Objective To study the preparation method of acellular vascular matrix and to evaluate its biocompatibil ity and safety so as to afford an ideal scaffold for tissue engineered blood vessel. Methods Fresh caprine carotids (length, 50 mm) were harvested and treated with repeated frozen (—80 )/thawing (37℃), cold isostatic pressing (506 MPa, 4 ), and 0.125% sodium dodecyl sulfate separately for preparation of acellular vascular matrix. Fluorescence staining and DNA remain test were used to assess the cell extracting results. Biological characteristics were compared with the raw caprine carotids using HE staining, Masson staining, scanning electron microscope (SEM), and mechanical test. Biocompatibil ity wasdetected using cell adhesion test, MTT assay, and subcutaneously embedding test. Ten SD rats were divided into 2 groups (n=5). In experimental group, acellular vascular matrix preserved by the combination of repeated frozen/thawing, ultrahigh pressure treatment and chemical detergent was subcutaneously embedded; and in control group, acellular vascular matrix preserved only by repeated frozen/thawing and ultrahigh pressure treatment was subcutaneously embedded. Results HE staining and Masson staining revealed that no nucleus was detected in the acellular vascular matrix. SEM demonstrated that a lot of collagen fibers were preserved which were beneficial for cell adhesion. Fluorescence staining and DNA remain test showed that the cells were removed completely. There was no significant difference in stress and strain under the maximum load between before and after treatment. Mechanical test revealed that the acellular vascular matrix reserved mechanical properties of the raw caprine carotids. Cell adhesion test and MTT assay confirmed that cytotoxicity was grade 0-1, and the acellular vascular matrix had good compatibil ity to endothel ial cells. After subcutaneously embedding for 8 weeks, negl igible lymphocyte infiltration was observed in experimental group but obvious lymphocyte infiltration in control group. Conclusion The acellular vascular matrix, which is well-preserved by the combination of repeated frozen/thawing, ultrahigh pressure treatment, and chemical detergent, is an ideal scaffold for tissue engineered blood vessel.
Objective To observe the biocompatibility of the acellular corneal stroma materials prepared by three different methods. Methods Three different serial digestion methods were used to produce the acellular corneal stroma materials. The biocompatibility of the materials was investigated by the cell seeding and the materials were implanted into the rabbit corneal stroma layer. Results The cells in the materials 1 and 2 were not decellularized completely. The rabbit corneal fibroblasts died on the materials 1 and 2 after the cell seeding for 3-4 days. An obvious rejection could be observed after the implantation. The cells in material 3 were decellularized completely and the collagen fibers or elastic fibers were reserved integrally，showing a typical three-dimensional net work. The rabbit corneal fibroblasts could expand on the materials in vitro. No obvious rejection could be observed and the materials were gradually absorbed. Conclusion The acellular porcine cornea stroma materials prepared by trypsin-Dnase-Rnase are suitable for reconstruction of the tissue engineered cornea.