Incision concrescence of a nano-sized hydroxyapatite-zirconia bioceramical scalpel

Zhuju WANG; Wenbo HAN; Shuqing TAO

ABSTRACT

BACKGROUND:

Hydroxyapatite is a kind of ideal orthopedic material, but its Iow strength and brittleness need to improve. The research suggested that the improvement of the toughness and strength of bioceramics which composite hydroxyapatite (HAP) and zirconia (3% mol yttria-stabilized cubic zirconia) and fabricated ceramic scalpel possesses of the wound recover faster with smaller side. So it is significant that research on the incision concrescence of nano-sized hydroxyapatite-zirconia bioceramical scalpel.

OBJECTIVE:

To observe the effects of incision using nano-sized HAP-TZP bioceramics as scalpel.

DESIGN:

A single sample study.

SETTING:

Second Department of Orthopaedics, the Second Affiliated Hospital of Harbin Medical University and Harbin Institute of Technology.MATERIALS The experiment was carried out in the Animal Laboratory of the Second Affiliated Hospital of Harbin Medical University (Provincial Laboratory) from March to May 2006. A total of 54 SD rats, of 4 months old, weighing 120-180 g, of both genders, were selected in this study. The experiment materials included nano-sized hydroxyapatite Quartz Clock Company), ammonia (Suihua Chemical Reagent Company), and anhydrous ethanol (Tianjin Chemical Reagent Company).

METHODS:

The nano-sized Hydroxyapatite/zirconia composite powder was synthesis by rubbing according to 40% hydroxyapatite + 60% zirconia powders (mass ratio) were mixed and milled. The knife-edge biomaterials, which fabricated by hot pressed sintering, was grinding and used in incision experiment after autoclaving. The back of the rats was shaved and removing a patch of skin under ether anesthesia made a length of 2 cm open excision wound and stitched up the tear by 1# string. The each 18 rats were sacrificed on 3, 7 and 14 days post-wounding and used for analyses respectively. A full-thickness specimen containing the wound was dissected out from each of the surgical sites. The hematoxylin-eosin (HE) staining was applied in the pathological observation.MAIN OUTCOME

MEASURES:

The tissue sections of back and the results of pathological observation.

RESULTS:

All 54 rats were involved in the results analysis without any loss. There was long gap with minimal cellular reaction in the scalpel wounds that has not healed on day 3. There was inflamed cells infiltration at the wounded margin edge. By week 1, the tiny detritus which some of them appear the repaired response of epidermis rend were still obviously found in the area of the scalpel wounds where the detritus was found to be significantly less, the wounds changed smooth and started to heal. The optical microscopy observed indicated that there was incomplete epithelialization and hyalinization of dermal collagen at the wounded area. There were obvious inflamed cells to infiltrate in the margin subcutaneous tissue of the wounds where the newborn loose collagenous fibers filled in scalpel wounds was the tissue repairing response phase. There was a great deal of the infiltrated white blood cells in the subcutaneous tissue. The tiny detritus of epidermis by the optical microscopy observed rend could not be found in the area of the scalpel wounds which were healed by week 2. The newborn capillary nets appeared in the newborn repaired collagen fibers tissue. The inflamed cells to be infiltrated were reduced. The compact and strong collagenous fibers filled in scalpel wounds were the normal wound repairing and tissue. The white blood cells infiltrated obvious reduction in the subcutaneous tissue. The normal blood cells in the newborn capillaries could be seen.

CONCLUSION:

The experiments prove that a HAP-ZTP bioceramic scalpel, which possesses excellent bioactive, is nontoxic, nonallergenic and noncarcinogenic for incisions.