Present invention depicts a poly-porous (micropore) hollow screws as 
diffusion chamber filled with core matrix for targeted delivery of growth factors and 
bone marrow stem cells. The screws comprise at least two parts: the distal part of the screw consists of the tip of the screw made of poly porous material and hollow inside proximally. It has threaded 
navel attached to the threaded nipple of the distal part of the proximal screw which has the 
screw head and is made of the 
solid material of the same kind. The 
screw head had hexagonal recess targeted for screw driver 
insertion. 
Assembly of screw created a chamber in the middle of the screw. The chamber is filled with core matrix consisting of 
gelatin nano-particles pre-impregnated with BMPs (BMP2 / BMP7 for bone or BMP12 for 
tendon, 
ligament) and 
fibrin sealants or 
Chitosan dispersed with 
bone marrow stem cells and / or other growth factors. Bioactive 
protein core material is prepared during the 
surgery and filled the chamber of the screw by the surgeon. 
Fibrin sealants or 
Chitosan will polymerize to form a gel to hold the growth factors and 
stem cell in place. The screw can be used as the 
lag screw or other function to provide mechanical fixation in variety of condition. Once the screw implanted in the 
human body, the 
fibrin sealant or Chitosin / 
gelatin nano-particles are gradually degraded and slowly release growth factors and stem cells via micropores of screw to facilitate the 
bone healing and regeneration. The 
gelatin nanoparticles and 
fibril sealant / or 
Chitosan matrix also serve as the 
scaffold and platform for bone in-growth to the screw or alternatively, the 
stem cell inside of screw can regenerate new bone, providing the biological fixation. At the mean time as the bone regenerate and / or in growth, 
mechanical strength of the screw increased.