Bioengineered tissue substitutes

An implantable medical device intended for implantation to a target tissue, comprising a tubular scaffold, said scaffold comprising two or more arrays of microfibers, the two or more arrays being oriented in regularly spaced, concentric layers,

• wherein each array consists of a regularly spaced, helically wound microfiber, the spacing between adjacent microfibers being between 40 and 60 micrometers,
• wherein longitudinal spacers are provided to separate the two or more arrays into the regularly spaced, concentric layers,
• wherein the scaffold is designed to mimic the configuration of one or more structural elements in the target tissue, and
• wherein the microfibers are prepared from one or more polymers having a modulus comparable to or slightly greater than that of one or more structural elements in the target tissue.

A method for forming a target tissue substitute, comprising:

• (a) determining the modulus of one or more structural elements in the target tissue;
• (b) forming a scaffold comprising two or more arrays of microfibers, the two or more arrays being oriented in regularly spaced, parallel layers,
• wherein each array consists of a plurality of regularly spaced, parallel microfibers, the spacing between the microfibers being between 40 and 60 micrometers,
• wherein at least one spacer is provided to separate the two or more arrays into the regularly spaced, parallel layers,
• wherein the microfibers in one of the arrays are aligned in parallel or at a defined angle with respect to the microfibers in at least one other of the arrays, and
• wherein the scaffold is designed to mimic the configuration of one or more structural elements in the target tissue;
• and
• (c) culturing cells on the scaffold to produce a target tissue substitute.

A method for forming a tubular target tissue substitute, comprising:

• (a) determining the modulus of one or more structural elements in the target tissue;
• (b) forming a scaffold comprising two or more arrays of microfibers, the two or more arrays being oriented in regularly spaced, concentric layers,
• wherein each array consists of a regularly spaced, helically-wound microfiber, the spacing between the adjacent microfibers being between 40 and 60 micrometers,
• wherein longitudinal spacers are provided to separate the two or more arrays into the regularly spaced, concentric layers,
• wherein the microfibers in one of the arrays of microfibers are aligned at a defined angle with respect to the microfibers in at least one other of the arrays, and
• wherein the scaffold is designed to mimic the configuration of one or more structural elements in the target tissue;
• and
• (c) culturing cells on the scaffold to produce a target tissue substitute.

An implantable medical device intended for implantation to a target tissue,

• said implantable medical device comprising a tubular scaffold comprising two or more arrays of microfibers, the two or more arrays being oriented in regularly spaced, concentric layers,
• wherein each array consists of a regularly spaced, helically wound microfiber, the spacing between adjacent microfibers being between 40 and 60 micrometers,
• wherein longitudinal spacer fibers are provided to separate the two or more arrays into the regularly spaced, concentric layers,
• wherein the scaffold is designed to mimic the configuration of one or more structural elements in an arterial blood vessel, and
• wherein the arrays of microfibers are prepared from one or more polymers having a modulus comparable to or slightly greater than that of elastin in the medial layer of an arterial blood vessel.

A method for forming a blood vessel substitute, comprising:

• (a) forming a tubular scaffold comprising two or more arrays of microfibers, the two or more arrays being oriented in regularly spaced concentric layers,
• wherein each array consists of a regularly spaced, helically wound microfiber, the spacing between the adjacent microfibers being between 40 and 60 micrometers,
• wherein longitudinal spacer fibers are provided to separate the two or more arrays into the regularly spaced, concentric layers,
• wherein the scaffold is designed to mimic the configuration of elastin in the medial layer of an arterial blood vessel, and
• wherein the arrays of microfibers are formed from one or more polymers having a modulus comparable to or slightly greater than that of elastin in the medial layer of an arterial blood vessel;
• and
• (b) culturing cells on the scaffold to produce the blood vessel substitute.