Effect of preservation methods on the performance of bovine pericardium graft in a rat model

This study investigates the effect of preservation methods on the performance of bovine parietal pericardium grafts in a rat model. Mid-ventral full thickness abdominal wall defects of 3x2.5 cm in size were created in 90 male Sprague-Dawley rats (300-400 g), which were divided into three groups of 30 rats each. The abdominal defects of group one and two were repaired with lyophilized and glycerolized bovine pericardium grafts, while the defects of group three were repaired with expanded polytetrafluoroethylene (ePTFE) Mycro Mesh as a positive control. Another group of 30 rats underwent sham operation and was used for comparison as negative control. Each group of rats (n=30) was divided into five subgroups (n=6) and killed at 1, 3, 6, 9 and 18 weeks post-surgery for gross and morphological evaluations. The rats tolerated the surgical procedure well with a total mortality of 0.05%. No serious post-operative clinical complications or signs of rejection were encountered. Adhesions between the grafts and the underlying visceral organs observed in the study were mostly results of post-surgical complications. Glycerol preservation delayed degradation and replacement of the grafts, whereas lyophilization caused early resorption and replacement of the grafts. The glycerolized grafts were replaced with thick dense fibrous tissue, and the lyophilized grafts were replaced with thin loose fibrous tissue. The healing characteristic of the bovine pericardium grafts was similar to those of the sham-operated group, and quite different from those of the ePTFE Mycro Mesh. The outcome of the present study confirmed the superiority of glycerolized bovine pericardium grafts over its lyophilized counter part

Comparative evaluations of the processed bovine tunica vaginalis implant in a rat model

The aim of the present study was to evaluate the lyophilized and glycerolized bovine parietal tunica vaginalis for repair of a full-thickness abdominal wall defect and to compare their effectiveness with expanded polytetrafluoroethylene (ePTFE) Mycro Mesh (Gore-Tex® MYCRO MESH®; Gore and Designs, W. L. Gore & Associates, Flagstaff, AZ, USA) in a rat model. Fresh bovine parietal tunica vaginalis sacs collected from an abattoir were processed and preserved by freeze-drying and by using 99.5% glycerol. Full-thickness abdominal wall defects (3×2.5 cm) created surgically in 90 male Sprague-Dewaly rats (300–400 g) were repaired with the same size of lyophilized, glycerolized or ePTFE Mycro Mesh with 30 rats in each group. Six rats from each group were killed at post-implantation intervals of 1, 3, 6, 9 and 18 weeks for macroscopic, microscopic and tensiometric evaluations. All rats survived the procedure, except for one rat in the ePTFE Mycro Mesh group. Implants of bovine origin were gradually resorbed and replaced with recipient fibrous tissue, whereas the mesh implant was encapsulated with fibrous tissue and remained without any marked changes throughout the study period. Adhesions between the implant and underlying visceral organs were encountered in 10, 6.6 and 3.3% of rats implanted with lyophilized, glycerolized or ePTFE Mycro Mesh, respectively. Foreign body giant cells and calcification were demonstrated in fibrous capsule and mesh matrix, respectively, in rats implanted with ePTFE Mycro Mesh. Neither of these characteristics were observed in rats implanted with processed bovine tunica vaginalis. Macrophages engorged with lipofuchsin pigments were observed in the recipient tissue that replaced the implants of bovine origin at 3–18 weeks post-implantation. There were no significant (P > 0.05) differences in total mean values of healing tensile strength, load at break and Young’s modulus of elasticity between the three implant groups. The results of the present study encourage further investigation into the use of processed bovine parietal tunica vaginalis in clinical practice

Evaluation of rat soft tissue response to implantation of glycerolized bovine tunica vaginalis

The aim of this study was to evaluate glycerolized bovine parietal tunica vaginalis implant in rat model. Pieces of 3_2.5 cm bovine parietal tunica vaginalis preserved in 99.5% glycerol and stored at 4 degrees C were used to repair 3_2.5 cm full thickness abdominal wall defects created in a group of 30 male Sprague Dawley rats (300-400 g). Another group of 30 rats were underwent sham operation and used for comparison. Each group was divided into five subgroups (n=6) and sacrificed at post-surgical intervals of 1, 3, 6, 9 and 18 weeks for macroscopical, histological and mechanical evaluation. Loose adhesions were observed between the implanted graft and underlying visceral organs in 6.6% of the treated group. Histologically the graft was biocompatible and gradually replaced by the recipient fibers tissue. The graft healing tensile strength increased with time in both groups and no significant different (P>0.05) was observed between the overall means of healing tensile strength of the two groups. The outcome of this study revealed that glycerolized bovine tunica vaginalis is biocompatible surgical patch that can be used for reconstruction of soft tissue defects. However, further investigation is required regarding the glycerol preservation efficiency

Review of fracture cases in cats and dogs presented to the Veterinary Teaching Hospital UPM

A review of the distribution of fracture cases in cats and dogs presented in the UVH-UPM within period of 10 years (1991 to 2001) are discussed

Morphological features of natural cryptorchid sheep testes: a case study

The present study compares the morphological features of abdominal testes of natural bilateral cryptorchid adult sheep with that of scrotal testes in normal adult sheep. Specimens obtained from cryptorchid local sheep testes and epididymides were fixed and processed for light and scanning electron microscopy. Testes of normal sheep were fixed and processed in the same way and used for comparison. The retained testes that were detected in the pelvic cavity were small and flabby with indistinct superficial blood vessel ramification compared to the scrotal testes. Histologically, the seminiferous tubules of the retained testes were small, empty, lined with a single layer of degenerated cells resting on a thickened basement membrane surrounded with abundant interstitial tissue compared to the scrotal testis. The epididymis of the retained testes was empty and lined with high pseudostratified columnar epithelium with long streocillia, while the scrotal testis epididymis was distended with stored sperms and lined with low epithelial layer with indistinct streocillia. The connective tissue layers around the epididymis were very thick in retained testes compared to that of the scrotal testes. The outcome of this study demonstrates microscopic and macroscopic changes in cryptorchid testes. Further investigations are required regarding the ultrastructural changes in abdominal testis

Effect of freeze-drying and gamma irradiation on biomechanical properties of bovine pericardium

Freeze-drying and gamma irradiation are the techniques widely use in tissue banking for preservation and sterilization of tissue grafts respectively. However, the effect of these techniques on biomechanical properties of bovine pericardium is poorly known. A total of 300 strips of bovine pericardium each measured 4 cm × 1 cm were used in this study to evaluate the effect of freeze-drying on biomechanical properties of fresh bovine pericardium and the effect of gamma irradiation on biomechanical properties of freeze-dried bovine pericardium. The strips were divided into three equal groups, which consist of 100 strips each group. The three groups were fresh bovine pericardium, freeze-dried bovine pericardium and irradiated freeze-dried bovine pericardium. The biomechanical properties of the pericardial strips were measured by a computer controlled instron tensiometer while the strips thickness was measured by Mitutoyo thickness gauge. The results of the study revealed that freeze-drying has no significant (p > 0.05) effect on the tensile strength, Young’s modulus (stiffness) and elongation rate of fresh bovine pericardium. Irradiation with 25 kGy gamma rays caused significant decreased in the tensile strength, Young’s modulus and elongation rate of the freeze-dried pericardium. However, gamma irradiation has no significant effect on the thickness of freeze-dried bovine pericardium, while freeze-drying caused significant decreased in the thickness of the fresh bovine pericardium. The outcome of this study demonstrated that freeze-drying has no significant effect on the biomechanical properties of fresh bovine pericardium, and gamma irradiation caused significant effect on the biomechanical properties of freeze-dried bovine pericardium

A novel method for the synthesis of calcium carbonate (aragonite) nanoparticles from cockle shells

We report a simple, novel and low-cost method for the synthesis of aragonite nanoparticles from cockle shells. Aragonite is one of the least abundant biogenic polymorphs of calcium carbonate and is widely used as a biomaterial for the repair of fractured bone, development of advanced drug delivery systems, and tissue scaffolds. The method involves a simple mechanical grinding of the micron-sized cockle shell powders in the presence of a non-toxic and non-hazardous biomineralization catalyst, dodecyl dimethyl betaine (BS-12). The method produces rod-shaped aragonite particles with a diameter of 20 ± 5 nm with good reproducibility and without any additional impurities. This was confirmed by a combined analysis of variable pressure scanning electron microscopy (VPSEM), transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), X-ray diffraction spectroscopy (XRD) and energy dispersive X-ray analyser (EDX). The method should find potential applications in industry for the large scale synthesis of aragonite nanoparticles from a low cost but abundant natural resource such as cockle shells

Characterization and In Vitro evaluation of a novel coated nanocomposite porous 3D scaffold for bone repair

The aim of this study is to tissue engineer a 3D scaffold that can be used for load bearing segmental bone defects (SBDs) repair. Three different scaffolds were fabricated using cockle shell-derived CaCO3 aragonite nanoparticles (CCAN), gelatin, dextran and dextrin with coated framework via Freeze-Drying Method (FDM) labeled as 5211, 5211GTA+Alginate, 5211PLA. Scaffolds were assessed using Scanning Electron Microscopy (SEM). The cytocompatibility of the organized scaffolds was assessed using cells multiplication and alkaline phosphatase (ALP) concentration via In Vitro cell culture using human Fetal OsteoBlast cells line (hFOB). The results showed a substantial difference in ALP concentrations between the cultures of different scaffolds leachable medium during the study period. The biological evaluation also showed that three scaffolds did enhanced the osteoblast proliferation rate and improved the osteoblast function as demonstrated by the significant increase in ALP concentration. Engineering analyses showed that scaffolds possessed 3D interconnected homogenous porous structure with a porosity ranging 6%-49%, pore sizes ranging 8-345 µm, mechanical strength ranging 20-65 MPa, young’s modulus ranging 166-296 MPa and enzymatic degradation rate between 16%-38% within 2-10 weeks. The in vitro evaluation revealed that the scaffold 5211, 5211GTA+Alginate and 5211PLA fulfill all the main requirements to be considered as an ideal bone replacement

Preparation and characterization of cockle shell aragonite nanocomposite porous 3D scaffolds for bone repair

The demands for applicable tissue-engineered scaffolds that can be used to repair load-bearing segmental bone defects (SBDs) is vital and in increasing demand. In this study, seven different combinations of 3 dimensional (3D) novel nanocomposite porous structured scaffolds were fabricated to rebuild SBDs using an extraordinary blend of cockle shells (CaCo3) nanoparticles (CCN), gelatin, dextran and dextrin to structure an ideal bone scaffold with adequate degradation rate using the Freeze Drying Method (FDM) and labeled as 5211, 5400, 6211, 6300, 7101, 7200 and 8100. The micron sized cockle shells powder obtained (75 µm) was made into nanoparticles using mechano-chemical, top-down method of nanoparticles synthesis with the presence of the surfactant BS-12 (dodecyl dimethyl bataine). The phase purity and crystallographic structures, the chemical functionality and the thermal characterization of the scaffolds’ powder were recognized using X-Ray Diffractometer (XRD), Fourier transform infrared (FTIR) spectrophotometer and Differential Scanning Calorimetry (DSC) respectively. Characterizations of the scaffolds were assessed by Scanning Electron Microscopy (SEM), Degradation Manner, Water Absorption Test, Swelling Test, Mechanical Test and Porosity Test. Top-down method produced cockle shell nanoparticles having averagely range 37.8±3–55.2±9 nm in size, which were determined using Transmission Electron Microscope (TEM). A mainly aragonite form of calcium carbonate was identified in both XRD and FTIR for all scaffolds, while the melting (Tm) and transition (Tg) temperatures were identified using DSC with the range of Tm 62.4–75.5 °C and of Tg 230.6–232.5 °C. The newly prepared scaffolds were with the following characteristics: (i) good biocompatibility and biodegradability, (ii) appropriate surface chemistry and (iii) highly porous, with interconnected pore network. Engineering analyses showed that scaffold 5211 possessed 3D interconnected homogenous porous structure with a porosity of about 49%, pore sizes ranging from 8.97 to 337 µm, mechanical strength 20.3 MPa, Young's Modulus 271±63 MPa and enzymatic degradation rate 22.7 within 14 days