**6. Arthroscopic subchondral drilling augmented with peripheral blood progenitor cells (PBPC)**

Our laboratory has had increased interest in the used of peripheral blood progenitor cells (PBPC) over the use of bone marrow derived progenitor cells (BMPC). A study report published in April 2011 by the first author's group (Saw et al, 2011) confirmed that articular hyaline cartilage regeneration was possible with arthroscopic subchondral drilling followed by postoperative intraarticular injections of autologous PBPC in combination with HA.

Treatment involving progenitor cells stems from the hematology/oncology profession: Given the potential morbidity associated with iliac crest harvest, cell collection for bone marrow repopulation now involves mobilization of multipotential progenitor cells through hormonal stimulation and collection via a peripheral automated cell separator machine. This process, commonly referred to as apheresis, has potential for increased magnitude of harvest. Studies involving review of healthy donors have shown this to be a safe and effective procedure for the production and harvest of cells (Ceselli et al, 2009 & Holig et al, 2009). Recent study into the properties of these PBPC has shown that they are similar to embryonal stem cells in that they express transcription factors specific to pluripotential cells, have proliferative potential, have the ability to differentiate into a multitude of cell types, and are more immature than

factor (TGF-M1), fibroblast growth factor (FGF). Early research has shown that mesenchymal stem cells and chondrocytes exposed to PRP have increased cell proliferation and production of proteoglycans and collagen type II (Fortier et al, 2011). In a clinical cohort comparing hyaluronic acid with PRP injections, PRP had improved pain scores (Sanchez et al, 2008). However, the quality and longevity of the repair tissue generated by the adjunct of

**used Status** 

Animal (ovine) study

Animal (porcine model)

Animal (Caprine model)

Human

Gelform

None

None

Collagen type I hydrogels

**Applications Techniques Scaffolds** 

Direct intra-articular injection of autologous mesenchymal stem cells suspended in hyaluronic acid ( Lee et al,

Direct intra-articular injection of

( Murphy et al, 2003)

(Wakitani et al , 2004)

autologous mesenchymal stem cells in a dilute solution of hyaluronic acid

Autologous mesenchymal stem cells seeded with collagen type I hydrogels

**6. Arthroscopic subchondral drilling augmented with peripheral blood** 

Our laboratory has had increased interest in the used of peripheral blood progenitor cells (PBPC) over the use of bone marrow derived progenitor cells (BMPC). A study report published in April 2011 by the first author's group (Saw et al, 2011) confirmed that articular hyaline cartilage regeneration was possible with arthroscopic subchondral drilling followed by postoperative intraarticular injections of autologous PBPC in

Treatment involving progenitor cells stems from the hematology/oncology profession: Given the potential morbidity associated with iliac crest harvest, cell collection for bone marrow repopulation now involves mobilization of multipotential progenitor cells through hormonal stimulation and collection via a peripheral automated cell separator machine. This process, commonly referred to as apheresis, has potential for increased magnitude of harvest. Studies involving review of healthy donors have shown this to be a safe and effective procedure for the production and harvest of cells (Ceselli et al, 2009 & Holig et al, 2009). Recent study into the properties of these PBPC has shown that they are similar to embryonal stem cells in that they express transcription factors specific to pluripotential cells, have proliferative potential, have the ability to differentiate into a multitude of cell types, and are more immature than

2007)

Table 1. Examples of clinical applications of hMSC

Autologous mesenchymal stem cells seeded onto Gelform scaffold containing TGF-β1 growth factor, then transplanted to injury site (McCarty et al, 2010)

PRP is still unproven.

Growth plate cartilage injury

Large cartilage

Osteoarthritis

Full-thickness cartilage defects

**progenitor cells (PBPC)** 

combination with HA.

defects

BMPC (Ceselli et al, 2009). In addition, when injected subcutaneously into mice, these cells were found to migrate to multiple organs and integrate and function as the surrounding cells (Ceselli et al, 2009). In addition to implementing evidence from recent animal studies, we have sought to make use of clinical evidence regarding the potential and safety of PBPC, preferring to use PBPC as opposed to BMPC because of the ease of harvest, decreased harvest-site morbidity, and increased potential with these cells (Ceselli et al, 2009; Holig et al, 2009 & Ordemann et al, 1998). In the clinical setting, we prefer to use PBPC as opposed to BMPC due to the ease of harvest and the increased potential with these cells. Subsequently, we have developed a method involving standard marrow stimulation in the form of subchondral drilling and novel postoperative intraarticular injections of autologous PBPC in combination with HA to regenerate articular cartilage.
