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.