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The objective of the current study is to evaluate using of platelet-rich fibrin (PRF) or adipose-derived stem cells (ADSCs) for the therapy of rabbit ear cartilage defects. Nine adult New Zealand white rabbits were divided into three groups. The rabbit ears developed two defects in the cartilage. Phosphate-buffered saline (PBS) was injected subperichondrially into Group I, adipose-derived MSCs (ADMSCs) were injected into Group II, and platelet-rich fibrin (PRF) was injected into Group III in the defective ear. After 4 weeks, the auricular defect was examined morphologically, histologically, and immunohistochemically. In addition, the gene expression of the collagen type II (Col II) and aggrecan. Anatomically, the auricles of all treatments seemed to be fully healed with smooth surfaces. Histopathologically, a small region of immature cartilage was seen in the control positive group's defects. While the group treated with PRF and ADSCs demonstrated the normal characteristics of new cartilage development, including mature chondrocytes within their lacunae and rich extracellular matrix (ECM). The PRF-treated group responded to Masson's trichrome and orcein stains, while produced a faint staining in the case of the control positive and ADMSC groups. Immunohistochemically, there was a strong positive S100 expression in ADSCs and PRF but mild reaction in the control group. The expression of relative col II and aggrecan was substantially highest in PRF (± 0.72 and ± 0.57, respectively). While, Control positive and ADMSC groups recorded (± 0.41 : ± 0.21, ± 0.6 : ± 0.44) respectively. The PRF had the highest rate of proliferation and chondrogenic potential when compared to the ADMSCs and control groups. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the suitability of the collagen matrix as a dural graft in the repair of experimental spinal dura mater defects. Materials and Methods: In the study 30 New Zealand white rabbits were used. The rabbits were divided into a study and control group. In both groups, following exact laminectomy (Th 10 and 11) in rabbits under the isoflorane anesthesia, a spinal dural defect 1x0.5 cm in size was formed. In the study group, the dura mater defect was covered with collagen matrix; in the control group, the excised dura was sutured back to its original position. At the end of the follow-up period, the rabbits were sacrificed. In all subjects, the vertebral colon was excised completely and it was fixed in 10% formaldehyde solution. Sections 3 pm thick were taken from the specimens, stained with hematoxylin and eosin, and examined under a light microscope. The stained sections were evaluated under light microscopy with regard to the cellular inflammatory response, fibroblastic proliferation, foreign body reaction, and capsule formation. Results: The collagen matrix was completely absorbed, and it was easy to use since it did not require sutures. Foreign body reactions were minimal in the early period and were resolved entirely in the end. Inflammatory response against the collagen matrix was no greater than in the control group in which the dura was sutured primarily and then closed, eventually disappearing entirely, and no adhesion formation resulted. Collagen permits successful regeneration by combining with the dura mater No capsule formation was observed in either group. Conclusion: This study shows that collagen is suitable for duraplastic procedures and that it may be a useful agent in patients in whom the dura cannot be closed primarily due to retraction, constriction, or excision. [ABSTRACT FROM AUTHOR]

The use of prosthetic material in severe cases of congenital diaphragmatic hernia is complicated by infection, bowel adhesion, and patch dehiscence. We hypothesized that a bioprosthetic collagen patch would reduce these complications and be remodeled into autogenous tissue over a short period of time. Thirty-two New Zealand White rabbits had two 2 2-cm left diaphragmatic defects created. One of these defects was repaired with a collagen bioprosthetic patch (n = 20) and the other with a polytetrafluoroethylene (PTFE) patch (n = 20). Members of a control group (n = 12) had their defects closed primarily. The animals were then placed in either a 6- or 12-week survival cohort. At necrosectomy the repairs were assessed histologically, graded for adhesion formation, and tensiometrically tested. The PTFE patch was noted to have a significantly higher average adhesion grade than the collagen patch. The tensile strength of the two repair methods was statistically equivalent at both time intervals. On histologic examination the collagen patches were surrounded by an increased number of macrophages and fibroblasts. The PTFE patch exhibited no neovascularization or fibroblast deposition at the periphery, but had a much greater surrounding inflammatory response. Thus, there was evidence of early remodeling of the collagen with no increase in the amount of adhesions or loss of strength when compared to the PTFE, while the PTFE patches exhibited a more severe grade of adhesions. [ABSTRACT FROM AUTHOR]