Tissue engineering aims to develop functional substitutes for damaged or diseased tissues through complex constructs of living cells, bioactive molecules and three-dimensional porous scaffolds, which support cell attachment, proliferation and differentiation. Such constructs can be formed either by seeding cells within a pre-formed scaffold or through injection of a solidifiable precursor and cell mixture to the defective tissue. As cell and bioactive molecule carriers, injectable scaffolds are appealing, particularly from the clinical point of view, because they offer the possibility of homogeneously distributing cells and molecular signals throughout the scaffold and can be injected directly into cavities, even of irregular shape and size, in a minimally invasive manner. In this paper the challenges in designing an injectable scaffold from the viewpoint of materials chemistry and the solidification mechanisms of injectable precursors are discussed. The applications of injectable scaffolds in angiogenesis, bone repair and cartilage regeneration are described.

Cultured meat, as a cellular agriculture product, utilizes tissue engineering techniques and consequently faces not only cell culture challenges but also scale-up limitations. To ensure cultured meat is financially viable, efficient bioprocess design for scale-up is required. In this mini-review we focus on the design of the expansion bioreactor, and put it in context of the entire bioprocess by providing an overview of the upstream and downstream process considerations. As a full-scale cultured meat bioprocess is still hypothetical we include a review of the key factors and fundamental cell biology parameters required as input data for the design of a process with a product that is not only viable but price competitive. This review highlights the vital aspects of a cultured meat bioreactor design that are often overlooked when parallels are drawn against fermentation processes such as brewing or recombinant protein production in the pharmaceutical industry. Practical application and awareness of the concepts presented here will enable more accurate estimation of the production expenses and raw material requirements. This will form a basis for both further academic research and the design of industrial-scale processes in the field of cultured meat and the wider field of tissue engineering-based cellular agriculture.

An efficient two-step synthesis of pyrazoline ligand 1 is described which is an effective “turn on” fluorescent sensor for Cd²⁺ in MeCN. Oxidation to the corresponding pyrazole ligand 2 creates a “turn on” fluorescent sensor now selective for Zn²⁺ and able to distinguish it from Cd²⁺.

The mammalian cell surface is a highly heterogeneous chemical environment with proteins, carbohydrates, lipids and composite molecules controlling vital cell functions. Chemical modification of this environment is a challenge due to the complexity of the surface chemistry and the fragility of the cell. Here, we review recent attempts to perform targeted, non-genetically controlled, changes to cell surface chemistry. Potential applications of cell surface engineering are presented.

Microcarrier cell scaffolds have potential as injectable cell delivery vehicles or as building blocks for tissue engineering. The use of small cell carriers allows for a 'bottom up' approach to tissue assembly when moulding microparticles into larger structures, which can facilitate the introduction of hierarchy by layering different matrices and cell types, while evenly distributing cells through the structure. In this work, silk fibroin (SF), purified from Bombyx mori cocoons, was blended with gelatin (G) to produce materials composed of varying ratios of the two components (SF: G 25:75, 50:50, and 75:25). Cell compatibility to these materials was first confirmed in two-dimensional culture and found to be equivalent to standard tissue culture plastic, and better than SF or G alone. The mechanical properties of the blends were investigated and the blended materials were found to have increased Young's moduli over SF alone. Microcarriers of SF/G blends with defined diameters were generated in a reproducible manner through the use of an axisymmetric flow focussing device, constructed from off-the-shelf parts and fittings. These SF/G microcarriers supported adhesion of rat mesenchymal stem cells with high degrees of efficiency under dynamic culture conditions and, after culturing in osteogenic differentiation medium, cells were shown to have characteristics typical of osteoblasts. This work illustrates that microcarriers composed of SF/G blends are promising building blocks for osteogenic tissue engineering.