Ultrasound stimulus to enhance the bone regeneration capability of gelatin cryogels

In the present study, gelatin-based cryogels have been seeded with human SAOS-2 osteoblasts. In order to overcome the drawbacks associated with in vitro culture systems, such as limited diffusion and inhomogeneous cell-matrix distribution, this work describes the application of ultrasounds (average power, 149 mW; frequency, 1.5 MHz) to physically enhance the cell culture in vitro. The results indicate that the physical stimulation of cell-seeded gelatin-based cryogels upregulates the bone matrix production

Biopolymers in Drug Delivery and Regenerative Medicine

Biopolymers including natural (e.g., polysaccharides, proteins, gums, natural rubbers, bacterial polymers), synthetic (e.g., aliphatic polyesters and polyphosphoester), and biocomposites are of paramount interest in regenerative medicine, due to their availability, processability, and low toxicity. Moreover, the structuration of biopolymer-based materials at the nano- and microscale along with their chemical properties are crucial in the engineering of advanced carriers for drug products. Finally, combination products including or based on biopolymers for controlled drug release offer a powerful solution to improve the tissue integration and biological response of these materials. Understanding the drug delivery mechanisms, efficiency, and toxicity of such systems may be useful for regenerative medicine and pharmaceutical technology. The main aim of the Special Issue on “Biopolymers in Drug Delivery and Regenerative Medicine” is to gather recent findings and current advances on biopolymer research for biomedical applications, particularly in regenerative medicine, wound healing, and drug delivery. Contributions to this issue can be as original research or review articles and may cover all aspects of biopolymer research, ranging from the chemical synthesis and characterization of modified biopolymers, their processing in different morphologies and hierarchical structures, as well as their assessment for biomedical uses

Stimuli-responsive hydrogels: smart state of-the-art platforms for cardiac tissue engineering

Biomedicine and tissue regeneration have made significant advancements recently, positively affecting the whole healthcare spectrum. This opened the way for them to develop their applications for revitalizing damaged tissues. Thus, their functionality will be restored. Cardiac tissue engineering (CTE) using curative procedures that combine biomolecules, biomimetic scaffolds, and cells plays a critical part in this path. Stimuli-responsive hydrogels (SRHs) are excellent three-dimensional (3D) biomaterials for tissue engineering (TE) and various biomedical applications. They can mimic the intrinsic tissues’ physicochemical, mechanical, and biological characteristics in a variety of ways. They also provide for 3D setup, adequate aqueous conditions, and the mechanical consistency required for cell development. Furthermore, they function as competent delivery platforms for various biomolecules. Many natural and synthetic polymers were used to fabricate these intelligent platforms with innovative enhanced features and specialized capabilities that are appropriate for CTE applications. In the present review, different strategies employed for CTE were outlined. The light was shed on the limitations of the use of conventional hydrogels in CTE. Moreover, diverse types of SRHs, their characteristics, assembly and exploitation for CTE were discussed. To summarize, recent development in the construction of SRHs increases their potential to operate as intelligent, sophisticated systems in the reconstruction of degenerated cardiac tissues

Progenitor cells in auricular cartilage demonstrate promising cartilage regenerative potential in 3D hydrogel culture

The reconstruction of auricular deformities is a very challenging surgical procedure that could benefit from a tissue engineering approach. Nevertheless, a major obstacle is presented by the acquisition of sufficient amounts of autologous cells to create a cartilage construct the size of the human ear. Extensively expanded chondrocytes are unable to retain their phenotype, while bone marrow-derived mesenchymal stromal cells (MSC) show endochondral terminal differentiation by formation of a calcified matrix. The identification of tissue-specific progenitor cells in auricular cartilage, which can be expanded to high numbers without loss of cartilage phenotype, has great prospects for cartilage regeneration of larger constructs. This study investigates the largely unexplored potential of auricular progenitor cells for cartilage tissue engineering in 3D hydrogels

Stem cell based therapy retards the progression of osteoarthritis and promotes repair of meniscus injury of sheep model knee joint

ABSTRACT The aim of this study to determine if intra-articular injection of autologous bone marrow mesenchymal stem cells (ABMSCs) could repair surgically induced osteoarthritis in sheep model. Eighteen male healthy sheep (weighed 18-20kg) were divided into two test groups and one control group. The control groups were not different from the test groups with respect to age and weight, but the test animals underwent a bone marrow aspira- tion for cell preparation in the same time of osteoarthritis induction. ABMSCs were isolated from sheep bone marrow and divided into two groups, namely test group A; ABMSCs cultured in FD medium supplemented with 10% fetal bovine serum (FBS), Test group B; ABMSCs were cultured in FD medium supplimented with 1% FBS and 10 ng/ml TGFβ-3 for three weeks. OA was induced by complete excision of the medial meniscus and resection of the anterior cruciate ligament (ACL). Sheep were subjected to exercise for three weeks post OA induction. After 6 weeks post-operation, test groups received direct intra-articular injection of a single dose 10x106 cells suspended in basal medium into injured sheep knee joint. Con- trol animals received basal medium alone. Six weeks post- cel injection, the femoral condyle and the tibial plateau from test and control groups were removed,fixed,photographed, and assessed by two blinded evaluators based on ICRS grading system, decalcified. Specimens were sectioned into 5 µm and stained with H & E and Safranin O. The result demonstrated that Gross observation of femoral condyle and tibia plaetue of the operated knee joint had OA. The severe OA was clearly observed in in control group knee joints. Test group received intra-articular injection of ABMSCs alone showed moderate OA. Interestingly test group B that received intra-articularinjection of TGF-β3 induced ABMSCs showed mild OA. The histological examination showed clear evidence of articular cartilage and menicscus regeneration in test group B of sheep injured knee joint that received TGF-β3 induced ABMSCs when compared with other groups