Method and mixture for in vivo photochemical cross-linking of collagen

Abstract

A method and a composition for photochemical cross linking of collagen by photoactive agent in-vivo are presented. The method includes a non-toxic photoactive formulation of the composition with collagen, which is administered to treatment area locally; followed by irradiation with suitable wavelength. In one of the embodiment liposomal formulated mTHPC is added to the collagen and is irradiated with a 652 nm laser, resulting in producing efficient collagen scaffolds with strengthen and stabilized microstructure, thus improving the physiochemical properties of the collagen scaffold. It improves the thermostability, mechanical property and swelling ratio of newly formed scaffold. Photochemical cross-linked collagens shows antimicrobial effect, when irradiated with suitable wavelength it disinfects the treatment site and curbs microbial growth.

1 . A formulation for in vivo photochemical cross-linking of collagen or other protein scaffolds comprising; a mixture of a structural protein like collagen and a photosensitizer, which is photoactivated in vivo by a wavelength in the range from about 530 nm to 750 nm. 
   
   
       2 . The formulation according to  claim 1  wherein said mixture is in a final form selected from the group consisting of an injectable solution, a sponge, and a wound dressing. 
   
   
       3 . The formulation according to  claim 1  wherein said photosensitizer is a hydrophobic photosensitizer. 
   
   
       4 . The formulation according to  claim 3 , wherein said photosensitizer is temoporfin, 5,10,15,20-tetra[m-hydroxyphenyl]chlorin (mTHPC). 
   
   
       5 . A method for in vivo cross-linking of structural proteins comprising the steps of:
 formulating a mixture of a photosensitizer and said structural protein;   introducing said mixture to tissue to be treated in a patient;   irradiating said treated tissue at a preselected wavelength photoactivating said photosensitizer; and   substantially simultaneously disinfecting the treatment site through photochemical reactions following photoactivation of said photosensitizer.   
   
   
       6 . The method for in vivo cross-linking of structural proteins according to  claim 5 , wherein said irradiating step employs electromagnetic radiation with a wavelength between about 530 nm and 750 nm, in which a specific selected wavelength overlaps sufficiently with said photosensitizer's absorption spectrum to activate said photosensitizer. 
   
   
       7 . The method for in vivo cross-linking of structural proteins according to  claim 5 , wherein said preselected wavelength is about 652 nm, said photosensitizer is temoporfin (mTHPC), and said structural protein is collagen.