Bacterial cellulose (BC) is a high-purity nanometer cellulose secreted by some bacteria. Compared with plant cellulose, it possesses an array of unique properties, including high crystallinity, high water content, good biocompatibility, high mechanical strength and an ultra-fine fiber network. BC is prosperous as a new type of biomedical material, which has medical applications such as wound dressing, artificial skin, artificial blood vessels and tissue engineering scaffolds. There are, however, some problems to be solved on the large-scale application of BC, such as the high cost, low yield, and poor mechanical stability and so on.
Meniscus injury has been one of the most common knee injuries in current society. The research on artificial meniscus implants as substitutes in meniscus reconstruction therapy has become global focus in order to solve clinical problems such as irreparable meniscus injury and symptoms after full or partial meniscectomy. At present, researches on artificial meniscus implants mainly focus on biodegradable meniscus scaffolds and non-biodegradable meniscus substitutes. Although the commercialized meniscal implants, such as CMI®, Actifit® and NUsurface®, have been applied in the clinical, none of them can perfectively restore or permanently replace the natural meniscus tissue, effectively solve the symptoms after meniscectomy, and prevent cartilage degenerative diseases. The research progress, application, advantages and disadvantages of different kinds of artificial meniscus implants are reviewed in this manuscript, and the prospect is provided.
Tricalcium phosphate (TCP) is one of the most widely used bioceramics for constructing bone tissue engineering scaffold. The three-dimensional (3D) printed TCP scaffold has precise and controllable pore structure, while with the limitation of insufficient mechanical properties. In this study, we investigated the effect of sintering temperature on the mechanical properties of 3D-printed TCP scaffolds in detail, due to the important role of the sintering process on the mechanical properties of bioceramic scaffolds. The morphology, mass and volume shrinkage, porosity, mechanical properties and degradation property of the scaffold was studied. The results showed that the scaffold sintered at 1 150℃ had the maximum volume shrinkage, the minimum porosity and optimal mechanical strength, with the compressive strength of (6.52 ± 0.84) MPa and the compressive modulus of (100.08 ± 18.6) MPa, which could meet the requirements of human cancellous bone. In addition, the 1 150℃ sintered scaffold degraded most slowly in the acidic environment compared to the scaffolds sintered at the other temperatures, demonstrating its optimal mechanical stability over long-term implantation. The scaffold can support bone mesenchymal stem cells (BMSCs) adherence and rapid proliferation and has good biocompatibility. In summary, this paper optimizes the sintering process of 3D printed TCP scaffold and improves its mechanical properties, which lays a foundation for its application as a load-bearing bone.
ObjectiveTo review the application of cell derived decellularized extracellular matrix (CDM) in tissue engineering. Methods The literature related to the application of CDM in tissue engineering was extensively reviewed and analyzed. Results CDM is a mixture of cells and their secretory products obtained by culturing cells in vitro for a period of time, and then the mixture is treated by decellularization. Compared with tissue derived decellularized extracellular matrix (TDM), CDM can screen and utilize pathogen-free autologous cells, effectively avoiding the possible shortcomings of TDM, such as immune response and limited sources. In addition, by selecting the cell source, controlling the culture conditions, and selecting the template scaffold, the composition, structure, and mechanical properties of the scaffold can be controlled to obtain the desired scaffold. CDM retains the components and microstructure of extracellular matrix and has excellent biological functions, so it has become the focus of tissue engineering scaffolds. ConclusionCDM is superior in the field of tissue engineering because of its outstanding adjustability, safety, and high bioactivity. With the continuous progress of technology, CDM stents suitable for clinical use are expected to continue to emerge.