Adaptation and delimitation: some thoughts about the Kanurization of the Gamergu

The area around the Lake Chad is characterized as an example for a region where ethnic changes abundantly took place and still do. For example some Kanuri districts, or the leaders of those districts, are (unofficially) named after other ethnic names (e.g. Margi, Shuwa) or Kanuri clan names are identical with ethnic names of other groups, eg. Tera, Bade. Both people speak a Chadic language and live in the south and west of the Kanuri respectively. These are indications that the Kanuri formerly absorbed and integrated these peoples. These processes are not only a phenomenon of the past. In the case of the neighbouring Gamergu people an ongoing process of ethnic change towards a Kanuri identity is observed until present. The research projects1 have revealed that the concept of "ethnic units" is far from being static which the term may suggest. This especially applies to the German Stamm, which implies a static concept of ethnicity. However, in Borno the dynamics of ethnic and linguistic change are prevailing. Therefore Ronald Cohen rejected the term "ethnic unit", or even "tribe" for the Kanuri and preferred "nation" instead. Umara Bulakarima argued along the same line but used "ethnic group" for Kanuri subunits, e.g. Manga, Mowar, Suwurti. There is no doubt that the Kanuri played a dominant part in the history of the Lake Chad area during the past centuries. Therefore the "Kanurization" process may not surprise. However, in the following it will be revealed that the processes of contact and resulting adaptations and delimitations are not necessarily unidirectional from Kanuri to other groups. At least in some cases they may go into the opposite direction, e.g. from Gamergu to Kanuri

Extraction and Characterisation of Chitin and Chitosan from Mussel Shell

In view of the increasing littering of the river banks by shells of crustaceans, a study was carried out to investigate the extraction and characterization of chitin and chitosan from mussel shell. Chitin and chitosan was extracted and characterized from mussel shell found in banks of the Gubi Dam in Bauchi, Nigeria using the conventional methods of pretreatment, demineralization, deprotienization and deacetylation. The results obtained revealed that  carbon nitrogen ratio of the chitosan extracted was 5.9 with a degree of deacetylation of 60.69% and 60.66% calculated from the elemental analysis and the FTIR spectra of chitosan respectively. The FTIR spectra for chitosan gave a characteristic –NH2 band of 3447 cm-1 and a carbonyl group band of   1477 cm-1. The mussel shell was discovered to contain a mineral content of 51.62% and a chitin composition was found to be 21.32%. KEYWORDS: Characterisation, Chitin, Chitosan, Extraction, Mussel

Formulation and evaluation of ciprofloxacin-cockle shells derived calcium carbonate aragonite nanoparticles physicochemical properties mediated in vitro bactericidal activity in Salmonella Typhimurium

Since the use of classical antibiotics in the management of resistant bacterial infections requires high dosage and regular administration for a lengthy duration, the enhanced delivery system that will ensure sustained release of antibiotic to the Site of action is important. We synthesized and formulated ciprofloxacin-cockle shell derived calcium carbonate aragonite nanoparticles (C-CSCCAN), appropriately analysed its physicochemical properties mediated antibacterial activity in Salmonella Typhimurium. The size of the formulated nanoparticles were in the range of 13.94 and 23.95 nm and Zeta potential was optimally negative. Diffraction pattern by X-ray powder diffraction (XRD) revealed strong crystallizations in all the formulations. Fourier-transform (FT-IR) spectra displayed evidence of interactions between the drug and nanoparticles at the molecular level and no change in peaks position was observed prior to and after the synthesis of the nanoparticles. Higher encapsulation (99.5) and loading capacity (5.9%) were attained at ciprofloxacin to nanoparticles ratio 1:17. No burst effect but a sustained drug release was observed from the formulation. C-CSCCAN suspension exhibited higher antibacterial activity than free ciprofloxacin. It was concluded that physicochemical properties of CSCCAN enhanced susceptibility of Salmonella Typhimurium, which could potentially improve the clinical efficacy of ciprofloxacin

Safety assessments of subcutaneous doses of aragonite calcium carbonate nanocrystals in rats

Calcium carbonate nanoparticles have shown promising potentials in the delivery of drugs and metabolites. There is however, a paucity of information on the safety of their intentional or accidental over exposures to biological systems and general health safety. To this end, this study aims at documenting information on the safety of subcutaneous doses of biogenic nanocrystals of aragonite polymorph of calcium carbonate derived from cockle shells (ANC) in Sprague-Dawley (SD) rats. ANC was synthesized using the top-down method, characterized using the transmission electron microscopy and field emission scanning electron microscope and its acute and repeated dose 28-day trial toxicities were evaluated in SD rats. The results showed that the homogenous 30 ± 5 nm-sized spherical pure aragonite nanocrystals were not associated with mortality in the rats. Severe clinical signs and gross and histopathological lesions, indicating organ toxicities, were recorded in the acute toxicity (29,500 mg/m2) group and the high dose (5900 mg/m2) group of the repeated dose 28-day trial. However, the medium- (590 mg/m2 body weight) and low (59 mg/m2)-dose groups showed moderate to mild lesions. The relatively mild lesions observed in the low toxicity dosage group marked the safety margin of ANC in SD rats. It was concluded from this study that the toxicity of CaCO3 was dependent on the particulate size (30 ± 5 nm) and concentration and the route of administration used

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

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

Formulation of a sustained release docetaxel loaded cockle shell-derived calcium carbonate nanoparticles against breast cancer

Purpose: Here, we explored the formulation of a calcium carbonate nanoparticle delivery system aimed at enhancing docetaxel (DTX) release in breast cancer. Methods: The designed nano- anticancer formulation was characterized thorough X-ray diffraction (XRD), Fourier transformed infrared (FTIR), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) and Brunauer-Emmett-Teller (BET) methods. The nano- anticancer formulation (DTX- CaCO3NP) was evaluated for drug delivery properties thorough in vitro release study in human body simulated solution at pH 7.4 and intracellular lysosomal pH 4.8. Results: Characterization revealed the successful synthesis of DTX- CaCO3NP, which had a sustained release at pH 7.4. TEM showed uniformly distributed pleomorphic shaped pure aragonite particles. The highest entrapment efficiency (96%) and loading content (11.5%) were obtained at docetaxel to nanoparticles ratio of 1:4. The XRD patterns revealed strong crystallizations in all the nanoparticles formulation, while FTIR showed chemical interactions between the drug and nanoparticles with negligible positional shift in the peaks before and after DTX loading. BET analysis showed similar isotherms before and after DTX loading. The designed DTX- CaCO3NP had lower (p 0.05) effects at 48 h and 72 h. However, the DTX- CaCO3NP released less than 80% of bond DTX at 48 and 72 h but showed comparable effects with free DTX. Conclusions: The results showed that the developed DTX- CaCO3NP released DTX slower at pH 7.4 and had comparable cytotoxicity with free DTX at 48 and 72 h in MCF-7 cells

Antibacterial Activity of Ciprofloxacin-Encapsulated Cockle Shells Calcium Carbonate (Aragonite) Nanoparticles and Its Biocompatability in Macrophage J774A.1

The use of nanoparticle delivery systems to enhance intracellular penetration of antibiotics and their retention time is becoming popular. The challenge, however, is that the interaction of nanoparticles with biological systems at the cellular level must be established prior to biomedical applications. Ciprofloxacin–cockle shells-derived calcium carbonate (aragonite) nanoparticles (C-CSCCAN) were developed and characterized. Antibacterial activity was determined using a modified disc diffusion protocol on Salmonella Typhimurium (S. Typhimurium). Biocompatibilittes with macrophage were evaluated using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-Bromo-2′-deoxyuridine (BrdU) assays. Transcriptional regulation of interleukin 1 beta (IL-1β) was determined using reverse transcriptase-polymerase chain reaction (RT-PCR). C-CSCCAN were spherical in shape, with particle sizes ranging from 11.93 to 22.12 nm. Encapsulation efficiency (EE) and loading content (LC) were 99.5% and 5.9%, respectively, with negative ζ potential. X-ray diffraction patterns revealed strong crystallizations and purity in the formulations. The mean diameter of inhibition zone was 18.6 ± 0.5 mm, which was better than ciprofloxacin alone (11.7 ± 0.9 mm). Study of biocompatability established the cytocompatability of the delivery system without upregulation of IL-1β. The results indicated that ciprofloxacin–nanoparticles enhanced the antibacterial efficacy of the antibiotic, and could act as a suitable delivery system against intracellular infections

Development and in vitro bioevaluation of cockle shell-calcium carbonate (Aragonite) nanoparticles for intracellular drug delivery

The use of safe and efficient delivery systems, capable of delivering therapeutic agents to subcellular levels are an ultimate goal in enhancing therapeutic effect. It is also a promising strategy in overcoming microbial resistance and the emergence of intracellular bacterial infections. The challenge, however, is that the interaction of nanoparticles with biological systems at the cellular level must be established prior to biomedical applications. In this study,ciprofloxacin conjugated cockle shells-derived calcium carbonate (aragonite) nanoparticle (CCSCCAN) was developed and characterized for its physicochemical properties and antibacterial activities. Biocompatibilities were evaluated on macrophage cell line (J774.A1) using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-Bromo-2ʹ-deoxyuridine (BrdU) assays. The nanoparticles were spherical in shape, with particles sizes ranging from 11.93 to 22.12 nm as determined through a transmission electron microscope (TEM). The highest percentage entrapment efficiency (EE) and loading content (LC) were 99.5% and 5.9%, respectively, with an optimum negative zeta potential. X-ray diffraction (XRD) patterns revealed strong crystallity of the formulations. Fourier transforms infrared (FT-IR) spectra shows evident of interactions exist between the drug and nanoparticles at the molecular level. No burst effect, but a sustained drug release was observed from the formulation. The mean diameter of inhibition zone was 18.6 ± 0.5 mm, which was better than ciprofloxacin alone (11.7 ± 0.9 mm), while the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the formulation were lower than those of free drugs. Study of biocompatability suggested non-toxic effects of the formulations. In conclusion, the results indicated that the ciprofloxacin- nanoparticle conjugate (C-CSCCAN) enhanced susceptibility of Salmonella and antibacterial efficacy of the antibiotic, which could potentially improve the clinical efficacy of the drug