Traction and attraction: haptotaxis substrates collagen and fibronectin interact with chemotaxis by HGF to regulate myoblast migration in a microfluidic device.

Cell migration is central to development, wound healing, tissue regeneration, and immunity. Despite extensive knowledge of muscle regeneration, myoblast migration during regeneration is not well understood. C2C12 mouse myoblast migration and morphology were investigated using a triple-docking polydimethylsiloxane-based microfluidic device in which cells moved under gravity-driven laminar flow on uniform (=) collagen (CN=), fibronectin (FN=), or opposing gradients (CN-FN or FN-CN). In haptotaxis experiments, migration was faster on FN= than on CN=. At 10 h, cells were more elongated on FN-CN and migration was faster than on the CN-FN substrate. Net migration distance on FN-CN at 10 h was greater than on CN-FN, as cells rapidly entered the channel as a larger population (bulk-cell movement, wave 1). Hepatocyte growth factor (HGF) stimulated rapid chemotaxis on FN= but not CN=, increasing migration speed at 10 h early in the channel at low HGF in a steep HGF gradient. HGF accelerated migration on FN= and bulk-cell movement on both uniform substrates. An HGF gradient also slowed cells in wave 2 moving on FN-CN, not CN-FN. Both opposing-gradient substrates affected the shape, speed, and net distance of migrating cells. Gradient and uniform configurations of HGF and substrate differentially influenced migration behavior. Therefore, haptotaxis substrate configuration potently modifies myoblast chemotaxis by HGF. Innovative microfluidic experiments advance our understanding of intricate complexities of myoblast migration. Findings can be leveraged to engineer muscle-tissue volumes for transplantation after serious injury. New analytical approaches may generate broader insights into cell migration.

Recent Advances in Natural Gum-Based Biomaterials for Tissue Engineering and Regenerative Medicine: A Review.

The engineering of tissues under a three-dimensional (3D) microenvironment is a great challenge and needs a suitable supporting biomaterial-based scaffold that may facilitate cell attachment, spreading, proliferation, migration, and differentiation for proper tissue regeneration or organ reconstruction. Polysaccharides as natural polymers promise great potential in the preparation of a three-dimensional artificial extracellular matrix (ECM) (i.e., hydrogel) via various processing methods and conditions. Natural polymers, especially gums, based upon hydrogel systems, provide similarities largely with the native ECM and excellent biological response. Here, we review the origin and physico-chemical characteristics of potentially used natural gums. In addition, various forms of scaffolds (e.g., nanofibrous, 3D printed-constructs) based on gums and their efficacy in 3D cell culture and various tissue regenerations such as bone, osteoarthritis and cartilage, skin/wound, retinal, neural, and other tissues are discussed. Finally, the advantages and limitations of natural gums are precisely described for future perspectives in tissue engineering and regenerative medicine in the concluding remarks.

Emerging Development of Microfluidics-Based Approaches to Improve Studies of Muscle Cell Migration.

IMPACT STATEMENT: The essential interactions between and among cells in the three types of muscle tissue in development, wound healing, and regeneration of tissues, are underpinned by the ability of cardiac, smooth, and skeletal muscle cells to migrate in maintaining functional capacity after pathologies such as myocardial infarction, tissue grafting, and traumatic and postsurgical injury. Microfluidics-based devices now offer significant enhancement over conventional approaches to studying cell chemotaxis and haptotaxis that are inherent in migration. Advances in experimental approaches to muscle cell movement and tissue formation will contribute to innovations in tissue engineering for patching wound repair and muscle tissue replacement.

Biocompatibility evaluation of a new hydrogel dressing based on polyvinylpyrrolidone/polyethylene glycol.

The composition of the dressings is based on polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and agar. The electron beam irradiation technique has been used to prepare hydrogel wound dressings. The in vitro biocompatibility of the hydrogel was investigated by check samples (hydrocolloid Comfeel), antibacterial test (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia Coli k12), anti fungal test (Candida Albicans) and cytotoxicity test (Fibroblast L929). Results have shown cell attachment characteristics and nontoxicity of all samples. Antibacterial testing also showed that the antibacterial effect of the hydrogel sample to the check sample increased to 30%. Also, investigation of antifungal analysis did not show any trace of fungi growth on the surface of the hydrogel, whereas antifungal effect did not observe on the surface of the check sample. Finally, this hydrogel sample showed a good in vitro biocompatibility.