Expandable tissue thickness compensator

An article selected from an anvil of a stapling apparatus and a staple cartridge for a stapling apparatus, the article comprising:

• a tissue thickness compensator comprising:
• a biocompatible material;
• a first component;
• and
• a second component;
• wherein the first component and second component form a reaction product to expand the tissue thickness compensator, and wherein the first component comprises a hydrophilic material embedded in the biocompatible material and the second component is a bodily fluid.

An article selected from an anvil of a stapling apparatus and a staple cartridge for a stapling apparatus, the article comprising:

• a tissue thickness compensator comprising:
• a biocompatible material;
• a first component;
• and
• a second component;
• wherein the first component and second component form a reaction product to expand the tissue thickness compensator, wherein the tissue thickness compensator comprises a first encapsulated component comprising the first component and a second encapsulated component comprising the second component, and wherein the first encapsulated component is configured to release the first component when the first encapsulated component is ruptured, and the second encapsulated component is configured to release the second component when the second encapsulated component is ruptured.

An article selected from an anvil of a stapling apparatus and a staple cartridge for a stapling apparatus, the article comprising:

• a tissue thickness compensator comprising:
• a biocompatible material;
• a first component;
• and
• a second component;
• wherein the first component and second component form a reaction product to expand the tissue thickness compensator, and wherein the reaction product is formed in situ by contacting the first component and the second component.

An article selected from an anvil of a stapling apparatus and a staple cartridge for a stapling apparatus, the article comprising:

• a tissue thickness compensator comprising:
• a biocompatible material;
• a first component;
• and
• a second component;
• wherein the first component and second component form a reaction product to expand the tissue thickness compensator, and wherein the first component comprises a first hydrogel precursor, the second component comprises a second hydrogel precursor, and the reaction product comprises a hydrogel.