Abstract

Collagens are a major constituent of the extracellular matrices of many biological tissues. Their structural and biological roles in animal tissues have inspired the development of regenerative therapies that incorporate collagen as a base material, thus providing a naturally recognisable surface for cell attachment and proliferation. In this review, recent collagen-related patents / patent applications are divided into three main areas: methods of collagen extraction / purification / synthesis (Area 1), methods of collagen molecular modification / processing (Area 2) and collagen scaffolds / implants (Area 3). Within Area 1, there are disclosures for methods of obtaining collagenous materials, including a method that uses urea to isolate collagen from collagen-containing natural fibres. Methods have also emerged to avoid the risk of cross-species infection including the extraction of collagen from marine sources and the synthesis of modular collagenlike peptides in bacterium models. Within Area 2, there are recently disclosed methods that can increase the resistance of collagen to degradation, including covalent / non-covalent crosslinking and a method of stabilising the collagen triple helix through O-methylation. Methods have also been recently disclosed to remove antigenic surface carbohydrate moieties and for processing collagen to induce fibril fusion. Within Area 3, there have been developments in the functional use of collagen in regenerative therapies, including a method to decellularise thick collagen-rich tissue extracts for use as a scaffold, a method to provide a support mesh for collagen scaffolds such that they hold their external shape on implantation and a method which allows the creation of composite scaffolds and multi-layer scaffolds for trans-tissue implants. In addition, two recent patents disclose the use of collagen injections for the treatment of synovial joints and intervertebral discs. The recent advances in the art represent a culmination of many years of progressive work on collagenous materials from many scientific fields; there now exists a plethora of techniques to obtain collagen, to modify its structure / properties and to implement the material into a functional embodiment for tissue regeneration.

Keywords: Collagen, extraction, implants, patents, processing, regenerative medicine, scaffolds, synthesis, proliferation, collagen injections