular constructs (1)
- tumor heterogeneity (1)
- tunable ultra‐thin biphasic membrane (1)
- unidirectional freezing (1)
- vascular biofabrication (1)
- vascular network and hierarchical organized vessels (1)
- zonal (1)
- zonal construct (1)
- α-tricalcium phosphate (1)
Institute
- Abteilung für Funktionswerkstoffe der Medizin und der Zahnheilkunde (82) (remove)
Polymeric Janus Fibers
(2023)
Janus fibers are a class of composite materials comprising mechanical and chemical to biological functionality. Combining different materials and functionalities in one micro- or even nanoscale fiber enables otherwise unreachable synergistic physicochemical effects with unprecedented opportunities for technical or biomedical applications. Here, recent developments of processing technologies and applications of polymeric Janus fibers will be reviewed. Various examples in the fields of textiles, catalysis, sensors as well as medical applications, like drug delivery systems, tissue engineering and antimicrobial materials, are presented to illuminate the outstanding potential of such high-end functional materials for novel applications in the upcoming future.
Augmenting the vascular supply to generate new tissues, a crucial aspect in regenerative medicine, has been challenging. Recently, our group showed that calcium phosphate can induce the formation of a functional neo-angiosome without the need for microsurgical arterial anastomosis. This was a preclinical proof of concept for biomaterial-induced luminal sprouting of large-diameter vessels. In this study, we investigated if sprouting was a general response to surgical injury or placement of an inorganic construct around the vessel. Cylindrical biocement scaffolds of differing chemistries were placed around the femoral vein. A contrast agent was used to visualize vessel ingrowth into the scaffolds. Cell populations in the scaffold were mapped using immunohistochemistry. Calcium phosphate scaffolds induced 2.7–3 times greater volume of blood vessels than calcium sulphate or magnesium phosphate scaffolds. Macrophage and vSMC populations were identified that changed spatially and temporally within the scaffold during implantation. NLRP3 inflammasome activation peaked at weeks 2 and 4 and then declined; however, IL-1β expression was sustained over the course of the experiment. IL-8, a promoter of angiogenesis, was also detected, and together, these responses suggest a role of sterile inflammation. Unexpectedly, the effect was distinct from an injury response as a result of surgical placement and also was not simply a foreign body reaction as a result of placing a rigid bioceramic next to a vein, since, while the materials tested had similar microstructures, only the calcium phosphates tested elicited an angiogenic response. This finding then reveals a potential path towards a new strategy for creating better pro-regenerative biomaterials.
Present surgical situations require a bone adhesive which has not yet been developed for use in clinical applications. Recently, phosphoserine modified cements (PMC) based on mixtures of o-phosphoserine (OPLS) and calcium phosphates, such as tetracalcium phosphate (TTCP) or α-tricalcium phosphate (α-TCP) as well as chelate setting magnesium phosphate cements have gained increasing popularity for their use as mineral bone adhesives. Here, we investigated new mineral-organic bone cements based on phosphoserine and magnesium phosphates or oxides, which possess excellent adhesive properties. These were analyzed by X-ray diffraction, Fourier infrared spectroscopy and electron microscopy and subjected to mechanical tests to determine the bond strength to bone after ageing at physiological conditions. The novel biomineral adhesives demonstrate excellent bond strength to bone with approximately 6.6–7.3 MPa under shear load. The adhesives are also promising due to their cohesive failure pattern and ductile character. In this context, the new adhesive cements are superior to currently prevailing bone adhesives. Future efforts on bone adhesives made from phosphoserine and Mg2+ appear to be very worthwhile.
3D bioprinting often involves application of highly concentrated polymeric bioinks to enable fabrication of stable cell-hydrogel constructs, although poor cell survival, compromised stem cell differentiation, and an inhomogeneous distribution of newly produced extracellular matrix (ECM) are frequently observed. Therefore, this study presents a bioink platform using a new versatile dual-stage crosslinking approach based on thiolated hyaluronic acid (HA-SH), which not only provides stand-alone 3D printability but also facilitates effective chondrogenic differentiation of mesenchymal stromal cells. A range of HA-SH with different molecular weights is synthesized and crosslinked with acrylated (PEG-diacryl) and allylated (PEG-diallyl) polyethylene glycol in a two-step reaction scheme. The initial Michael addition is used to achieve ink printability, followed by UV-mediated thiol–ene reaction to stabilize the printed bioink for long-term cell culture. Bioinks with high molecular weight HA-SH (>200 kDa) require comparably low polymer content to facilitate bioprinting. This leads to superior quality of cartilaginous constructs which possess a coherent ECM and a strongly increased stiffness of long-term cultured constructs. The dual-stage system may serve as an example to design platforms using two independent crosslinking reactions at one functional group, which allows adjusting printability as well as material and biological properties of bioinks.
3D neuronal cultures attempt to better replicate the in vivo environment to study neurological/neurodegenerative diseases compared to 2D models. A challenge to establish 3D neuron culture models is the low elastic modulus (30–500 Pa) of the native brain. Here, an ultra-soft matrix based on thiolated hyaluronic acid (HA-SH) reinforced with a microfiber frame is formulated and used. Hyaluronic acid represents an essential component of the brain extracellular matrix (ECM). Box-shaped frames with a microfiber spacing of 200 µm composed of 10-layers of poly(ɛ-caprolactone) (PCL) microfibers (9.7 ± 0.2 µm) made via melt electrowriting (MEW) are used to reinforce the HA-SH matrix which has an elastic modulus of 95 Pa. The neuronal viability is low in pure HA-SH matrix, however, when astrocytes are pre-seeded below this reinforced construct, they significantly support neuronal survival, network formation quantified by neurite length, and neuronal firing shown by Ca\(^{2+}\) imaging. The astrocyte-seeded HA-SH matrix is able to match the neuronal viability to the level of Matrigel, a gold standard matrix for neuronal culture for over two decades. Thus, this 3D MEW frame reinforced HA-SH composite with neurons and astrocytes constitutes a reliable and reproducible system to further study brain diseases.
In 3D bioprinting for cartilage regeneration, bioinks that support chondrogenic development are of key importance. Growth factors covalently bound in non-printable hydrogels have been shown to effectively promote chondrogenesis. However, studies that investigate the functionality of tethered growth factors within 3D printable bioinks are still lacking. Therefore, in this study, we established a dual-stage crosslinked hyaluronic acid-based bioink that enabled covalent tethering of transforming growth factor-beta 1 (TGF-β1). Bone marrow-derived mesenchymal stromal cells (MSCs) were cultured over three weeks in vitro, and chondrogenic differentiation of MSCs within bioink constructs with tethered TGF-β1 was markedly enhanced, as compared to constructs with non-covalently incorporated TGF-β1. This was substantiated with regard to early TGF-β1 signaling, chondrogenic gene expression, qualitative and quantitative ECM deposition and distribution, and resulting construct stiffness. Furthermore, it was successfully demonstrated, in a comparative analysis of cast and printed bioinks, that covalently tethered TGF-β1 maintained its functionality after 3D printing. Taken together, the presented ink composition enabled the generation of high-quality cartilaginous tissues without the need for continuous exogenous growth factor supply and, thus, bears great potential for future investigation towards cartilage regeneration. Furthermore, growth factor tethering within bioinks, potentially leading to superior tissue development, may also be explored for other biofabrication applications.
Melt electrowriting (MEW) is an additive manufacturing process that produces highly defined constructs with elements in the micrometer range. A specific configuration of MEW enables printing tubular constructs to create small-diameter tubular structures. The small pool of processable materials poses a bottleneck for wider application in biomedicine. To alleviate this obstacle, an acrylate-endcapped urethane-based polymer (AUP), using a poly(ε-caprolactone) (PCL) (molar mass: 20 000 g mol\(^{−1}\)) (AUP PCL20k) as backbone material, is synthesized and utilized for MEW. Spectroscopic analysis confirms the successful modification of the PCL backbone with photo-crosslinkable acrylate endgroups. Printing experiments of AUP PCL20k reveal limited printability but the photo-crosslinking ability is preserved post-printing. To improve printability and to tune the mechanical properties of printed constructs, the AUP-material is blended with commercially available PCL (AUP PCL20k:PCL in ratios 80:20, 60:40, 50:50). Print fidelity improves for 60:40 and 50:50 blends. Blending enables modification of the constructs' mechanical properties to approximate the range of blood vessels for transplantation surgeries. The crosslinking-ability of the material allows pure AUP to be manipulated post-printing and illustrates significant differences in mechanical properties of 80:20 blends after crosslinking. An in vitro cell compatibility assay using human umbilical vein endothelial cells also demonstrates the material's non-cytotoxicity.
Mucin, a high molecular mass hydrophilic glycoprotein, is the main component of mucus that coats every wet epithelium in animals. It is thus intrinsically biocompatible, and with its protein backbone and the o-glycosidic bound oligosaccharides, it contains a plethora of functional groups which can be used for further chemical modifications. Here, chain-growth and step-growth (thiol-ene) free-radical cross-linked hydrogels prepared from commercially available pig gastric mucin (PGM) are introduced and compared as cost-efficient and easily accessible alternative to the more broadly applied bovine submaxillary gland mucin. For this, PGM is functionalized with photoreactive acrylate groups or allyl ether moieties, respectively. Whereas homopolymerization of acrylate-functionalized polymers is performed, for thiol-ene cross-linking, the allyl-ether-functionalized PGM is cross-linked with thiol-functionalized hyaluronic acid. Morphology, mechanical properties, and cell compatibility of both kinds of PGM hydrogels are characterized and compared. Furthermore, the biocompatibility of these hydrogels can be evaluated in cell culture experiments.
A novel approach, in the context of bioprinting, is the targeted printing of a defined number of cells at desired positions in predefined locations, which thereby opens up new perspectives for life science engineering. One major challenge in this application is to realize the targeted printing of cells onto a gel substrate with high cell survival rates in advanced bioinks. For this purpose, different alginate-dialdehyde—polyethylene glycol (ADA-PEG) inks with different PEG modifications and chain lengths (1–8 kDa) were characterized to evaluate their application as bioinks for drop on demand (DoD) printing. The biochemical properties of the inks, printing process, NIH/3T3 fibroblast cell distribution within a droplet and shear forces during printing were analyzed. Finally, different hydrogels were evaluated as a printing substrate. By analysing different PEG chain lengths with covalently crosslinked and non-crosslinked ADA-PEG inks, it was shown that the influence of Schiff's bases on the viscosity of the corresponding materials is very low. Furthermore, it was shown that longer polymer chains resulted in less stable hydrogels, leading to fast degradation rates. Several bioinks highly exhibit biocompatibility, while the calculated nozzle shear stress increased from approx. 1.3 and 2.3 kPa. Moreover, we determined the number of cells for printed droplets depending on the initial cell concentration, which is crucially needed for targeted cell printing approaches.
Melt electrowriting, a high-resolution additive manufacturing technique, is used in this study to process a magnetic polymer-based blend for the first time. Carbonyl iron (CI) particles homogenously distribute into poly(vinylidene fluoride) (PVDF) melts to result in well-defined, highly porous structures or scaffolds comprised of fibers ranging from 30 to 50 µm in diameter. This study observes that CI particle incorporation is possible up to 30 wt% without nozzle clogging, albeit that the highest concentration results in heterogeneous fiber morphologies. In contrast, the direct writing of homogeneous PVDF fibers with up to 15 wt% CI is possible. The fibers can be readily displaced using magnets at concentrations of 1 wt% and above. Combined with good viability of L929 CC1 cells using Live/Dead imaging on scaffolds for all CI concentrations indicates that these formulations have potential for the usage in stimuli-responsive applications such as 4D printing.