Title of Invention

A METHOD FOR OBTAINING A BONE MARROW FRACTION IN VITRO .

Abstract A method for obtaining a bone marrow fraction in vitro, comprising: a) mixing an obtained bone marrow sample and an obtained peripheral whole blood sample which is separate from said bone marrow sample in a volume ratio in the range of 1:100 to 100:1 to prepare a biological sample; b) centrifuging the biological sample to provide separation of components of the sample based on density, said separation providing the following fractions in decreasing order of density: (i) a fraction rich in red blood cells; (ii) a buffy coat fraction; (iii) a platelet rich fraction; (iv) a platelet poor fraction; and (c) isolating the buffy coat fraction alone or in combination with all or part of the platelet rich fraction to form an isolate rich in connective tissue growth promoting components.
Full Text A METHOD FOR OBTAINING A BONE MARROW
FRACTION IN VITRO
This application claims the benefit of U.S. Patent Serial Nos. 60/485,445 filed July
9, 2003, which is hereby incorporated herein by reference in its entirety. This application
is also related to U.S. Patent Application Serial No. 10/116,729, filed April 4,2002
(published as U.S. Patent Application Publication No. 2002/0182664 on December 5,
2002) which is incorporated herein by reference in its entirety.
The instant invention does not use mesenchymal cells derived
from the human embryo.
The present application relates generally to compositions and methods of promoting
tissue growth and, in particular, to a bone marrow isolate rich in one or more connective
tissue (e.g., bone) growth promoting components, methods of forming the isolate and
methods of promoting connective tissue growth using the isolate.
Currently, when bone marrow is used in a bone grafting procedure, the marrow is
typically aspirated from the iliac crest and placed directly on the bone graft without any
secondary processing of the bone marrow. The majority of the bone marrow aspirate is
blood which offers minimal benefit to facilitating bone formation. Further, there is a large
content of platelets in blood that release undesirable growth factors such as PDGF (platelet
derived growth factor), TGF-beta (transforming growth factor beta), and FGF (fibroblast
growth factor) that have been shown under some circumstances to have an inhibitory
effect on bone formation.
Accordingly, there exists a need for improved or alternative techniques for
isolating components from bone marrow, particularly components which promote
connective tissue formation, and using the isolated components in connective tissue
repair procedures such as bone grafting and cartilage repair.
In one embodiment, the invention provides a method for obtaining a bone marrow
fraction. This method includes centrifuging a biological sample including whole blood
and bone marrow to provide a separation of components of the sample based upon density.
This separation provides the following tractions in decreasing order of density: (1) a
fraction rich in blood cells; (2) a buffy coat fraction; (3) a platelet rich fraction; and (4) a
platelet poor fraction. The buffy coat fraction is isolated alone or in combination with all
or part of the platelet rich fraction, so as to form an isolate rich in connective tissue growth
promoting components.
In another embodiment, the invention provides a method for treating a patient. The
method includes isolating a bone marrow fraction including components that promote
connective tissue formation, and implanting the bone marrow fraction into a patient at a
tissue defect site. In accordance with the invention, the isolation of the bone marrow
fraction is performed intraoperatively with the implantation.
In another embodiment, the invention provides a method for treating a patient that
includes obtaining a sample from bone marrow of the patient, and centrifuging the sample
to separate tire sample into fractions based upon density, the fractions including a fraction
rich in tissue promoting components. The fraction rich in tissue growth promoting
components is isolated and is implanted into the patient. In accordance with the invention,
the obtaining, centrifuging, and isolating steps are performed intraoperatively with the
implanting step.
In another embodiment, the invention provides a method for obtaining a bone
marrow fraction rich in connective tissue growth promoting components. The method
includes centrifuging a biological sample comprising bone marrow to separate components
of the sample into fractions based upon density, the fractions including a fraction rich in
growth promoting components. The fraction rich in tissue growth promoting components
is then isolated.
Additional embodiments of the invention as well as features and advantages will
be apparent from the descriptions herein.
FIGS. 1-6 show testing results for the separation and isolation of a fraction rich
connective tissue growth promoting components from biological samples comprising
whole blood and bone marrow aspirate from six different donors wherein FIG. 1 shows the
testing results for donor number 30500, FIG. 2 shows the testing results for donor number
30501, FIG. 3 shows the testing results for donor number 30506, FIG. 4 shows the testing
results for donor number 30526, FIG. 5 shows the testing results for donor number 30527,
and FIG. 6 shows the testing results for donor number 30561.
For the purposes of promoting an understanding of the principles of the invention,
reference will now be made to certain embodiments thereof and specific language will be
used to describe the same. It will nevertheless be understood that no limitation of the
scope of the invention is thereby intended, and alterations and modifications in the.
illustrated implants, and further applications of the principles of the invention as illustrated
herein are contemplated as would normally occur to one skilled in the art to which the
invention relates.
As disclosed above, the present invention provides isolates that are rich in one or
more connective tissue (e.g., bone) growth promoting components derived from bone
marrow, methods of forming the isolates and methods of promoting connective tissue
growth using the isolates.
Whole blood includes the following components: plasma, red blood cells, white
blood cells and platelets. The liquid portion of whole Wood, which is referred to as
plasma, is a protein-salt solution in which red and white blood cells and platelets are
suspended. Plasma, which is 90 percent water, constitutes about 55 percent of the total
blood volume. Plasma contains albumin (the chief protein constituent), fibrinogen
(responsible, in part, for the clotting of blood), globulins (including antibodies) and other
clotting proteins. Plasma serves a variety of functions, from maintaining a satisfactory
blood pressure and providing volume to supplying critical proteins for blood clotting and
immunity. Plasma is obtained by separating the liquid portion of blood from the cells
suspended therein. Red blood cells (erythrocytes) contain hemoglobin, an iron-containing
protein that carries oxygen throughout the body while giving blood its red color. The
percentage of blood volume composed of red blood cells is called the "hematocrit." White
blood cells (leukocytes) are responsible for protecting the body from invasion by foreign
substances such as bacteria, fongi and viruses. Several types of white blood cells exist for
this purpose, such as granulocytes and macrophages which protect against infection by
surrounding and destroying invading bacteria and viruses, and lymphocytes which aid in
the immune defense. Platelets (thrombocytes) are small cellular components of blood that
help the clotting process by sticking to the lining of blood vessels. Platelets prevent both
massive blood loss resulting from trauma and blood vessel leakage that would otherwise
occur.
If whole blood is collected and prevented from clotting by the addition of an
appropriate anticoagulant, it can be centrifuged into its component parts. Centrifugation
will result in the red blood cells, which have the highest density, packing to the most outer
portion of the rotating container, while plasma, being the least dense will settle in the inner
portion of the rotating container. Separating the plasma and red blood cells is a thin white
or grayish layer called the buffy coat. The buffy coat layer includes the white blood cells
and platelets, which together make up about 1 percent of the total blood volume.
Bone marrow is a complex tissue comprised of hematopoietic stem cells, red and
white blood cells and their precursors, mesenchymal stem and progenitor cells, stromal
cells and their precursors, and a group of cells including fibroblasts, reticulocytes,
adipocytes, and endothelial cells which form a connective tissue network called "stroma".
Cells from the stroma morphologically regulate the differentiation of hematopoietic cells
through direct interaction via cell surface proteins and the secretion of growth factors and
are involved in the foundation and support of the bone structure. Studies using animal
models have suggested that bone marrow contains "pre-stromal" cells which have the
capacity to differentiate into cartilage, bone, and other connective tissue cells. Beresfotd
"Osteogenic Stem Cells and the Stromal System of Bone and Marrow", Clin. Orthop.,
240:270,1989. Recent evidence indicates that these cells, called pluripotent stromal stem
cells or mesenchymal stem cells, have the ability to generate into several different types
of cell lines (i.e., osteocytes, chondrocytes, adipocytes, etc.) upon activation. However,
the mesenchymal stem cells are present in the tissue in very minute amounts with a wide
variety of other cells (i.e., erythrocytes, platelets, neutrophils, lymphocytes, monocytes,
eosinophils, basophils, adipocytes, etc.), and, in an inverse relationship with age, they are
capable of differentiating into an assortment of connective tissues depending upon the
influence of a number of bioactive factors.
According to one embodiment of the invention, a biological sample comprising
bone marrow is centrifuged to separate the components of the sample into various
fractions based on density, including a fraction rich in connective tissue growth promoting
components such as mesenchymal stem cells. The fraction rich in connective tissue
growth promoting components is then isolated. The resulting isolate can contain one or
more connective tissue growth components at a higher concentration than present in the
original sample. The resulting isolate can be applied directly to the site of a bone or other
tissue defect. Alternatively, the isolate can be combined with a carrier and the resulting
implant can be applied to the site of a bone or other tissue defect. In these regards, in
certain embodiments of the invention, a cell-containing isolate fraction can be applied to
the tissue defect site either alone or in combination with a carrier or other substance (e.g.
another therapeutic substance) without any ex vivo expansion or other culturing of the
isolate. In such uses, the isolate fraction can, if desired, be loaded into a suitable delivery
device such as a syringe, catheter, or the like, without any such expansion or other
culturing. The isolate can also be modified (e.g., by transfection with a nucleic acid
encoding an osteogenic polypeptide) prior to application to the site of a bone or other
tissue defect or for other uses. The isolate can consist essentially of bone marrow (e.g.,
bone marrow aspirate). For example, according to one embodiment of the invention, bone
marrow aspirate can be the only cell-containing component of the isolate.
As well, the biological sample that is centrifuged can be free from cell culture
medium materials, and in certain forms of the invention the biological sample that is
centrifuged can consist essentially of tissue material (e.g. bone marrow material optionally
in combination with blood or other tissue material) fiom a patient into which the resulting
isolate fraction is to be implanted, optionally containing one or more anticoagulants.
According to a further embodiment of the invention, a biological sample
comprising whole blood (e.g. peripheral blood) and bone marrow is centrifuged to
separate components of the sample based on density. Separation of the sample results in
formation of the following fractions in decreasing order of density: a red blood cell rich
fraction; a white blood cell rich or buffy coat fraction; a platelet rich fraction and a platelet
poor fraction. The buffy coat fraction, potentially along with all or part of the platelet rich
fraction adjacent the buffy coat fraction, can then be isolated to form an isolate rich in
connective tissue growth promoting components. The resulting isolate can contain one or
more connective tissue growth components at a higher concentration than present in the
original sample. Connective tissue growth components include, but are not limited to,
mononuclear cells such as hematopoietic and mesenchymal stem cells. The connective
tissue growth components can include, for example, connective tissue progenitor cells.
In addition to or as an alternative to the use of whole blood in a mixture with bone
marrow material, a fraction of whole blood may be mixed with the bone marrow material
in the formation of a biological sample to be processed by centrifugation. Illustratively, a
red blood cell containing fraction or a plasma fraction of whole blood may be used in a
biological sample to be processed in accordance with the present invention.
The whole blood or fraction thereof to be used in the preparation of the biological
sample to be processed in accordance with the invention can, for example, be human
tissue material. When being used to generate a material for implantation into a patient, the
whole blood or whole blood fraction may be autologous, allogenic, or xenogenic to the
patient. In allogenic situations, the whole blood or fraction may be typed and HLA
matched blood relative to the patient.
The biological sample and/or isolate rich in connective tissue growth promoting
components may also include an anti-coagulant. Suitable anticoagulants include, but are
not limited to, heparin, sodium citrate and EDTA.
Further, the isolate rich in connective tissue growth promoting components can be
combined with a solution (e.g., a sterile isotonic solution). Suitable isotonic solutions
include, but are not limited to, phosphate buffered saline and tissue culture medium such
as minimal essential medium.
As set forth above, a centrifuge can be used to separate a biological sample
comprising bone marrow into various fractions including a fraction rich in
connective tissue growth promoting components. The fraction rich in connective tissue
growth promoting components can then be isolated and the resulting isolate can then be
used in a bone grafting procedure. For example, the isolate can be placed onto or
combined with autogenous bone graft and/or bone graft substitutes to improve their bone
forming potential and fusion rate of the graft.
According to a further embodiment of the invention, a biological sample
comprising bone marrow can be optimized for bone forming effectiveness by
selectively isolating components from the sample that promote bone formation or by
reducing the concentration of components in the sample which inhibit bone formation.
According to an embodiment of the invention, this optimization can be performed in the
operating room with the use of a portable centrifuge such as the Magellan™ centrifuge
system which is manufactured by Medtronic, Inc. The resulting bone marrow isolate,
which is rich in connective tissue growth components, can then be used directly or
combined with a carrier such as autogenous bone graft or a bone graft substitute. The
isolate can be formed (i.e., the biological sample comprising bone marrow can be
obtained, separated into fractions and the fraction rich in connective tissue growth
components isolated) and applied to a tissue defect site in a single procedure (i.e.,
intraoperatively). The tissue defect site can be a bone defect site.
In another embodiment of the invention, the isolate can be formed and applied to a
tissue defect site in a patient in separate procedures. For example, in a first procedure, a
bone marrow sample can be obtained from the patient. The bone marrow sample thus
obtained can be processed in accordance with the invention to obtain an isolate rich in
tissue promoting growth components. This processing can include processing in
conjunction with a sample of whole blood, e.g. peripheral blood, of the patient, which can
also be obtained during the first procedure. In a second procedure, the isolate obtained
including the tissue growth promoting components can be implanted in the patient at a
tissue defect site, such as a bone defect site.
As noted above, the biological sample from which the connective tissue growth
rich fraction is isolated can comprise a mixture of blood (e.g., peripheral blood) and bone
marrow (e.g., bone marrow aspirate). According to one embodiment of the invention, the
sample can contain one part (by volume) of bone marrow to two parts by volume of blood
(i.e., 1:2 volume ratio of bone marrow to blood). Other volume ratios of bone marrow to
blood can also be used in the sample. For example, the volume ratio of bone marrow to -
blood in the sample can be 1:1,2:1,1:3, 3:1, etc. The volume ratio of bone marrow to
blood may for example be in the range of 1:100 to 100:1, more typically in the range of
1:3 to 3:1, and can be adjusted to achieve the desired processing characteristics and
amount of isolate.
The bone marrow can be from any source, including for example, from spaces
between trabeculae of cancellous or spongy bone, from medulary cavities of long bones,
and/or from haversian canals. The bone marrow may be from a human or other
mammalian source and, when the bone marrow is to be used to prepare material for
implant in a patient, the bone marrow can be autologous, allogenic, or xenogenic with
respect to the patient. For example, the bone marrow can be aspirated bone marrow
(e.g., bone marrow aspirated from the iliac crest). The blood and bone marrow can each
be taken from a patient, combined into a sample, and the connective tissue growth
component rich fraction of the sample isolated (e.g., via centrifugation) and the isolate
rich in connective tissue growth components applied to a tissue defect site. The
procedure involving forming the isolate and applying the isolate to the defect site can be
carried out during a single operation (i.e. intraoperatively).
According to further embodiments of the invention, the isolate rich in connective
tissue growth components can have a platelet yield (i.e., platelet concentration in the
isolate divided by platelet concentration in initial sample) that is greater than 2 times, 3
times or 4 times that of the initial sample. The isolate
rich in connective tissue growth components can also have a hematocrit content ofless
than 50%, less than 25% or less than 12.5% by volume. According to one embodiment of
the invention, the isolate rich in connective tissue growth components can have a platelet
yield (i.e., platelet concentration in the isolate divided by platelet concentration in initial
sample) greater than 4 times that of the initial sample and a hematocrit content of less than
12.5% by volume.
As set forth above, separation of the biological sample comprising bone marrow
into various fractions including a fraction rich in connective tissue growth components can
be performed using a centrifuge system. Any centrifuge system capable of separating a
biological sample (e.g., a sample comprising blood) into fractions can be used. An
exemplary centrifuge is the Magellan™ Autologous Platelet Separator (APS) system,
manufactured by Medtronic, Inc. Centrifuge systems and methods of separating blood
into various fractions are disclosed in the following U.S. patent applications: U.S. Patent
Application Serial No. 09/832,517, filed April 9,2001, published February 21,2002 as
U.S. Patent Application Publication No. 20020022213; U.S. Patent Application Serial No.
09/832,463, filed April 9, 2001, published October 10,2002 as U.S. Patent Application
Publication No. 20020147094; U.S. Patent Application Serial No. 09/833,234, filed April
9,2001, published December 27, 2001 as U.S. Patent Application Publication No.
20010055621; U.S. Patent Application Serial No. 09/961,793, filed September 24,2001,
published March 27, 2003 as U.S. Patent Application Publication No. 20030060352; U.S.
Patent Application Serial No. 10/116,729, filed April 4,2002, published December 5,
2002 as U.S. Patent Application Publication No. 20020182664; and U.S. Patent
Application Serial No. 09/833,230, fled April 9,2001, published October 10, 2002 as U.S.
Patent Application Publication No. 20020147098. Each of these applications is
incorporated herein by reference in its entirety. The methods and systems disclosed in
these applications can be used to isolate the connective tissue growth component rich
fraction from a biological sample comprising bone marrow. In particular, a sample
comprising blood and bone marrow can be centrifuged and the fraction corresponding to
the buffy coat fraction (i.e., the second most dense fraction) and all or part of the platelet
rich plasma fraction (i.e., the denser region of the plasma layer adjacent the buffy coat
fraction) can be isolated using an apparatus and method as disclosed in the aforementioned
applications. According to an embodiment of the invention, the apparatus can comprise a
sensor assembly which can be used to identify the interfaces between separated fractions
of the sample based on changes in fluid density. For example, the interface between the
region rich in red blood cells and the buffy coat fraction or platelet rich plasma fraction
and the interface between the platelet rich plasma fraction and a platelet poor plasma
fraction can be identified using a sensor assembly as set forth in the aforementioned
applications. Knowledge of the location of the interfaces between the separated fractions
of the sample can be used to isolate the desired fraction from the sample.
The connective tissue growth component rich fraction which is isolated from the
biological sample can comprise the buffy coat fraction (i.e., the second most dense
fraction) and all or part of the platelet rich plasma fraction (i.e., the denser region of the
plasma layer adjacent the buffy coat fraction) resulting from the separation of the sample
comprising blood and bone marrow. According to a further embodiment of the invention,
the isolate can comprise up to 50% by volume of the sample. For example, the isolate can
comprise up to 40%, 30%, or 20% by volume of the sample. According to a preferred
embodiment of the invention, the connective tissue growth component rich fraction which
is isolated from the biological sample can comprise from 5 to 17 percent by volume of the
original sample. For example, in a 60cc sample, the isolate can have a volume of from 3
to 10cc. According to a further embodiment, the isolate can comprise approximately 10 %
by volume of the original sample (e.g., 6 cc of isolate for a 60cc sample). Although a 60cc
sample volume is disclosed above, larger or smaller volume biological samples can also be
used. For example, the volume of the biological sample can be chosen based on the
amount of blood or bone marrow available and/or on the amount of isolate required for a
given procedure. For example, the biological sample can have a volume of up to lOOcc,
75cc, 50cc, or 25cc.
Centrifugation of the sample is conducted for a time and at a rate of rotation
sufficient to achieve the desired degree of separation. For example, centrifugation can be
conducted for approximately 60 seconds to 10 minutes at a rate of rotation between 0 and
5,000 rpm. According to one embodiment of the invention, centrifugation is conducted
for 17 to 20 minutes. It will be understood by those of skill in the art that faster speeds of
rotation will generally separate the components of the biological sample in a shorter period
of time. Generally, it will be desirable to achieve the separation over a period of tirne of
about 60 minutes or less. Further, when a bone marrow material is harvested from a
patient to develop a fraction for re-implantation, the centrifugation of the biological
sample including bone marrow is desirably conducted soon after harvest of the bone
marrow, for example within about 2 hours and desirably within about 1 hour. As well, the
re-implantation of such an isolate fraction in accordance with the invention can take place
soon after obtaining the isolate fraction, for example within about 2 hours, and desirably
within about 1 hour. In still further embodiments of the invention, the harvest of the bone
marrow fraction, the centrifugation to obtain the isolate fraction, and the implantation of
the isolate fraction can all occur on the same day, e.g. in the course of no more than about
3 hours.
As disclosed above, in one mode of use, an isolated fraction of the invention can be
used for implantation in a patient. As well, isolates of the invention can be used as a
source of components which may be further purified, e.g. in the recovery of isolated cells
from the isolate fraction, and/or in diagnostics or research pertaining to the components
therein, for example in research pertaining to cells contained in an isolate fraction.
The implantation of isolates in accordance with the invention can be made in order
to treat a broad variety of tissue defects for maladies. Illustrative tissue defects that may
be treated include defects in bone, neural, muscle, tendon, dermis, and marrow stroma
tissues. Illustrative bone tissues that may be repaired include those of the sternum,
cranium, long bones, spinal elements such as vertebra, and generally in the repair of tissue
damage relating to bone cysts. Illustrative neural tissues that may be repaired include both
central and peripheral nervous tissue. Cartilaginous tissue can also be treated with
implants in accordance with the invention, including treatments for joint repair, in
providing therapy for osteoporosis, or in the repair of tendons and ligaments in general.
Implants in the treatment of muscle tissue may be made in either cardiovascular or skeletal
muscle. Implants of the invention can also be used within the spinal disc space in the
repair or supplementation of disc nucleus tissue, and in implants for dental applications,
for example involving bone and/or gingival tissue. In each of these or other treatments,
isolates of the invention can be introduced in combination with proteins or other
therapeutic substances, genes, or other beneficial materials.
In the repair of bone tissue, the isolate of the invention can optionally be combined
with at least one bioactive factor that induces or accelerates the differentiation of
progenitor or stem cells into the osteogenic lineage. The isolate can be contacted with the
bioactive agent ex-vivo, or injected into the defect site before, during, or after the
implantation of the isolate. The bioactive agent can be a member of the TGF-ss
superfamily that includes various tissue growth factors, including bone morphogenic
proteins such as BMP-2, BMP-3, BMP-4, BMP-6, and BMP-7.
In the repair of cartilaginous tissue, isolates of the invention may be implanted to
treat shallow cartilage chondral defects or full thickness cartilage defects, to treat patellar
or spinal disc cartilage, or to regenerate articular joint cartilage, e.g. in patients with
osteoporosis. Joints that may be treated with isolates of the invention include, but are not
limited to, knee joints, hip joints, shoulder joints, elbow joints, ankle joints, tarsal and
metatarsal joints, wrist joints, spinal joints, carpal and metacarpal joints, and the temporal
mandibular joint.
According to a further embodiment of the invention, the connective tissue growth
component rich isolate can be modified prior to implantation. For example, cells (e.g.,
mesenchymal stem cells) in the connective tissue growth component rich isolate can be
modified using appropriate genes and/or proteins to direct a lineage specific expansion
and/or differentiation or a multi-lineage expansion or differentiation.
According to an embodiment of the invention, cells (e.g., mesenchymal stem cells)
in the connective tissue growth component rich factor can be transfected
with a nucleic acid comprising a nucleotide sequence which encodes an osteoinductive
protein or polypeptide. Exemplary osteoinductive proteins which can be encoded by the
nucleotide sequence include, but are not limited to, a BMP, an LMP or a sMAD protein
or an active (i.e., an osteoinductive) portion thereof. The nucleotide sequence which
encodes the osteoinductive protein or polypeptide can be operably linked to a promoter.
For example, the nucleotide sequence can be in a vector such as an expression vector
(e.g., an adenovirus).
Nucleic acids comprising nucleotide sequences encoding LIM mineralization
proteins (LMPs) and vectors and techniques for transfecting cells with nucleic acids
comprising nucleotide sequences encoding LIM mineralization proteins are disclosed in
the following U.S. Patent Applications: U.S. Patent Application Serial No. 09/124,238,
filed July 29,1998, now U.S. Patent No. 6,300,127; U.S. Patent Application Serial No.
09/959,578, filed April 28,2000, pending; U.S. Patent Application Serial No.
10/292,951, filed November 13,2002, published September 25,2003 as U.S. Patent
Application Publication No. 20030180266; and U.S. Patent Application Serial No.
10/382,844, filed on March 7,2003, published December 4, 2003 as U.S. Patent
Application Publication No. 20030225021. Each of these applications is incorporated by
reference herein in its entirety. Any of the materials and techniques disclosed in these
applications can be used to modify cells in the connective tissue growth component rich
factor.
The osteoinductive polypeptide encoded by the nucleic acid can be an active
(i.e., osteoinductive) portion of a human LIM mineralization protein (e.g., hLMP-1 or
hLMP-3). For example, the osteoinductive polypeptide can comprise at least "n"
consecutive amino acids from the sequence of hLMP-1 or hLMP-3 wherein n is 5, 10, 15
or 20.
According to a further embodiment of the invention, the osteoinductive
polypeptide can be an osteoinductive portion of hLMP-1 or hLMP-3 which comprises
at least "n" consecutive amino acids from the amino acid sequence:
ASAPAADPPRYTFAPSVSLNKTARPFGAPPPADSAPQQNG (SEQ ID NO:l)
or at least "n" consecutive amino acids from the amino acid sequence:
ASAPAADPPRYTFAPSVSLNKTARPFGAPPPADSAPQQN (SEQ ID NO:2)
wherein n is 5, 10, 15 or 20. According to a further embodiment of the invention, the
osteoinductive polypeptide can be an osteoinductive portion of hLMP-1 or hLMP-3 which
comprises at least "n" consecutive amino acids from the amino acid sequence:
P P P A D S A P Q (SEQ IDNO:3)
wherein n is 4, 5,6,7 or 8. According to a further embodiment of the invention, the
osteoinductive polypeptide can be an osteoinductive portion of hLMP-1 or hLMP-3
which comprises the sequence:
P P P A D (SEQ ID NO:4).
The osteoinductive polypeptide (e.g., the osteoinductive portion of the hLMP-1 or
hLMP-3 protein) can comprise up to 15 amino acid residues. According to further
embodiments of the invention, the osteoinductive polypeptide (e.g., the osteoinductive
portion of the hLMP-1 or hLMP-3 protein) can comprise up to 20,25,30, 35, 40,45 or
50 amino acid residues.
The osteoinductive polypeptide can be a synthetic polypeptide. For example, the
osteoinductive polypeptide can be a synthetic polypeptide having a sequence
corresponding to an osteoinductive portion of hLMP-1 or hLMP-3.
The isolate rich in connective tissue growth promoting components can also be
modified with a conjugate of a protein transduction domain (PTD) and an osteoinductive
protein or a nucleic acid encoding an osteoinductive protein. For example, cells (e.g.,
mesenchymal stem cells) in the connective tissue growth component rich factor can be
contacted with a conjugate of a protein transduction domain (PTD) and an osteoinductive
polypeptide or a nucleic acid encoding an osteoinductive polypeptide. The osteoinductive
polypeptide can be a BMP, an LMP, a sMAD protein or an active (i.e., osteoinductive)
portion of an osteoinductive protein. Conjugates of PTDs and osteoinductive proteins are
disclosed in Provisional U.S. Patent Application Serial No. 60/456,551, filed
March 24, 2003 which is incorporated by reference herein in its entirety. Any of the
conjugates and techniques disclosed in that application can be used to modify cells in the
connective tissue growth component rich factor. Conjugates of a PTD and an active (i.e.,
osteoinductive) portion of a human LIM mineralization protein (e.g., hLMP-1 or hLMP-3)
as set forth above can also be used to modify cells in the connective tissue growth rich
component rich isolate.
Cells (e.g., mesenchymal stem cells) in the connective tissue growth component
rich isolate can also be contacted with an osteoinductive polypeptide. For example, the
isolate can be combined with an osteoinductive protein (e.g., BMP-2). The modified
isolate can then be placed on a carrier and implanted into a patient.
In this regard, carriers that may be used with isolate materials of the invention
can be a dimensionally-stable or non-dimensionally-stable (e.g. paste or putty) carrier.
The carrier can, for example, be a resorbable porous matrix. In this regard, the
resorbable porous matrix is collagenous in certain embodiments. A wide variety of
collagen materials are suitable for the resorbable matrix. Naturally occurring
collagens may be subclassified into several different types depending on their amino
acid sequence, carbohydrate content and presence or absence of disulfide cross-links.
Types I and HI collagen are two of the most common subtypes of collagen. Type I
collagen is present in skin, tendon and bone whereas Type III collagen is found
primarily in skin. The collagen in the matrix may be obtained from skin, bone, tendon,
or cartilage and purified by methods known in the art. Alternatively, the collagen may
be purchased commercially. The porous matrix composition desirably includes Type
I bovine collagen.
The collagen of a carrier matrix can further be atelopeptide collagen and/or
telopeptide collagen. Moreover, non-fibrillar and/or fibrillar collagen may be used. Non-
fibrillar collagen is collagen that has been solubilized and has not been reconstituted into
its native fibrillar form.
Suitable resorbable carrier matrix materials may also be formed of other
organic materials such as natural or synthetic polymeric materials, in addition to or as
an alternative to collagen. For example, the resorbable carrier may comprise gelatin
(e.g. foamed gelatin), or resorbable synthetic polymers such as polylactic acid
polymers, polyglycolic acid polymers, or co-polymers thereof. Other natural and
synthetic polymers are also known for the formation of biocompatible resorbable
matrix materials, and can be used in the invention.
The carrier may also be or include a natural and/or synthetic mineral component.
For example, the mineral component can be provided by a particulate mineral material,
including either powder form or larger particulate mineral materials. In certain
embodiments, the particulate mineral component is effective in providing a scaffold for
bone ingrowth as the resorbable matrix material is resorbed. The mineral material may for
example be bone, especially cortical bone, or a synthetic bioceramic such as a
biocompatible calcium phosphate ceramic. Illustrative ceramics include tricalcium
phosphate, hydroxyapatite, and biphasic calcium phosphate. These mineral components
may be purchased commercially or obtained or synthesized by methods known in the art.
As noted above, biphasic calcium phosphate can be used to provide a mineral-
containing carrier in the invention. Desirably, such biphasic calcium phosphate will have a
tricalcium phosphate:hydroxyapatite weight ratio of about 50:50 to about 95:5, more
preferably about 70:30 to about 95:5, even more preferably about 80:20 to about 90:10,
and most preferably about 85:15.
The carrier can include an amount of mineral that will provide a scaffold effective
to remain in a patient for a period of time sufficient for the formation of osteoid in the void
for which bone growth is desired. Typically, this period of time will be about 8 to about
12 weeks, although longer or shorter periods may also occur in particular situations. The
minimum level of mineral that must be present in the carrier for these purposes is also
dependent on the level of activity of the tissue growth promoting components in the isolate
and whether other substances such as BMP or other osteogenic proteins are incorporated
into the carrier in combination with the tissue growth promoting components of the
isolate.
In certain forms of the invention, the carrier may include a particulate mineral
component embedded in a porous organic matrix formed with a material such as collagen,
gelatin or a resorbable synthetic polymer. In this regard, the particulate mineral:resorbable
porous matrix weight Tatio of the first implant material may be at least about 4:1, more
typically at least about 10:1. In highly mineralized carriers, the particulate mineral will
constitute at least 95% by weight of the first implant material. For example, carrier
materials may be provided comprising about 97% to about 99% by weight particulate
mineral and about 1% to about 3% of the collagen or other matrix forming material.
Moreover, the mineral component may for example have an average particle size of at
least about 0.5 mm, more preferably about 0.5 mm to about 5 mm, and most preferably
about 1 mm to about 3 mm.
Carriers used in combination with the isolate may be non-dimensionally-stable, for
example as in flowable or malleable substances such as pastes or putties. Illustratively,
the carrier may include a biologically resorbable, non-dimensionally-stable material
having properties allowing its implantation and retention at a tissue defect site. Such
carriers can include resorbable organic materials such as macromolecules from biological
or synthetic sources, for example gelatin, hyaluronic acid carboxymethyl cellulose,
collagen, peptides, glycosaminoglycans, proteoglycans, and the like. Such materials can
be used with or without an incorporated particulate mineral component as described
hereinabove. In certain forms, the resorbable carrier can be formulated into the
composition such that the composition is flowable at temperatures above the body
temperature of a patient into which the material is to be implanted, but transitions to be
relatively non-flowable at or slightly above such body temperature. The resorbable carrier
may be formulated into the implanted composition so the flowable state is a liquid or a
flowable gel, and the non-flowable state is a stable gel or solid. In certain embodiments of
the invention, the resorbable carrier can include gelatin, and/or can incorporate a
particulate mineral in an amount that constitutes about 20% to about 80% by volume of
the carrier composition, more typically about 40% to about 80% by volume.
In certain forms of the invention, the carrier can be an osteoinductive matrix
providing biologically inert surfaces which are receptive to the growth of new host bone.
For example, the carrier can be a collagen sponge or another dirnensionally-stable or non-
dimensionalty stable carrier as described above having these characteristics.
The carrier can comprise growth factors which can modulate the growth or
differentiation of other cells. Growth factors which can be used include, but are not limited
to, bone morphogenic proteins, sMAD proteins, and LIM mineralization proteins.
Demineralized bone matrix can also be included in the carrier. For example, powders or
granules of demineTalized bone matrix can be incorporated into the carrier.
The isolate can also be combined with allograft and/or autograft bone. For
example, the isolate can be combined with allograft and/or autograft bone and the
resulting implant can then be implanted into a host. As well, before or after implantation,
an isolate of the invention can be combined with one or more platelet activating agents, for
example thrombin, to activate any platelets contained in the isolate, and/or with other
substances relating to the blood clotting cascade such as fibrinogen.
The isolate or an implant comprising the isolate can enhance or accelerate the
growth of new bone tissue by one or more mechanisms such as osteogenesis,
osteoconduction and or osteoinduction. For example, the isolate or an implant
comprising the isolate can have osteoinductive properties when implanted into a
host. Thus, the isolate or implant comprising the isolate can recruit cells from the host
which have the potential for repairing bone tissue.
The isolate rich in connective tissue growth components or an implant comprising
the isolate can be used in bone repair. For example, the isolate or an implant comprising
the isolate can be applied at a bone repair site, e.g., one resulting from injury, defect
brought about during the course of surgery, infection, malignancy or developmental
malformation. The isolate or an implant comprising the isolate can be used in a wide
variety of orthopedic, periodontal, neurosurgical and oral and maxillofacial surgical
procedures including, but not limited to: the repair of simple and compound fractures and
non-unions; external and internal fixations; joint reconstructions such as arthrodesis;
general arthroplasty; cup arthroplasty of the hip; femoral and humeral head replacement;
femoral head surface replacement and total joint replacement; repairs of the vertebral
column including spinal fusion and internal fixation; tumor surgery, e.g., deficit filing;
discectomy; laminectomy; excision of spinal cord tumors; anterior cervical and thoracic
operations; repairs of spinal injuries; scoliosis, lordosis and kyphosis treatments;
intermaxillary fixation of fractures; mentoplasty; temporomandibular joint replacement;
alveolar ridge augmentation and reconstruction; inlay osteoimplants; implant placement
and revision; sinus lifts; cosmetic enhancement; etc. Specific bones which can be repaired
or replaced with the isolate or implant comprising the isolate include, but are not limited
to: the ethmoid; frontal; nasal; occipital; parietal; temporal; mandible; maxilla; zygomatic;
cervical vertebra; thoracic vertebra; lumbar vertebra; sacrum; rib; sternum; clavicle;
scapula; humerus; radius; ulna; carpal bones; metacarpal bones; phalanges; ilium;
ischium; pubis; femur; tibia; fibula; patella; calcaneus; tarsal and metatarsal bones.
The isolate rich in connective tissue growth components or an implant comprising
the isolate can also be used in cartilage repair. For example, the isolate or an implant
comprising the isolate can be applied at a cartilage defect site. For example, the isolate can
be used at the site of an articular cartilage defect.
The isolate rich in connective tissue growth components or an implant
comprising the isolate can also be used in soft tissue repair.
The bone marrow can be aspirated bone marrow. The bone marrow can be
autologous bone marrow aspirated from the patient being treated for a tissue defect. The
bone marrow can be obtained using known techniques. According to an embodiment of
the invention, the bone marrow can be aspirated (e.g., from the iliac crest) using Jamshedi
needles.
The methods described herein for isolating a fraction rich in connective tissue
growth promoting components offer numerous advantages. First, the methods do not
require the use of separation media such as density gradient media, although it will be
understood that in certain embodiments of the invention, the use of such separation media
will be encompassed. These separation media are not approved for introduction into
humans. Therefore, when separation media that cannot be introduced into the patient are
employed, a series of washing steps are required to eliminate the separation media from
the isolated cell populations. The preferred methods disclosed herein can be used to
isolate the desired cells without the use of a separation media and therefore do not require
separate washing steps. Accordingly, isolates of the invention to be implanted can be
loaded into delivery devices, such as syringes, catheters, and the like, without any
intervening washing step. The preferred methods described herein also allow for the
intraoperative isolation and use of the isolate for tissue repair. Further, the preferred
methods described herein allow for the use of relatively small sample sizes (e.g., 60 cc or
less).
For the purpose of promoting a further understanding of the invention, the
following Experimentals are provided. It will be understood that these Experimentals are
illustrative and not limiting of the invention.
Experimental 1
The following non-limiting examples are intended to illustrate methods of forming
an isolate rich in connective tissue growth promoting components from a biological
sample comprising whole blood and bone marrow.
Biological samples comprising mixtures of 20 mL anticoagulated bone marrow and 40 mL
anticoagulated blood were processed using the Magellan™ APS system. The fraction rich
in connective tissue growth promoting components from each run was then isolated. The
resulting isolate was then evaluated for platelet yield (i.e., platelet concentration in the
isolate divided by the platelet concentration in the initial sample) and for hematocrit
content. For each run, the isolate had a volume of approximately 6cc and included the
buffy coat fraction and portions of the adjacent platelet rich fraction of the sample.
The testing results for each run are set forth in FIGS. 1-6 wherein FIG. 1 shows
the testing results for donor number 30500, FIG. 2 shows the testing results
for donor number 30501, FIG. 3 shows the testing results for donor number 30506, FIG. 4
shows the testing results for donor number 30526, FIG. 5 shows the testing results for
donor number 30527, and FIG. 6 shows the testing results for donor number 30561. In
FIGS. 1-6, the fraction rich in connective tissue growth promoting components is
designated "PRP". Other fractions of the biological sample are designated "PPP" for
platelet poor plasma (i.e., the lowest density fraction), and "PRBC" for the red blood cell
containing fraction (i.e., highest density fraction). Runs that were deemed unacceptable
were excluded from the analysis. An acceptable separation run is defined as a run in which
no untoward incidences are encountered. These untoward incidences include, but are not
limited to: Failures due to operator error; Loss of ability to perform CBC counts in a
reliable manner, and; Excessive platelet activation during venipuncture or transport which
is manifested by excessive platelet clumping during or immediately after the separation
process.
Equiptnent/Fixturing/Gauging Used
Magellan™ APS instrument, s/n MAG1000185 (equipped with software v. 2.3)
Cell Dyn 1700 cell counter, Medtronic Equipment #133506.
Materials/Samples Used
Magellan™ Disposable kits, sterilized
Poietics Human Bone Marrow - Product Code 1M-125. Lot Numbers 030500,
030501, 030506, 030526, 030527, 030561. Poietics Normal.
Human Peripheral Blood - Product Code 1 W-406. Lot Numbers 030500, 030501,
030506, 030526,030527,03056.
Results and Data
The results of each run are summarized in the following table which shows the
platelet yield and the % hematocrit by volume for the isolate rich in connective tissue
growth components from each sample. Platelet Yield is the ratio of the platelet
concentration in the isolate to that in the initial sample.
Conclusion
As can be seen from the above data, all six (6) separation runs conducted with the
Magellan™ APS system had a concentration of platelets in the isolate rich in connective
tissue growth promoting components (i.e., the PRP fraction) of greater than 4 times that of
the original sample. In addition, all six (6) separation
runs also resulted in an isolate rich in connective tissue growth promoting components
(i.e., a PRP fraction) having a hematocrit (HCT) content of less than 12.5%.
Experimental 2
A connective tissue growth component rich fraction of a sample comprising blood
and bone marrow has been isolated. Cells including mesenchymal stem cells in the isolate
were then transfected with various doses of an adenoviral vector for hLMP-1 (i.e.,
AdVLMP). The cells were then implanted into rats using an athymic rat ectopic model.
While the foregoing specification teaches the principles of the present invention,
with examples provided for the purpose of illustration, it will be appreciated by one skilled
in the art from reading this disclosure that various changes in form and detail can be made
without departing from the true scope of the invention.
All publications cited in the foregoing specification are hereby incorporated by
reference in their enthety as if each had been individually incorporated by reference and
fully set forth.
WE CLAIM :
1. A method for obtaining a bone marrow fraction in vitro, comprising:
a) mixing an obtained bone marrow sample and an obtained peripheral whole
blood sample which is separate from said bone marrow sample in a volume ratio in the
range of 1:100 to 100:1 to prepare a biological sample;
b) centrifuging the biological sample to provide separation of components of the
sample based on density, said separation providing the following fractions in decreasing
order of density:
(i) a fraction rich in red blood cells;
(ii) a buffy coat fraction;
(iii) a platelet rich fraction;
(iv) a platelet poor fraction; and
(c) isolating the buffy coat fraction alone or in combination with all or part of the
platelet rich fraction to form an isolate rich in connective tissue growth promoting
components.
2. The method as claimed in claim 1, wherein:
said whole blood and bone marrow are from the same mammalian source.
3. The method as claimed in claim 2, wherein:
said mammalian source is a human.
4. The method as claimed in claim 1, also comprising combining said isolate
rich in connective tissue growth promoting components with a carrier.
5. The method as claimed in claim 1, wherein said isolate rich in connective
tissue growth promoting components comprises mesenchymal stem cells.
6. The method as claimed in claim 1, wherein said peripheral whole blood
and said bone marrow are mixed in a volume ratio of 1:3 to 3:1.
7. The method as claimed in claim 1, wherein:
said bone marrow was harvested from a patient during a surgical procedure.
8. The method as claimed in claim 1, wherein said biological sample consists
essentially of an anticoagulated mixture of bone marrow and whole blood.
9. The method as claimed in claim 1, wherein:
said biological sample is centrifuged in the absence of any synthetic density
gradient material.
10. The method as claimed in claim 1, wherein:
said centrifuging provides a platelet yield of at least 2.
11. The method as claimed in claim 1, wherein:
said isolate rich in connective tissue growth components has a hematocrit content
of less than 50% by volume.
12. The method as claimed in claim 1, wherein:
said isolate rich in connective tissue growth components has a platelet
concentration greater than 4 times that of said biological sample, and a hematocrit content
of less than 12.5% by volume.
13. A method for obtaining a bone marrow fraction rich in connective tissue
growth promoting components, the method comprising:
providing a biological sample, said biological sample prepared by mixing separate
samples including bone marrow and peripheral whole blood, respectively, in a volume
ratio in the range of 1:100 to 100:1.
centrifuging the biological sample to separate components of the sample into
fractions based on density, said fractions including a fraction rich in tissue promoting
components; and
isolating said fraction rich in tissue growth promoting components.
14. The method as claimed in claim 13, wherein:
said fraction has a platelet concentration greater than 2 times that of said
biological sample.
15. The method as claimed in claim 14, wherein:
said fraction has a hematocrit content of less than 12:5% by volume.
16. The method as claimed in claim 13, wherein:
said biological sample is centrifuged in the absence of any synthetic density
gradient material.
17. The method as claimed in claim 13, wherein:
said biological sample consists essentially of an anticoagulated mixture of bone
marrow and peripheral blood of the patient.
18. The method as claimed in claim 13, wherein:
said centrifuging and isolating are effective to enrich said fraction in said growth
promoting components relative to said biological sample.
19. The method as claimed in claim 18, wherein said growth promoting
components include cells, and also comprising genetically modifying said cells.
20. A method for preparing a medical implant material for delivery, the
method comprising:
(a) centrifuging a biological sample including a bone marrow material and whole
blood mixed in a volume ratio in the range of 1:00 to 100:1 in the absence of a synthetic
density gradient material and under conditions effective to separate a fraction including
bone marrow components that promote tissue growth; and
(b) loading the fraction into a device for delivering the fraction to a patient without
washing the fraction.
21. The method as claimed in claim 20, wherein said whole blood is peripheral
whole blood.
22. The method as claimed in claim 20, wherein said volume ratio is in the
range of 1:3 to 3:1.
23. The method as claimed in claim 20, also comprising;
obtaining a first sample including said bone marrow material;
obtaining a second sample including said whole blood; and
mixing said first sample with said second sample.
A method for obtaining a bone marrow fraction in vitro, comprising:
a) mixing an obtained bone marrow sample and an obtained peripheral whole
blood sample which is separate from said bone marrow sample in a volume ratio in the
range of 1:100 to 100:1 to prepare a biological sample;
b) centrifuging the biological sample to provide separation of components of the
sample based on density, said separation providing the following fractions in decreasing
order of density:
(i) a fraction rich in red blood cells;
(ii) a buffy coat fraction;
(iii) a platelet rich fraction;
(iv) a platelet poor fraction; and
(c) isolating the buffy coat fraction alone or in combination with all or part of the
platelet rich fraction to form an isolate rich in connective tissue growth promoting
components.


Documents:

220-KOLNP-2006-FOR ALTERATION OF ENTRY IN THE PATENT REGISTER.pdf

220-KOLNP-2006-FORM 15.pdf

220-KOLNP-2006-FORM-27.pdf

220-kolnp-2006-granted-abstract.pdf

220-kolnp-2006-granted-assignment.pdf

220-kolnp-2006-granted-claims.pdf

220-kolnp-2006-granted-correspondence.pdf

220-kolnp-2006-granted-description (complete).pdf

220-kolnp-2006-granted-drawings.pdf

220-kolnp-2006-granted-examination report.pdf

220-kolnp-2006-granted-form 1.pdf

220-kolnp-2006-granted-form 13.pdf

220-kolnp-2006-granted-form 18.pdf

220-kolnp-2006-granted-form 3.pdf

220-kolnp-2006-granted-form 5.pdf

220-kolnp-2006-granted-form 6.pdf

220-kolnp-2006-granted-reply to examination report.pdf

220-kolnp-2006-granted-specification.pdf


Patent Number 233685
Indian Patent Application Number 220/KOLNP/2006
PG Journal Number 14/2009
Publication Date 03-Apr-2009
Grant Date 01-Apr-2009
Date of Filing 30-Jan-2006
Name of Patentee WARSAW ORTHOPEDIC, INC.
Applicant Address 2500 SILVEUS CROSSING WARSA W, INDIANA
Inventors:
# Inventor's Name Inventor's Address
1 MARX, JEFFERY, C. 2019, HOCKING COVE, GERMANTOWN, TN 38139
2 MCKAY, WILLIAM, F. 3870, MCELRIE COVE, MEMPHIS, TN 38133
PCT International Classification Number A61K 35/28
PCT International Application Number PCT/US2004/021164
PCT International Filing date 2004-07-01
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/485,445 2003-07-09 U.S.A.