A method of making a tissue or organ replacement composition comprising: fabricating a biocompatible support structure; fabricating a tissue-engineered construct comprising: depositing a bio ink in or around the biocompatible support structure wherein the bio ink comprises 5 mg/ml to 200 mg/ml of collagen; crosslinking the bio ink, and optionally repeating the depositing and crosslinking steps, to form the tissue-engineered construct; and curing the tissue or organ replacement composition; wherein: the replacement composition has a 3D shape wherein the tissue-engineered construct is in the shape of an organ or tissue of a subject; the biocompatible support structure comprises one or more external supports and one or more internal supports of biocompatible material, wherein external supports refers to one or more structural components customized into various 2D or 3D shapes and sizes and configured to serve as an exoskeletal structure covering one or more surfaces of the tissue-engineered construct, and wherein internal support refers to one or more structural components customized into various 2D or 3D shapes and sizes and configured to serve as an internal skeletal structure that is fully or partially encapsulated by the tissue-engineered construct; and the biocompatible material is present in an amount of 1% to 100% by weight of the biocompatible support structure. fabricating a biocompatible support structure; fabricating a tissue-engineered construct comprising: depositing a bio ink in or around the biocompatible support structure wherein the bio ink comprises 5 mg/ml to 200 mg/ml of collagen; crosslinking the bio ink, and optionally repeating the depositing and crosslinking steps, to form the tissue-engineered construct; and depositing a bio ink in or around the biocompatible support structure wherein the bio ink comprises 5 mg/ml to 200 mg/ml of collagen; crosslinking the bio ink, and optionally repeating the depositing and crosslinking steps, to form the tissue-engineered construct; and curing the tissue or organ replacement composition; wherein: the replacement composition has a 3D shape wherein the tissue-engineered construct is in the shape of an organ or tissue of a subject; the biocompatible support structure comprises one or more external supports and one or more internal supports of biocompatible material, wherein external supports refers to one or more structural components customized into various 2D or 3D shapes and sizes and configured to serve as an exoskeletal structure covering one or more surfaces of the tissue-engineered construct, and wherein internal support refers to one or more structural components customized into various 2D or 3D shapes and sizes and configured to serve as an internal skeletal structure that is fully or partially encapsulated by the tissue-engineered construct; and the biocompatible material is present in an amount of 1% to 100% by weight of the biocompatible support structure. the replacement composition has a 3D shape wherein the tissue-engineered construct is in the shape of an organ or tissue of a subject; the biocompatible support structure comprises one or more external supports and one or more internal supports of biocompatible material, wherein external supports refers to one or more structural components customized into various 2D or 3D shapes and sizes and configured to serve as an exoskeletal structure covering one or more surfaces of the tissue-engineered construct, and wherein internal support refers to one or more structural components customized into various 2D or 3D shapes and sizes and configured to serve as an internal skeletal structure that is fully or partially encapsulated by the tissue-engineered construct; and the biocompatible material is present in an amount of 1% to 100% by weight of the biocompatible support structure.