Buhlthuesen6116

Human mesenchymal stem cells (hMSCs) are an attractive source for cell therapies because of their multiple beneficial properties, i.e. via immunomodulation and secretory factors. Microfluidics is particularly attractive for cell encapsulation since it provides a rapid and reproducible methodology for microgel generation of controlled size and simultaneous cell encapsulation. Here, we report the fabrication of hMSC-laden microcarriers based on in situ ionotropic gelation of water-soluble chitosan in a microfluidic device using a combination of an antioxidant glycerylphytate (G1Phy) compound and tripolyphosphate (TPP) as ionic crosslinkers (G1PhyTPP-microgels). These microgels showed homogeneous size distributions providing an average diameter of 104 ± 12 μm, somewhat lower than that of control (127 ± 16 μm, TPP-microgels). The presence of G1Phy in microgels maintained cell viability over time and upregulated paracrine factor secretion under adverse conditions compared to control TPP-microgels. Encapsulated hMSCs in G1PhyTPP-microgels were delivered to the subcutaneous space of immunocompromised mice via injection, and the delivery process was as simple as the injection of unencapsulated cells. Immediately post-injection, equivalent signal intensities were observed between luciferase-expressing microgel-encapsulated and unencapsulated hMSCs, demonstrating no adverse effects of the microcarrier on initial cell survival. Cell persistence, inferred by bioluminescence signal, decreased exponentially over time showing relatively higher half-life values for G1PhyTPP-microgels compared to TPP-microgels and unencapsulated cells. In overall, results position the microfluidics generated G1PhyTPP-microgels as a promising microcarrier for supporting hMSC survival and reparative activities.Modifying living cells using in-situ synthesized nanomaterials to endow them with new functions is highly desirable. Herein we report intra- and extra-cellular dual-modified red blood cells (RBCs) with intracellular CaCO3 nanoparticles (NPs) and extracellular polypyrrole-folic acid (PPy-FA) coating, which are exploited as a bifunctional drug carrier. The functionalized living cells (CaCO3@RBC@PPy-FA) are fabricated through first the intracellular in situ reaction of exogenous Ca2+ and CO32- ions to generate CaCO3 NPs, then polymerization of pyrrole and finally modification of folic acid (FA) on the membrane of individual cells, forming a CaCO3@RBC@PPy-FA structure. As a result, such dual-modified RBCs not only preserve the original performances of the cells but also possess the desirable properties as a drug carrier, such as high loading capacity due to the action of CaCO3 NPs, targeting and light-controlled drug release due to the action of PPy-FA. Under NIR laser stimulation, these bifunctional RBCs (DOX-CaCO3@RBC@PPy-FA) present an instant release profile of doxorubicin (DOX) and have high targeting-ability toward cancer cells, achieving a marked synergistic combined photothermal-chemotherapy effect.Development of a biomimetic tubular scaffold capable of recreating developmental neurogenesis using pluripotent stem cells offers a novel strategy for the repair of spinal cord tissues. Recent advances in 3D printing technology have facilitated biofabrication of complex biomimetic environments by precisely controlling the 3D arrangement of various acellular and cellular components (biomaterials, cells and growth factors). Here, we present a 3D printing method to fabricate a complex, patterned and embryoid body (EB)-laden tubular scaffold composed of polycaprolactone (PCL) and hydrogel (alginate or gelatine methacrylate (GelMA)). Our results revealed 3D printing of a strong, macro-porous PCL/hydrogel tubular scaffold with a high capacity to control the porosity of the PCL scaffold, wherein the maximum porosity in the PCL wall was 15%. The method was equally employed to create spatiotemporal protein concentration within the scaffold, demonstrating its ability to generate linear and opposite gradients of model molecules (fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) and rhodamine). 3D bioprinting of EBs-laden GelMA was introduced as a novel 3D printing strategy to incorporate EBs in a hydrogel matrix. Cell viability and proliferation were measured post-printing. Following the bioprinting of EBs-laden 5% GelMA hydrogel, neural differentiation of EBs was induced using 1 μM retinoic acid (RA). The differentiated EBs contained βIII-tubulin positive neurons displaying axonal extensions and cells migration. Finally, 3D bioprinting of EBs-laden PCL/GelMA tubular scaffold successfully supported EBs neural differentiation and patterning in response to co-printing with 1 μM RA. 3D printing of a complex heterogeneous tubular scaffold that can encapsulate EBs, spatially controlled protein concentration and promote neuronal patterning will help in developing more biomimetic scaffolds capable of replicating the neural patterning which occurs during neural tube development.In order to increase the bone forming ability of MBG-PCL composite scaffold, microporosity was created in the struts of 3D-printed MBG-PCL scaffolds for the manufacturing of a construct with a multiscale porosity consisting of meso- micro- and macropores. 3D-printing imparted macroporosity while the microporosity was created by porogen removal from the struts, and the MBG particles were responsible for the mesoporosity. The scaffolds were 3D-printed using a mixture of PCL, MBG and phosphate buffered saline (PBS) particles, subsequently leached out. Microporous-PCL (pPCL) as a negative control, microporous MBG-PCL (pMBG-PCL) and non-microporous-MBG-PCL (MBG-PCL) were investigated. Scanning electron microscopy, mercury intrusion porosimetry and micro-computed tomography demonstrated that the PBS removal resulted in the formation of micropores inside the struts with porosity of around 30% for both pPCL and pMBG-PCL, with both constructs displaying an overall porosity of 8090%. In contrast, the MBG-PCL group had a microporosity of 6% and an overall porosity of 70%. Early mineralisation was found in the pMBG-PCL post-leaching out and this resulted in the formation a more homogeneous calcium phosphate layer when using a biomimetic mineralisation assay. selleck chemical Mechanical properties ranged from 5 to 25 MPa for microporous and non-microporous specimens, hence microporosity was the determining factor affecting compressive properties. MC3T3-E1 metabolic activity was increased in the pMBG-PCL along with an increased production of RUNX2. Therefore, the microporosity within a 3D-printed bioceramic composite construct may result in additional physical and biological benefits.