About this Research Topic
In their natural environment, cells are surrounded by an intricate network of extracellular molecules, called the Extracellular Matrix, that influences proximal cell structure and function. Due to limitations raised by traditional 2D cell culture techniques, wherein this extracellular environment is absent (or vastly reduced), alternative tissue engineering approaches have been explored in an effort to mimic the ECM. Among these, 3D hydrogel networks have attracted the greatest interest. Owing to their high water content, as well as their amenability to mechanical and biochemical optimization, 3D hydrogels lend themselves as excellent microenvironments for cell colonization. However, before their applications may be expanded, some limitations of 3D hydrogel properties remain to be overcome, including the fact that they are still far from the mechanical or biological properties of native tissues. Therefore, several strategies are being explored to enhance the application of hydrogels, including the addition of fillers (inorganic and organic) in order to improve the mechanical properties, as well as functionalization in order to better mimic the natural extracellular environment.
In this respect, composite (meaning addition of fillers in the polymeric matrix) or functionalized (chemical-physical grafting of biomolecules to the polymeric matrix) hydrogels offer to achieve superior performances (e.g. enhanced viscoelasticity) compared with bare hydrogels. Furthermore, these hydrogels can allow the fine-tuning of swelling and degradation profiles, providing new tools to predict the hydrogels’ in vivo behavior. Moreover, these strategies could lead to stimuli-responsive release kinetics that will be useful to deliver the effective amounts of a bioactive molecule in a specific target site. Furthermore, with the range of innovative hydrogel manufacturing techniques now available (e.g. 3D printing), it is possible to directly encapsulate cells during gel preparation, opening new landscapes in tissue engineering and regenerative medicine. This aspect can overcome the current limitation of the hydrogels in providing appropriate outcomes in vivo.
This Research Topic aims to gather contributions describing application-driven 3D composite and/or functionalized hydrogel design and preparation of cell-laden hydrogels by innovative manufacturing techniques. Moreover, studies related to hydrogels characterization (e.g. mechanical, biological, physico-chemical and morphological) will be welcomed as well. Finally, papers describing composite materials that have demonstrated improved in vivo outcome are encouraged also. We welcome submissions covering the following topics:
• Functionalization of hydrogels for enhancing biological properties
• Composite hydrogels (eg. inorganic fillers addition) for improving the mechanical properties
• Novel composite hydrogels based on interpenetrating networks of 2 or more materials
• Advanced manufacturing of composite hydrogel-based constructs for tissue engineering
• Studies on the rheological properties of composite hydrogels and how the mechanical properties can influence in vitro response
• Composite hydrogels with encouraging and successful in vivo outcomes.
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.