To develop new treatments for incurable diseases, understanding complex human biological systems is crucial. However, the size and fragility of human organs present challenges, leading most research to rely on small tissue samples. This talk introduces mELAST (magnifiable entangled link-augmented stretchable tissue-hydrogel), a novel biotechnology transforming the human brain into an elastic, expandable, and transparent polymer hydrogel composite. This technology synthesizes a highly-entangled, superhydrophilic polymer chains in situ with endogenous biomolecules (e.g., proteins) within the nanoporous structure of human brain tissues, effectively modifying their physicochemical properties. mELAST allows large-scale tissue processing, rapid multiplexed immunostaining and repeated physical expansion/shrinkage for multi-scale three-dimensional molecular bioimaging. mELAST is expected to significantly enhance understanding of human organ functions and disease mechanisms, catalyzing novel therapeutic discoveries.