The article reviews the design and application of biodegradable hydrogels for cell encapsulation in tissue engineering. Hydrogels, which are highly hydrated, tissue-like environments, offer advantages such as ease of handling and the ability to form in vivo. The crosslinked structure of hydrogels, controlled by processing conditions, influences properties like swelling, mechanical properties, degradation, and diffusion. Degradation can be tuned by incorporating labile segments or using biopolymers susceptible to enzymatic degradation. The mild nature of the encapsulation process allows for injectable systems and enhanced adhesion to adjacent tissues. Recent advances in hydrogel design, including synthetic hydrogels and bioactive hydrogels, have improved control over these properties. Key considerations for designing biodegradable hydrogels include precursor choice, gelation mechanisms, hydrogel structure, and chemistry. Liquid precursors and gelation mechanisms, such as radical chain polymerization and chemical crosslinking, are discussed, along with their cytocompatibility and degradation profiles. The article also highlights the importance of practical considerations for successful cell encapsulation, such as scalability, marketability, and FDA approval. Finally, it reviews the applications of various hydrogels, including naturally derived, synthetic, and biomimetic hydrogels, in tissue engineering, emphasizing their potential for regenerative medicine.The article reviews the design and application of biodegradable hydrogels for cell encapsulation in tissue engineering. Hydrogels, which are highly hydrated, tissue-like environments, offer advantages such as ease of handling and the ability to form in vivo. The crosslinked structure of hydrogels, controlled by processing conditions, influences properties like swelling, mechanical properties, degradation, and diffusion. Degradation can be tuned by incorporating labile segments or using biopolymers susceptible to enzymatic degradation. The mild nature of the encapsulation process allows for injectable systems and enhanced adhesion to adjacent tissues. Recent advances in hydrogel design, including synthetic hydrogels and bioactive hydrogels, have improved control over these properties. Key considerations for designing biodegradable hydrogels include precursor choice, gelation mechanisms, hydrogel structure, and chemistry. Liquid precursors and gelation mechanisms, such as radical chain polymerization and chemical crosslinking, are discussed, along with their cytocompatibility and degradation profiles. The article also highlights the importance of practical considerations for successful cell encapsulation, such as scalability, marketability, and FDA approval. Finally, it reviews the applications of various hydrogels, including naturally derived, synthetic, and biomimetic hydrogels, in tissue engineering, emphasizing their potential for regenerative medicine.