3D Bioprinted Alginate-Silk-Based Smart Cell-Instructive Scaffolds for Dual Differentiation of Human Mesenchymal Stem Cells

Kaur

ACS Appl. Mater. Interfaces

et al. 2022

Self Cite

Medical dressings play an important role in the field of tissue engineering owing to their ability to accelerate the process of wound healing. Great efforts have been made to fabricate wound dressings with distinctive features for promoting wound healing. However, most of the current synthesis methods either generate dressings of uniform size or involve complex fabrication techniques, thus limiting their commercialization for the personalized dressings. We report here a dressing, which presents a paradigm shift in the design of the dressing from uniform films to a micro-patterned film. The hypothesis driving the design is the ability of the 3D patterns to provide an efficient transient matrix filling the depth of the wound rather than just providing a barrier and slight re-epithelialization. We demonstrate the use of the digital light processing 3D printing technique to generate micro-pyramid-decorated wound healing dressings with individualized design and with bio-compatible gelatin methacryloyl to contact the wounded areas. In addition to providing better adhesion to the migratory cells, the micro-pyramids also enable covalent conjugation of heparin, providing capability to sequester endogenous growth factors (GFs). Based on these advantages, the developed dressing not only adheres strongly to the wound bed but also promotes the treatment of a rat wound model by utilizing the power of endogenous GFs for tissue regeneration. Thus, it is believed that the developed dressing can break through the limitation of traditional wound treatment and be an ideal candidate for wound healing.

Section: Resultsmentioning

confidence: 99%

Light-Mediated 3D Printing of Micro-Pyramid-Decorated Tailorable Wound Dressings with Endogenous Growth Factor Sequestration for Improved Wound Healing

Kaur

ACS Appl. Mater. Interfaces

et al. 2022

Self Cite

“…Gelatin is added in alginate hydrogels to improve their mechanical integrity. , In the study of Yang et al, 5% gelatin/8% alginate and 5% gelatin/8% alginate/4% HAp (with a pore size of 200 μm) as cartilage and bone layer, respectively, were 3D bioprinted with an extrusion-based printer at 37 °C to produce bilayer scaffolds. Before cross-linking alginate, addition of 5% gelatin was found to help keep the integrity of the scaffold structure which otherwise collapsed.…”

Section: Hydrogelsmentioning

confidence: 99%

Is 3D Printing Promising for Osteochondral Tissue Regeneration?

Ege

Hasırcı²

2023

ACS Appl. Bio Mater.

Osteochondral tissue regeneration is quite difficult to achieve due to the complexity of its organization. In the design of these complex multilayer structures, a fabrication method, 3D printing, started to be employed, especially by using extrusion, stereolithography and inkjet printing approaches. In this paper, the designs are discussed including biphasic, triphasic, and gradient structures which aim to mimic the cartilage and the calcified cartilage and the whole osteochondral tissue closely. In the first section of the review paper, 3D printing of hydrogels including gelatin methacryloyl (GelMa), alginate, and polyethylene glycol diacrylate (PEGDA) are discussed. However, their physical and biological properties need to be augmented, and this generally is achieved by blending the hydrogel with other, more durable, less hydrophilic, polymers. These scaffolds are very suitable to carry growth factors, such as TGF-β1, to further stimulate chondrogenesis. The bone layer is mimicked by printing calcium phosphates (CaPs) or bioactive glasses together with the hydrogels or as a component of another polymer layer. The current research findings indicate that polyester (i.e. polycaprolactone (PCL), polylactic acid (PLA) and poly(lactide-co-glycolide) (PLGA)) reinforced hydrogels may more successfully mimic the complex structure of osteochondral tissue. Moreover, more recent printing methods such as melt electrowriting (MEW), are being used to integrate polyester fibers to enhance the mechanical properties of hydrogels. Additionally, polyester scaffolds that are 3D printed without hydrogels are discussed after the hydrogel-based scaffolds. In this review paper, the relevant studies are analyzed and discussed, and future work is recommended with support of tables of designed scaffolds. The outcome of the survey of the field is that 3D printing has significant potential to contribute to osteochondral tissue repair.

“…This is due to the multi-directional differentiation potential of stem cells, and their proliferative capabilities being much stronger than those of adult cells, which plays a key role in biomedical fields and 3D bioprinting, especially when building complex organs. The cell population is essential for vascular network formation and subsequent physiological functionalization [37,[202][203][204][205][206].…”

Section: Cellsmentioning

confidence: 99%

Bioprinting Technologies and Bioinks for Vascular Model Establishment

Kong

Wang

2023

IJMS

Clinically, large diameter artery defects (diameter larger than 6 mm) can be substituted by unbiodegradable polymers, such as polytetrafluoroethylene. There are many problems in the construction of small diameter blood vessels (diameter between 1 and 3 mm) and microvessels (diameter less than 1 mm), especially in the establishment of complex vascular models with multi-scale branched networks. Throughout history, the vascularization strategies have been divided into three major groups, including self-generated capillaries from implantation, pre-constructed vascular channels, and three-dimensional (3D) printed cell-laden hydrogels. The first group is based on the spontaneous angiogenesis behaviour of cells in the host tissues, which also lays the foundation of capillary angiogenesis in tissue engineering scaffolds. The second group is to vascularize the polymeric vessels (or scaffolds) with endothelial cells. It is hoped that the pre-constructed vessels can be connected with the vascular networks of host tissues with rapid blood perfusion. With the development of bioprinting technologies, various fabrication methods have been achieved to build hierarchical vascular networks with high-precision 3D control. In this review, the latest advances in 3D bioprinting of vascularized tissues/organs are discussed, including new printing techniques and researches on bioinks for promoting angiogenesis, especially coaxial printing, freeform reversible embedded in suspended hydrogel printing, and acoustic assisted printing technologies, and freeform reversible embedded in suspended hydrogel (flash) technology.