This talk will describe two polymer systems which have been functionalized with norbornene groups to enable hydrogel formation via thiol-ene chemistry. For both systems, an all-inone pot approach was used to form the hydrogels in cell-permissive conditions. Peptide sequences cleavable by cell-secreted matrix metalloproteinases flanked by cysteines were used as cross-linkers. Polymers were rendered cell adhesive by binding of cysteineterminated RGD sequences. Cell were included to the mix. LAP was used as photoinitiator, and pre-gel solution exposed to 30 seconds of UV light to induce cross-linking. The first system is based on naturally-derived polysaccharide alginate. By tuning polymer and cross-linker concentrations a stiffness range between 300 to 2100 Pa was achieved. Full cross-linking occured at 12 seconds post UV irradiation, as determined by photorheometry. Scanning electron microscopy showed a highly porous ultrastructure. Hydrogels degraded upon exposure to exogenous collagenase. Pre-gel solutions could be successfully bioprinted with a pneumatic extrusion-based system. A variety of delicate cell types were encapsulated in the hydrogels. Human endometrial organoids presented high cell viability, grew in size over time, presented spherical morphology, and expressed cell-cell contacts E-cadherin and proliferation marker ki67. Encapsulated mouse embryonic stem cell-derived thyroid follicles produced thyroglobulin and T4. Mouse intestinal organoids adopted a proliferative phenotype. Vascularization inside the hydrogels was achieved using endothelial cells and supporting cells (single cell suspension and spheroids). Neurite outgrowth, both small and thick bundles, from encapsulated iPSC-derived neurospheres demonstrated the hydrogel’s reinnervation potential. The second system is based on synthetic polyvinyl alcohol (PVA). PVA is water soluble, biocompatible, has good mechanical properties and is highly amenable to chemical modifications. At 5% w/v hydrogels had a stiffness of approximately 2000 Pa. Exogenous collagenase degraded hydrogels cross-linked with MMP, but not when PEG was used. Dermal fibroblasts were encapsulated and presented elongated and spread morphology. Granular hydrogels were obtained upon secondary cross-linking of packed hydrogel particles formed by extrusion fragmentation and by emulsion in silicon oil. Fibroblasts could attach onto the surface of the hydrogel particles and migrate through the microporous structure. Future work will focus on studying the influence of inter-particle crosslinking on cell behavior, and the biofabrication of hierarchical constructs using granular hydrogels. These two polymer platforms allow high tunability of mechanical and biological properties to tailor the needs of cell culture, which could be an alternative to basement-membrane extracts.