Crosslinked biocompatible polymer networks offer unique potential for biomedical applications that demand high resilience under repetitive load-bearing conditions. However, conventional hydrogels often exhibit poor mechanical strength and irreversible damage under cyclic deformation, while traditional dental resins lack strong bonding to mineralized tissues and suffer from limited biofunctionality. To address these challenges, this work presents two classes of engineered polymer networks designed for enhanced mechanical robustness and interfacial performance: (1) cryogel-based double-network (DN) hydrogels and (2) thiol-ene-click-based dental resins.In the first system, collagen cryogels were formed through glutaraldehyde (GA) crosslinking, producing hyperelastic and macroporous scaffolds with shape-memory behavior. These cryogels served as the first network of DN hydrogels, further reinforced by an ionically crosslinked alginate network. Mechanical testing, including uniaxial compression, cyclic loading, and hyperelastic modeling, revealed excellent mechanical resilience (recovery after 90% compression), compressive modulus tunability (10-200 kPa), and peak stresses among 0.2~15 MPa. These hydrogels also demonstrated cytocompatibility, making them suitable for dynamic applications in soft robotics, tissue engineering, and mechanobiology research. In the second system, a photocurable resin formulation combining trimethylolpropane triacrylate (TMPTA) with 2-mercaptoethyl methacrylate phosphate (BMEP) was developed to enhance bonding to hydroxyapatite-rich substrates. Mechanical and morphological analysis at the dentin-resin interface, including shear bond strength tests and SEM-based hybrid layer visualization, confirmed a ~10% increase in interfacial thickness and significantly improved adhesion performance compared to the commercial primer. Together, these findings establish a framework for designing polymer networks that balance biocompatibility, resilience, and functionality under repetitive loading. The DN hydrogel systems exhibit reversible deformation and programmable mechanics, while the phosphate-functionalized resins achieve adhesion to mineralized interfaces. These materials offer new opportunities for load-bearing tissue regeneration, minimally invasive implants, wearable devices, and long-lasting dental restorations. By combining network architecture with functional chemistry, this research advances the next generation of durable, adaptive biomaterials for clinical and translational use.