A common problem in the design of tissue engineered scaffolds using electrospun scaffolds is the poor cellular infiltration into the structure To tackle this issue, three approaches to scaffold design using electrospinning were investigated: selective leaching of a water-soluble fiber phase (poly ethylene oxide (PEO) or gelatin), the use of micron-sized fibers as the scaffold, and a combination of micron-sized fibers with codeposition of a hyaluronic acid-derivative hydrogel, Heprasil These designs were achieved by modifying a conventional electrospinning system with two charged capillaries and a rotating mandrel collector Three types of scaffolds were fabricated: medical grade poly(epsilon-caprolactone)/collagen (mPCL/Col) cospun with PEO or gelatin, mPCL/Col meshes with micron-sized fibers, and mPCL/Col microfibers cosprayed with Heprasil All three scaffold types supported attachment and proliferation of human fetal osteoblasts However, selective leaching only marginally improved cellular infiltration when compared to meshes obtained by conventional electrospinning Better cell penetration was seen in mPCL/Col microfibers, and this effect was more pronounced when Heprasil regions were present in the structure Thus, such techniques could be further exploited for the design of cell permeable fibrous meshes for tissue engineering applications

Combining electrospun scaffolds with electrosprayed hydrogels leads to three-dimensional cellularization of hybrid constructs

Biodegradable and biomimetic elastomeric scaffolds for tissue-engineered heart valves.

https://hal.archives-ouvertes.fr/hal-02415223/document

Heart on a chip: Micro-nanofabrication and microfluidics steering the future of cardiac tissue engineering

Geometrical cues provided by the intrinsic architecture of tissues and implanted biomaterials have a high relevance in controlling cellular behavior. Knowledge of how cells sense and subsequently respond to complex geometrical cues of various sizes and origins is needed to understand the role of the architecture of the extracellular environment as a cell-instructive parameter. This is of particular interest in the field of tissue engineering, where the success of scaffold-guided tissue regeneration largely depends on the formation of new tissue in a native-like organization in order to ensure proper tissue function. A well-considered internal scaffold design (i.e., the inner architecture of the porous structure) can largely contribute to the desired cell and tissue organization. Advances in scaffold production techniques for tissue engineering purposes in the last years have provided the possibility to accurately create scaffolds with defined macroscale external and microscale internal architectures. Using the knowledge of how cells sense geometrical cues of different size ranges can drive the rational design of scaffolds that control cellular and tissue architecture. This concise review addresses the recently gained knowledge of the sensory mechanisms of cells towards geometrical cues of different sizes (from the nanometer to millimeter scale) and points out how this insight can contribute to informed architectural scaffold designs.

Cellular Geometry Sensing at Different Length Scales and its Implications for Scaffold Design.

The global transplantation market size was valued at USD 8.4 billion in 2020 and is expected to grow at a compound annual growth rate of 11.5% over the forecast period. The increasing demand for tissue transplantation has inspired researchers to find alternative approaches for making artificial tissues and organs function. The unique physicochemical and biological properties of biopolymers and the attractive structural characteristics of aerogels such as extremely high porosity, ultra low-density, and high surface area make combining these materials of great interest in tissue scaffolding and regenerative medicine applications. Numerous biopolymer aerogel scaffolds have been used to regenerate skin, cartilage, bone, and even heart valves and blood vessels by growing desired cells together with the growth factor in tissue engineering scaffolds. This review focuses on the principle of tissue engineering and regenerative medicine and the role of biopolymer aerogel scaffolds in this field, going through the properties and the desirable characteristics of biopolymers and biopolymer tissue scaffolds in tissue engineering applications. The recent advances of using biopolymer aerogel scaffolds in the regeneration of skin, cartilage, bone, and heart valves are also discussed in the present review. Finally, we highlight the main challenges of biopolymer-based scaffolds and the prospects of using these materials in regenerative medicine.

G.S. Bhuvaneshwar

Papers

Engineering of a polymer layered bio-hybrid heart valve scaffold

Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering

Nanosecond laser ablation enhances cellular infiltration in a hybrid tissue scaffold.