Core-shell nanofibers containing L-arginine stimulates angiogenesis and full thickness dermal wound repair.

Despite the advances in medicine, wound healing is still challenging and piques the interest of biomedical engineers to design effective wound dressings using natural and artificial polymers. In present study, coaxial electrospinning was employed to fabricate core-shell nanofiber-based wound dressing, with core composed of polyacrylamide (PAAm) and shell comprising 0.5 % solution of L-Arginine (L-Arg) in aloe vera and keratin (AloKr). Aloe vera and keratin were added as natural polymers to promote angiogenesis, reduce inflammation, and provide antibacterial activity, whereas PAAm in core was used to improve the tensile properties of the wound dressing. Moreover, L-Arg was incorporated in shell to promote angiogenesis and collagen synthesis. The fiber diameter of PAAm/(AloKr/L-Arg) core-shell fibers was (93.33 ± 35.11 nm) with finer and straighter fibers and higher water holding capacity due to increased surface area to volume ratio. In terms of tensile properties, the PAAm/(AloKr/L-Arg) core-shell nanofibers with tensile strength and elastic modulus of 2.84 ± 0.27 MPa and 62.15 ± 5.32 MPa, respectively, showed the best mechanical performance compared to other nanofibers tested. Furthermore, PAAm/(AloKr/L-Arg) exhibited the highest L-Arg release (87.62 ± 3.02 %) and viability of L929 cells in vitro compared to other groups. In addition, the highest rate of in vivo full thickness wound healing was observed in PAAm/(AloKr/L-Arg) group compared to other groups. It significantly enhanced the angiogenesis, neovascularization, and cell proliferation. The prepared PAAm/(AloKr/L-Arg) core-shell nanofibrous dressing could be promising for full-thickness wound healing.

Keratin-containing scaffolds for tissue engineering applications: a review.

In tissue engineering and regenerative medicine applications, the utilization of bioactive materials has become a routine tool. The goal of tissue engineering is to create new organs and tissues by combining cell biology, materials science, reactor engineering, and clinical research. As part of the growth pattern for primary cells in an organ, backing material is frequently used as a supporting material. A porous three-dimensional (3D) scaffold can provide cells with optimal conditions for proliferating, migrating, differentiating, and functioning as a framework. Optimizing the scaffolds' structure and altering their surface may improve cell adhesion and proliferation. A keratin-based biomaterials platform has been developed as a result of discoveries made over the past century in the extraction, purification, and characterization of keratin proteins from hair and wool fibers. Biocompatibility, biodegradability, intrinsic biological activity, and cellular binding motifs make keratin an attractive biomaterial for tissue engineering scaffolds. Scaffolds for tissue engineering have been developed from extracted keratin proteins because of their capacity to self-assemble and polymerize into intricate 3D structures. In this review article, applications of keratin-based scaffolds in different tissues including bone, skin, nerve, and vascular are explained based on common methods of fabrication such as electrospinning, freeze-drying process, and sponge replication method.

Modified poly(3-hydroxybutyrate)-based scaffolds in tissue engineering applications: A review.

As a member of the polyhydroxyalkanoate (PHAs) family, Poly(3-hydroxybutyrate) (PHB) has attracted much attention for a variety of medical applications because of its desirable properties such as high biocompatibility, nontoxic degradation products and high mechanical strength in comparison to other polymers in different fields including tissue engineering. There are different approaches such as making PHB alloy scaffolds, using PHB as a coating for ceramic-based scaffolds and producing composite scaffolds by using a mixture of PHB with ceramic particles utilized to improve hydrophobicity, degradation rate and brittleness. In this review, different applications of PHB, its alloys and composites in tissue engineering are explained based on the common methods of fabrication such as polymeric sponge replication, electrospinning and salt leaching.

Polymethyl Methacrylate-Based Bone Cements Containing Carbon Nanotubes and Graphene Oxide: An Overview of Physical, Mechanical, and Biological Properties.

Every year, millions of people in the world get bone diseases and need orthopedic surgery as one of the most important treatments. Owing to their superior properties, such as acceptable biocompatibility and providing great primary bone fixation with the implant, polymethyl methacrylate (PMMA)-based bone cements (BCs) are among the essential materials as fixation implants in different orthopedic and trauma surgeries. On the other hand, these BCs have some disadvantages, including Lack of bone formation and bioactivity, and low mechanical properties, which can lead to bone cement (BC) failure. Hence, plenty of studies have been concentrating on eliminating BC failures by using different kinds of ceramics and polymers for reinforcement and also by producing composite materials. This review article aims to evaluate mechanical properties, self-setting characteristics, biocompatibility, and bioactivity of the PMMA-based BCs composites containing carbon nanotubes (CNTs), graphene oxide (GO), and carbon-based compounds. In the present study, we compared the effects of CNTs and GO as reinforcement agents in the PMMA-based BCs. Upcoming study on the PMMA-based BCs should concentrate on trialing combinations of these carbon-based reinforcing agents as this might improve beneficial characteristics.