Stem cell transplantation for articular cartilage repair

From Wikipedia for FEVERv2
Jump to navigation Jump to search

Mesenchymal stem cells (MSCs) are multipotent cells found in multiple human adult tissues including bone marrow, synovial tissues, and adipose tissues. Stem cell transplantation for articular cartilage repair_sentence_0

Since they are derived from the mesoderm, they have been shown to differentiate into bone, cartilage, muscle, and adipose tissue. Stem cell transplantation for articular cartilage repair_sentence_1

MSCs from embryonic sources have shown promise scientifically while creating significant controversy. Stem cell transplantation for articular cartilage repair_sentence_2

As a result, many researchers have focused on adult stem cells, or stem cells isolated from adult humans that can be transplanted into damaged tissue. Stem cell transplantation for articular cartilage repair_sentence_3

Because of their multi-potent capabilities, mesenchymal stem cell (MSC) lineages have been used successfully in animal models to regenerate articular cartilage and in human models to regenerate bone. Stem cell transplantation for articular cartilage repair_sentence_4

Recent research demonstrates that articular cartilage may be able to be repaired via percutaneous introduction of mesenchymal stem cells (MSC's). Stem cell transplantation for articular cartilage repair_sentence_5

Current research Stem cell transplantation for articular cartilage repair_section_0

Research into MSC's has exploded in recent years. Stem cell transplantation for articular cartilage repair_sentence_6

As an example, a PubMed search for the year 1999 reveals about 90 papers published under the MESH heading of “Mesenchymal Stem Cells”, the same search ran for the year 2007 reveals more than 4,000 entries. Stem cell transplantation for articular cartilage repair_sentence_7

The most commonly used source of MSC's is bone marrow aspirate. Stem cell transplantation for articular cartilage repair_sentence_8

Most of the adult bone marrow consists of blood cells in various stages of differentiation. Stem cell transplantation for articular cartilage repair_sentence_9

These marrow components can be divided into plasma, red blood cells, platelets, and nucleated cells. Stem cell transplantation for articular cartilage repair_sentence_10

The adult stem cell fraction is present in the nucleated cells of the marrow. Stem cell transplantation for articular cartilage repair_sentence_11

Most of these cells are CD34+ heme progenitors (destined to differentiate into blood components), while very few are actually MSC's capable of differentiating into bone, cartilage, or muscle. Stem cell transplantation for articular cartilage repair_sentence_12

As a result, that leaves the very small number of MSC's in the marrow as cells capable of differentiating into tissues of interest to joint preservation. Stem cell transplantation for articular cartilage repair_sentence_13

Of note, this may be one of the reasons that commercially available centrifuge systems that concentrate marrow nucleated cells have not shown as much promise in animal research for cartilage repair as have approaches where MSC's are expanded in culture to greater numbers. Stem cell transplantation for articular cartilage repair_sentence_14

Mesenchymal stem cell applications Stem cell transplantation for articular cartilage repair_section_1

Marrow nucleated cells are used every day in regenerative orthopedics. Stem cell transplantation for articular cartilage repair_sentence_15

The knee microfracture surgery technique relies on the release of these cells into a cartilage lesion to initiate fibrocartilage repair in osteochondral defects. Stem cell transplantation for articular cartilage repair_sentence_16

In addition, this cell population has also been shown to assist in the repair of non-union fractures. Stem cell transplantation for articular cartilage repair_sentence_17

For this application, bed side centrifugation is commonly used. Stem cell transplantation for articular cartilage repair_sentence_18

Again, these techniques produce a very dilute MSC population, usually a yield of 1 in 10,000–1,000,000 of the nucleated cells. Stem cell transplantation for articular cartilage repair_sentence_19

Despite this low number of MSC's, isolated bone marrow nucleated cells implanted into degenerated human peripheral joints have shown some promise for joint repair. Stem cell transplantation for articular cartilage repair_sentence_20

As the number of MSC's that can be isolated from bone marrow is fairly limited, most research in cartilage regeneration has focused on the use of culture expanded cells. Stem cell transplantation for articular cartilage repair_sentence_21

This method can expand cell numbers by 100-10,000 fold over several weeks. Stem cell transplantation for articular cartilage repair_sentence_22

Once these MSCs are ready for re-implanation, they are usually transferred with growth factors to allow for continued cell growth and engraftment to the damaged tissue. Stem cell transplantation for articular cartilage repair_sentence_23

At some point, a signal is introduced (either in culture or after transplant to the damaged tissue) for the cells to differentiate into the end tissue (in this discussion, cartilage). Stem cell transplantation for articular cartilage repair_sentence_24

Recent developments Stem cell transplantation for articular cartilage repair_section_2

Until recently, the use of cultured mesenchymal stem cells to regenerate cartilage has been primarily in research with animal models. Stem cell transplantation for articular cartilage repair_sentence_25

There are now, however, two published case reports of the above technique being used to successfully regenerate articular and meniscus cartilage in human knees. Stem cell transplantation for articular cartilage repair_sentence_26

This technique has yet to be shown effective in a study involving a larger group of patients, however the same team of researchers have published a large safety study (n=227) showing fewer complications than would normally be associated with surgical procedures. Stem cell transplantation for articular cartilage repair_sentence_27

Another team used a similar technique for cell extraction and ex vivo expansion but cells were embedded within a collagen gel before being surgically re-implanted. Stem cell transplantation for articular cartilage repair_sentence_28

They reported a case study in which a full-thickness defect in the articular cartilage of a human knee was successfully repaired. Stem cell transplantation for articular cartilage repair_sentence_29

While the use of cultured mesenchymal stem cells has shown promising results, a more recent study using uncultured MSC's has resulted in full thickness, histologically confirmed hyaline cartilage regrowth. Stem cell transplantation for articular cartilage repair_sentence_30

Researchers evaluated the quality of the repair knee cartilage after arthroscopic microdrilling (also microfracture) surgery followed by post-operative injections of autologous peripheral blood progenitor cells (PBPC) in combination with hyaluronic acid(HA). Stem cell transplantation for articular cartilage repair_sentence_31


Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Stem cell transplantation for articular cartilage repair.