Zuki Abu Bakar

Characterization and stability evaluation of thymoquinone nanoemulsions prepared by high-pressure homogenization

Despite the pharmacological properties of thymoquinone (TQ), its administration in vivo remains problematic partly due to its poor water solubility, leading to low absorptivity and bioavailability. Hence, the objective of this study is to prepare, characterize, and evaluate the stability of TQ nanoemulsion (TQNE). Conventional emulsion from TQ (TQCE) and empty nano- and conventional emulsions fromTriolein (TRNE and TRCE) are also produced for comparison purposes. The oil-in-water nanoemulsions of TQ and Triolein were produced by high-pressure homogenization. Emulsions were characterized physically by droplet size, polydispersity index, zeta potential, and refractive index. The changes of these parameters in TQNE samples stored for 6 months at 4 and 25°C were not statistically significant (P < 0.05). In addition, the initial particle sizes of TQNE and TRNE were 119.6 and 119.5 nm, respectively. Stability studies were also performed for the period of 6 months. At the end of the experiment, the percent of remaining TQ in TQNE at 4, 25, and 40°C was 90.6, 89.1, and 87.4 % respectively. Slower degradation of TQ indicated the chemical stability of TQ in TQNE samples. These results indicated that TQNE is stable over a period of 6 months.

Dietary (n-6 : n-3) Fatty Acids Alter Plasma and Tissue Fatty Acid Composition in Pregnant Sprague Dawley Rats

The objective of this paper is to study the effects of varying dietary levels of n-6 : n-3 fatty acid ratio on plasma and tissue fatty acid composition in rat. The treatment groups included control rats fed chow diet only, rats fed 50% soybean oil (SBO): 50% cod liver oil (CLO) (1 : 1), 84% SBO: 16% CLO (6 : 1), 96% SBO: 4% CLO (30 : 1). Blood samples were taken at day 15 of pregnancy, and the plasma and tissue were analyzed for fatty acid profile. The n-3 PUFA in plasma of Diet 1 : 1 group was significantly higher than the other diet groups, while the total n-6 PUFA in plasma was significantly higher in Diet 30 : 1 group as compared to the control and Diet 1 : 1 groups. The Diet 1 : 1 group showed significantly greater percentages of total n-3 PUFA and docosahexaenoic acid in adipose and liver tissue, and this clearly reflected the contribution of n-3 fatty acids from CLO. The total n-6 PUFA, linoleic acid, and arachidonic acid were significantly difference in Diet 30 : 1 as compared to Diet 1 : 1 and control group. These results demonstrated that the dietary ratio of n-6 : n-3 fatty acid ratio significantly affected plasma and tissue fatty acids profile in pregnant rat.

Synthesis, characterization, and cytocompatibility of potential cockle shell aragonite nanocrystals for osteoporosis therapy and hormonal delivery

Calcium carbonate is a porous inorganic nanomaterial with huge potential in biomedical applications and controlled drug delivery. This study aimed at evaluating the physicochemical properties and in vitro efficacy and safety of cockle shell aragonite calcium carbonate nanocrystals (ANC) as a potential therapeutic and hormonal delivery vehicle for osteoporosis management. Free and human recombinant parathyroid hormone 1-34 (PTH 1-34)-loaded cockle shell aragonite calcium carbonate nanocrystals (PTH-ANC) were synthesized and evaluated using standard procedures. Transmission electron microscopy and field emission scanning electron microscopy results demonstrated highly homogenized spherical-shaped aragonite nanocrystals of 30±5 nm diameter. PTH-ANC had a zeta potential of −27.6±8.9 mV. The encapsulation efficiency of the formulation was found to be directly proportional to the concentrations of the drug fed. The X-ray diffraction patterns revealed strong crystallizations with no positional change of peaks before and after PTH-ANC synthesis. Fourier transform infrared spectroscopy demonstrated no detectable interactions between micron-sized aragonite and surfactant at molecular level. PTH-ANC formulation was stabilized at pH 7.5, enabling sustained slow release of PTH 1-34 for 168 h (1 week). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytocompatibility assay in Human Foetal Osteoblast Cell Line hFOB 1.19 showed that ANC can safely support osteoblast proliferation up to 48 h whereas PTH-ANC can safely support the proliferation at 72 h and beyond due to the sustained slow release of PTH 1-34. It was concluded that due to its biogenic nature, ANC is a cytocompatible antiosteoporotic agent. It doubles as a nanocarrier for the enhancement of efficacy and safety of the bone anabolic PTH 1-34. ANC is expected to reduce the cost, dosage, and dose frequency associated with the use of PTH 1-34 management of primary and secondary forms of osteoporosis.

Clinico-pathology, hematology, and biochemistry responses toward Pasteurella multocida Type B: 2 via oral and subcutaneous route of infections

Background: Pasteurella multocida a Gram-negative bacterium has been identified as the causative agent of many economically important diseases in a wide range of hosts. Hemorrhagic septicemia is a disease caused by P. multocida serotype B:2 and E:2. The organism causes acute, a highly fatal septicemic disease with high morbidity and mortality in cattle and more susceptible in buffaloes. Therefore, the aim of this study was to investigate the clinical signs, blood parameters, post mortem and histopathology changes caused by P. multocida Type B:2 infections initiated through the oral and subcutaneous routes. Methods: Nine buffalo heifers were divided equally into 3 treatment groups. Group 1 was inoculated orally with 10 ml of phosphate buffer saline; Groups 2 and 3 were inoculated with 10 ml of 1012 colony forming unit of P. multocida Type B:2 subcutaneously and orally respectively. Results: There was a significant difference (p<0.05) in temperature between the subcutaneous and the control group. The results revealed significant differences (p<0.05) in erythrocytes, hemoglobin, packed cell volume, leukocytes, monocytes, and A: G ratio between the subcutaneous and the control group. Furthermore, there were significant differences (p<0.05) in leukocytes, band neutrophils, segmented neutrophils, lymphocytes, eosinophils, basophils, thrombocytes, plasma protein, icterus index, gamma glutamyl tranferase and A: G ratio between the oral and the control group. The post mortem lesions of the subcutaneous group buffaloes showed generalized hyperemia, congestion and hemorrhage of the immune organs, gastro-intestinal tract organs and vital organs. The oral group buffaloes showed mild lesions in the lung and liver. Histologically, there were significant differences (p<0.05) in hemorrhage and congestion; necrosis and degeneration; inflammatory cells infiltration; and edema in between the groups. Conclusion: This study was a proof that oral route infection of P. multocida Type B:2 can be used to stimulate host cell responses where oral vaccine through feed can be developed in the near future.

Cockle Shell-Based Biocomposite Scaffold for Bone Tissue Engineering

Bone transplantation is a rapidly growing and expanding field, and has a significant impact on improving the quality of life of patients suffering from bone tissue damage and disease. Bone is the second most frequently transplanted tissue in humans after the blood. Secondary bone tumour, trauma or deformity often presents a significant problem for bone surgery (Boyne et al., 2002). Grafting is regularly used in medical procedures to replace damaged tissue. Bone grafting involves replacing damaged bone with harvested bone from donors or from another location within the body. Traditionally, bone graft treatments, such as autografting, allografting, and xenografting were used to replace or repair damaged bone tissue. These processes can be long, painful, and have the possibility of being rejected by the body. Autografts are osteoinductive, osteoconductive and have osteogenic properties (Cypher and Grossman, 1996). Although autografts are considered the gold standard of bone transplantation, they also have certain limitations due to possible donor site morbidity, low tissue availability and may introduce additional medical complications (Younger and Chapman, 1989; Moore et al., 2001). Allografts are grafts made of tissue from a human donor, usually during post-mortem. This method rules out the limitations of auotgrafts technique, but have their own limitations including donor shortages and risks of infections. Xenografts are bone grafts from different species such as bovine, porcine or coralline bone that can be implanted into human graft site. Xenografts offer the advantage of availability in a variety of shapes and sizes, but they are also subjected to problems of immunogenicity and have the tendency to denature or decompose in room temperature (Vaccaro et al., 2002). Distraction osteogenesis is another technique for bone treatment used to promote bone growth using the body’s innate bone-healing mechanisms. The process is lengthy and painful, in which the two sides of a bone fracture are separated by a short distance every few weeks until the desired length of bone has been regrown (Chang et al., 2004). Other treatment options, the man-made devices, such as bone cement fillers and prosthetics made of metals, ceramics and polymers are also used for bone defect repair or replacing damaged bone tissue. All the conventional methods for bone repair and replacement can be long, painful and have the possibility of being rejected by the body (Ducheyne et al., 1992). Alternative approaches have been heavily researched and investigated based on a tissue engineering strategy, in an effort to overcome the inherent limitations of the currently available solutions to bone defects. In this approach, a tissue engineered bone is produced by seeding cells that can become osteoblasts on highly porous biomaterials (Hardin-Young et al., 2000).

Involvement of the nervous system following experimental infection with Pasteurella multocida B:2 in buffalo (Bubalus bubalis): A clinicopathological study

Haemorrhagic septicaemia (HS) is an acute, fatal, septicaemic disease of cattle and buffaloes caused by one of two specific serotypes of Pasteurella multocida B:2 and E:2 in Asian and African, respectively. It is well known that HS affect mainly the respiratory and digestive tracts. However, involvement of the nervous system in pathogenesis of HS has been reported in previous studies without details. In this study, nine buffalo calves of 8 months old were distributed into three groups. Animals of Group 1 and 2 were inoculated orally and subcutaneously with 10 ml of 1 × 10(12) cfu/ml of P. multocida B:2, respectively, while animals of Group 3 were inoculated orally with 10 ml of phosphate buffer saline as a control. All calves in Group 1 and Group 3 were euthanised after 504 h (21 day) post-infection, while calves in Group 2 had to euthanise after 12 h post-infection as they develop sever clinical signs of HS. Significant differences were found in Group 2 in the mean scores of clinical signs, gross and histopathological changes which mainly affect different anatomic regions of the nervous system. In addition, successful bacterial isolation of P. multocida B:2 were obtained from different sites of the nervous system. On the other hand, less sever, clinical, gross and histopathological changes were found in Group 1. These results provide for the first time strong evidence of involving of the nervous system in pathogenesis of HS, especially in the peracute stage of the disease.

Toxicity and Safety Evaluation of Doxorubicin-Loaded Cockleshell-Derived Calcium Carbonate Nanoparticle in Dogs

Doxorubicin (DOX) is a potent anticancer agent with cytotoxic effects which limit its clinical usage. This effect is due to its nonselective nature causing injury to the cells as a result of reactive free oxygen radicals release. Cockleshell-derived calcium carbonate nanoparticle (CS-CaCO3NP) is a pH-responsive carrier with targeted delivery potentials. This study aimed at evaluating the toxicity effects of repeated dose administration of DOX-loaded CS-CaCO3NP in healthy dogs. Fifteen dogs with an average body weight of 15 kg were randomized equally into 5 groups. Dogs were subjected to 5 doses at every 3-week interval with (i) normal saline, (ii) DOX, 30 mg/m2, and the experimental groups: CS-CaCO3NP-DOX at (iii) high dose, 50 mg/m2, (iv) clinical dose, 30 mg/m2, and (v) low dose, 20 mg/m2. Radiographs, electrocardiography, and blood samples were collected before every treatment for haematology, serum biochemistry, and cardiac injury assessment. Heart and kidney tissues were harvested after euthanasia for histological and ultrastructural evaluation. The cumulative dose of DOX 150 mg/m2 over 15 weeks revealed significant effects on body weight, blood cells, functional enzymes, and cardiac injury biomarkers with alterations in electrocardiogram, myocardium, and renal tissue morphology. However, the dogs given CS-CaCO3NP-DOX 150 mg/m2 and below did not show any significant change in toxicity biomarker as compared to those given normal saline. The study confirmed the safety of repeated dose administration of CS-CaCO3NP-DOX (30 mg/m2) for 5 cycles in dogs. This finding offers opportunity to dogs with cancer that might require long-term administration of DOX without adverse effects.

Skeletal Muscle Tissue Engineering Using Biological Scaffolds for Repair of Abdominal Wall Defects in a Rabbit Model

The repair of large soft tissue defects, especially abdominal wall defects, is still a challenge for surgeons and continues to be a significant problem for patients (Gangwar et al., 2006; Lai et al., 2003). Free muscle transfer from local or distant sites is commonly employed for the surgical repair of muscle-tissue defects, but this practice is frequently associated with significant donor-site morbidity (Wei et al., 1995). A potential alternative includes the in vitro development of a functional three-dimensional muscle for transplantation or the construction of implantable biological biomaterials to direct myogenesis at the target site. The ideal biomaterial for abdominal wall repair should possess adequate strength, no hypersensitivity reactions, and biocompatibility to facilitate tissue ingrowths, which may help long-term maintenance of mechanical strength (Lai et al., 2003). In the reconstruction of a new tissue, two components are usually very important: the cells and the matrix (scaffolds) where they are seeded. Tissue engineering is an interdisciplinary field which applies the principles and methods of engineering and the life sciences towards the fundamental understanding of structural and functional relationships in normal and pathological tissue and the development of biological substitutes to restore, maintain or improve function (Skalak & Fox, 1988). The creation of skeletal muscle tissue using tissue engineering methods holds promise for the treatment of a variety of muscle diseases, including skeletal myopathies such as muscular dystrophy or spinal muscular atrophy, traumatic injury and aggressive tumor ablation (Guettier-Sigrist et al., 1998; Law et al., 1993). Tissues that are engineered using the patient’s own cells, or immunologically inactive allogenic or xenogenic cells have the potential to overcome current problems of replacing lost tissue function and offer new therapeutic options for diseases where currently no options are available. Moreover, this technology can play a vital role in the future management of paediatrics patients (Saxena et al., 1999a).