The healing of load-bearing segmental defects in long bones is a challenge due to the complex nature of the weight that affects the bone part and due to bending, shearing, axial, and torsional forces. An innovative porous 3D scaffolds implant of CaCO 3 aragonite nanocomposite derived from cockle shell was advanced for substitute bone solely for load-bearing cases. The biomechanical characteristics of such materials were designed to withstand cortical bone strength. In promoting bone growth to the implant material, an ideal surface permeability was formed by means of freeze drying and by adding copolymers to the materials. The properties of coating and copolymers supplement were also assessed for bone-implant connection resolutions. To examine the properties of the material in advanced biological system, an experimental trial in an animal model was carried out. Critical sized defect of bone was created in rabbit’s radial bone to assess the material for a load-bearing application with a short and extended period assessment with histological evaluation of the incorporated implanted material to the bone of the host. Trials in animal models proved that the material has the capability of enduring load-bearing conditions for long-term use devoid of breaking or generating stress that affects the host bone. Histological examination further confirmed the improved integration of the implanted materials to the host bone with profound bone development into and also above the implanted scaffold, which was attained with negligible reaction of the tissues to a foreign implanted material.

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 CaCO 3 aragonite nanoparticles (CCAN), gelatin, dextran and dextrin with coated framework via Freeze-Drying Method (FDM) labeled as 5211, 5211 GTA+Alginate , 5211 PLA. 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, 5211 GTA+Alginate and 5211 PLA fulfill all the main requirements to be considered as an ideal bone replacement.

The aim of this study was to investigate the effects of Corynebacterium pseudotuberculosis and phospholipase D (PLD) on buck's fertility, specifically, testosterone concentration, scrotal circumference and semen quality. Crossbred Boer goats (n=13) aged 12-14 months were divided into three groups. The first group (n=3) was inoculated with one ml sterile phosphate buffer saline subcutaneously into subaxillary area as the control. The second group (n=5) was inoculated with live C. pseudotuberculosis 1×10 9 cfu subcutaneously into subaxillary area. The third group (n=5) was inoculated with PLD 1 ml/20 kg BW intravenously into jugular vein. Blood collection was done twice a week over a period of three months for testosterone analyses. Semen was collected using electro-ejaculator once every two weeks whilst scrotal circumference was measured once every three weeks. Semen volume, semen pH and sperm progressive motility, concentration, live/dead percentage and morphology were evaluated. Bucks were euthanized three months' post inoculation and histopathological examination of the testicles and epididymis was performed. The results showed seven folds' significant decrease (P<0.05) in testosterone concentration in both C. pseudotuberculosis and PLD inoculated groups compared to the control. Semen volume, percentage of dead/live and abnormal sperm morphology showed significant increase (P<0.05) in both inoculated groups compared to the control. The following sperm defects were observed; tapered sperm, decapitated and knobbed head, thickened midpiece, distal and proximal droplet, sterilizing tail and folded tail. Scrotal circumference, semen pH, semen wave pattern, sperm motility and concentration showed significant decrease (P<0.05) in both inoculated groups compared to the control. The testicles showed varied degrees of degeneration and necrosis with shrunken seminferous tubules. In conclusion, testosterone concentration, scrotal circumference and semen quality were negatively affected in both inoculated groups. Moreover, percentages of live/dead and abnormal sperm morphology were also increased. The results suggest that both C. pseudotuberculosis and PLD had detrimental effects on buck's fertility.

Issues of safety are very crucial with biomaterials and medical devices. Sixteen male New Zealand White rabbits equally into four groups: Group A, rabbits had part of their radial bone (2 cm, mid shaft) and left empty as a control. Group B, rabbits were implanted with scaffold 5211. Group C, rabbits were implanted with scaffold 5211GTA+Alginate. Group D, rabbits were implanted with 5211PLA. All scaffolds were prepared by freeze-drying method. Blood samples were collected at day 0 and 1 st , 2 nd , 3 rd , 4 th and 8 th week after implantation. The blood examination included complete hemogram and certain serum biochemical parameters. The results showed that there was no significant difference (P>0.05) among each treatment group in comparison with control group (day 0). However, red blood cells, hemoglobin, packed cell volume, mean corpuscular hemoglobin concentration, monocyte, plasma protein, inorganic phosphate, sodium, chloride and urea were significantly increased (P<0.05) among treatment groups at week 8. An abnormal architecture of viscera was observed in all animals, thus indicating a form of toxicity related to the degrading scaffold materials. The severity of histopathological lesions in viscera was not coated polymers dependent nor development materials. In conclusion, implantation of 5211 scaffold with or without coated framework has a significant impact on histopathological and certain hematological and biochemical parameters.

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