Abstract: In one aspect, the present invention provides hydrogels comprising polymer molecules and bridging molecules, wherein substantially all the polymer molecules are cross-linked by hydrogen bonds between polymer molecules and bridging molecules, wherein each bridging molecule is linked to at least two polymer molecules, and wherein there are substantially no covalent linkages between the polymer molecules. In some embodiments, the polymer molecules are poly(vinyl alcohol) (PVA) and the bridging molecules are amino acids. Some embodiments of the invention provide devices comprising hydrogels, and pharmaceutical compositions comprising biologically active molecules within hydrogels. Another aspect provides methods for forming hydrogels of the invention.

Abstract: In one aspect the present invention provides biodegradable, porous structures that each include a structural framework, wherein the structural framework includes: (a) a solidified mixture of polymer molecules and amino acid molecules, wherein at least some of the amino acid molecules are linked to other amino acid molecules within the framework; and (b) a multiplicity of interconnected spaces defined by the structural framework. In some embodiments, the porous structures of the invention are adapted to physically support the growth of living cells in vitro or in vivo, and can be used to grow living tissue and/or living organs. The present invention also provide methods for making the biodegradable, porous structures of the invention.

Abstract: In one aspect, the present invention provides hydrogels comprising polymer molecules and bridging molecules, wherein substantially all the polymer molecules are cross-linked by hydrogen bonds between polymer molecules and bridging molecules, wherein each bridging molecule is linked to at least two polymer molecules, and wherein there are substantially no covalent linkages between the polymer molecules. In some embodiments, the polymer molecules are poly(vinyl alcohol) (PVA) and the bridging molecules are amino acids. Some embodiments of the invention provide devices comprising hydrogels, and pharmaceutical compositions comprising biologically active molecules within hydrogels. Another aspect provides methods for forming hydrogels of the invention.

Abstract: In one aspect, the present invention provides hydrogels comprising polymer molecules and bridging molecules, wherein substantially all the polymer molecules are cross-linked by hydrogen bonds between polymer molecules and bridging molecules, wherein each bridging molecule is linked to at least two polymer molecules, and wherein there are substantially no covalent linkages between the polymer molecules. In some embodiments, the polymer molecules are poly(vinyl alcohol) (PVA) and the bridging molecules are amino acids. Some embodiments of the invention provide devices comprising hydrogels, and pharmaceutical compositions comprising biologically active molecules within hydrogels. Another aspect provides methods for forming hydrogels of the invention.

Abstract: In one aspect the present invention provides biodegradable, porous structures that each include a structural framework, wherein the structural framework includes: (a) a solidified mixture of polymer molecules and amino acid molecules, wherein at least some of the amino acid molecules are linked to other amino acid molecules within the framework; and (b) a multiplicity of interconnected spaces defined by the structural framework. In some embodiments, the porous structures of the invention are adapted to physically support the growth of living cells in vitro or in vivo, and can be used to grow living tissue and/or living organs. The present invention also provide methods for making the biodegradable, porous structures of the invention.