This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent), and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.

Cockayne syndrome (CS) is a severe, complex, progressive and autosomal recessive disease characterized by developmental, skeletal, neurological and muscular failure, as well as a premature aging phenotype [1]. Patients with CS can be assigned to two different complementation groups, with the majority carrying mutations in the CSB gene [2]. A clinically identified CSB truncation (CS1AN) has been genetically introduced into a mouse, which displays similar but milder CS phenotypes [3]. The CSB protein plays distinct roles in different DNA repair pathways. It is involved in the transcriptioncoupled repair of UV-induced DNA damage, which is reflected by the sensitivity of human and murine csb m ⁄ m fibroblasts to UV radiation. Furthermore, CSB is involved in the global repair of different types of endogenously formed DNA damage and also participates in regulation of the major nuclear and mitochondrial 8-oxoguanine (8oxoG) Cockayne syndrome (CS) is a complex, progressive disease that involves neurological and developmental impairment and premature aging. The majority of CS patients have mutations in the CSB gene. The CSB protein is involved in multiple DNA repair pathways and CSB mutated cells are sensitive to a broad spectrum of genotoxic agents. We tested the hypothesis that sensitivity to such genotoxins could be mediated by mitochondrial dysfunction as a consequence of the CSB mutation. mtDNA from csb m ⁄ m mice accumulates oxidative damage including 8-oxoguanine, and cells from this mouse are hypersensitive to the mitochondrial oxidant menadione. Inhibitors of mitochondrial complexes and the glycolysis inhibitor 2-deoxyglucose kill csb m ⁄ m cells more efficiently than wild-type cells, via a mechanism that does not correlate with mtDNA damage formation. Menadione depletes cellular ATP, and recovery after depletion is slower in csb m ⁄ m cells. The bioenergetic alteration in csb m ⁄ m cells parallels the simpler organization of supercomplexes consisting of complexes I, III and IV in addition to partially disassembled complex V in the inner mitochondrial membrane. Exposing wild-type cells to DNA intercalating agents induces complex alterations, suggesting a link between mtDNA integrity, respiratory complexes and mitochondrial function. Thus, mitochondrial dysfunction may play a role in the pathology of CS.Abbreviations