Search

Bone defects resulting from trauma, disease, or aging present significant challenges in the clinic. Although biomaterial scaffolds for bone-tissue engineering have shown promising results, challenges remain, including the need for adequate mechanical strength and suitable bioactive agents within scaffolds to promote bone formation. Oxygen is a critical factor for successful bone formation, and low oxygen tension inhibits it. In this study, we developed gelatin methacryloyl (GelMA) hydrogel-impregnated electrospun polycaprolactone (PCL) scaffolds that can release oxygen over 3 weeks. We investigated the potential of composite scaffolds for cell survival in bone-tissue engineering. Our results showed that the addition of an increased amount of CaO2 nanoparticles to the PCL scaffolds significantly increased oxygen generation, which was modulated by GelMA impregnation. Moreover, the resulting scaffolds showed improved cytocompatibility, pre-osteoblast adhesion, and proliferation under hypoxic conditions. This finding is particularly relevant since hypoxia is a prevalent feature in various bone diseases. In addition to providing oxygen, CaO2 nanoparticles also act as reinforcing agents improving the mechanical property of the scaffolds, while the incorporation of GelMA enhances cell adhesion and proliferation properties. Overall, our newly developed self-oxygenating composite biomaterials are promising scaffolds for bone-tissue engineering applications. [ABSTRACT FROM AUTHOR]

Abstract Intentional and regulated induction of blood vessels formation which is generally referred to as therapeutic angiogenesis has a lot of potential in the management of various kinds of ischemic complications as well as in wound healing, bone regeneration and tissue engineering. Conventionally, therapeutic angiogenesis relies on the controlled application of growth factors that helps to initiate the formation of blood vessels in the target tissues and bioengineered constructs. The emergence of nanotechnology in medicine, particularly its application in molecular medicine has the potential for a tremendous progress in the therapeutic angiogenesis interventions. Although a good number of systems, which include growth factor delivery, use of gene therapeutic agents, and nanomaterials, are in experimental or preclinical phase, there is a huge potential for them in the clinical implication in upcoming years. In this article, we review the main advances of therapeutic angiogenesis over the past few years, explore the application prospects and discuss about the principles, approaches, importance and challenges with the aim of facilitating its clinical translation in near future. Graphical abstract Unlabelled Image Highlights • Importance of therapeutic angiogeneis has been detailed. • Therapeutic angiogenesis is a promising approach in the treatment of ischemic disease and chronic wounds. • Conventional approaches like VEGF application and cell-based approaches provided significant progress. • Use of various nanoparticles is a novel approach in therapeutic angiogenesis. • Clinical translation of recent angiogenesis approaches still needs a lot of validations. [ABSTRACT FROM AUTHOR]

• O 2 -generating tissue engineering scaffolds minimize hypoxia-induced cell death. • It is critical to minimize the free radical formation for prevention of cytotoxicity. • Controlled delivery of O 2 from engineered scaffolds is crucial for cell survival. • O 2 -generating scaffolds are promising for ex vivo and in situ tissue engineering. • O 2 -generating bioinks provide additional O 2 to the cells in bioprinted constructs. The lack of oxygen supply in engineered constructs has been an ongoing challenge for tissue engineering and regenerative medicine. Upon implantation of an engineered tissue, spontaneous blood vessel formation does not happen rapidly, therefore, there is typically a limited availability of oxygen in engineered biomaterials. Providing oxygen in large tissue-engineered constructs is a major challenge that hinders the development of clinically relevant engineered tissues. Similarly, maintaining adequate oxygen levels in cell-laden tissue engineered products during transportation and storage is another hurdle. There is an unmet demand for functional scaffolds that could actively produce and deliver oxygen, attainable by incorporating oxygen-generating materials. Recent approaches include encapsulation of oxygen-generating agents such as solid peroxides, liquid peroxides, and fluorinated substances in the scaffolds. Recent approaches to mitigate the adverse effects, as well as achieving a sustained and controlled release of oxygen, are discussed. Importance of oxygen-generating materials in various tissue engineering approaches such as ex vivo tissue engineering, in situ tissue engineering, and bioprinting are highlighted in detail. In addition, the existing challenges, possible solutions, and future strategies that aim to design clinically relevant multifunctional oxygen-generating biomaterials are provided in this review paper. [ABSTRACT FROM AUTHOR]

The development of highly porous cell supportive polymeric scaffolds with sufficient mechanical strength has always been a challenging task in tissue engineering. The widely used nanofiber fabrication methods like electrospinning are time consuming and the obtained nanofibrous scaffolds are generally consist of compactly packed fibers, which affect proper cell penetration. On the other hand, air-jet spinning is an upcoming, less explored alternative approach for generating loosely arranged nanofibrous scaffolds within short time. However, air-jet spun scaffolds show inferior mechanical properties due to loosely organized fibers. Herein, we report the fabrication and detailed characterization of polycaprolactone (PCL) tissue engineering scaffolds loaded with diamond nanosheets (DNS) by air-jet spinning. Our results showed that the inclusion of DNS could improve the mechanical strength of the scaffolds. In vitro biocompatibility, and in vivo implantation studies demonstrated that PCL-DNS scaffolds are highly biocompatible and are suitable for tissue engineering applications. Our studies showed that mammalian cells can proliferate well in the presence of PCL-DNS scaffolds and the nanocomposite scaffolds implanted in rats did not show any considerable adverse effects. Overall, the findings show that the developed novel air-jet spun PCL-DNS nanocomposite scaffolds can be used as cell supportive scaffolds for various tissue engineering applications. [Display omitted] • Diamond nanosheets loaded Air-jet spun PCL scaffolds were fabricated. • Diamond nanosheets improved the mechanical properties of PCL scaffolds. • Diamond nanosheets loaded scaffolds were biocompatible in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Electrospun membranes of polycaprolactone are widely used for biomedical applications such as wound dressings and tissue engineering scaffolds. It is important to sterilize this material using the most accepted method, the gamma irradiation. In this study, the authors evaluated the sterilizability of electrospun polycaprolactone membranes with gamma radiation of varying doses. The irradiated materials were assessed for the changes in morphology, crystallinity, surface degradation, hydrophilicity, mechanical property, sterility, and the cell proliferation. The results demonstrate that electrospun polycaprolactone can be effectively sterilized by gamma irradiation, however a higher dose of radiation affects the materials properties. The irradiated membranes showed improved hydrophilicity and fibroblast cell proliferation. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is one of the leading causes of mortality worldwide. Cardiac tissue engineering strategies focusing on biomaterial scaffolds incorporating cells and growth factors are emerging as highly promising for cardiac repair and regeneration. The use of stem cells within cardiac microengineered tissue constructs present an inherent ability to differentiate into cell types of the human heart. Stem cells derived from various tissues including bone marrow, dental pulp, adipose tissue and umbilical cord can be used for this purpose. Approaches ranging from stem cell injections, stem cell spheroids, cell encapsulation in a suitable hydrogel, use of prefabricated scaffold and bioprinting technology are at the forefront in the field of cardiac tissue engineering. The stem cell microenvironment plays a key role in the maintenance of stemness and/or differentiation into cardiac specific lineages. This review provides a detailed overview of the recent advances in microengineering of autologous stem cell-based tissue engineering platforms for the repair of damaged cardiac tissue. A particular emphasis is given to the roles played by the extracellular matrix (ECM) in regulating the physiological response of stem cells within cardiac tissue engineering platforms. [Display omitted] • Comprehensive review of the stem cell microenvironment in tissue engineering. • Outline of cardiac tissue engineering approaches targeting stem cell microenvironment. • Application and function of stem cell-based cardiac tissue engineering constructs. • The challenges and prospects of stem cell based cardiac tissue engineering. [ABSTRACT FROM AUTHOR]

In situ tissue engineering is emerging as a novel approach in tissue engineering to repair damaged tissues by boosting the natural ability of the body to heal itself. This can be achieved by providing suitable signals and scaffolds that can augment cell migration, cell adhesion on the scaffolds and proliferation of endogenous cells that facilitate the repair. Lack of appropriate cell proliferation and angiogenesis are among the major issues associated with the limited success of in situ tissue engineering during in vivo studies. Exploitation of metal oxide nanoparticles such as yttrium oxide (Y 2 O 3) nanoparticles may open new horizons in in situ tissue engineering by providing cues that facilitate cell proliferation and angiogenesis in the scaffolds. In this context, Y 2 O 3 nanoparticles were synthesized and incorporated in polycaprolactone (PCL) scaffolds to enhance the cell proliferation and angiogenic properties. An optimum amount of Y 2 O 3 -containing scaffolds (1% w/w) promoted the proliferation of fibroblasts (L-929) and osteoblast-like cells (UMR-106). Results of chorioallantoic membrane (CAM) assay and the subcutaneous implantation studies in rats demonstrated the angiogenic potential of the scaffolds loaded with Y 2 O 3 nanoparticles. Gene expression study demonstrated that the presence of Y 2 O 3 in the scaffolds can upregulate the expression of cell proliferation and angiogenesis related biomolecules such as VEGF and EGFR. Obtained results demonstrated that Y 2 O 3 nanoparticles can perform a vital role in tissue engineering scaffolds to promote cell proliferation and angiogenesis. Unlabelled Image • PCL tissue engineering scaffolds incorporated with Y2O3 nanoparticles have been developed. • Results of cell culture study showed that Y 2 O 3 nanoparticles can enhance the cell proliferation. • Presence of Y 2 O 3 nanoparticles in the scaffolds enhanced the angiogenesis. • Y 2 O 3 nanoparticles upregulated the expression of VEGF and EGFR in the tissue isolated from implanted scaffolds. [ABSTRACT FROM AUTHOR]

Tissue engineering aims to exploit the regenerative capacity of cells and connect the inherent ability of the body to repair and regenerate. Cells are seeded onto a porous three-dimensional scaffold in tissue engineering, which will provide protection and direct cells to the development of new tissue-like structures. These scaffolds can provide a medium for the delivery, under controlled conditions of growth factors release and drug delivery. Herein, nanocellulose was extracted from Ixora coccinea L. plant root, plasticized scaffold of nanocellulose were prepared by using glycerol, gelatin, and PEG 600 followed by morphological characterized by FTIR, XRD, SEM, and tensile modulus analysis. FTIR indicated extracted nanocellulose is without any hemicelluloses, lignin, and non-cellulosic materials. XRD data displayed the extracted nanocellulose has a crystal size of around 3.6 nm while SEM data revealed the fiber diameter was around 20 µm. In the tensile modulus analysis, 1% PEG 600 exhibited the highest (tensile strength 69 MPa with young's modulus 67.326 MPa) as compared to glycerol and gelatin and hence selected for further studies. The In vitro cytocompatibility studies revealed that nanocellulose and 1% PEG 600 incorporated nanocellulose scaffolds were cell-friendly, promote cell proliferation, and do not show RBC aggregation as well as haemolysis suggesting its potential in various tissue engineering applications. The novelty of this work is that the nanocellulose extracted from the root of I. coccineahas traditional medicinal values in Ayurveda. [ABSTRACT FROM AUTHOR]