Platelet-rich plasma and latissimus dorsi fascia with blood vessels in the vascularization of tissue-engineered bone: A histological & radiological observation

Tao CHEN; Ningyi LI

ABSTRACT

BACKGROUND:

It is still disputed whether several growth factors of platelet-rich plasma and the fascia with blood vessels can promote bone regeneration and vascularization.

OBJECTIVE:

To evaluate the effects of platclet-rich plasma and the fascia with blood vessels on the vascularization of tissue-engineered bone composited by marrow stromal stem cells (MSCs) and decalcified bone matrix (DBM). DESIGN, TIME AND

SETTING:

The present single-sample observation, self-control animal experiment was performed at the Central Laboratory Center, Affiliated Hospital of Qingdao University Medical College between October 2004 and November 2007. MATERIALS Twelve healthy hybrid dogs, aged 11-12 months, weighing 20-25 kg, equal number of males and females, were included for this study.

METHODS:

①MSCs were isolated from dog bone marrow by density gradient centrifugation, followed by in vitro adherent culture and ontogenesis culture.Dog femur was taken for preparation of DBM and composited with MSCs.②The back of each dog was divided into 4 regions (A,B,C,and D).In the regions A and B, DBM/MSCs/platelet-rich plasma composites were transplanted. In the regions C and D, DBM/MSCs composites were transplanted. The implants for the regions A and C were wrapped with latissimus dorsi fascia with blood vessels. The implants for the regions B and D were wrapped with blood vessels-free superficial fascia from back. At weeks 4,8,and 12,4 dogs comprising 2 males and 2 females, were sacrificed following anesthesia for specimen harvesting. MAIN OUTCOME

MEASURES:

①MSC morphology was observed utilizing a phase contrast microscope, and cell growth curves were portrayed by methyl thiazolyl tetrazolium colorimetric assay.②Morphology of osteoblasts induced was observed by modified alkaline phospharase (ALP) staining (Ca-Co method), Von Kossa method, alizarin red method and calcium node staining.③Composite structure was observed through the use of inverted phase contrast microscope and scanning electron microscope.④Gross, radiological, and histological observations.

RESULTS:

①Both induced osteoblasts and MSCs exhibited ALP and calcium node stainings positive.②The growth curves of induced osteoblasts and MSCs presented with typical "S" shape.③Following composite culture of allogenic DBM and MSCs, MSCs grew well, rapidly proliferated and could secrete a great amount of extraccllular matrix.④At each time point, osteogenic bone mass, bone absorbance, and vascularization were better in regions A,B,and C than in region D (P＜0.05).

CONCLUSION:

Histological and radiological observations have confirmed that both platelet-rich plasma and the fascia with blood vessels can synergistically promote the formation and vascularization of tissue-engineered bone.