Purpose
This paper aims to discuss the successful fabrication of customized tubular scaffolds for tracheal tissue engineering with a novel route using solvent-based extrusion 3D printing.
Design/methodology/approach
The manufacturing approach involved extrusion of polymeric ink over a rotating predefined pattern to construct customized tubular structure of polycaprolactone (PCL) and polyurethane (PU). Dimensional deviation in thickness of scaffolds were calculated for various layer thicknesses of 3D printing. Physical and chemical properties of scaffolds were investigated by scanning electron microscope (SEM), contact angle measurement, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD). Mechanical characterizations were performed, and the results were compared to the reported properties of human native trachea from previous reports. Additionally, in vitro cytotoxicity of the fabricated scaffolds was studied in terms of cell proliferation, cell adhesion and hemagglutination assay.
Findings
The developed fabrication route was flexible and accurate by printing customized tubular scaffolds of various scales. Physiochemical results showed good miscibility of PCL/PU blend, and decrease in crystalline nature of blend with the addition of PU. Preliminary mechanical assessments illustrated comparable mechanical properties with the native human trachea. Longitudinal compression test reported outstanding strength and flexibility to maintain an unobstructed lumen, necessary for the patency. Furthermore, the scaffolds were found to be biocompatible to promote cell adhesion and proliferation from the in vitro cytotoxicity results.
Practical implications
The attempt can potentially meet the demand for flexible tubular scaffolds that ease the concerns such as availability of suitable organ donors.
Originality/value
3D printing over accurate predefined templates to fabricate customized grafts gives novelty to the present method. Various customized scaffolds were compared with conventional cylindrical scaffold in terms of flexibility.
Extracellular vesicles (EVs) are subcellular messengers that aid in the formation and spread of cancer by enabling tumor-stroma communication. EVs develop from the very porous structure of late endosomes and hold information on both the intrinsic “status” of the cell and the extracellular signals absorbed by the cells from their surroundings. These EVs contain physiologically useful components, including as nucleic acids, lipids, and proteins, which have been found to activate important signaling pathways in tumor and tumor microenvironment (TME) cells, aggravating tumor growth. We highlight critical cell biology mechanisms that link EVS formation to cargo sorting in cancer cells in this review.Sorting out the signals that control EVs creation, cargo, and delivery will aid our understanding of carcinogenesis. Furthermore, we reviewed how cancer development and spreading behaviors are affected by coordinated communication between malignant and non-malignant cells. Herein, we studied the reciprocal exchanges via EVs in various cancer types. Further research into the pathophysiological functions of various EVs in tumor growth is likely to lead to the discovery of new biomarkers in liquid biopsy and the development of tumor-specific therapies.
Nanotechnology advancements and applications have paved
the way
for new possibilities in regenerative medicine and tissue engineering.
It is a relatively new field that has the potential to improve stem
cell differentiation and therapy greatly. Numerous studies have demonstrated
that nanomaterials can function as a physiological niche for the formation
and differentiation of stem cells. However, quantum dots (QDs), such
as carbon quantum dots (CQDs) and graphene quantum dots (GQDs), have
shown considerable promise in the field of regenerative medicine.
To date, most research has focused on stem cell tracking and imaging
using CQDs. However, their interaction with stem cells and the associated
possibility for differentiation by selectively focusing chemical signals
to a particular lineage has received scant attention. In this mini-review,
we attempt to categorize a few pathways linked with the role of CQDs
in stem cell differentiation.
The journey into the field of stem cell biology has been
an endeavor
of paramount advancement in biomedicine, establishing new horizons
in the avenue of materiobiology. The creative drive of the scientific
community focuses on ameliorating the utilization of stem cells, which
is currently untapped on a large scale. With similar motivation, we
present a nascent strategy of maneuvering biogenic carbon quantum
dots (CQDs) to eclipse the toxic hurdles of chemical synthesis of
carbon allotropes to serve as a biocompatible trident in stem cell
biology employing a three-prong action of stem cell differentiation,
imaging, and migration. The derivation of CQDs from garlic peels as
a biogenic precursor abets in realizing the optophysical features
of CQDs to image mesenchymal stem cells without hampering the biological
systems with cytotoxicity. We report the versatility of biogenic CQDs
to generate reactive oxygen species (ROS) to robustly influence stem
cell migration and concomitantly chondrocyte differentiation from
human Wharton’s jelly mesenchymal stem cells (hWJ-MSCs). This
was orchestrated without the use of chondrogenic induction factors,
which was confirmed from the expression of chondrogenic markers (Col
II, Col X, ACAN). Even the collagen content of cells incubated with
CQDs was quite comparable with that of chondrocyte-induced cells.
Thus, we empirically propose garlic peel-derived CQDs as a tangible
advancement in stem cell biology from a materiobiological frame of
reference to hone significant development in this arena.
Nanoconfinement within flexible interfaces is a key step towards exploiting confinement effects in several biological and technological systems wherein flexible 2D materials are frequently utilized but are arduous to prepare. Hitherto unreported, the synthesis of 2D Hydrogel nanosheets (HNS) using a template- and catalyst-free process is developed representing a fertile ground for fundamental structure-property investigations. In due course of time, nucleating folds propagating along the edges trigger co-operative deformations of HNS generating regions of nanoconfinement within trapped water islands. These severely constricting surfaces force water molecules to pack within the nanoscale regime of HNS almost parallel to the surface bringing about phase transition into puckered rhombic ice with AA and AB Bernal stacking pattern, which was mostly restricted to Molecular dynamics (MD) studies so far. Interestingly, under high lateral pressure and spatial inhomogeneity within nanoscale confinement, bilayer rhombic ice structures were formed with an in-plane lattice spacing of 0.31 nm. In this work, a systematic exploration of rhombic ice formation within HNS has been delineated using High-resolution transmission electron microscopy (HRTEM), and its ultrathin morphology was examined using Atomic Force Microscopy (AFM). Scanning Electron Microscopy (SEM) images revealed high porosity while mechanical testing presented young’s modulus of 155 kPa with ~84% deformation, whereas contact angle suggested high hydrophilicity. The combinations of nanosheets, porosity, nanoconfinement, hydrophilicity, and mechanical strength, motivated us to explore their application as a scaffold for cartilage regeneration, by inducing chondrogenesis of human Wharton Jelly derived mesenchymal stem cells (hWJ MSCs). HNS promoted the formation of cell aggregates giving higher number of spheroid formation and a marked expression of chondrogenic markers (ColI, ColII, ColX, ACAN and S-100), thereby providing some cues for guiding chondrogenic differentiation.
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